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This is my web log which contains all sorts of random thoughts I felt it necessary to record for posterity here. I've recorded ideas on all sorts of topics in here so I hope you find something interesting, and maybe even useful!

Show entries, about containing for the year


More New Meds

2018-12-26. Science. Rating 3. ID 1957.

Earlier this year a Chinese medical researcher, He Jankui, announced that he had used CRISPR technology to modify the genetics of embryos during an IVF treatment. The genetic modification was to remove a gene which allowed the HIV virus to attach to cells. The father was HIV positive so this gave his children a chance to be free of AIDS.

I have heard a lot of condemnation towards this work, even though there is no reason to believe there were any negative consequences. In fact, the big hazard with CRISPR - the possibility that other genes were modified accidentally - has already been ruled out.

So what's the problem? This seems to be a positive step and an interesting demonstration of how this new technology can be used in real medicine, even though it is only being used for scientific research elsewhere. The problem is that there was little control over what was done. There was apparently no ethics approval, no authorisation from a recognised international medical organisation, and no significant pre-treatment trials or other rigorous testing.

Superficially it seems that most people think that this work was unethical, that proper procedures should have been followed, and that the researcher should be disciplined (I later heard that he had "disappeared", which is a bad sign in China). But I am tempted to suggest that many other people might think this was a good thing, because it might speed up the adoption of a useful technology and bypass a lot of possibly unnecessary bureaucracy.

As far as my opinion is concerned, I am somewhere in the middle. I think there are dangers in proceeding with the use of new technology too quickly, but I also think that progress is stifled by excessive bureaucracy (as it is in almost every area of human endeavour). So it is difficult to establish where the optimum balance is between caution and progress, but in some ways it is good that China is tipping the balance a bit more in the direction of progress.

It would be different if the decisions on how new discoveries could be used were made from an entirely scientific perspective by experts, but they aren't. Instead, they are made by progressional bureaucrats, who often have backgrounds in science or medicine, but are primarily motivated by management or political objectives instead. I accept that some of that is my opinion rather than established fact, but it is difficult to deny based on past decisions (such as those concerning the use of embryonic stem-cells).

Another possible reason for the criticism might be that some researchers are both worried about, and jealous of, the freedoms their Chinese colleagues get, which is ironic in itself. Maybe they are worried that the excessive bureaucracy in the Western World might allow China to get ahead of them.

There is also the legal risk element of these decisions. Everyone knows there is a significant risk of massive loss through law suits against companies who sell treatments which are later shown to cause harm. That could easily be stifling progress by making people act too conservatively.

Now look at this from a philosophical perspective, specifically through the lens of consequentialism. Are the consequences of this sort of treatment worth the risk in using them?

It seems to me that in most cases they are. If this treatment hadn't been performed what would have been the counter-factual for the children (twin girls, in this case)? Maybe the parents would have thought the risk was too great and they would not have been born at all, or maybe they might have had to face life battling AIDS. Either way, the current situation seems preferable. So a case could be made to say that the researcher took the most moral action.

And a similar argument could be made in regards to all new medical treatments. People die from diseases which might be cured by new treatments which haven't yet been through a full testing regime. Applying the consequentialist argument again: letting them die seems worse than almost any possible result from an experimental treatment, especially if the patient makes the decision to go ahead based on full knowledge.

The difference is, of course, that the children born after the current treatment didn't give permission, because the treatment is done at the single-cell stage of development. And it's even worse than that, because the treatment at that stage means all the cells in their bodies are affected, including their eggs, which means their children and all other future descendents are also affected.

But it's easy to over-think this and look for potentially bad results, without balancing that against potentially good ones. In fact, maybe it's best to forget about the "potentially" part and look at the actual consequences, as consequentialism would suggest.

And we could look at this statistically too. Even if a certain percentage of outcomes were bad, it might still be worth the risk to get the good ones too. After all, that is a standard part of medicine, where there is always a risk of a treatment not working or even possibly making a situation worse.

So, despite the widespread outrage and condemnation I have heard so much of in this case, I don't think I would agree. At the very least there should be a discussion on where the appropriate balance is between risk and progress, because that doesn't seem to be happening much now. Potentially it could greatly speed up the introduction of more new meds.


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To the Stars

2018-08-24. Science. Rating 1. ID 1931.

The world seems very disunited at the moment. People have become increasingly tribal with big differences between the left and right becoming more apparent in recent times. What we need is a project which everyone can get on board with. In the 1960s the project was the attempt to land humans on the Moon, which was achieved in 1969. But we haven't been back since Apollo 17 in 1972, and even though there have been some significant achievements since then (the LHC and discovery of the Higgs boson, LIGO's discovery of gravity waves, etc) nothing has really captured the public imagination in the same way.

Sending humans to Mars seems like the next most logical mission which everyone could get excited about, but that is unlikely to happen soon for various reasons, which are partly technical (the flight is long, and keeping humans safe that long is really hard) and partly political (the cost involved is more than any one government would want to spend on a mission with limited practical benefits).

So why not send an automated mission to another star instead? Even though this would seem like a far more difficult task, it doesn't need to be. The nearest star - or more correctly the three stars in the Alpha Centauri system - are 4.2 light years away. That is 42 trillion kilometers. Mars is just 55 million kilometers away at its closest. That difference represents a factor of almost a million. At the same speed a spacecraft which took six months to get to Mars would take almost 400,000 years to get to Alpha Centauri.

That is a non-trivial difference! But there is one factor in favour of the interstellar mission: that it is automated and has no humans on board. That means that a very small spacecraft could be sent and this allows use of a new technology which can overcome the speed limitation of current rockets.

The problem at the moment is that rockets carry their fuel with them, making them really heavy. And the heavier they are, the more fuel they need, which makes them still heavier. So the problem is that the solution to the problem of propelling a heavier spacecraft by using more fuel makes the original problem worse.

The answer is to provide the propulsion from outside the spacecraft, and the most feasible way to do that now is to use a laser beam to push the spacecraft towards its destination.

By applying the laser for a few minutes near the start of the journey, the spacecraft could be accelerated at 60,000 Gs to a speed of 20% the speed of light, or 215 million kilometers per hour. At this speed it would take "just" 20 years to get to Alpha Centauri. To get an idea of how fast this actually is though, consider that it would take less than a second at that speed to travel completely around the Earth!

Laser technology is getting better at a rate that would make this mission possible in a few years. And there is another, equally important, factor. That is miniaturisation. When I said the interstellar spacecraft could be small I really did mean that. One possible implementation of this technology specifies a spacecraft weighing about as much as a paperclip!

This tiny object would contain all the electronics needed to gather details, including photos, of the stars and planets in the Alpha Centauri and send them back to Earth. Of course, even at the speed of light, the signal would take over 4 years to get back here.

There are many issues, including the fact that a collision with even a single atom at that speed could be disastrous, but a spherical shell surrounding the spacecraft could be used for protection. In addition, the heating from colliding particles could be used as a thermal gradient to generate power. And if the laser beam, which would actually be a beam from many individual laser sources, was made "hollow" (more powerful at the edges) it would push the craft back to the center.

It all seems very clever and - most importantly - practical. Except for a couple of issues...

First, despite it being many times less expensive than a manned Mars mission it still isn't cheap and could be accused of having no "practical benefits" (in other words, no one can make any money out of it). So funding would be an issue, although a Russian billionaire is considering funding one mission of this type called "Breakthrough Starshot".

Second, lasers of the power required would also make good weapons. In fact, unless the reflectivity of the sail used by the spacecraft isn't almost perfect it would be instantly vapourised! So politically, building these large lasers would be difficult. And there is already an example of scientific advances being reduced by political agreements because it is against international agreements to use nuclear power in space, even though it is often the logical choice.

But, despite all of these difficulties I would propose this technology as our next big project. Once the lasers are built they could be used for many projects, including sending many miniature spacecraft on long journeys, and even sending bigger craft to different destinations around the Solar System.

Multiple missions could be monitored by anyone on the internet, and people could participate in data analysis in a similar way to many projects today, such as SETI@Home.

I'm not naive enough to think that this would really make a lot of difference to political disagreements in the world today. People today are only distracted by anything for short periods of time. The coolness of anything would wear off fairly quickly and the political bickering would start again. But I still think the interstellar "nanocraft" is worth doing. Let's go to the stars!


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Introduction to the Elements

2017-12-30. Science. Rating 1. ID 1891.

The Greek philosophers were incredibly smart people, but they didn't necessarily know much. By this I mean that they were thinking about the right things in very intelligent and perceptive ways, but some of the conclusions they reached weren't necessarily true, simply because they didn't have the best tools to investigate reality.

Today we know a lot more, and even the most basic school science course will impart far more real knowledge to the average school student than what even the greatest philosophers, like Aristotle, could have known.

I have often thought about what it would be like to talk to one of the ancient Greeks about what they thought about the universe and what we have found out since, including how we know what we know. Coincidentally, this might also serve as a good overview of our current knowledge to any interested non-experts today.

Of course, modern technology would be like total magic to any ancient civilisation. In fact, it would seem that way to a person from just 100 years ago. But in this post I want to get to more fundamental concepts than just technology, mostly the ancient and modern ideas about the elements, so let's go...

The Greeks, as well as several other ancient cultures, had arrived at the concept of there being elements, which were fundamental substances which everything else was made from. The classic 4 elements were fire, air, water, and earth. In addition, a fifth element, aether, was added to account for the non-material and heavenly realm.

This sort of made sense because you might imagine that those components resulted when something changed form. So burning wood releases fire and air (smoke) and some earth (ash) which seemed to indicate that they were original parts of the wood. And sure, smoke isn't really like air but maybe that's because it was made mainly from air, with a little bit of earth in it too, or something similar.

So I would say to a philosopher visiting from over 2000 years ago that they were on the right track - especially the atomists - but things aren't quite the way they thought.

Sure, there are elements, but none of the original 4 are elements by the modern definition. In fact, those elements aren't even the same type of thing. Fire is a chemical reaction, air is a mixture of gases, water is a molecule, and earth is a mixture of fine solids. The ancient elements correspond more to modern states of matter, maybe matching quite well with plasma, gas, liquid and solid.

The modern concept of elements is a bit more complicated. There are 92 of them occurring naturally, and they are the basic components of all of the common materials we see, although not everything in the universe as a whole is made of elements. The elements can occur by themselves or, much more commonly, combine with other elements to make molecules.

