In what sense do photons exist?


What Would Richard Feynman Do?
What Would Richard Feynman Do? (Photo credit: Maitri)

This is a genuine question on my part – and I would be grateful for any answers!

The inspiration for asking the question comes from Genius: Richard Feynman and Modern Physics – my current “listen while running” book – along with Feynman’s own description of radiation in QED – The Strange Theory of Light and Matter.

Feynman argues that there is no radiation without absorption: in other words a tree that falls in an empty forest does indeed make no sound (if we imagine the sound is transmitted by photons, that is).

This sounds like a gross violation of all common sense – how could a photon know when it leaves a radiating body that it is to be absorbed?

But then, general relativity comes to our rescue – because in the photon’s inertial frame the journey from radiator to absorber is instantaneous.

But how can a body that exists for no time at all, exist at all?

Then again my assumption in asking this question is that time is in some sense privileged as a dimension of spacetime. This is a pretty deep controversy in theoretical physics these days and I am not qualified to shed much light on it – but let us assume that a body can exist with a zero dimension in time but real dimensions in space, can we then have bodies which have zero dimensions in space but a real dimension in time? If so, what are they?

 

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Another example of “Delingpole-ism”


Picture of Daniel Hannan at a conference in th...
Picture of Daniel Hannan at a conference in the Grosvenor House hotel in London (Photo credit: Wikipedia)

Yesterday I highlighted the attack made on the BBC’s science reporting by James Delingpole, a novelist, English Lit graduate and – as I argued – under-qualified crank.

Delingpole claimed that the BBC should be “impartial” on science – by which he meant it should give an equal weighting to the views of the tiny minority of scientists who dispute the fundamentals of the consensus on climate change. This is a ridiculous position to take when reporting science qua science – as it would, as I suggested as an example, require us to have given equal billing to the theory of “Supersymmetry” even as the evidence to support the “Standard Model” piled up.

To argue in this way is to treat science as though it were just politics by another means. It is not.

I would not normally write about economics here but the case I am about to highlight is such an egregious example of “Delingpole-ism” that it deserves the maximum publicity.

In one corner stands Daniel Hannan MEP, who claims that the UK is “the fourth largest exporter”. Except it is not.

Pointing out Mr Hannon’s error – the UK is the sixth largest exporter or (arguably, given the fuzziness of the data) equal fifth – does not lead to a correction but instead to a torrent of ad hominem abuse towards the respected economist, Jonathan Portes, who challenged Hannan’s factual inexactitude, and a rather childish rant about how nasty the BBC are to poor people like Hannan.

As Portes states, Hannan (and I think Delingpole), are members of a form of “celebrity culture” that gives them the confidence to make ridiculous, fact-free or fact-ignoring, statements about subjects in which they have no legitimate locus and then to claim they are victims of a powerful liberal/Marxist/establishment conspiracy when someone points out they are talking out of their hat.

On climate change, science is not “impartial”


DSC_1035
(Photo credit: The Freedom Association)

Reading the history of mathematics and science and you will come across stories about the various cranks and obsessives who, lacking all training, claim they have solved the great problems or proved that the accepted solutions are false.

Even now there are those trying to show that Cantor’s diagonalisation argument is false, just as there were many who were said to have proved Fermat’s Last Theorem long before that was actually done. Others say that evolution is a lie or that Bishop Ussher was right and the Earth is just a few thousand years old.

Is it fair to place James Delingpole – a novelist and English Literature graduate – in the same camp as these cranks because he claims to have authority on global warming, able to gainsay the vast bulk of the scientists who study these matters and conduct scientific discourse through the institutions of the academy and the rigours of peer review?

Yes, is my view.

Delingpole’s latest foray into science is an attack on the BBC for not being “impartial” on the science of climate change. Here’s the thing, the science is not impartial. The fact that the scientific consensus does not fit with Delingpole’s world view does not mean that Delingpole’s world view has a right to an equal hearing, it does not.

To be fair to Delingpole, despite his explicit rejection of the institutions of science…

we should set too much store by the Appeal To Authority. If someone has his facts right on climate change, then he’s still right regardless of whether he’s a geneticist, a marine geologist, or the bastard offspring of Adolf Hitler.

…he seeks to back his claim for equal validity for “denial” by quoting a man who has had peer reviewed work published which broadly aligns with Delingpole’s worldview – Professor Robert Carter.

