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Jobs, Hitchens, Hawking

March 21, 2018 3 comments

Is it normal to feel a real sense of loss when people you never even met die? I’m not sure, but there have been three occasions where this has happened for me. Anyone who really knows me might be able to guess the three people involved, especially when one of them should be fairly obvious given recent events. But I would like to discuss briefly these three and why they had that effect.

Obviously the third is Stephen Hawking, but who are the other two? Well, if you haven’t read every blog entry I have ever written (why not, because I’ve only done 1905 at the time I wrote this) you might still guess that the first is Steve Jobs, and the second is Christopher Hitchens.

I often say that I’m not into hero worship, but that doesn’t stop me from recognising a few really special people who I do admire more than most, even when they are flawed or controversial in some way (actually, for me, that makes them even better).

In fact, what is the point of being any sort of public figure or even being a person who participates meaningfully in modern society if you are not controversial? Really all that means is you don’t accept every rule or bias currently imposed by society. If you don’t have at least one controversial belief then why even bother existing? And if you have these beliefs why not share them, discuss them, and maybe even have your mind changed on the subject or possibly convert other people to your ideas?

Looked at this way it is everyone’s duty to be controversial, although there is a fine line between offering genuine controversial and original opinions and just being a troll for the sake of it – a line I might have even crossed myself on occasions!

But back to the three people. Maybe the most interesting aspect of my list is that it is so short, and doesn’t include any pop (movie, music) heroes, politicians, etc, which many other people might be tempted to choose. Also, the three people are from quite different backgrounds: Jobs was a business person and tech entrepreneur; Hitchens was a critic, essayist, and journalist; and Hawking was a theoretical physicist.

They all died after significant battles with diseases: pancreatic cancer in the case of Jobs, esophageal cancer for Hitchens, and amyotrophic lateral sclerosis for Hawking. All of them knew the disease was going to kill them, but at least Hawking survived about 50 years longer than expected.

The battles they all had against these disabilities were quite inspiring, especially in the case of Hawking, and Hitchens wit and thoughtfulness about his imminent demise was made more compelling by the fact that his smoking and drinking habits were the likely cause.

Why I admired Steve Jobs is difficult to explain. He was fundamentally a business person, which is a category I don’t usually have much respect for, but Jobs was so atypical that he seemed above the others, except maybe for Tesla and now Elon Musk, who are similar types of characters.

Jobs wasn’t a tech genius and he wasn’t a business genius either. He was an ideas man and someone who could make his ideas happen, usually by ruthlessly utilising people who really were geniuses, especially in tech. There is no doubt that some parts of his character could be seen as being unpleasant, but what he did worked, at least most of the time.

I enjoy debating and arguing with people, and Christopher Hitchens was perhaps the greatest debater I have ever heard. I often felt sorry for his opponents before the debate even started because I knew Hitch would destroy them. Of course, he did tend to take on religious and excessively politically correct people, so my sympathy for them was limited!

But his recall of facts, use of language, and general knowledge of politics, history, and religion, amongst other topics, was impressive. Sure, his knowledge of science and tech was limited but that didn’t seem to matter in most of the situations he was in.

Some of his quotes are brilliant to, and include many of my favourites, like this one: “Beware the irrational, however seductive. Shun the transcendent and all who invite you to subordinate or annihilate yourself. Distrust compassion; prefer dignity for yourself and others. Don’t be afraid to be thought arrogant or selfish. Picture all experts as if they were mammals. Never be a spectator of unfairness or stupidity. Seek out argument and disputation for their own sake; the grave will supply plenty of time for silence. Suspect your own motives, and all excuses. Do not live for others any more than you would expect others to live for you.”

Finally, what about Hawking? Well he was a legendary figure in popular culture as well as in real science. If anyone was asked to name a cosmologist (or maybe even just a scientist) Hawking would be a common choice, because of his appearance due to his disability which required he live in a wheelchair and use a speech synthesiser, and for his appearances in popular TV shows such as the Simpsons and Big Bang Theory.

The speech synthesiser voice became so well known that it was like his trade mark and he didn’t want it changed even when more natural sounding synthetic voices were available.

Hawking is often pictured sitting in front of a blackboard full of obscure mathematical formulae, a sort of stereotyped image which goes back at least as far as Einstein. But he couldn’t write on a blackboard, and instead he manipulated complex mathematics purely in his mind. It is an astonishing ability and many of his great discoveries were made after his disability became more serious. Maybe being cut off from the world to some extent actually helped him focus on the science (he once said “I can’t say that my disability has helped my work, but it has allowed me to concentrate on research without having to lecture or sit on boring committees”).

I’m not the only one to be affected by the loss of these people. I was quite surprised to see Hawking being mentioned in so many mainstream news services recently, and not just on the day of his death. It’s good to know that genuinely great people can get some recognition as well as the more mundane examples of celebrity, such as movie stars and other entertainers.

Finally, here are a couple of Hawking quotes I like: “Science is not only a disciple of reason but, also, one of romance and passion.” And, “Look up at the stars and not down at your feet. Try to make sense of what you see, and wonder about what makes the universe exist. Be curious.”