The elements are all atoms, but despite the name, these are not the smallest indivisible particles, because atoms are in turn made from electrons, protons, and neutrons, and then the protons and neutrons are made of quarks. As far as we know, these cannot be divided any further. But to complicate matters a bit more there are many other indivisible particles. The most well known of these from every day life is the photon, which makes up light.

Different atoms all have the same structure: classically thought of as a nucleus containing a certain number of protons and neutrons surrounded by a cloud of electrons. There are the same number of protons (which have a positive charge) and electrons (which have a negative charge) in all neutral atoms. It is the number of protons which determines which atom (or element) is which. So one proton means hydrogen, 2 helium, etc, up to uranium with 92. That number is called the "atomic number".

The number of neutrons (which have no charge) varies, and the same element can have different forms because they have a different number of neutrons. When this happens the different forms are called isotopes.

Protons and neutrons are big and heavy and electrons are light, so the mass of an atom is made up almost entirely of the protons and neutrons in the nucleus. The electrons are low mass and "orbit" the nucleus at a great distance compared with the size of the nucleus itself, so a hydrogen atom (for example, but this applies to all atoms and therefore everything made of atoms, which is basically everything) is 99.9999999999996% empty space!

When I say protons are big and heavy I mean this only relatively, because there are 50 million trillion atoms in a single grain of sand (which means a lot more protons because silicon and oxygen, the two main elements in sand, both have multiple protons per atom).

When atoms combine we describe it using chemistry. This involves the electrons near the edge of an atom (the electrons form distinct "shells" around the nucleus) combining with another atom's outer electrons. How atoms react is determined by the number of electrons in the outer shell. Atoms "try" to fill this shell and when they do they are most stable. The easiest way to fill a shell is to borrow and share electrons with other atoms.

Atoms with one electron in the outer shell or with just one missing are very close to being stable and are very reactive (examples: sodium, potassium, fluorine, chlorine). Atoms with that shell full don't react much at all (examples: helium, neon).

There are far more energetic reactions which atoms can also participate in, when the nucleus splits or combines instead of the electrons. We call these nuclear reactions and they are much harder to start or maintain but generate huge amounts of energy. There are to types: fusion where small atoms combine to make bigger ones, and fission where big atoms break apart. The Sun is powered by fusion, and current nuclear power plants by fission.

After the splitting or combining the resulting atom(s) has less mass/energy (they are the same thing, but that's another story) than the original atom(s) and that extra energy is released according to a formula E=mc^2 discovered by Einstein. This means you can calculate how much energy (E) comes from a certain amount of mass (m) by multiplying by the speed of light squared (90 thousand trillion). This number is very high which means that a small amount of mass creates a huge amount of energy.

Most reactions involve a bit of initial energy to start it, then they will release energy as the reaction proceeds. That's why lighting a match next to some fuel starts a reaction which makes a lot more energy.

So water is a molecule made from one oxygen atom and two hydrogen atoms. But gold is an element all by itself and doesn't bond well with others. And when two elements bind and form a molecule they are totally different from a simple mixture of the two elements. Take some hydrogen and oxygen and mix them and you don't get water. But light a match and you get a spectacular result, because the hydrogen burns in the oxygen forming water in the process. The energy content of water is lower than the two constituent gases which explains all that extra energy escaping as fire. But the fire wasn't an elementary part of the original gases and neither was the water. You can see how the Greeks might have reached that conclusion though.

Basic classical physics and chemistry like this make a certain amount of intuitive sense, and the visting philosopher would probably understand how it works fairly quickly. But then I would need to reveal that it is all really just an approximation to what reality is really like.

There would be a couple of experiments I could mention which would be very puzzling and almost impossible to explain based on the classical models. One would be the Michelson–Morley experiment, and the other would be the infamous double-slit experiment. These lead to the inevitable conclusion that the universe is far stranger than we imagined, and new theories - in this case relativity and quantum theory - must be used.

Whether our philosopher friend could ever gain the maths skills necessary to fully understand these would be difficult to know. Consider that the Greeks didn't really accept the idea of zero and you can see that they would have a long way to go before they could use algebra and calculus with any competence.

But maybe ideas like time and space being dynamic, gravity being a phenomenon caused by warped space-time, particles behaving like waves and waves behaving like particles depending on the experiment being performed on them, single particles being in multiple places at the same time, and particles becoming entangled, might be comprehensible without the math. After all, I have a basic understanding of all these things and I only use maths like algebra and calculus at a simple level.

It would be fun to list some of the great results of the last couple of hundred years of experimental science and ask for an explanation. For example, the observations made by Edwin Hubble showing the red-shifts of galaxies would be interesting to interpret. Knowing what galaxies actually are, what spectra represent, and how galactic distances can be estimated, would seem to lead to only one reasonable conclusion, but it would be interesting to see what an intelligent person with no pre-conceived ideas might think.

As I wrote this post I realised just how much background knowledge is necessary as a prerequisite to understanding our current knowledge of the universe. I think it would be cool to discuss it all with a Greek philosopher, like Aristotle, or my favourite Eratosthenes. And it would be nice to point out where they were almost right, like Eratosthenes' remarkable attempt at calculating the size of the Earth, but it would also be interesting to see their reaction to where they got things badly wrong!


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Cosmological Musings

2017-11-30. Science. Rating 2. ID 1887.

Recently I have listened to a few podcasts featuring some of the most well known scientists of today. Specifically, I mean Lawrence Krauss, Sean Carroll, and Neil deGrasse Tyson. These aren't general scientists obviously, since they all specialise in physics and cosmology, but that's the area I want to concentrate on in this post.

I admire these three in particular for a number of reasons: first, they are clearly brilliant and highly intelligent people, or they wouldn't have got to the positions they have; second, they are good public communicators of the often difficult subjects they specialise in; and third, they aren't scared to call out BS where they see it, and Carroll and Krauss in particular are very critical of religion and other forms of irrationality.

But it isn't the politically or socially controversial topics I want to cover here, it is the scientifically contentious or speculative stuff instead. So let's get started talking about some of the more speculative ideas I have heard discussed recently. Note that these aren't necessarily directly attributable to the people I mentioned above, and they represent my interpretation of what I have heard, and I am not an expert in this subject. But that has never stopped me before, so let's go!

The origin, and underlying nature of the universe is not well understood. This has been a problem for a while, because the actual point where the Big Bang started is hidden in a singularity of infinite density. Physics breaks down there, just like it does in a black hole, so nothing much can be said about it with any certainty. It is possible to use existing theories to get really close to time zero - a tiny fraction of second - but beyond that is inaccessible to current theories.

And the best direct evidence we have comes from the light of early galaxies and the cosmic microwave background (CMB). But even the CMB only formed after 300,000 years, which is s small fraction of the age of the universe (13.7 billion years) but still not as early as we would like.

So clearly this is a difficult subject, but here are a few observations and speculations about the universe which might assist in understanding what is going on...

The first point is that the total energy of the universe might be zero. This seems totally absurd on the surface, because of all the obvious energy sources we see, like stars, and all the mass which we know is the equivalent of energy through the famous equation E=mc^2. But that's where a convention in physics makes the reality quite different from what most people intuitively believe.

Gravitational energy has always been thought of as negative. This is nothing to do with the Big Bang or cosmology, it is just a natural consequence of the maths. If we accept this it turns out that the gravitational energy of the universe cancels the other energy exactly. So the universe has zero energy which means that any process making a universe can do so easily, meaning there could quite conceivably be an infinite number of them.

While some people dismiss this as a "trick" it really isn't. If cosmologists had said something like "we need to get the total energy to zero so let's just say gravity is negative and voila!" then that would be a trick. But this was an established fact long before the total energy of the universe was being considered and this gives it far more credibility.

And while we thinking about the idea of more than one universe, what about the idea that there could be many universes - each with slightly different properties - which might explain why many of the properties of our universe seem to be quite well tuned for the existence of life?

What I am saying here is that various constants seem to have values which make chemistry possible and that, in turn, makes life possible. But there seems to be no reason why the constants could not have totally different values and this could lead to a universe where stars could not form, and no stars means no energy source for life.

And the old argument about life which is entirely different from the type we see now doesn't really save us because any form of life needs both energy and heavy atoms, and stars are the only likely source for these.

But if there are an infinite, or very large, number of universes, with different constants, then it is inevitable that some will have the values which make life possible. In fact, it's possible to imagine a universe which is even better than ours for life, so there could be many which have life. In fact, if there are an infinite number of universes, there will be an infinite number with life as well!

A concept I have sometimes heard in both pop science and science fiction is the idea that at very large scales and very small scales there might be other universes hidden. For example, an atom could be a universe made of its own tiny atoms which in turn could be universes, etc. And going the other way, our universe could be an atom in a bigger universe above ours, ad infinitum. This idea might arise from the popular notion that an atom is like a miniature solar system (which it isn't).

It's a cute idea, but unfortunately it can be ruled out by applying the laws of physics. Sub-atomic particles have no details and no uniqueness. For example, every electron is a single point (or "cloud" of probability) with no structure and which is completely indistinguishable from every other electron. This doesn't seem like a good candidate for a whole universe!

What about the "oscillating universe" or "big crunch" theory? This is the idea that the universe expands but the expansion slows down until it stops at a certain point, then it starts contracting again, reaches a singularity, and is "reborn" in a new Big Bang. At this point any vestige of the old universe is erased and all the energy is replenished. This would be a process which recurs infinitely in both the future and past.

This is quite an appealing notion, because it tells us what was before the current Big Bang, and previously it was thought that gravity might have been slowing the rate of expansion. Unfortunately for this theory new evidence shows us that the rate of expansion is actually increasing, because of dark energy, so the contraction and "Big Crunch" can never happen.

There's nothing fundamental in physics which seems to stop processes running backwards in time. I have heard an idea that maybe the universe was created as a result of a signal sent backward from a future form of the universe itself. This removes the need for an initial cause which in turn might need a cause, leading to an infinite regress of causes.

Signals going back in time should be considered somewhat controversial, of course, because of the principles of causality, so I would be hesitant to take this too seriously unless some clarification on the exact mechanism arose.

Here's another one: new universes appear inside black holes created in existing universes. These universes all have slightly different attributes than the universe they came from, but inherit the starting parameters from them.

This is nice because it sets up an "evolution" model where "the survival of the fittest" applies to whole universes! Only universes which can make black holes will create new universes. To create a black hole the universe needs to have a fairly long life, a way to concentrate matter, a way to allow matter to "condense" out of energy, etc. These attributes also lead to laws and constants suitable for the development of life.

