The Truth is Out There … isn’t it?

April 17, 2014

Its disconcerting reading/watching the news from Ukraine. Not just because of the fear of decades of war to come, but the temptation to slide into relativism. Statements and stories from various quarters vary from the vaguely inconsistent to the baldly contradictory. Its tempting to think “well, they are all lying”, or “hmm.. it all depends on your point of view”. You slide down that slope and pretty soon there is no truth. We can’t let that happen. The truth is out there somewhere. Its just hard to extract from the filtered messages. As scientists, our philosophical stance is that we must be personally sceptical; you should not trust authority blindly. That’s all very well but I ain’t going to Kharkiv to make my own observations. I have to trust somebody don’t I? But who? In descending order of reliability, I guess its (1) The Guardian and the BBC (2) Our own governments (3) The Ukrainian government (4) The Russian government (5) My mate Kevin who is usually down the Dog and Ferret on a Friday, and (6) The Daily Mail.

Mind you, some days science is just as hard. I mean research, the process of uncovering new truths. The truth is out there, but its hard work to find. There are no tablets of stone. You’ve been working on something for months, but every so often you wake up in a sweat thinking oh crap it could all be wrong. Suppose X is going on instead of Y? (Radio loops versus inflationary polarisation anyone?) The philosophy of science doesn’t help. Most scientists claim to be Popperians. You can never prove, you can only falsify. All models are provisional. But its such a small step from there to “all truth is provisional”. Somehow we have to cling on to the belief that there IS a definite truth; its just that we can never have it.

A further problem is the same one we get in trying to understand Ukraine: the human filter. We can’t make all our own measurements. We have to read other people’s papers, go to conferences, and so forth. But we are all human; chasing our careers; making our pitch; following fashions; squabbling with rivals. This doesn’t mean we are not sceptical and rational; we are. But the messages are filtered through biology.

Our biology filtering a truth that is out there is essentially the message of much of Eastern mysticism and Buddhism. I have long been fascinated by where mysticism chimes with science, and where it jars. Definitely some of each. I am sitting through a MOOC on Buddhism and Modern Psychology which is quite fun. (Partly of course in mentally preparing myself for my upcoming AstroTech MOOC. Scarily soon. Gulp.) Anyway…  Zen holds that at least in principle once the biases and illusions have been stripped, you can actually personally and directly perceive the truth. Satori. Unexcelled Complete Awakening.

Boy. I’d just love a kind of mini-Satori on the structure of quasars.


Concrete Science Epiphanies

April 9, 2014

The title is a kinda cultural reference to Musique Concrete, don’t you know. Maybe should be read in French.  Sea-onss kon-krett. Pretentious, Moi?

Anyhoo. I have always loved that moment when Jane Public looks through a real telescope and sees the rings of Saturn. Suddenly its real. Not on TV. Seen with her own eyes. There is a physical context. She had to walk up some stairs to the roof, queue up, bend at an awkward angle, and squint. Mental processing is good, but physicality is also good. It helps the scientific understanding, and it has a separate cultural impact which has its own importance. Its a kind of epiphany, an awakening.

I encountered two more such epiphanies yesterday. Here in Edinbrr its Science Festival time. (In Edinburgh, if you miss a Festival, don’t worry. There will be another one along in a minute.)  During the day I donned my STFC tee-shirt and helped out at the STFC roadshow, Seeing The Universe In All Its Light. This has all sorts of groovy things, but the bit I loved best is dead simple. We had a bunch of TV remote controls and pointed them at people’s camera phones. You can see the IR beam, which you can’t see with your naked eye. People almost gasp. There are invisible things in the Universe, but they are really there. You don’t need a million pound device. I can see it with with my own phone.

