Archive for July 7, 2009

Why the Big Bang is Wrong…

Posted in Biographical, The Universe and Stuff with tags , , on July 7, 2009 by telescoper

I suspect that I’m not the only physicist who has a filing cabinet filled with unsolicited correspondence from people with wacky views on everything from UFOs to Dark Matter. Being a cosmologist, I probably get more of this stuff than those working in less speculative branches of physics. Because I’ve written a few things that appeared in the public domain (and even appeared on TV and radio a few times), I probably even get more than most cosmologists (except the really  famous ones of course).

I would estimate that I get two or three items of correspondence of this kind per week. Many “alternative” cosmologists have now discovered email, but there are still a lot who send their ideas through regular post. In fact, whenever I get a envelope with an address on it that has been typed by an old-fashioned typewriter it’s usually a dead giveaway that it’s going to be one of  those. Sometimes they are just letters (typed or handwritten), but sometimes they are complete manuscripts often with wonderfully batty illustrations. I have one in front of me now called Dark Matter, The Great Pyramid and the Theory of Crystal Healing. I might even go so far as to call that one bogus. I have an entire filing cabinet in my office at work filled with things like it. I could make a fortune if I set up a journal for these people. Alarmingly, electrical engineers figure prominently in my files. They seem particularly keen to explain why Einstein was wrong…

I never reply, of course. I don’t have time, for one thing.  I’m also doubtful whether there’s anything useful to be gained by trying to engage in a scientific argument with people whose grip on the basic concepts is so tenuous (as perhaps it is on reality). Even if they have some scientific training, their knowledge and understanding of physics is usually pretty poor.

I should explain that, whenever I can, if someone writes or emails with a genuine question about physics or astronomy – which often happens – I always reply. I think that’s a responsibility for anyone who gets taxpayers’ money. However, I don’t reply to letters that are confrontational or aggressive or which imply that modern science is some sort of conspiracy to conceal the real truth.

One particular correspondent started writing to me after the publication of my little book, Cosmology: A Very Short Introduction. I won’t gave his name, but he was an individual who had some scientific training (not an electrical engineer, I hasten to add). This chap sent a terse letter to me pointing out that the Big Bang theory was obviously completely wrong.  The reason was  obvious to anyone who understood thermodynamics. He had spent a lifetime designing high-quality refrigeration equipment  and therefore knew what he was talking about (or so he said).

His point was that, according to  the Big Bang theory, the Universe cools as it expands. Its current temperature is about 3 Kelvin (-270 Celsius or therabouts) but it is now expanding. Turning the clock back gives a Universe that was hotter when it was younger. He thought this was all wrong.

The argument is false, my correspondent asserted, because the Universe – by definition –  hasn’t got any surroundings and therefore isn’t expanding into anything. Since it isn’t pushing against anything it can’t do any work. The internal energy of the gas must therefore remain constant and since the internal energy of an ideal gas is only a function of its temperature, the expansion of the Universe must therefore be at a constant temperature (i.e. isothermal, rather than adiabatic, as in the Big Bang theory). He backed up his argument with bona fide experimental results on the free expansion of gases.

I didn’t reply and filed the letter away. Another came, and I did likewise. Increasingly overcome by some form of apoplexy his letters got ruder and ruder, eventually blaming me for the decline of the British education system and demanding that I be fired from my job. Finally, he wrote to the President of the Royal Society demanding that I be “struck off” – not that I’ve ever been “struck on” – and forbidden (on grounds of incompetence) ever to teach thermodynamics in a University.

Actually, I’ve never taught thermodynamics in any University anyway, but I’ve kept the letter (which was cc-ed to me) in case I am ever asked. It’s much better than a sick note….

This is a good example of a little knowledge being a dangerous thing. My correspondent clearly knew something about thermodynamics. But, obviously, I don’t agree with him that the Big Bang is wrong.

Although I never actually replied to this question myself, I thought it might be fun to turn this into a little competition, so here’s a challenge for you: provide the clearest and most succint explanation of why the temperature of the expanding Universe does fall with time, despite what my correspondent thought.

Answers via the comment box please, in language suitable for a nutter non-physicist.