Clearly this is difficult to evaluate because we don't know what happens inside black holes, because as I said above, the infinite density of matter causes current theories to break down. There is no compelling reason to think universes are formed from black holes so it's probably best to disregard this idea unless some new, relevant information becomes available.

Finally, how about the idea that the purpose of a universe is to allow intelligent life to form which, in turn advances to the point where it figures out how to make universes?

This also sets up a potential evolutionary scenario, but we have no idea whether any intelligent life form, no matter how advanced, could create a universe, so again this seems to be somewhat unworthy of spending too much time speculating about at this stage.

Well, wasn't that fun! Obviously we don't know the truth about the origin or fundamental nature of the universe, not because we have no ideas, but because we have too many! I'm fairly sure that when real theories are created to explain these phenomena that none of what I have said here will be the real explanation, but it's still fun to speculate!


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Do It Yourself

2017-03-03. Science. Rating 3. ID 1840.

I was going to post this comment as part of an anti-creationist rant but I realised that there was so much to it that I really needed to post it as a separate item. The issue I wanted to tackle was how many believers in mysticism base their beliefs on revealed sources, such as holy books, but the same criticism could be made against "rational" people, like myself, because I also use sources (such as science books, Wikipedia, etc).

So basically what I wanted to do was to show that anyone can discover significant things about the real world by themselves without relying on any information from existing sources, and that they can show anyone how to do the same observation/experiment which would prove their point beyond any reasonable doubt.

I decided to choose the age of the universe as a suitable subject, because it was a controversial subject (there are many young Earth creationists), and it was relatively easy to test. Of course, as I intimated above, it got more complex than I imagined. However, here is my proof - which anyone with a bit of time and a small budget can follow - that the universe, and therefore the Earth, is much older than the 6000 years the young Earth creationists claim.

I could start by trying to establish the age of the oldest things I know of. I could use biology, archaeology, chemistry or physics here, but I know a bit more about astronomy, so let's use that.

We know the light from stars travels through space at the speed of light. If the stars are far enough away that the light took more than 6000 years to get here then the universe must be more than 6000 years old, so creationism is wrong. I know there are some possible objections to these initial assumptions but let's leave those aside for now.

First, how fast is the speed of light? Can I figure this out for myself or do I need to take it on trust (some would say faith) from a book? Well it is actually quite easy to figure this out because we can use a highly regular event at a known distance to calculate the time it took for light to reach us. The most obvious choice is timings of Jupiter's moons.

The moons of Jupiter (there are 4 big ones) take precise times to complete an orbit. I can figure that time out by just watching Jupiter for a few weeks. But we would expect a delay in the times because the light from an event (like a Moon going in front of or behind Jupiter) will take a while to reach us.

Conveniently, the distance from the Earth to Jupiter varies because some times the Earth and Jupiter are on the same side of the Sun, and others the opposite side. So when they are on the same side the distance from the Earth is the radius of Jupiter's orbit minus the radius of the Earth's, and when they are on opposite sides it is the radius of Jupiter's orbit PLUS the radius of the Earth's. Note that the size of Jupiters orbit doesn't matter because the difference is just double the size of the Earth's (in fact it is double the radius, or the diameter).

So now we need to know the size of the Earth's orbit. How would we do that? There is a technique called parallax which requires no previous assumptions, it is just simple geometry. If you observe the position of an object from two locations the angle to the object will vary.

It's simple to demonstrate... Hold your finger up in from of your eyes and look at it through one eye and then the other. The apparent position against a distant background wall will change. Move your finger closer and the change will be bigger. If you measure that change you can calculate the distance to your finger with some simple maths.

In astronomy we can do the same thing, except for distant objects the change is small... really small. And we also need two observing locations a large distance apart (the further apart they are, the bigger the change is and therefore the easier it is to measure). Either side of the Earth is OK for close objects, like the Moon (a mere 384000 kilometers away) but for stars (the closest is 42 trillion kilometers away) we need something more. Usually astronomers use the Earth on either side of its orbit (a distance of 300 million kilometers) so the two observations will be 6 months apart.

So getting back to our experiment. You might think we could measure the distance to a star, or a planet like Jupiter, or the Sun using this technique but it's not quite so simple because the effect is so small. What we do instead is measure the distance to the Moon (which is close) using parallax from two widely separated parts on the Earth. I admit this needs a collaborator on the other side of the Earth, so it involves more than just one individual person, but the principle is the same.

Once we know that it can be used to measure other distances. For example, if we measure the angle between the Moon and Sun when the Earth-Moon-Sun angle is a right angle we can use trigonometry to get the distance to the Sun. It's not easy because the angle is very close to 90 degrees (the Earth-Sun side of the triangle is much longer than the Earth-Moon side) but it can be done.

So now we know the difference in distance between the Earth and Jupiter in the two situations I mentioned at the start of this post. If we carefully measure the difference in time between the timings of Jupiter's Moons from Earth when Earth is on either side of its orbit we get a difference of about 16 minutes. So light is taking half of that time to travel from the Sun to the Earth. We know that distance from the previous geometric calculations, so we know the speed of light.

Note that none of this is open to any reasonable criticism. It is simple, makes no assumptions which can fairly be questioned, and anyone can do it without relying on existing knowledge. Note that if you want to derive the basic trig calculations that is fairly easy too, but few people would argue about those.

So the Sun is 8 light minutes away meaning the light we see from the Sun left it 8 minutes ago. We are seeing the Sun literally as it was 8 minutes in the past. This means it must have existed 8 minutes in the past. But who cares? Well this is interesting but looking at more distant objects - those not just light minutes away but light years, thousands of light years, millions of light years away say more about the true age of the Universe.

So we can use this idea in reverse. Above we calculated a distance based on a time difference and the speed of light. Now we will calculate a time based on distance and the speed of light. If a star is 10,000 light years away the light left it 10,000 years ago, so it existed 10,000 years ago, so the universe is at least 10,000 years old.

There is only one direct method to calculate distance and that is parallax. But even from opposite sides of the Earth's orbit - a baseline of 300 million kilometers - parallax angles are ridiculously small. But with a moderate size telescope (one which many amateurs could afford), and careful observation, they can be measured. The parallax angle of the closest star is about 800 milliarcseconds, or 0.01 degrees. That gives an angle which is the equivalent of the width of a small coin about 5 kilometers away.

Do this observation, then a simple calculation, and the nearest star turns out to be 40 trillion kilometers (4 light years) away. When we see that star we see it as it was 4 years ago. In that time the star could have gone out or been swallowed by a black hole (very unlikely) and we wouldn't know.

The greatest distance so far detected using parallax is 10,000 light years, but that was with the Hubble Space Telescope, so that is beyond the direct experience of the average person! However note that using this direct, uncontroversial technique, the universe is already at least 10,000 years old, making young Earth creationism impossible.

Another rather obvious consequence of these distance measures is that stars are like our Sun. So if we know how bright stars are we can compare that with how bright they appear to be and get a distance approximation. If a star looks really dim it must be at a great distance. The problem is, of course, that stars vary greatly in brightness and we can't assume they are all the same brightness as the Sun.

There is another feature of stars which even an amateur can make use of though - that is the spectrum. Examining the spectrum can show what type of star produced the light. The amateur observer can even calibrate his measurements using common chemicals in a lab. The chemicals in the star are the same and give the same signatures (approximately, at least).

So knowing the type of star gives an approximation of the brightness and that can be used to get the distance. The most distant star visible to the naked eye is 16,000 light years away. This would be bright enough to get a spectrum in a telescope, determine the type of star, and estimate the distance. Of course, it would be hit and miss trying to find a distant star to study (because we're not supposed to use any information already published) but enough persistence would pay off eventually.

There are objects in the sky called globular clusters. These are collections of a few hundred thousand to a few million stars, quite close together. To the naked eye they look like a fuzzy patch but through a small telescope they can be seen to be made of individual stars. A simple calculation based on their apparent brightness shows they are tens of thousands of light years away. A similar technique can be applied to galaxies but these give distances of millions of light years.

In addition, an amateur with a fairly advanced telescope and the latest digital photography equipment - all of which is available at a price many people could afford - could do the investigation of red-shifts originally done by Edwin Hubble over 100 years ago.

A red shift is the shift in the spectrum of an object caused by its movement away from us. As I said above, the spectra of common chemicals can be tested in the lab and compared with the spectrum seen from astronomical objects. As objects get more distant they are found to be moving away more quickly and have higher red shifts. So looking at a red shift gives an approximate measure of distance.

This technique can only be used for really distant objects, like galaxies, so it is a bit more challenging for an amateur, but it will give results of millions to billions of light years, meaning the objects are at least millions or billions of years old.

There are some possible objections to everything I have discussed above. First, maybe the speed of light was much faster in the past meaning that the light could have travelled the vast distances in less time than assumed, meaning the universe could still be just 6000 years old.

Second, the light from the objects could have been created in transit. So a galaxy could have been created 2 million years ago but its light could also be created already travelled 99% of the way to the Earth.

Finally, maybe there is a supernatural explanation that cannot be explained through science or logic, or maybe all of the evidence above is just the malicious work of the devil trying to lead us all astray.

The second and third objections aren't generally supported, even by most creationists, because they imply that nothing we see can be trusted, and God is not usually thought to be deliberately misleading.

The first one isn't totally ridiculous though, and there is some serious science suggesting the speed of light might have been faster in the past. But do the calculations and that speed would have to be ridiculously fast - millions of times faster than it is now. If it was changing at that rate then we would see changes over recorded history. So that claim could also be checked by anyone who was prepared to dig into old sources for timings of eclipses, the length of the day, etc.

Astronomy is an interesting science because so much of it is still do-able by amateurs. Follow the steps above and not only will you get a perspective on some of the greatest work done in the past, but you will also make for yourself a truly fundamental discovery about the universe: that it is really old.

It requires no faith in authority, no reference to trusted texts, and no unfounded assumptions. It just involves a few years of dedicated observation and study. I admit I haven't done all of this myself, but it's good to know I could if I wanted to.


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The Fermi Paradox Again

2017-02-23. Science. Rating 1. ID 1839.

NASA recently announced the discovery of 7 Earth-like planets orbiting the relatively close star, Trappist-1, and that 3 are in the "Goldilocks Zone" (not too hot, not too cold). It is now expected (at least I have heard this although I don't think it is officially stated anywhere) that almost all stars have planets and that a significant fraction of them might have conditions similar to Earth.