Wind forward to the evening, where I was part of the SCART Connection, a strange event that presented the results of pairing up scientists from the School of Physics and Astronomy with artists from the Edinburgh College of Art to see what they would come up with. This involved microscopic pictures of sludge crystals, sculptures of Ice-2,  Fibonacci spirals, a social soundscape project, and yours truly pontificating about cosmic violence to the accompaniment of electronic music by a local composer.  All very weird and wonderful. One thing that struck me was people’s reactions to a movie of those tiny sludge crystals. You could see them jiggling – Brownian motion in action. When told that this was caused by buffeting by atoms, their eyes bulged. Atoms? I can see them in a movie made by a guy from the Art College? Wooaahh.



Deadlines. We love ‘em

January 5, 2014

Happy New Year all. Virtual Handshake.

Just discovered a groovy new web comic called Toothpaste for Dinner thanks to Tweeter @Mariancall via @CatherineQ . Well, its new to me anyway. This one is The Creative Process and will cause both giggles and nods from anybody who does anything creative which involves a deadline. This includes writing a paper or submitting a proposal…

We all love deadlines. The usual joke is “I love the whooshing noise as they go past me” which is tres amusant, but the real problem is that we tend to meet them by the skin of our teeth and let them destroy our sanity. As in aforelinked cartoon. (NB WordPress confirms my creativity. In the edit box every neologism is underlined in red. Bizarrely, this is true of “WordPress”. Anyway. Yes. Where was I?)

I have noticed a consistent pattern, especially coming up to observing runs.

  1. Start work nice and early, in a relaxed manner.
  2. Two weeks somehow drifts by.
  3. Make a plan, organise work into sections.
  4. This isn’t really working and time is passing. Getting somewhat nervous. Realise what you need is a priority list of tasks. Start working down from the top in a firm manner.
  5. The first task is half done and there is a few days to go. Getting distinctly twitchy. Miss coffee break and grab sandwich lunch but still hard to concentrate.
  6. Your flight is day after tomorrow. Feeling of desperation building. Suddenly realise got this list thing wrong. Start working up from the bottom crossing off things that aren’t essential.
  7. Flight is tomorrow. Half list crossed off from bottom. Panic starting. Go back to top and fiercely ask of each item – right, will it be a disaster if I don’t do this?
  8. Six pm in your office. Standing in middle of room unable to move because pulled in multiple directions, and muttering “not physically possible … not physically possible..”
  9. Midnight. Suddenly think “screw it, thats good enough”. Immense feeling of relief washes over you and you to go to bed.
  10. Catch flight, have perfectly good observing run etc. Possibly a few things have to be improvised.

Of course, that last minute improvising thing is a bit tricky when making ESO style Observing Blocks. For the benefit of any ESO staff that may be reading this blog I should of course clarify that I always make OBs in a calm, efficient and timely manner, with no errors. Hem.


Marginal solution

November 27, 2013

Okey dokey. Better reveal the solution to the stat-geek marginalisation quiz. There were sixty two votes.

The popular winner was the economics/marginal profits idea, with 31 votes. Plausible but wrong.

The second most popular was the “marginal interest” idea. Well… this is what the term has more or less drifted into meaning, because (almost) everybody has forgotten the true origin. So… wrong.

Nobody voted for “lost in the mists of time”, which proves you all care. How nice.

Only two people voted for EB Margin being the pseudonym of WR Gossett. This disappointed me, both because it is funny and because it was supposed to be a cunning false trail. WS Gosset in fact published his papers under the name of “Student”, which is why we have the “Student’s t test’.

So of course the correct answer was other. Sorry if that was an annoying tactic, but I think if I’d made the right answer one of the choices, it would have been too obvious. Amongst the 6 suggestions, two were for our amusement :

“I’d write the reason here but there’s not enough room in the margin”
“To marginalise those who don’t know”

and four were were spot on or more or less right

“Refers to margins of a contingency table”
“thought it was to do with averaging rows, with answer stuck in the margin”
“your are projecting the 2D pdf onto the “margin” of the plot”
“Sweeping the probability to the edge (=margin) of the paper?”