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Introduction to the Elements

December 29, 2017 Leave a comment

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!

Cosmological Musings

November 30, 2017 Leave a comment

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!

Don’t Take it Seriously

September 12, 2017 2 comments

They say that people who cannot laugh at themselves leave the job for someone else. I think there is a lot of truth in that idea because too many people take themselves, and their beliefs, far too seriously, and they don’t usually look good as a result.

In the end, most everyday issues which people get upset and very serious about are really unbelievably trivial. As an amateur astronomer and science enthusiast I know enough about the universe as a whole (or maybe even the multiverse) to know that practically everything that people take so seriously is nothing more than the tiniest, most frivolous absurdity when you look at the big picture.

To provide examples I would like to pick on some of my usual targets: managers and other bureaucrats, and religious people.

Recently I commented that a good test for Muslims who would like to move to New Zealand to live would be to have them prove that they don’t take their religion too seriously by eating a pork sausage. That was deliberately provocative, because eating pork is haram (forbidden) by the Quran, except in extreme circumstances such as starvation.

Why would I want to impose such an offensive (according to some people) test? Well, I wouldn’t really, of course, because it was a rhetorical point I was trying to make, rather than a serious one, but this does show how a non-serious point can be effective. Maybe a better test would be to have them have a laugh at a cartoon featuring the prophet Mohammed. Yes, I’m only somewhat more serious about that.

But why have a test at all? Well, people who have extreme views on religion tend to be dangerous. They might be more likely to carry out terrorist acts, for example, because despite the protestations of the politically-correct left, religion is the major motivating factor for most terrorists.

And even if their serious religious “philosophy” doesn’t motivate them to wanting to blow themselves up, along with whatever other innocent people might be in range, it might still encourage them towards other regressive ideas, such as being against equality for women, wanting to punish homosexuals, or wanting to enforce their primitive social standards on others.

Naturally, I would not want anyone to think that this process would stop at Islam. Extremist Christians would also need to be vetted by a similar process. I have plenty of “offensive” cartoons featuring Jesus that they could have a little laugh at. For example: Jesus is hanging on his cross, after a while he dies and the Romans dangle him on strings from the cross like a puppet and reanimate him, people see this and think Jesus has risen from the dead, and the Romans think it’s hilarious!

And it could go beyond religion, too. For example, Apple zealots, like me, could be challenged by having to laugh at a cartoon of Jony Ive making some pretentious pronouncement about his design philosophy (I just Googled that and there are plenty out there).

Many might say that an “offensive” computer cartoon hardly rates at a similar level to an “offensive” religious one, but I disagree. If someone takes their religion more seriously than I take good design of computer technology then they are taking it too seriously, and that’s my whole point. After all, their religion isn’t actually true, so treating it with a bit less sincerity seems entirely sensible.

I know religious people who I like to gently and respectfully debate regarding their beliefs, and I expect to get the same back again. If someone wants to criticise me based on my “beliefs” (I am atheist, pro-science, liberal but anti-political correctness, pro-Apple) then that’s fine – I don’t take it too seriously, at least as long as they don’t.

When I look at the latest HST image of the universe and see thousands of galaxies in a small area of sky smaller than the Moon, and I realise there are hundreds of billions of stars (and presumably hundreds of billions of planets, and probably life, and maybe intelligent life, and just possibly some civilisations far more advanced than ours) in each one, then it’s pretty hard to take the inane assertions of any religion seriously.

It’s also hard to take any debate on what the best type of computer is seriously, it’s hard to take any pathetic rules and regulations created by bureaucrats seriously… hey, let’s just take this to the logical conclusion: you cannot take anything seriously.

So lighten up everyone. We live in a magnificent universe and our problems, thoughts, and beliefs are of no consequence at all, really. Why not just accept the obvious absurdity of human existence and not take things so seriously.

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.

Life’s Just a Game

July 5, 2016 Leave a comment

Is life a game? Is the whole universe just one big game or simulation? It’s an interesting question and one which might not be quite as frivolous as many people think. Before I explain why, I should revise a few of the common musings on the subject often found on the internet.

First there’s this one: Yes, life is a game. And according to the laws of thermodynamics, there are four inviolable rules: Zeroth: You must play the game. First: You can’t win. Second: You can’t break even. Third: You can’t quit the game.

The first and second in particular do reflect the real rules of thermodynamics quite well. Very crudely put, the first says that energy cannot be created nor destroyed, it can only change forms, and the second law says the entropy (simply put, the amount of disorder) in a system will increase.

Then there’s this idea from the arts: “All the world’s a stage, and all the men and women merely players: they have their exits and their entrances; and one man in his time plays many parts, his acts being seven ages.” – William Shakespeare

But what about more serious, scientific and philosophical thoughts on the subject?

Recently, I read that Elon Musk thinks that we are probably characters in some advanced civilisation’s video game. In other words, he thinks life is a game. This isn’t a new idea, despite some of the news outlets making it seem like Musk is onto some new, brilliant form of ontological understanding of our most basic existence. In fact, the idea goes back at least 60 years in fiction and was discussed in a serious way by philosopher Nick Bostrom in a 2003 paper called “Are You Living in a Computer Simulation?”