This is significant because for many years no one knew how many planets existed in the universe (although there were some discoveries going back to 1988 it was only Kepler, HARPS, and some other new advanced telescopes more recently that lead to significant numbers of discoveries). So it was generally assumed that planets were common but there was no way of knowing.

Another great mystery of the universe is how likely is life to arise and under what conditions. Here we are even worse off than with the planets because we are literally working with a sample size of 1. No other life has been discovered outside of the Earth, although there have been some interesting discoveries on Mars, none have lead to any proof of even primitive life.

It is generally assumed that life will have to be broadly similar to what we have here on Earth. I don't mean similar in any superficial sense but in broad principles. So it will be based on carbon, because carbon is the only element in the universe which bonds to other atoms (and itself) with sufficient complexity to form molecules suitable to base life on. We also know that the elements we know about are the only ones which can exist in the universe.

The chemistry of life also requires a solvent, and water is the obvious choice. So these chemical requirements limit the temperature and other factors that life would need, which is why we are so interested in "Earth-like" planets which are big enough to have strong gravity, are the right temperature to allow liquid water, and have solid surfaces allowing water to pool and to provide the other elements that life might need.

Note that it is possible that life might be able to exist in a wider variety of conditions but I'll stick to these, fairly conservative, assumptions.

Even when all the conditions are just right, or within certain limits, it's hard to know how often life might arise. Experiments in the lab and some observations of molecules in space indicate it might be really likely, but the failure to find life on Mars seems to contradict this.

But even if there was only one chance in a billion of life arising if conditions were suitable, that still means these should be a lot of it in our galaxy alone, and a lot more in the universe as a whole.

There are about half a trillion stars in our galaxy (although this number has gone up and down a bit, the latest number I heard was at this high end) and each star seems to have multiple planets (let's say 10 as an approximation) and it's likely that at least one might be in the correct temperature zone (some stars might have none in this zone but other, like Trappist-1, have many). This seems to indicate that there are as many Earth-like planets as there are stars.

A recent Hubble survey indicated there might be 2 trillion galaxies in the observable universe. So we have 2 trillion galaxies x 500 billion stars x 10 planets x 1/10 Earth-like, giving one trillion trillion places where life might evolve in the observable universe.

These numbers could be off by many orders of magnitude but who cares? Even if we are a billion times too optimistic that still means a thousand trillion places!

I have talked about the Fermi Paradox - the fact that according to best calculations there should be a lot of advanced life around, yet we never see it - in previous blog posts so I won't go into that again here except to say we aren't much further ahead in resolving it!

There is hope though. As telescope technology advances there will be techniques available which seemed impossible in the past. Detecting a planet orbiting another star is an incredible achievement in itself (the stars are really big and bright but at the distances of other stars the planets are very dim and small). But it should be possible to actually study their atmospheres in the future by analysing the light shining through the atmosphere from the star.

In that case it should be possible to learn a lot more about conditions on the planet (temperature, pressure, what elements are present, etc) and to even detect the chemical signatures of life.

And there are even serious proposals now to design small, robotic spacecraft which can be sent to close stars in a reasonable time (by reasonable here we mean decades rather than tens of thousands of years needed by current spacecraft). We know the closest star, a mere 4.2 light years (42 trillion kilometers) away, has a planet but it is unlikely to be suitable for life, but other relatively close stars could also be explored this way.

So how long will it be before we know that life exists on other planets? I predict hints of its existence within 10 years, strong evidence within 30, and proof within 50. And at that point, depending on the circumstances, it should be obvious just how likely life is. I predict we will start finding evidence for it everywhere.

But I still can't get past the problem presented by the Fermi Paradox. If life arises frequently, why don't we see signs of advanced, intelligent life? Maybe intelligence isn't a good evolutionary trait. And, especially given the state of the world at the moment, that is a worrying thought.


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I Demand My Moon Base!

2016-07-13. Science. Rating 2. ID 1801.

Our species has a lot to be proud of, right? Well yes, in a way that is true, but there are many places where we could do so much better too. For me, one of the more depressing areas is the failure to push the boundaries of exploration, to get out there, to take risks, to move forward.

This has happened in many places but I guess the most obvious example is in the space program. The last Apollo mission was Apollo 17 which landed in 1972. Since then no human has travelled beyond low Earth orbit. And since the demise of the Shuttle the leading space exploration nation hasn't had the capability to do that even if it wanted to.

So what's stopping progress in this, and many other areas? The most obvious answer is that the money isn't there, but as is always the case this simply isn't true. There's piles of money around and the capability to resume a serious space program could easily be achieved. We could easily have had a Moon colony by now, for example.

In fact I recently read an article in "Futurism" magazine on this exact subject. Futurism is a magazine whose mission is "...to empower our readers and drive the development of transformative technologies towards maximizing human potential". Sounds like a great aim and I found most of the material there quite interesting, although a little bit optimistic regarding technology.

Of course, I also believe technology (and not politics, religion, or business) is the answer to most of our problems and the underlying source of most of the positive benefits of modern society, so they are preaching to the converted there!

But to get back to the practicality and costs of building a Moon base. Futurism estimates the cost at $10 billion and that it could be done by 2022. Is that a lot of money? Well it's less than the cost of just one new aircraft carrier.

I wonder what proportion of the US population would be prepared to sacrifice just one carrier to get a Moon base. I really hope it would be most of them, or I would have to conclude that the country really has gone further down the path to self-destruction than I thought.

Let's look at the total US budget for 2015. The country spent $637 billion on defence out of a total spend of $3.97 trillion. This equates to 16% of the total - the only two higher categories were healthcare at 25% and social security at 24%. NASA's budget was $18 billion (just 2% of the military's or 0.5% of the total - the lowest it has been since NASA was created).

How much does that equate to as part of the total? Well, if you had a salary of $50,000 then 0.5% is 250 dollars - about what someone might spend on a moderately expensive family dinner at a restaurant. It doesn't really seem like a lot, does it?

But what about the argument over what the space program contributes to society? Well, there are three ways it contributes: direct beenfits like communications satellites; indirect but objective benefits like new technologies created while the program was being developed; and more subjective benefits which exist just because exploration and pushing the boundaries is inherently a good thing.

But that aside, we could make the same argument about the military, or social security, or health not contributing in an obvious way. From a conventional accounting perspective it's probably hard to justify those as well.

Perhaps the strangest thing is that it is often the more conservative members of society who want to "make America great again" who question the value of scientific programs but who fail to realise that it is exactly those programs which did make America great.

Another factor which might be holding up progress on space exploration is risk aversion. NASA has become extremely careful about balancing risk against moving forward. The Shuttle accidents didn't help of course, but space exploration is just hard and there will always be accidents. Some degree of caution is necessary but it shouldn't lead to a virtual paralysis.

Then there is the idea from some groups in society that science cannot be trusted, that it is out of favour in some way, and that it has an agenda contrary to it's stated one of establishing the truth about the natural world.

Some people reject evolution, some think climate change is a conspiracy, some think vaccinations cause autism, and others believe the Moon landings were a hoax. These are all totally irrational ideas but they all contribute to an acceptance of lower investment in science.

Finally there is the neoliberal dogma that free markets and profit-driven activities are always best. These people think that business generates all the benefits in society and that science is just a parasite on that.

But I would say that the opposite is true: business is a parasite on science and technology. For example, many companies (Google, Facebook, etc) make a lot of money from using the internet but the internet only exists because of military and scientific research organisations. The internet originated at DARPA (Defense Advanced Research Projects Agency, run by the US military) and the web began at CERN (the European Organization for Nuclear Research). So who is really exploiting the hard work and original ideas of others?

I'm not saying the military shouldn't be funded at all, although I hope there will be a time in the (perhaps distant) future when militaries are no longer necessary. What I am saying is that it wouldn't really hurt to spend a bit less on aircraft carriers and failed jet fighter projects and a little bit more on space exploration.

And yes, I demand my Moon base!


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Bordering on Impossible

2016-05-07. Science. Rating 1. ID 1788.

I have mentioned my admiration for the LIGO project before but since then it has actually achieved its goal so now might be a good time to discuss it again.

First, what is it? Well if you haven't heard the news (if you haven't you obviously don't follow science news at all) and haven't read my previous post on LIGO (titled "Ripples in Space-Time" from 2015-11-10) here's a brief summary...

LIGO is an experiment designed to detect gravity waves.

It consists of two detectors - one in Washington and one in Louisiana - which consist of two 4 kilometer long tubes, containing a high vacuum, at right angles to each other. A precision laser shines down the each tube and is reflected back to the central point.

If a gravity wave hits the experiment it warps the detectors (to be precise it warps the space-time the detectors occupy) very slightly and that can be measured by changes in the light beam, specifically by how the two beams interact. When there is no gravitational warping the two beams are in phase but if one is warped the beams interfere.

The reason there are two detectors (each with 2 lasers) rather than one is that local effects (traffic, small earthquakes, etc) can affect them far more than gravity, but these will only affect the nearby detector. Gravity waves will affect both (with a tiny interval of time between them).

It sounds simple but the complicating factor is the size of the effect. Imagine trying to measure the size of something to a precision of one part in one hundred million trillion. That precision can never be imagined in relation to normal size objects so let's compare it to the whole planet Earth.

The Earth is about 13,000 kilometers in diameter so to measure it with the same precision the measurement would need to be accurate to 0.00000000013 of a millimeter. If a single grain of sand interfered with that attempted measurement it would distort the measurement by a factor of 8 billion times too much. In other words, the precision is equivalent to measuring the width of the Earth accurate to one 8 billionth the width of a grain of sand.

A good phrase to describe the staggering difficulty of this task was "bordering on impossible". In fact, many people thought it really was impossible. But it wasn't. Because gravity waves were actually discovered at LIGO near the end of last year and officially announced earlier this year.

And there are a few interesting details of the discovery which make it even more incredible. Here's an overview of some of them...

The gravity waves which were detected were created in an event where two large black holes, each 20 to 30 times the mass of our Sun, merged. This happened 1.3 billion light years away which means it happened a billion years ago and the waves had taken that long to get here. The event was translated into a sound which has been described as a "chirp". It lasted just 0.2 of a second.