Sounds like the first two people knew, and the second two deduced the right answer. If you were one of those people, award yourself an extra biscuit at coffee time, and feel free to announce yourself.

Just to it spell out..  As physicists, we nearly always think in abstract mathematical terms, so we think of  “marginalisation” as a calculus problem – an integral. Even when thinking visually we picture a joint probability distribution as a smooth surface in three dimensions. But early statisticians were often concerned with tables of numbers, and worked on paper. Think of a joint frequency distribution as a grid of numbers in cells. Then  add up a row, and write the answer in the margin. When you have done this for all the rows, read down that margin, and – voila – the marginal distribution for y.

Don’t start me on regression…


A quiz of marginal interest

November 20, 2013

Two things we know.

(1) Scientific terminology is burdened with the baggage of history, which now makes no logical sense. So… early type galaxies are the ones with late type stars? Errr… And which of these terms relates to a sequence in time? Neither. Right. Very helpful.

(2) When you have to teach something, you finally figure out things that have been bugging you for years.

(3) Nobody expects the … oh. Anyway. Often (1) and (2) combine to make a particularly thick fog.

For some time the term “marginalisation” had been nagging at me, but I ignored it because I had other stuff to get on with. I am referring to the term in statistics. You have a probability density function of two variables, f(x,y), but decide that y is “interesting” and x is “uninteresting”. You then integrate over x to get a PDF p(y) for y alone. This known as “marginalising over x”.

So here is the quiz. My guess is only about seven people will want to take it, but I can’t resist it.

Rule (a) Andrew Liddle is not allowed because I already told him the answer in the pub. Rule (b) No Googling. Rule (c) Never talk about  Stats Club.


The Art of Scientific Knowledge

October 16, 2013

I find myself musing again on the links between Art and Science. No, not the fact that the latest Booker prize winner apparently has an astrological structure, sigh. No, not even The Falling Sky, intriguing blend though it is of academic angst and lesbian lust. No. Umm. Where was I? Oh yes. Art. Grayson Perry has been delivering the first ever cross-dressing Reith Lectures  and very fine they are too. Yesterday’s was about how you judge quality in Art, a famously heated topic. (Can you have a heated topic, rather than a heated debate? Ed.)

There is no objective formula. The choices seem to be (a) The Market. (b) The Club – curators, critics and successful artists. (c) Public Opinion. All the tension seems to come from (c) disagreeing with (b). I have always been fascinated by the way folk are not content to just not like something; they get angry with Art. “My Johnny can do better than that” etc. Oh. Right. How come your Johnny ain’t famous then? I saw this in action the previous summer when visiting a Tracey Emin exhibition at the lovely Turner Gallery in my old home town of Margate. (An art gallery! In Margate!!!) Tracey is not quite my cup of tea but I was giving it a go. Suddenly there were staff scurrying around because a small child had drawn on one of the sculptures. The crowd was instantly split into the horrified bourgeoisie and the cheering polloi. Pardon my mongrel language approach.

So. Thats Art. Science? When we try get all philosophically rigorous we also find it really hard to pin down an objective assurance of truth. Cue pub argument about Hume, Popper, Feyerabend etc. But day by day the situation is the opposite. We know in our guts that the whole point of science is the search for objective knowledge, and that we have found a strange paradoxical but reliable method of getting at it; knowledge comes from honest scepticism.

We also take for granted that the arbiters of good science are us gals and guys in the club. (More gals please.) We don’t think the public should vote on whats true and whats not. There is no market in science. You can’t simply proclaim yourself an expert (though some try). There are not even any gentleman amateur scientists any more. You pass your exams, convince an interview panel, take the Government Shilling or the University Penny, expose your work nervously at conferences full of other club members, and try to decide whether you want to play the Herd Member route or the Lone Wolf route. They can both work, as long as you keep publishing, although the latter is a harder trick to pull off.

But public opinion? You will note its called Public Outreach, not Public Insertion. We generously give them the benefit of our wisdom. Oh, but please, do explain again why you personally believe Einstein was wrong because public opinion is very important to us.  Yeah, right.


