Posts Tagged ‘astronomy’

Do It Yourself

March 3, 2017 Leave a comment

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.


The Fermi Paradox Again

February 23, 2017 Leave a comment

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.

Bordering on Impossible

May 7, 2016 Leave a comment

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.

Ripples in Space-Time

November 9, 2015 Leave a comment

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!

In Defence of SETI

April 11, 2014 Leave a comment

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!

Creation’s Cretins

February 16, 2014 Leave a comment

Some ideas are so ridiculous that they deserve no serious consideration at all. That’s one of the reasons that many people refuse to debate with creationists. But recently Bill Nye “the Science Guy” rather foolishly agreed to debate Ken Ham, a prominent creationist, and this has stirred up a lot of discussion in various forums.

It should be an easy victory, right? Because Nye has all the facts on his side, and Ham has nothing. But no, it wasn’t really that simple. Like most of these debates, there was no obvious victor because Nye was debating the facts and Ham was countering with creationist lies and propaganda.

Anyway that’s enough of the preamble. What I want to do in this blog entry is show how anyone can prove to themselves, beyond reasonable doubt, that creationism isn’t true. By “creationism” I mean the belief that the world is about 6000 years old; that the universe, Earth, and life were created as described in Genesis; and that the Flood was a real event. There are other forms of creationism (old Earth, for example) and there are other beliefs included in that view, but I’ll stick to these most important ones.

Creationists say the Universe is just (roughly) 6000 years old because that’s what the Bible seems to show, without explicitly stating it. OK, so is that true? Science says the Universe is about 13.8 billion years old, the Earth about 4.5 billion, and life and 3.6 billion. That’s a big difference, a factor of 2 million times greater (like saying I’m 10 minutes old instead of 50 years). Surely it should be easy to find which of those ages is correct. Well yes, it is.

What evidence do creationists have? The Bible. That’s it. And even then it is just one particular interpretation of the Bible because most Christians accept the Universe is much older. Apart from that creationists occasionally quote errors or inaccuracies in scientific dating techniques, some of which are real but have no effect on the overall findings.

What evidence does science have? Well there are so many independent sources that I can’t possibly list them all. An old Universe (and Earth) is required by the discoveries of astronomy, cosmology, chemistry, geology, physics, evolution, and virtually any other science you can think of.

The important thing is that all of these outcomes are independent. An error in one would not lead to the same error in another because they rely on completely different assumptions and methodologies. Yet the results match to a high degree of precision. So what’s more likely: that every branch of science has got the basics wrong and got them wrong in exactly the right way to give the same wrong results as each other, or that something written in an old book is wrong?

But that’s all just philosophical musings. Now I want to prove beyond reasonable doubt that the Universe is billions of years old. If you don’t trust science you can buy an amateur telescope and do all this yourself (it also requires a bit of maths), so you don’t even need to rely on those sneaky scientists with their an atheistic worldview and global conspiracy against God!

First, figure out the dimensions of the Solar System. This can be done by estimating the size of the Earth (something done by Eratosthenes about 2200 years ago) and then doing some timing at a transit of Venus or Mercury (unfortunately you just missed those but the calculation was done by Lalande in 1771). If you do that you can figure out the speed of light using timings of Jupiter’s satellites (originally done in 1676, by Danish astronomer, Romer).

Now figure out the distance to some close stars. This is difficult but was first done (by Friedrich Bessel in 1838) using relatively basic telescopes with the trigonometric parallax technique (which uses the size of the Solar System you calculated above). Now you can create some rules for estimating the real brightness of different stars by using closer stars (parallax is only practical for close stars) and using the apparent brightness and the distance.

Now observe some examples of particular stars, called Cepheid variables, which change brightness based on their mass (calibrate your measurements using the estimates above). You will find these bright stars can be used to calculate distances, even to other galaxies. You will find that some stars are visible at distances of millions of trillions of kilometers.

Now remember you calculated the speed of light earlier? Use that to calculate how long the light from those stars has been travelling through space. You will find it easy to prove that light has been travelling for tens of thousand, hundreds of thousands, or millions of years, even based on relatively “close” stars. But that’s far longer than the universe has existed according to creationists.

There are three possible excuses creationists might use here…

First, the speed of light was faster in the past. Unfortunately you will need to study some physics to understand why this can’t be the case to any significant extent because the speed of light is so fundamental to the universe it would be very obvious if it used to be faster by so many orders of magnitude.

The second possibility is that the stars were created a few thousand years ago (as creationist think) but the light they produce was created already travelling. Even the majority of creationists reject this possibility because God isn’t supposed to be deceptive. There would also be interesting effects on gravitational lenses and light echoes, which we don’t see.

The final possibility is that there is some special and poorly understood aspect of relativity or maybe quantum theory which causes some sort of unusual non-linear effect making the stars seem older. This approach has been attempted in the past but it just doesn’t work and no one takes that possibility seriously.

Of course, (going back to explanation 2) God could have made thousands of different phenomena just 100% right to deceive us into thinking that the universe is old when it isn’t, but if that’s the way he works how can we believe anything, including what creationists think he wrote in the Bible?

So really young Earth creationism is very easy to disprove. The method I described above is just one of many I could have used. If people want to believe in the myth of Christianity that is fine but they shouldn’t mention in public discussions that they are creationists because that really just makes them look like one of creation’s cretins!

Evidence for a Multiverse?

December 19, 2013 Leave a comment

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.