The detectors had been upgraded and had just been switched on again. An scientist in Germany first saw the signal and thought it might just be a test because there had been extensive testing of the new system up until then. But he soon found it wasn't and the timing of the event in the two facilities clearly showed a real gravity wave which could even be isolated to a line through the sky. The collision happened somewhere along that line.

If a third detector had been available the position could have been deduced by triangulation but unfortunately a third device in Europe which might have been used was being maintained. But hey, you win some and you lose some, and finding the event at all so quickly after an upgrade was a big win in itself. After all, massive black holes don't collide that often!

So what does it mean?

Well the observation finally confirms a prediction of Einstein's General Theory of Relativity which was published exactly 100 years prior to the confirming observation. Of course, many other aspects of the theory have already been confirmed but gravity waves were one of the few that hadn't. Relativity really is a remarkable theory and its predictive ability has never failed.

Gravity waves now allow astronomers to look at the universe in a whole new way. Instead of using electromagnetic radiation (light, radio waves, x-rays, microwaves, gamma waves) some super-energetic events can be observed using their gravity radiation.

And the confirmation of Relativity further strengthens its role as one of the core theories in physics. It is a theory related to the most basic levels of reality so there are few obvious practical benefits, but fundamental theories are what everthing in our modern, technological society are based on, so their importance cannot be overstated.

And like all great technical achievements which push the extreme boundaries of technology (the space program being the most obvious) there will be spin-offs from the actual construction of the facilities which will be used in diverse areas of technology in the future.

So yes, LIGO is an astonishing technological tour de force - on a similar level to the LHC, the Apollo program, and the Hubble Space telescope - something that every human on the planet should be truly proud of.


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Ripples in Space-Time

2015-11-10. Science. Rating 1. ID 1749.

Different people have different opinions on what are the most extreme and audacious activities our civilisation is involved in. Some think it is courageous and risky ventures in the business world, some think it is the production of great art, and some think it is impressive engineering projects.

I tend to admire our efforts at great scientific achievements most. In the past I have blogged about the Large Hadron Collider which I think is arguably our greatest scientific project ever (note that the engineering world shares substantially in this achievement) and this time I want to talk about another large scale project which also makes measurements with (literally) unbelievably exquisite precision.

The project is called LIGO, which stands for "Laser Interferometer Gravitational-wave Observatory". As the name suggests, this is an instrument (in fact 2, situated in Louisiana and Washington, USA) designed to measure gravity waves, and there are several other similar installations trying to do the same thing in other locations around the world.

The LIGO observatory consists of two tunnels in high vacuum, each 4 kilometers long and at right angles to each other. A laser is split and directed down the two arms and then reflected back with mirrors. As the two beams arrive back they interfere with each other and this can be used to measure the lengths of the two arms very precisely.

Why would they want to do this? Well, Einstein's Theory of Relativity predicts the existence of gravity waves which are "ripples" in space-time which travel out (at the speed of light) from events where mass changes configuration. The problem is that these waves are weak. Very weak. Even a massive catastrophic event like a star collapse only generates very small waves.

To detect these waves as they reach Earth it is necessary to measure how time and space is warped. Depending on the location of the source one arm of the tunnel at LIGO would be warped one way (it might get longer) and the other would be warped the opposite way (it would get shorter).

So that seems simple enough but the problem is how much the length changes. The effect which is trying to be measured is just one thousand trillionth of a meter over the 8000 meter journey of the laser. That's like measuring the distance around the Earth accurate to about one 10 billionth the width of a single hair.

Here are two other ways to visualise the tiny size of the distortion: a 1 km ring would deform no more than a one thousandth the size of an atomic nucleus; and it's like measuring the distance from the Earth to the Sun to the accuracy of the size of a hydrogen atom.

When I first read these numbers I thought I had misinterpreted them because it's almost impossible to believe that anything can be capable of such an astonishing feat of precision. But it's true according to several different sources.

Apart from simply how small the measurement is here are many factors which have to be considered. Even the tiny vibrations caused by traffic on distant roads is much greater than the distortion caused by gravity waves, for example. But this problem can be overcome. First, the two tunnels at right angles would warp in a particular way specific to the effects of gravity waves. Also, the two installations thousands of kilometers apart would both detect the gravity waves but would be affected differently by local noise.

So if one LIGO detected an event but the other didn't it would be assumed that it was due to local noise. But if both detected compatible events then a gravity wave is the best candidate for the cause. In addition, by timing when the event reached each observatory the direction the wave came from can be investigated.

For example, if the wave hit the Louisiana observatory before Washington then the event would have come from that direction. Of course, moving at the speed of light, the difference in time is small (a maximum of 10 milliseconds), but that's easy to measure compared with the other stuff being done there.

Finally I have to answer the obvious question: so what, who cares about gravity waves, and what practical purpose do they have? This is the question scientists hate, for two reasons: first, the pursuit of knowledge in itself is sufficient justification for this work; and second, discoveries which seem purely theoretical almost always have practical benefits later.

So the billions being spent on this should not be thought of as a waste of time and money, or as just a pet project for boffins, or as an expensive exercise in gaining theoretical and useless esoteric data. It should be seen as a way to learn more about the most basic attributes of the universe; of potentially gathering knowledge which can be used in future technology; and most importantly of all, as a way to do something which is just really cool!


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Do These Make Sense?

2015-08-08. Science. Rating 2. ID 1733.

I am currently reading a book (or, more accurately, listening to an audiobook) called "13 Things That Don't Make Sense" by science writer, Michael Brooks (the book has quite a lot of overlap with a list made by New Scientist which I blogged about in 2006). As the title suggests, it discusses several phenomena which don't seem to fit in with the current scientific understanding and I agree with his conclusions to varying degrees.

The author's overall tone seems to suggest that he thinks that science is too conservative and too reluctant to accept new ideas and therefore is missing out on a lot of potential new discoveries, and that there is a conscious effort to repress new ideas which don't fit in with the scientific orthodoxy.

But is he right?

Well those points do have a certain amount of truth to them but I think he significantly overstates one side of the argument, either because he just wants to make the cases he chose to cover in his book more interesting, or because he really doesn't understand the scientific process that well.

There is also the fact that when criticising science we need to say exactly what it is we are talking about. There is no accepted definition of what science is, for a start, and even if there was, all pure science is contaminated by politics, management, and commerce. Do we criticise science the way it should be or the way it is?

Since I criticise religion, democracy, and capitalism for what they are rather than what they should be in some idealised world, I really should apply the same rules to science. So yes, there are huge problems in the way that science is actually done and I'm sure that if it was allowed to progress in a "pure" form the world would be a much better place. But that is about as likely as religion or anything else proceeding in a pure form - approximately zero - so I will discuss what is, not what should be.

All of these points aside, the book (at least so far, because I am less than half way through) does over-state scientific resistance to change just to make its point. One subject, for example - the Pioneer Anomaly - has since been perfectly explained in simple, conventional terms which the book rejected or at least minimised. Note that the book was published 2008, and the anomaly was explained 2012.

That doesn't mean that the other phenomena will also be explained without making major changes to current scientific theories and it doesn't mean that science isn't too resistant to new ideas either, but it does mean that we shouldn't try to explain something caused by something simple by creating a new fundamental theory (in this case conventional thermal effects were the explanation and a new theory of gravity was unnecessary).

Conservatism is part of science because it's more effective to only change theories when the evidence is really strong rather than to pursue potentially false lines of evidence and then have to backtrack if that doesn't work out.

So that's the big picture. To finish this post I will quickly discuss some of the other things which "don't make sense" and how seriously I take them...

The missing universe (dark matter and dark energy). Well yes, it is a well-known source of embarrassment that science doesn't really understand the nature of over 95% of the mass/energy of the universe. But at least the issue is being investigated and several possible explanations are available.

There's nothing that really "doesn't make sense" here - it's more a matter of which of several possible answers is correct (if any because maybe there's another one not considered yet, although that is unlikely).

Varying constants. The author makes it seem like scientists are so ideologically opposed to varying constants and/or physical laws that they won't even contemplate the possibility. This is far from the truth. The idea is openly discussed by many physicists and the evidence is taken quite seriously (especially when considering the fine-structure constant).

But I do agree that constants (which as the name suggests are supposed to stay the same) changing over time or space does significantly change our approach to cosmology (in particular).

Cold fusion. This is a fascinating subject because it is such a mix of science, engineering, politics, and reporting. The original experimenters were forced by their university to release their findings in an unnecessarily sensational way. Many attempts at replication failed but others seemed to show positive results. Science politics intervened and generally discredited the whole field. Research has continued since and we still only have negative and inconsistent positive results.

I do have to say that it would be great if cold fusion was real but generally in these situations (when consistent results aren't produced from apparently identical scientific setups) there is some anomaly or error in the experiment. That is far from certain though and I think further research is quite justified, especially considering the slow progress with hot fusion!

The other topics on the book's list are: life, the Viking experiments, the Wow! signal, a giant virus, death, sex, free will, the placebo effect, and homeopathy.

It's certainly a fascinating mix and I look forward to hearing the rest. Looking at the list I predict there is nothing too extraordinary in many of them but I will reserve judgement until I hear the arguments. I think another blog post will be called for at that time!


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But is it Science?

2015-01-23. Science. Rating 1. ID 1697.

This year marks a hundred years since Einstein's General Theory of Relativity was released. It was his second theory of the type, the Special Theory was presented to the world ten years earlier. The other great area of science Einstein worked on was quantum physics and he actually gained his Nobel Prize in this area rather than Relativity which he is better known for.

After 1915 Einstein started work on integrating those two great theories of physics but, like everyone else, he failed to come up with a solution. So even now a hundred years later physicists are still trying to come up with a "theory of everything".

But there are some candidates and the most prominent is String Theory. This theory posits the existence of one dimensional strings in 11 dimensional space. That sounds fairly obscure, perhaps even totally crazy, I mean what actually is 11 dimensional space anyway? But as the great physicist Niels Bohr (allegedly) said: Your theory is crazy, but not crazy enough to be true. Still, that is a rather trite response. The question is, is there any reality in String Theory.

One rather derogatory description of String Theory is that it is "not even wrong" meaning that it cannot be tested so it can't be said to be right or wrong. In many ways, showing that it is wrong would be preferable because then physicist could move on to other possibilities.

But although it is difficult (some say impossible) to test in the real world, String Theory is so beautiful from a mathematical, abstract perspective (at least according to maths experts) that it is difficult to ignore. So now some theoretical physicists want to re-define science, and that's where things get interesting...