Higgsteria : tension builds

October 7, 2013

We’re all a bit tense here in Edinbrrr.  Peter H is understood to be in hiding and quite right too. He’s done more than his duty over many months waving the flag for Physics in general, for UK science, and for Edinburgh University. Adrian Bird didn’t get the Medicine Prize today, so the Edin.Univ. Powers will crossing all possible fingers and toes for tomorrow. Check here. Apparently we expect the announcement to be at 10:45 UK time, but it will initially be in Swedish, so there will be an extra minute or two of hypertension.

Well, we will know soon enough. If you want to entertain yourselves meanwhile, you could try Telescoper’s Poll. Or you could watch Frank Close’s wonderful seminar, which is the clearest explanation I have seen/heard of what its all about, and why a prize specifically for Peter is appropriate. The CERN version seems to be broken, but there is a recording of a version at SISSA that’s audible but bvisually murky. Fascinatingly, Close makes a case for Phil Anderson being an overlooked man, and shows how different parts of Physics can cross-fertilise.

Or if you really want some entertainment, you can see how you can make chocolate from nothing.


Update : Englert and Higgs get it ! But no CERN mega-prize.. Anyway, well done Peter and big cheers in Edinburgh


Truth, Belief, and Action

August 27, 2013

My daughter is doing a medical degree. At dinner the other day, I mentioned that a few years back everybody seemed to think that doctors would be replaced by expert systems. Did that happen? Oh no, she said, that’s never going to happen. Its the doctor’s job to decide. Hmm. I see a scientist’s job, much of the time, as a dogged persistence in avoiding deciding, as you hunt down the sometimes stubborn truth. You have to steer carefully between the Scylla of shallow herd fashion and the Charybdis of renegade self delusion, but the aim is constant – to discover what really is the case.

Of course we have statistical methods for dealing with uncertainty, whether it be missing information or true randomness. But even here, as scientists, we avoid jumping to a conclusion, as a fundamentally unsound thing to do. All I can do is tell you that on Hypothesis A, you would have been pretty unlikely to get that measurement. Doesn’t necessarily mean its wrong though… (Pour beer. Cue usual frequentist vs Bayesian argument. Fail to come to conclusion. Drink more beer.)

But for much of our worldly lives, its not about truth, and its not about decision – its about action. You can see this trio as a chain. You cannot take a sensible action unless you have made a wise decision. You cannot take a wise decision unless you know what is and what is not. Each step limits the landscape for the next, but does not fix the path. Well thats what Hume said, which is good enough for me, as he is an Edinburgh Local Hero. Got a statue on the High Street and everything.

We see this every day in public policy – should we punish Assad? Should we allow fracking? Anybody care to postulate the relevant probability distributions in the Syrian case? Thought not. What makes these debates so difficult is not just that we have to act before all the options or their consequences are clear; or that we have to decide whats going on before we know all the facts; its that different people are not even trying to achieve the same ends; and sometimes they don’t even realise this.

A curious and frustrating example is racial profiling. If your aim is to maximise the number of terrorists you stop, regardless of anything else, its hard to deny the statistical fact that if you randomly stop young asian looking men with beards you will do better than if you randomly stop middle aged white women. But if your aim is to minimise the number of terrorists you create over a period of years, you could be making a big mistake.

A few days back, I followed a Twitter link to this beautiful little video. A black American woman explains how she was asked out of the blue for two types of ID, and looked up in a bad-check book, at a supermarket checkout. Her white sister in-law, immediately in front of her, was not asked for ID. The  sister used her white privilege to step in and address the inequity, which is the political point of the story.

