Wednesday 7 January 2009

The Arrows of Time

I could be talking about Phil 'The Power' Taylor's remarkable victory in the World Darts Championship (Hurrah etc) recently but my point tonight is sightly more cerebral.

On that note, where did Phil get his nickname 'The Power'? As a Welshman, I would have thought it denoted his industry or job as I grew up with Powell 'The Milk' and Jones 'The Dentist' (no, not Ivor 'The Engine' before you say it) and those people had fine jobs as milkmen and dentist accordingly. But shouldn't Phil 'The Darter' Taylor be his real name? My assumption is that he worked for Eon or British Gas before being famous and I'm sticking to it.

I digress.

The Arrow of Time

Inspired by reading a copy of 'The New Scientist' while stuck at Milton Keynes with no 'Power' as in Phil, I was interested to see that a certain scientist had hypothesised, 'elegantly' as they always seem to do (maybe while wearing furs or a natty suit) that the 'Arrow of Time' flows the way we observe it due to the effects of gravity coming into play around 380,000 years after the Big Bang occurred.

The article does sort of tackle why 380,000 years was important as that was the time taken for photons to stop behaving badly and allow matter to start forming lumps and hence gravity, a force we know to act over long distances, to take effect and start shaping the Universe as we know it. The simple explanation was that it's all to do with Entropy - you know that property that measures chaos or disorder.

This is the odd thing that says eggs break rather than unbreak, coffee grows cold rather than hot and we grow old rather than young. Such changes are associated with entropy or a measure of disorder of a system and this happens because there are more possibilities of a disordered state than ordered for systems to evolve into.

With me so far? Because this means that the likeliest outcome for us all is a state of disorder and an increase in entropy. I suppose this means entropy is the only index that always goes up and not down - perhaps we ought to have an 'Entropy-linked Unit Trust' launched for our pensions as inflation has failed us.

The Science Bit (Like the Advert)

This of course assumes that we started from a highly ordered or very low entropy state (entropy could not increase otherwise) and apparently physicists don't like this idea as it sounds spooky if nothing else. But Lawrence Schulman of Clarkson University, NY claims that after 380,000 years (that magic number) our Universe switched to that low entropy state which was the first time it was cool enough for atoms to combine. Prior to this the 10 billion or so badly behaved photons in each atom annoyed the electrons enough to keep them from 'mating' and so preventing gravity, which occurs when matter clumps together, taking any effect. At this crucial 'switch on' point, gravity takes a hold and starts the long process of forming clumps and eventually stars, planets, galaxies etc. Before you start griping, the glowing fireball of the Big Bang is known to have spread evenly throughout the Universe according to cosmic background radiation measurements - the afterglow of the Big Bang. Think on that a second - for the background radiation from the Big Bang to be the same in all directions, it must have been evenly spread at the beginning.

The thing is, as Americans would say, a high entropy state is most likely when no long range force is acting like gravity BUT when gravity came into effect, the Universe switched to a state of low entropy. At that point everything starts to tend toward higher entropy or indeed, as the argument goes, the 'Arrow of Time' started in the direction we observe it today.

For The Vulcans Among Us

I am not the world's most logical thinker but I understand the concept of Einstein's word 'Relativity' even if the rest of the theory is high brow. The fact is, we humans observe time as it is and call the future that which we have yet to see. So if the 'Arrow of Time' were reversed, would we simple beasts have labelled what we observe today still as the present but what we haven't yet observed as the 'past' and what we have observed as the 'future'? I doubt it. We might have thought it really daft that we rose from the grave and ended up in the womb or never have invented omelettes as every time you went to cook an egg it formed a shell or sued McDonalds for coffee so cold it it didn't scald your lips.

It's a bit daft to think about really.
Poo Poo

Of course, the Luddites amongst us, while accepting this is a highly 'elegant' if simple solution to the question, why does time go one way only, it does tempt to ask the question, 'Fine, so what about before 380,000 years after the Big Bang? Which way did the arrow flow then, matey, because logic would say it must have flowed the same way the whole time?'

That is not a stupid point. This period of what scientists call 'The Deep Arrow of Time' would be pretty controversial if it was found to have flowed the opposite way. If that were the case then we would have simply counted back from 380,000 years to the Big Bang and game over. Err, then we would never be here to ask such daft questions, arguably. It's a zany thought about a version of our world where things effectively appear in reverse if time flowed the opposite way as would entropy by the same argument.

The trouble with science is that the answer to a question is often a question. However, in many zillion parallel universes perhaps time does flow the other way and zombies are revered as we revere babies. Perhaps in the same universe bankers would vie to get rid of as much wealth as possible - nope that doesn't work as ours actually got rid of all theirs not before taking a good cut. It does have its advantages though -you would never lose any golf balls as they would suddenly fly at you out of nowhere, your car keys would miraculously appear and the Directors would make multiple cuts of film beginnings rather than ends plus the person at the counter would pay you for having watched it in reverse.

But it would make rubbish Horror Movies if nothing else.

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