They say that some areas of research deal with abstractions and maths which are difficult to test in the real world. And they might never be able to test some ideas, such as String Theory and the Multiverse. But they don't care, and argue that a theory being elegant and explanatory is as important as it being testable.

Needless to say old school physicists are alarmed at this because they think that it undermines science. I would have to say that my initial reaction was to agree. But untestable theories often become testable and there are numerous examples of this in the past. And if theories are elegant and explanatory I think they still have value.

Testability has been an important attribute of science (although not quite an absolute requirement as some people like to suggest) especially since the work of philosopher Karl Popper (who worked here in New Zealand during WW2) so we shouldn't ignore it. On the other hand, science had been proceeding for many years before Popper's analysis and limiting it to one methodology seems unnecessary.

Maybe another suggestion made by these theorists might be preferable, that is to call this type of research something else. Maybe it is pure maths, or mathematical theoretical cosmology. Maths isn't really science because it is not tested in the real world in the same way as science is, so maybe we should say that string theory and other speculative theories should be thought of more as maths or philosophy than science.

But in the end who cares? These are just labels and there is always overlap between areas of human endeavour anyway. There are examples of highly theoretical maths which has turned out to be useful. And we should never forget the famous concept: the unreasonable effectiveness of mathematics in the natural sciences (initially from an article published in 1960 by the physicist Eugene Wigner). For some reason maths seems to describe the real world. There doesn't seem to be any good reason why, but it's true.

And the concept of beauty in maths is well known. I think the best expression of this might be by one of my favourite philosophers, Bertrand Russell, who said "Mathematics, rightly viewed, possesses not only truth, but supreme beauty - a beauty cold and austere, like that of sculpture, without appeal to any part of our weaker nature, without the gorgeous trappings of painting or music, yet sublimely pure, and capable of a stern perfection such as only the greatest art can show. The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as in poetry."

So yes, let the abstract theories continue. Let's not worry too much about practicality or unnecessarily limited definitions of science. Let's pursue these ideas for their own sake. But if anyone can think of a way to test them that would be great!


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In Defence of SETI

2014-04-11. Science. Rating 1. ID 1644.

I was surprised recently when I looked back through my records and realised that I have participated in the SETI at Home project for about 15 years now. If you haven't heard of this project, let me explain: SETI stands for the Search for Extra-Terrestrial Intelligence, and the project uses many ordinary computers to analyse enormous amounts of radio telescope data looking for signals of intelligent life.

It becomes quite competitive and some people use large numbers of computers to try to analyse more data (or "blocks" of data) than anyone else. I have used varying numbers with varying power to process data in the past but am currently just running a few.

I have been criticised on occasions because people see this project as a waste of time, internet bandwidth, or computer power; or as a frivolous extravagance; or even as a pseudoscientific pursuit with no basis in reality.

I disagree, and this blog entry is primarily to defend the SETI project and maybe the more controversial and quirky scientific projects in general.

For a start, this is a real science project and many other real science projects are being conducted this way today. Volunteers like me make our computers available to analyse data which would normally require expensive supercomputers. The data is generated as a side-effect of other science projects and is managed by Berkeley University, so any claim that this is pseudo-scientific is definitely untrue.

What about the claim of frivolity? Is it silly to look for "little green men" or other intelligent alien life? Unfortunately the real science has been confused with the pseudo-science of UFOlogy and other claims and conspiracies in this case. But the two aren't the same. SETI projects are a genuine attempt to look for intelligence using techniques which might get negative or positive results. There is no initial assumption that aliens exist. Most pseudo-scientific UFO "researchers" already "know" that aliens exist and pick and choose their evidence accordingly.

Finally, is this a waste of time, bandwidth, or computing power? In most cases these resources weren't originally purchased to run distributed experiments like SETI but there is very little loss involved and the potential gain is significant. Would the discovery of intelligent life elsewhere in the universe not be the greatest discovery of all time? How cool would it be if it was one of my computers which discovered the signal!

I have commented in the past how puzzling the lack of signs of intelligent life is, for example in a post titled "Science and Fiction" from 2013-01-15 where I discussed the Fermi Paradox: the fact that informal estimates indicate there should be plenty of life elsewhere in the universe, yet we see none.

This is surely one of the great mysteries of the universe. If we are the only intelligent life (and maybe the only life of any type) in the whole universe that would be totally astonishing, yet the opposite idea, that life is everywhere, is equally amazing.

Surely supporting the SETI projects by doing something as simple as installing the SETI at Home software and paying for a little bit of extra electricity and internet bandwidth is worth it. This is arguably the most awesome experiment the human race has ever attempted, and a lot of it is being performed on a bunch of ordinary computers around the world, including mine. The only criticism should be of those who don't participate!


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Evidence for a Multiverse?

2013-12-19. Science. Rating 3. ID 1609.

For many years now I have been intrigued by the idea of multiple universes. If they exist it would answer a lot of the problems we have with current theories, such as what happened before the Big Bang, what caused it, what it formed from, and why our universe seems so special (in terms of the physical constants seemingly being fine-tuned to allow life).

First I should briefly explain these problems. A question people often ask about the Big Bang is what happened before it and what caused it. If it really was the origin of our universe and there no other universes then those questions have no obvious answer, in fact the questions themselves may make no sense (because time and space didn't exist before our universe began).

Then there is the puzzling observation that many of the constants, such as the strength of gravity and electromagnetism, are not predicted by theory so could have any value. Yet if their values were much different to what they actually are life anywhere in the universe would not be possible. And that isn't just "life as we know it", it is any reasonable type of life (for reasons I won't go into here to save space).

But a multiverse theory can answer these questions in a rather elegant way.

If our universe is just one part of a multiverse, with an infinite number of universes in it, and ours "broke off" from the multiverse during the Big Bang then we avoid the origin problems. The multiverse would be infinite in time and space so asking what is outside the universe or what happened before is no problem: outside is just more universes embedded in a multiverse which has always existed.

We still can't say for sure what "caused" our universe to "break off" but I think it's fair to suggest it was one of those causeless, random quantum events. This idea is supported by the fact that the total energy in our universe seems to be zero.

So what about the fine tuning argument? This has been used as a reason to believe in a god. Some people say that the universe could only be the way it is if an intelligent entity had deliberately made it that way. Of course, like most theological theories, this one is absurd because it just pushes the problem back one step: we know why the universe is the way it is but why is god the way he is? It's really nothing more than a "god of the gaps" argument.

A multiverse answers this question very easily. If there are an infinite number of universes all with slightly different values for the constants then there is sure to be one which suits life. We live in that one because we couldn't live in any other, just like we evolved here on Earth because Venus is too hot and Mars too cold.

The whole idea is just perfect, except for one small issue: there has never been the slightest piece of evidence to support it! Perhaps until now...

Scientists who have studied radiation data gathered by Planck telescope think they have found evidence of other universes (although this is disputed). The theory says that during the first seconds of the universe it would be affected by other universes in the area and that would be detectable in background radiation patterns. And that's what some researchers think they have found.

I really do have to say that this stuff is rather speculative and quite preliminary at this point but I think I have noticed a trend over the last 10 years for multiverse theories to be taken more and more seriously. Maybe in the near future the evidence will be much better and the theory will be generally accepted. It's certainly an interesting idea and the best explanation yet of some of the most puzzling questions we have.


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Science isn't the Enemy

2013-11-23. Science. Rating 3. ID 1596.

I recently listened to a podcast where a professional astronomer was lamenting the current lack of respect given to her profession and to science in general. I think there are two elements to this point which I need to mention. First, the level of respect varies from one country to another and between groups within a country. And second, where it does exist it is more an anti-intellectual bias rather than one against astronomy (or any other less "practical" sciences) or science in particular.

I'm sure we have all come across the people who are actually proud of their ignorance. Sometimes I talk about how amazing the work being done at CERN is and a person might respond with "oh, I don't know anything about that" with a sort of self-satisfied expression as if that made them better in some way. Or I might mention how incredibly useful modern smartphones like the iPhone are and they will reply "I would never use something like that" even though they might have just been talking about a situation where GPS or some other technology would have helped them.

So astronomers shouldn't take the lack of respect for them as anything personal. I work with technology in a university and I often get the impression people see that as inferior in some way to managing a shop, or being an accountant, for example. And I have often come across the situation where people assume my colleagues working in the more esoteric fields such as quantum physics or organic chemistry are just viewed as boffins working on their own pet projects and as being of no real use to society.

It hasn't always been like this. In the past scientists and technology professionals were often viewed in a similar way to pop music performers or movie stars today. They toured and gave lectures to packed halls, they demonstrated new inventions and discoveries, and their contributions were seen as a way to achieve a better future.

I think there are several factors which have contributed to the decline of these attitudes. First, neo-liberalism (you didn't think I'd get through a blog post without mentioning that, did you?) has emphasised the alleged value of commerce over other activities. Second, science has challenged many established views (evolution and cosmology challenge religion, and climate science challenges some established conservative dogma, for example) so some groups have attempted to discredit it as a result. And third, the rise of environmentalism - which I agree has a lot of positive points - has often had an anti-progress aspect as well, such as begin against nuclear power and genetic engineering.

None of these are good reasons to be anti-science. If science disproves your religious beliefs then change them or do better science to show the original stuff is wrong. If science shows your political ideas won't work then you should be able to change those views to fit without abandoning your core ideals. And if new technology doesn't fit in with your environmental philosophy then maybe it is time to have a more pragmatic approach to your cause.

Whatever the case, science and technology are not the enemy of any reasonable and rational group. If you find yourself opposed to them then I think there's a very good chance that it is you who has got it wrong.


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Totally Baffling

2013-11-14. Science. Rating 1. ID 1591.

I've been thinking about wave-particle duality (as I'm sure we all have on occasions) and I have come to a conclusion which seems very obvious but which I don't think I have seen expressed much elsewhere. Before I say what my conclusion is I should explain what wave-particle duality, because I always like to talk about cool scientific principles in this blog.

OK, so we know what a wave and a particle are, right? A wave is a periodic movement of something, like waves on the sea are a series of higher and lower areas of water a particular distance apart (the distance we call the wavelength) and which go past at a particular rate (the number of waves which go past in a certain time is called the frequency).

A particle is just a very small component of matter. Many particles, like the electron, are indivisible (they aren't made of smaller particles) but others are made of even smaller particles (like the proton which is made from quarks).

So it's usually fairly obvious which things are waves and which are particles. Or is it?