However what I found intriguing is that the woman telling this depressingly normal story is so clearly middle class, articulate, intelligent and trustworthy. It sounds like the checkout girl was not being mean, but dim. At the back of her head was not necessarily emotional dislike, but instinctive statistical reasoning – if I stop black people, I will find more bad checks. Well this is probably true, but its a bit like the old gag about the price of fish in Billingsgate market being correlated with the size of women’s feet in China. Most bad checks will be written by members of the impoverished underclass. Due to hundreds of years of social, economic, and political repression, black people in the USA make up a larger then average fraction of the underclass. But the woman in that video is patently not a member of the impoverished stressed out underclass. So what’s depressing is that this isn’t obvious to a supermarket checkout girl. Why can’t she read the signals?

So.. I guess education, in the largest sense, is the answer. Maybe we can’t avoid profiling. We just want better profiling. Academic readers can draw the analogy with citation statistics and divert the conversation as they wish.

Anyway. Got some grant applications to re-read.


The Information Arms Race

August 11, 2013

This GCHQ / NSA / Snowden thing is confusing. Part of me is shocked and horrified. Another part of me is jadedly unsurprised. (Is “jadedly” a word?) I think I already assumed that they know everything they want to know. As Scott McNealy maybe did or didn’t say “you have no privacy, get used to it”.

Today a tweet from @Orbitingfrog alerted me to more disturbing news ; encrypted email company Lavabit have shut themselves down in protest over a mysterious government investigation that they are even forbidden from talking about; and Silent Circle, founded by Phil Zimmerman – the inventor of Pretty Good Privacy (PGP) – have pre-emptively shut down  their secure email service and deleted content so that they cannot be subject to the same pressure. Some years back Zimmerman was under criminal investigation for offering the PGP code worldwide, which the US government claimed breached laws against the export of munitions. Zimmerman printed the code in a hardback book and exported that instead.

Although the strong-arm stuff is scary, it kinda makes sense. The Lavabit episode seems to confirm that even the NSA cannot crack RSA-grade encrypted material. Instead of quietly snooping and leaving the public docile, they have no choice but to be honest and say “We are the government and we are in charge. Give us that stuff or you are fucked.”

Its more or less inevitable that there is a three-way information arms race between individuals, corporations, and government. Information is power. It is natural for governments to always want more information, more complete information, and more reliable information. Commercial corporations have the same instinct. You don’t have to assume they are evil; just trying to know their market. Consumers get no choice in this. You try buying a train ticket online without “registering”.  Oft and betimes, the consumer/voter just relaxes. Its kinda useful when I go back to GoCompare and they already know everything about me. But on the other hand, we instinctively bristle. They have the all power and we don’t!! The Freedom of Information Act tried to restore the balance, but its feeble.

Before you feel too powerless however, just recall that everything changed in 1976.  This is when Diffie and Helman published the key-exchange method, followed the next year by Rivest, Shamir, and Adelman’s publication of the RSA algorithm implementing the idea. Arranged carefully enough, you can make any communication completely secure. Wouldn’t this make any government terrified? What do you do? Well, partly you sniff as much as you can on the assumption that most traffic is not encrypted, or that you can read the envelope metadata if you can’t read the letter, or that you can intercept at the relay points that the internet relies on. The counter-thrust for the latter is envelope-content splitting.

But at the end of the day, the government can’t win the technology battle; they have to resort to legal restraint. An unsuccessful attempt was the Clipper Chip initiative. The idea was to generously provide to the world obligatory encryption methods which the Government could always decode. They gave up. A successful example is the infamous 1998 Digital Millenium Copyright Act. Entertainment corporations knew they couldn’t develop perfect DRM mechanisms. So they convinced the US government to make it illegal to deploy or develop technologies intended to circumvent DRM mechanisms.

My guess is that we will soon hear of plans in both the UK and the USA to make non-Government use of the RSA algorithm a criminal offence, or more generally to make it an offence to send communications that cannot in principle be decoded by appropriate authorities.

Before you accuse me of being a paranoid old hippy, let me just say that I am not even sure where my sympathies lie. I have a bristly rebel side and a  pragmatic patrician side. Viewed from above, its a fascinating struggle.


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