Sunday, February 24, 2008

Is Big Physics peddling science pornography?

Comment: Is Big Physics peddling science pornography?

Michael Hanlon is the science editor of the London Daily Mail and author of Ten Questions Science Can't Answer (Yet) (Macmillan)
From issue 2642 of New Scientist magazine, 09 February 2008, page 22

IF SOME Russian mathematicians are right, then 2008 will be a year to remember. Extraordinary as it sounds, this could be when humanity unwittingly creates its first time machine and we receive our first visitors from the future - presumably wearing, as future-fashion dictates, silver jumpsuits and driving flying cars.

These theorists speculate that at the much-delayed opening of the Large Hadron Collider (LHC) at CERN on the French-Swiss border, the assembled scientists and dignitaries may be treated to a big surprise. The LHC could, thanks to some mooted possibilities crashing around on the wilder shores of physics, become a time machine - specifically, the end of a "closed timelike curve" connected to the future (see "The accidental time machine").

This is not the first time we have been told that the LHC could change, or rather end, life as we know it. A few years ago someone calculated that the collider might create a mini black hole which would promptly set about eating the planet, starting with Switzerland. Or worse, create a weird subatomic particle called a strangelet that could devour the entire universe. Physics and cosmology stories are like this these days. Once it was all hard sums and red-shifted galaxies; awesome enough one would have thought. Now it's time machines and universe-eating particles.

Does any of this bear any relation to reality? Or is Big Physics guilty of some serious sexing-up, drifting away from the realm of hard data and into the softer universe of science pornography?

As well as accidental time machines we are told of cosmic strings - gigantic filaments of super-stuff that warp and tear space-time like ladders in a pair of celestial stockings - and crashing branes, titanic slabs of maths that give rise to the big bang in the exotically lovely ekpyrotic universe of Neil Turok.

Not crazy enough for you? What about the multiverse? One of the biggest sell-out lectures at last year's Hay-on-Wye festival in Wales starred the UK's astronomer royal, Martin Rees, who entertained his audience with a discussion of the possibility, indeed the probability, of multiple worlds - endless parallel realities existing in a gargantuan super-reality that makes what we think of as the universe as insignificant as a gnat on an elephant's backside. Or there's the simulation argument, philosopher Nick Bostrom's delicious idea that since it should be possible to replicate an entire universe in a computer, and that this could be done countless times, statistical cleverness proves that we are not the real McCoy but the figments of some electronic entity's imagination.

Don't get me wrong, I love parallel universes. I love the idea that, 10 to the power of 10 to the power of 10 to the power of 100 light years away is an identical me, sitting down at his computer writing this very same article in a world exactly the same as mine except that the gear stick on the Honda Accord is a slightly different shade of grey. And I love the idea that every time a subatomic particle goes hither or thither, a whole new creation is invoked; forget half-dead cats in boxes, we are talking worlds in which Hitler won the second world war, or where there was no Hitler, and no second world war and no Honda Accords at all.

It is fun to know that serious scientists believe the fabulous alternate realities of the Philip Pullman novels could be accurate descriptions of reality (for in a multiverse of infinite size and scope there will, somewhere and somewhen, be a world where a little girl called Lyra befriends a talking polar bear and where people's souls take the form of animal familiars).

Fun yes, but is it harmless? Scientists, and people like me who stick up for science, are happy to pour scorn on astrologers, homeopaths, UFO-nutters, crop-circlers and indeed the Adam-and-Eve brigade, who all happily believe in six impossible things before breakfast with no evidence at all.
Show us the data, we say to these deluded souls. Where are your trials? What about Occam's razor - the principle that any explanation should be as simple as possible? The garden is surely beautiful enough, we say, without having to populate it with fairies.

The danger is that on the wilder shores of physics these standards are often not met either.
There is as yet no observational evidence for cosmic strings. It's hard to test for a multiverse. In this sense, some of these ideas are not so far, conceptually, from UFOs and homeopathy. If we are prepared to dismiss ghosts, say, as ludicrous on the grounds that firstly we have no proper observational evidence for them and secondly that their existence would force us to rethink everything, doesn't the same argument apply to simulated universes and time machines?
Are we not guilty of prejudice against some kinds of very unlikely ideas in favour of others?

Believing in ghosts takes a different mindset to advocating parallel worlds or cosmic strings. But do we really believe that we are all the creations of a computer sitting in some higher-dimensional adolescent's bedroom, or that time travellers will land at the LHC? Or

are we, too, seeing fairies at the bottom of the garden?

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