The problem is that as things get smaller it becomes difficult to say what they actually are. The most obvious example is light. It's clearly a particle because it has energy and travels like a particle, but it is also clearly a wave because it shows interference effects (this is where two waves which cross can become higher and lower depending on whether the peaks coincide or a peak in is cancelled by the trough in the other).

So which is it? Well it depends on what type of experiment you do. If you do an experiment which is likely to show wave phenomena then it is a wave, but if you do one which shows particle phenomena then it will be a particle. Pretty weird, eh?

There's one obvious explanation. It's neither. Waves and particles are just two ideas human scientists, philosophers, and really just everyone (because everyone understands those two concepts) have invented which explain the macro (human size) world really well. But reality isn't like that at all. Real matter/energy is actually something else which just happens to look a lot like waves and particles.

I wanted to present this "brilliant conclusion" here after reading an entry on the excellent "Quora" web site (www.quora.com) on a page titled "What can you not fathom, understand, or reconcile no matter how hard you try" where people presented ideas which were completely baffling to them.

Well if wave-particle duality is baffling I'm not sure if my explanation makes it more or less so. I suspect reality can only really be explained with maths and never with natural language. Yeah, that's much less baffling!


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Fusion Power

2013-11-12. Science. Rating 1. ID 1589.

If there was one single technological capability which would "solve all of our problems" it would be limitless, clean energy. If we had that we could resolve many current issues, including transport, food production, materials manufacturing, etc. So is the idea even feasible, and if it is, what is the answer?

Well of course if you know anything about technology at all you wil instantly think of fusion power, unless you jump into really crazy realms and go for quantum fields, zero point energy, and other exotic stuff. But there's no need for that because fusion is sufficient, at least for the next few million years (so it's not truly limitless).

A bit of background first. Fusion is a form of "nuclear energy" but has many advantages over the more common form, nuclear fission. These advantages include: the fuel is virtually limitless (hydrogen from sea water), it produces no dangerous waste, and it produces much more power (potentially) than fission.

In fission big atoms (or at least the nuclei of big atoms, such as uranium) break apart to form smaller ones, plus energy. But in fusion the opposite happens: small atoms (nuclei of isotopes of hydrogen) combine to form bigger atoms (helium) plus energy.

This all happens at extreme temperatures, because the nuclei don't want to collide (they have the same positive charge). In the Sun (which produces energy through fusion) this happens at a mere 10 million degrees, but because of the much lower pressure here on Earth 200 million degrees is required. That's really hot!

So producing a fusion reaction is difficult because nothing can hold a plasma at that temperature, plus it takes a lot of energy to get something that hot to start with. In fact it usually takes more energy than what comes out of the fusion reaction itself! So you can get power from fusion but you need to use more power than you make.

At least that was the case until recently when the National Ignition Facility in California became the first lab to create a fusion reaction that generates more power than it took to get the reaction started.

But the NIF is still a long way from being a fusion power plant and another project, the European ITER fusion reactor in France, is probably a better path to that (although it is also a research facility). After recent funding issues this project is now progressing again and should be fully operational by 2027.

That's my short background for fusion. Tomorrow I will discuss some political issues and generally rant about how there is always insufficient funding for the really worthwhile projects, so stand by for that!


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Blue Skies

2013-11-03. Science. Rating 2. ID 1585.

Many people think our comfortable standard of living in the western world is a result of efficient commerce and the capitalist system working properly. I guess that's part of the reason but I think it is far from the whole truth. In reality I think that our success is mainly a result of science and technology, mostly driven by non-commercial processes, and that the capitalist system has simply exploited these advances for it's own benefit.

As I said, there is a fair case to say that free markets and capitalism has resulted in a far better utilisation of those benefits than a more central system (such as government control) might have done, but that is only a secondary factor to the original sci-tech itself.

So it might seem that the best outcomes could result from a synergy between sci-tech and business, which is the currently popular model in many countries, including New Zealand. Again, there is an element of truth in this, but I think there is one major error inherent in most implementations of this model. The error is that sci-tech is just seen as a way to feed business what it needs. Business is always the senior partner in the system and it has the most control. I think this is wrong.

In most cases the greatest advances in science have come from non-commercial research. Sometimes research which is done just for the search for knowledge rather than any "practical" purpose is known as blue skies research and it is often controversial. But it is almost inevitably how really significant progress is made. If we allow business to tell science what it needs we will inevitably lose the really big discoveries. Who would have paid Einstein to research something as esoteric and impractical as relativity, for example? What commercial use could it possibly have?

So there are two points here. First, the mere acquisition of knowledge should be sufficient justification for doing research. There should be no need to justify a scientific study with practical outcomes. Second, even if you do insist on practical outcomes there is no way of telling where even the most theoretical knowledge will lead. Who would have known that a highly mathematical theoretical examination of the quantum world would have lead to all of our modern electronics?

If commercial justification was necessary for research we wouldn't have GPS because we wouldn't have relativity, and we wouldn't have computers without quantum physics. Of course, these are just two examples of the many practical outcomes of the two most foundational theories of modern physics.

A final point which should be made too is that many commercial scientific advances are based on earlier work with less obvious commercial purpose which often come from universities and other non-commercial organisations. The university does the basic research which might initially have no obvious purpose, and that is used as a basis for more practical discoveries later.

So contrary to many people's ideology, it is science which leads and that is only followed by commerce. The intermediate between these is usually technology and that might or might not benefit from a commercial focus.

Two of the great technologist from about a century ago, Thomas Edison and Nikola Tesla, both made incredible contributions to electrical engineering but one was more commercially motivated (Edison) and the other more a pure technician. And Alan Turing probably made more contributions to the science of computing than anyone else but got no real commercial benefit from his work. Many other examples exist of progress made by pure scientists working on "pet projects" such as Maxwell, Hertz, and Faraday.

In summary, I would say the "blue skies" research is the most important and should be given the greatest resourcing. There's nothing wrong with research which has a commercial focus as well but that should be seen in context: as something which isn't going to really result in the big changes - the sort of changes which have given us the lifestyle we enjoy today. That almost inevitably has come from blue skies research and pet projects!


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Science as Salvation

2013-08-02. Science. Rating 3. ID 1557.

I recently discovered a discussion forum (through a convoluted path, as often happens) which tackled the topic of "amazing physics facts". One of the entries there seemed a bit odd which made it worth thinking about. It asked a series of intriguing questions which it claimed there were no answers to. It also seemed to question the validity of science as a mechanism to try to find the answers. Needless to say, I have to comment...

Here's the opening statement: "Let's admit it: Physics can't explain reality. All the current theories are incomplete at best and, at worst, flat out wrong. Midgley was correct when she wrote, 'Science as Salvation: The Modern Myth and its Making.' Salvation indeed."

As you might have already assumed, I disagree. Physics actually can explain a lot of reality. If you want to calculate the correct path to get a rocket to the Moon, for example, what do you do? Consult an astrologer, or a religious text, or a book on philosophy, or a work of fiction? No, you use physics and you get an answer which works, and has worked many times. Why does it work? Because physics explains reality.

That's not to say that physics can explain every aspect of the universe to an arbitrary degree of detail, but I think that requirement is misleading. Every understanding we have of the real world is necessarily an approximation. At the most basic levels uncertainty predominates and it is fundamentally impossible to get past that.

I haven't read any of Mary Midgley's works on evolution or science in general but I am aware of her arguments and I don't think they stand up to any scrutiny. She seems to rely primarily on straw-man arguments, especially against Richard Dawkins, so I don't think her opinion is particularly compelling.

Regarding whether science is a form of salvation and whether it is a myth, well that depends on your definitions of those words. Again, I would need to read the book to comment with certainty but if by "salvation" she means a way to save ourselves from superstition and false belief then sure, I totally agree. But I don't think there is any reasonable interpretation of the word "myth" which can be applied to science. The overwhelming fact-checking, peer review, and skepticism involved in the scientific process makes myths (in the form seen in religion, for example) in science very unlikely.

The poster went on to ask some questions under the title "amazing or not" and concluded with the claim that "There are, at present, no agreed-upon answers to these fundamental physical or philosophical questions." So let's look at these questions...

Question 1: What is attractive force of the universe?

Comment 1: Would that not be gravity, the strong force, the weak force, and the electromagnetic force? All of these are, or can be, attractive on different scales. All have been measured and we have some degree of understanding of them with excellent experimental verification. I think there is little doubt: we understand these forces quite well.

Question 2: What is the repulsive force in the universe?

Comment 2: The electromagnetic force can be repulsive which you can easily verify by trying to push to similar poles of magnets together. But maybe this is referring more to the cosmological repulsive force, or "dark energy" which really is a bit of a mystery. I will concede that no one really understand this at the moment.

Question 3: What puts spin on matter?

Comment 3: That would be a result of asymmetric forces applied to collapsing objects and other similar phenomena. The Big Bang was rather violent and material was thrown out in a chaotic way. As the gas clouds created in the BIg Bang collapsed they spun faster and faster and that is why everything in the universe spins. No great mystery there.

Question 4: What is energy?

Comment 4: The "what is" question can be asked about everything and inevitably it has to be answered using words which in turn can be questioned. In the end these scientific concepts are best explained using maths and from that perspective we know what energy is.

Question 5: What gave laws to the universe?

Comment 5: Now this is the sort of question which really is interesting. Or is it? I think in many ways it's a non-question: it cannot be answered because it shouldn't be asked. Inevitably any process which results in the creation of laws must itself follow laws which in turn must be explained, ad infinitum. Or maybe we should invoke some of the more radical ideas on the edges of physics and say the laws created themselves because reverse time-travel is OK according to most theories.

Question 6: Whence the order in the universe?

Comment 6: This is really just a re-statement of question 5 so I will apply the same type of response, that is, see comment 5.

Question 7: How is the universe complexifying?

Comment 7: Is "complexifying" even a word? If it isn't, maybe it should be because I know exactly what it means. The answer, of course, is that it isn't. Looking at the universe as a whole entropy in the universe is increasing (it's becoming more "chaotic") and increased complexity only occurs in systems with energy sources which drive the process (for example the Earth which has the Sun as an energy source). There's no totally unanswerable mystery here.

Question 8: How did the universe originate?

