Popper’s victory

June 18, 2012

Just been walking to work listening to Start the Week on my dPhone. Rather jolly as it featured Mark Henderson (wants more Geekdom in Government), David Nutt (kicked off advisory committee for speaking truth to power re drugs) and David Blunkett (weird mixture of refreshingly blunt and creepily political). Mark made a big point of the idea that we need not just to encourage the spread of scientific knowledge, but to cultivate the habit of scientific thinking : a certain approach to critical problem solving. Quite right too, but reminds me of the debate last week on Telescoper’s blog about whether we should be teaching Physics knowledge, Physics understanding, or Physics skills.

The related point, picked up and run with by the Marr, was that the striking thing about scientists is that they are always trying to prove themselves wrong. Popper-style bollocks. Why has this become the official philosophy of science ? Science progresses by people relentlessly chasing down ideas and facts within a safe framework. You can’t go trying to prove yourself wrong every day. That way lies madness. We change our minds either when some striking new fact accidentally emerges, or after years, as the evidence piles up and can no longer be squeezed into the theory : and then there is a BIG change. I guess you can tell that my instinct is closer to Kuhn, but even then only as a sociological description, not as a philosophical position.

I do understand the debating point; and clearly scientists are more open to change than politicians. But whats the fundamental point here ? Is it that as a point of principle we like proving ourselves wrong ? No. Its that we are committed to arriving at true knowledge. Scepticism is only one of several things in our armoury. Maybe its about timescales. The success of scientific research over four hundred years means that – at least as far as the behaviour of the physical world is concerned – moment by moment scepticism is almost pointless. But scepticism over years remains hugely important.

In case people think I am making an anti-scepticism argument, I see this as a practical issue, not a principled one. Where we do not yet have a sound underlying theory – eg human behaviour – moment by moment scepticism is very valuable. But do we really think every physicist wakes up each morning and says to herself : “Now, how can I go about proving Einstein wrong today”. Give us a break.

Everything you know is wrong – or is it ?

December 1, 2008

There is a paradox at the heart of science. The root of science is scepticism; doubt authority and do the experiment. However the result of all that scepticism and experiment over four hundred years is the most secure body of knowledge ever produced. If you go around doubting Newton’s Laws every day you’re a nutter.

Around the edges of the clearing, where we still face the darkness of the forest, its a different story. We could be hacking uselessly into dense growth, when the path to the meadow is hidden just a few yards away to the left. Its fashionable now to be sceptical about String Theory  – see Lee Smolin’s book The Trouble With Physics – but inflationary cosmology worries others, and some folks are still nervous about the logical basis of quantum mechanics. Three years ago in Warsaw I saw David Gross and and Roger Penrose  give alternating public talks. This was very entertaining. Penrose’s title was “Faith, Fashion, and Fantasy in Modern Physics” – thats Quantum Mechanics, Inflation, and String Theory. You could almost hear David Gross’ teeth grinding. More recently, Robert Simpson (the Orbiting Frog) wrote a lovely post called Five Scientific Ideas that could just be Bullsh*t . Do give it a read.

Of course some people are just career long rebels. Recently on astro-ph Geoff Burbidge set out his dish of sour grapes yet again. Mostly this was quietly ignored, but over at Cosmic Variance Sean Carroll picked it apart. But its not just Burbidge you know. Accomplished, distinguished and terribly serious young cosmologist Douglas Scott, along with his possibly even more distinguished colleague Dr Frolop, has written a series of three papers questioning many of the key assumptions of modern cosmology : see here, here, and here.

So here’s some fun. Below I paraphrase a few statements from Burbidge and Scott, not saying which is which. A big no-prize for who-ever can give the best one-sentence rebuttal or confirmation of each statement. John Peacock has to wait until everybody else has finished.

(1) Dark Energy is just Hoyle and Narlikar’s C-field, so the Steady State Universe can come back.

(2) H_0 * t_0 is consistent with 1.0 to within 3%;  there is no reason this should be the case, so it tells us we are missing something obvious.

(3) We believe in a hot Big Bang because there isn’t time to make the Helium in stars; but if the Universe is cyclic, with a bounce before the Big Crunch, some stars could be much much older, and the Helium can be easily made.

(4) We believe that black holes powering radio galaxies are 10% efficient; however, man made particle accelerators like SLAC are a thousand times less efficient than this, so we are almost certainly kidding ourselves.

(5) The biggest galaxies have the oldest stars; younger galaxies are smaller; therefore galaxies are coming apart.

(6) If likewise clusters of galaxies are breaking up, the virial theorem doesn’t apply, and there is no need for dark matter.

(7) The energy density in the CMB is almost exactly the energy density associated with converting Hydrogen to the observed density of Helium; therefore the latter is the cause of the former.