Yes, I realise that a simulation is not necessarily a game and vice versa, but many games do involve simulating of the real world (combat simulators, flight simulators, etc) and the distinction isn’t important to the main point here. Maybe Musk thought that saying we are part of a computer game just sounded a bit cooler!

So what is the simulation hypothesis all about? Well, first I will present it in my own way which seems to lead to the conclusion that the simulation exists…

The universe is a big place, perhaps the biggest (according to author, Kurt Vonnegut) so we would expect that there must be many more places in the universe, apart from the Earth, where life, and intelligent life, has arisen.

We might also expect that in many places that intelligent life has advanced to a point far beyond where we are now. After all, the universe is 13.8 billion years old and humans (in the current form) have only been around 0.001% of that time. Surely other species on other planets became intelligent and capable of advanced technology far before we did.

We would also expect that computer technology would be an important part of any technological culture’s abilities. Since computers have only been around for 70 years and have already advanced to a remarkable level, we would expect that more advanced civilisations would have computer technology billions of times more capable than ours.

We have already reached the point where some simulations are almost indistinguishable from reality so those far more advanced systems might actually be literally indistinguishable from, or at least so close to reality that it would be almost impossible to tell the difference.

These advanced races with computer systems capable of creating artificial realities would probably want to model universes which would be virtually indistinguishable from real universes.

There might be many of these artificial realities and perhaps only one real reality.

So why should we think that our reality is the real one when it is far more likely to be one of the artificial ones?

In other words, it is just common logic to accept that we really do live inside a simulation, or, to put it another way, life is just a game!

Bostrom presented the idea in a different way which lead to three possible conclusions, one of which (and the one which some people think is the most likely) was the same as mine, above…

Given all the points I have already made, he thought that one of these three conclusions must be true…

1. Either “the fraction of human-level civilizations that reach a posthuman stage (that is, one capable of running high-fidelity ancestor simulations) is very close to zero”. In other words, there are almost no advanced civilisations capable of running these simulations.

2. Or, “the fraction of posthuman civilizations that are interested in running ancestor-simulations is very close to zero”. In other words, the advanced civilisations exist, but they don’t want to run the simulations for some reason.

3. Or, “the fraction of all people with our kind of experiences that are living in a simulation is very close to one”. In other words, we live in a simulation.

Here are a few interesting points Bostrom makes about his idea…

1. He isn’t claiming we live in a simulation. He just presents that as one possibility. He has said he thinks the likelihood is about 20% (but then adds “perhaps” and maybe”). He also notes that people who hear the argument usually think that one of the three conclusions is obviously true, but that there is no consensus on which one!

2. He also notes that people who claim to have experienced odd (supernatural, for example) phenomena should not claim these as evidence of glitches or bugs in the simulation. We would expect this sort of thing occasionally, even if our universe is real, simply because of mis-reporting and misunderstandings.

3. Maybe the most important point Bostrom makes is regarding whether the idea can be tested or not. One way would be if the aliens running the simulation wanted to show us that it existed. A phenomenon impossible in the natural world might occur (but see 2 above) making it clear our universe isn’t natural. Or we could reach a stage of technology where we ourselves could create a simulation of this sort. There’s no reason why one simulation couldn’t run a second one.

And if we reached an insurmountable problem which prevented us reaching a more advanced state (total destruction in a nuclear war for example) or we realised that there are fundamental limits on simulations which can never be overcome, then this would be evidence against the simulation option being true.

4. Bostrom doesn’t see any direct connection between the hypothesis and religion but there is an undeniable indirect connection, especially in relation to intelligent design. He quotes one atheist as saying this is the best evidence for God yet!

And finally, these are my additional thoughts on the subject…

1. I put this in a similar category to the search for extraterrestrial intelligence (although its scope is even greater, of course). But like SETI we are working with very little initial data. Of course, Bostrom is a philosopher, not a scientist, so we shouldn’t necessarily expect the same level of rigour as we would from science.

2. There are several major (and a few minor) assumptions we must make in order for the idea to even pass the first stage of appraisal. First, there must be life elsewhere in the universe; second, life must reach a level of intelligence where advanced technology is possible; third, computer technology must be capable of creating a simulation of sufficient accuracy that it is virtually identical to reality (whatever that is); and finally the “sims” must gain consciousness (whatever that is).

3. Most simulations have a degree of “granularity” where, if you look with sufficient precision, you will see a limit to their accuracy. You will reach a “pixel” size which cannot be divided any further. Well, I must mention the Planck length and Planck time here. These can be interpreted as the basic units of space and time in our universe, just like we would expect in a simulation!

The Planck length is 1.61 x 10^-35 meters, which means the resolution of our universe is about 4 billion trillion trillion dots per inch. Sure sounds like a simulation – and a very good one – to me.

So yes, it looks like life really is just a big computer game. Can we have a reboot?