Comment 8: This is another interesting question which many people would like to answer. But the fact is we don't know at this point, although there are many ideas out there which cannot be conclusively tested yet. We know that the universe started in a Big Bang (the evidence is overwhelming) but what caused that is far more difficult. Maybe our universe is just one of a repeating sequence going on infinitely in the past and future. Or maybe it is one "small bubble" in an infinite multiverse. Or maybe the universe created itself through one of those reverse time events! I admit we don't know but we are getting closer to an answer.

Question 9: How did life originate?

Comment 9: Unfortunately, because life on Earth originated billions of years ago and involved no material which could be easily preserved this is always going to be a difficult problem. But it's not so much that the process is difficult to explain, it's more that there are so many possible ways it could have happened that we find it hard to distinguish which one was responsible. Maybe life originated through processes involving starlight acting on organic chemicals which we know exist in space. Or maybe it started in Earth's oceans. Or on the surface of clay. There are many ideas and maybe it will never be possible to know the exact mechanism. But at least there are many possibilities which make a lot of sense.

So there's a bit of a mixture here: some of these are very good questions with no current answer, and the rest are quite well understood already. But whatever the status of these questions one thing is sure, science is the only way we have which will ever find the answers.


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Random Astronomy Facts

2013-06-21. Science. Rating 3. ID 1545.

When someone wants to describe a number as being really big they often use the word "astronomical", presumably because astronomy involves so many big numbers. Big numbers are cool in themselves but more interesting when the significance of big numbers can be used to make a more relevant point. So that's what i am going to try to do here, in my next instalment in my "random facts" series, which will probably be slightly less controversial than the last one!

One of the first questions people ask about the universe is how big it is. I will answer this question through the use of some of my random facts from my "Astronomy Random Facts" file (as explained in the entry "Random Environment Facts" from 2013-05-20).

Fact 1: There are 5 times as many stars as grains of sand on every beach on Earth. (source: Infinite Monkey Cage podcast, 20 Jun 2011)

Discussion: The IMC podcast is (was) hosted by well known astronomer Brian Cox so you would expect it to have a certain amount of credibility. But this number varies greatly depending on the source and method used to do the estimate. Some estimates suggest the number of grains of sand and stars is about the same. But either way, that is a lot of stars.

Remember that stars are huge balls of glowing plasma, just like our Sun. The Sun is 1.3 million times bigger (in volume) than the Earth and many stars are much bigger than even that. A star called VY Canis Majoris (a red hypergiant) is often quoted as the biggest known. It's volume is almost 4 billion times bigger than the Sun or 7 thousand trillion times bigger than the Earth!

Plus the distance between stars is huge. Even in our galaxy the distance between stars is 50 million times bigger than the size of the star itself. And stars are grouped into galaxies where the distance between them is generally very large (millions of times greater than the distance between stars).

So, in summary, the universe has a vast number of really big stars separated by huge distances. So yes, the universe is big. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space. - Douglas Adams, The Hitchhiker's Guide to the Galaxy

Fact 2: If you attempted to count to stars in a galaxy at a rate of one every second it would take around 3,000 years to count them all. And fact 3: The Hubble Space Telescope (HST) site estimates there is hundreds of billions of galaxies in the universe. A recent German super-computer simulation estimates that the number may be as high as 500 billion.

Discussion: Just to reinforce the number of stars out there, this is the same information presented in a different way. Again, the number is an estimate which varies greatly. The only thing which is certain is that it's big!

I often wonder what people with "human-centric" worldviews think of this sort of thing. For example, the Bible strongly implies that the Universe is here for our benefit, yet we only experience a tiny fraction of it and practically the whole Universe is unsuitable for life as we know it. Why? How can that possibly fit in with a human-centric belief system?

Fact 4: It looks like we live in a flat universe where the total energy is zero.

Discussion: To many people this seems bizarre. How can the Universe have zero energy? After all, there are all those stars and other high energy phenomena, aren't there? Yes, there is a lot of energy in the Universe but there is a lot of negative energy too. Gravitational energy is always stated as negative and it exactly balances the other forms as far as we can tell.

Is this merely coincidental or a side-effect of the measurement techniques, or is it something fundamentally important about the Universe? We don't know for sure but it is interesting to note that something with near-zero energy can easily be created from a vacuum with no underlying cause according to quantum physics. Perhaps the whole Universe is a vacuum fluctuation.

Fact 5: Sun leaks 7 billion tonnes of coronal mass every second into space. And fact 6: The Sun would only burn for about 5000 years if it was made of coal.

Discussion: Stars like our Sun are truly mighty objects. Every second the Sun loses billions of tonnes of it's mass into space yet it has been doing that for billions of years and that has barely made a difference.

But even with such a huge mass it could only produce energy at the rate it does for 5000 years if it utilised conventional combustion. The fact that it has "burned" for a million times as long yet has only used less than 1% of it's total fuel shows how incredibly efficient nuclear fusion is. And that's why we want to use this energy source (not quite the same but very similar to stars) for power production on Earth.

Fact 7: At its closest approach to Earth, Mars appears about as big as a tennis ball viewed from a distance of one and a half miles (two and a quarter kilometers).

Discussion: When I used to teach astronomy to the public there were two responses I commonly got when viewing the sky. The first was the delight that people could actually see those objects (especially Saturn) which they had only seen in books. And the second was disappointment in the image size and clarity we often had. The fact that we were observing from inside a city with a lot of street lights and heat sources didn't help, of course!

But observational astronomy is just inherently difficult. Apart from the Moon everything is too far away to make detailed observation easy. Even the closest objects like Mars (technically the third closest large body after the Moon an Venus) is very small even in large telescopes. When I taught astronomy we didn't have the HST photos we do now so expectations weren't quite as high. It must be a lot more difficult now!

So Mars is very small and it's sometimes difficult to see much more than a small orange disk, but what about genuinely distant objects? What about the closest star? Well that is about the same size as the Sun so it is about 100 times the diameter of Mars. That means that if Mars was a tennis ball, the star would be 6.5 meters across (about 20 feet). But the star is 40 trillion kilometers away compared with a mere 40 million for Mars. That is a million times further.

So the star is a hundred times bigger but a million times further away making it appear 10,000 times smaller. And that's the closest star! In effect this means that stars tend to be just points of light in even the biggest telescope. The damn Universe is just too big to be convenient!

Last fact: Virtually every atom in your body (other than hydrogen) was created in the core of an exploding star over five billion years ago.

Discussion: As Carl Sagan said: we are all star stuff.


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You Want the Truth?

2013-03-05. Science. Rating 3. ID 1505.

In recent discussions I have often encountered the question of what is the best way to establish the truth. Generally this question is used as a cover for religious people to reject the findings of science because they claim science can't discover certain types of truth and that alternative methods must be employed instead.

Before even examining that issue we must face the problem of is there really a thing called "truth" anyway? Maybe there is no truth at all (a type of epistemological or ontological nihilism), or maybe there are multiple truths depending on your philosophical approach (relativism), or maybe there is a truth but we can never know it for sure (classical skepticism).

Philosophers can debate these problems of epistemology for as long as they like. I fully understand that we can never be totally sure about anything regarding the nature of reality but I prefer to take a more pragmatic approach. We all act as if there is a reality and that we can know it to some extent so let's keep the whole debate reasonable and start with the assumption that there is an underlying reality and that we can know something about it even if we can never fully understand it.

The scientific method has emerged over the last couple of hundred years as the way to do this, at least in my opinion, but not according to everyone as we will see later. This method is basically a cycle of formulating an hypothesis to test, creating an experiment (using appropriate blinding, baseline testing, controls, etc) or making an observation to test the hypothesis, carefully examining the results, writing up the method and conclusions in a formal way, having other people repeat the experiment, and looking for consistent outcomes and establishing theories based on those.

I would assert that the method works for two reasons: first, it just simply makes sense that it should because careful formulation, testing, and repetition is just naturally a logical way to proceed; and second, it gets results.

Yes, science does get results. We can look at the outcome of science-based interventions such as antibiotics and see the effectiveness, but look at the outcome of other processes based on alternative worldviews (such as religion, spirituality, etc) and you will see a mixture of good, bad, and inconclusive results (the efficacy of prayer would be a good example) which is generally a sign that there is no real effect.

There is a criticism of what I have just said however. That is that I am proposing using a scientific testing regime to test both science and other systems. Is that fair? Maybe not.

But now I get to the core question in this blog entry. That is: what is the alternative? If anyone disagrees with the scientific method then I would like to hear them propose something better. When I challenge someone this way I usually don't get an answer at all and if I do get an answer it usually makes very little sense.

For example someone might suggest that faith is a good alternative. OK, let's look at that idea. Faith is a belief in something without good supporting evidence. How do I decide which thing to believe? For example, if it is a religion then how do I decide which religion to have faith in? Many people will say it obviously has to be Christianity but that is just a consequence of being born in a country with where Christianity is the dominant religion. If I asked the same question in Saudi Arabia I would be told Islam is the obvious answer, or in India I might be encouraged to follow Hinduism.

This does not sound like a good way to establish a real, objective truth, because it depends so much on totally arbitrary starting parameters. Is the truth different depending on which religion is popular in the country you were born in?

Another possible solution is to look at the contents of the belief system in question and see if they fit the facts. But this isn't faith any more, is it? In fact taking the ideas of a belief system and testing them sounds more like science! Unfortunately when you do this in every case the belief system is found to be severely lacking in which case it is necessary to revert to faith. So around and around the old circular logic roundabout we go!

If anyone believes in something based on faith we can almost immediately assume it is untrue because if faith is necessary to support something you can be fairly sure that it has failed all the real reality tests and faith is the only option left.

But what about revealed knowledge? The sort of thing found in holy books, like the BIble. Exactly the same criticism applies. Which holy book should we choose? And if we use real scientific investigation to test these books why do they always fail?

So let's move beyond religious answers and look at other alternatives. What about philosophy? Well I have a lot of regard for philosophy but so much of it (not all) is somewhat pointless because it is untestable. If a number of philosophical theories are devised and there is no way to distinguish which is true then what is the point? I would suggest that the value of these theories is somewhat limited.

So now it all gets back to my second reason for supporting science: it gets results. Look back at the history of civilisation. Where has almost all of our real progress come from? Is it from religion, or philosophy or science (and its natural end result, technology)? I think if anyone was truly honest they would agree that science is the system which has produced the real results.

So there's an open challenge to everyone. If you really think science has problems and is imperfect (it is) and you want to reject it based on that then tell me what is better. Whatever flaws science has I would claim it is much better than anything else we have. If you disagree let's hear your better idea!


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