Carter, at least in the recent past, has also been paid a stipend by the notorious “Heartland Institute” and that doesn’t seem to be his only connection to them, as John Ashton recounts in his description of the BBC’s approach to the issue (the BBC subsequently admitted they’d got this wrong, which is what has irked Delingpole):

At breakfast time, Radio 4’s Today programme informed listeners that despite extensive efforts, the BBC had been unable to find a single British scientist willing to challenge the IPCC‘s findings. At that point the BBC might have concluded that the IPCC’s views represent an overwhelming consensus and left it at that.

Instead, BBC news editors evidently cast their net wider. By lunchtime World at One was introducing Prof Carter as an Australian geologist, speaking for the “Nongovernmental International Panel on Climate Change“, or NIPCC. Someone who is not a climate scientist, in other words, representing a Not-The-IPCC body. Indeed, it turns out that the NIPCC is backed by the Heartland Institute, a US-based free-market thinktank that opposes urgent action on climate change.

In a remarkable interview that dominated the entire World at One coverage, Carter poured scorn on the IPCC’s findings. He drew on his geological expertise to argue that there was no more point in trying to mitigate climate change than in trying to prevent earthquakes. He claimed that, unlike the intensively peer-reviewed findings of more than 800 IPCC researchers, the NIPCC’s work was truly independent, while cheerfully admitting that family foundations in America paid for it. He implied that it represented a widely held scholarly view, pointing to “around 47” scientific collaborators. He did not specify how many of these were climate scientists.

Reading this, the point seems to be that the BBC tried far too hard to find views that disagreed with the scientific consensus: they accepted Delingpole’s false claim that there is some form of “impartiality” when it comes to competing scientific explanations.

And presumably they did so because climate change science is politically controversial. But that controversy has nothing to do with the science.

Think of it this way … the evidence in support of the Higgs mechanism has been piling up of late. But not every scientist accepts the Standard Model which is built on top of the Higgs mechanism – and many can point to holes in the model that means that it is unlikely to be a complete explanation in any case, even as the experimental evidence mounts for its fundamental correctness.

But did the BBC respond to the award of the Nobel Prize to Peter Higgs by scouring the globe for an advocate of supersymmetry to rubbish the Higgs mechanism and the standard model? Of course they didn’t. They would not have dared because they are not qualified to make that judgement.

So why do they feel they can do otherwise with climate change? The circumstances are very similar – the evidence for the “standard model” here has been piling up, though few would dispute there is much we still don’t fully know or understand. There are some scientists who dispute the standard model but they are in a minority and they are visibly losing the argument as the experimental evidence piles up. That doesn’t make them bad scientists, but it is bad journalism to treat them as though their view is of equal weight with the advocates of the scientific consensus.

Schooling, heritability and IQ


In recent recent weeks, in the UK, there has been renewed interest in the question of heritability and educational performance, after Dominic Cummings, the outgoing advisor to Michael Gove, the education secretary, claimed that some sort of left wing conspiracy in the educational establishment – “the blob” as Cummings calls it – were resisting the facts of science over the issue.

Tory house journal The Spectator joined in the debate, publishing a piece by psychology lecturer Kathryn Asbury which talks of a “genetically sensitive school”. I don’t know about you but that sounds like nothing good to me.

So it is a pleasure to read the counter blast by Steven Rose, professor emeritus of biology at the Open University, in this week’s New Scientist.

To quote just two paragraphs of Rose’s article…

Psychometricians have by and large settled on a figure of 50 per cent for heritability based on what is now seen as a simplistic calculation that variance in a given environment for a trait – such as IQ – equals the sum of genetic and environmental contributions, plus a small component for the interaction of these two inputs. Robert Plomin, Gove’s behavioural genetics advisor and a prominent spokesman for this long psychometric tradition, puts it higher, at around 70 per cent, the figure cited by Cummings.

However, the calculation is almost meaningless. It depends on there being a uniform environment – fine if you are studying crop or milk yields, where you can control the environment and for which the measure was originally derived, but pretty useless when human environments vary so much. Thus some studies give a heritability estimate of 70 per cent for children in middle class families, but less than 10 per cent for those from poor families, where the environment is presumably less stable. And it is a changing environment, rather than changing genes, which must account for the increase in average IQ scores across the developed world by 15 points over the past century, to the puzzlement of the determinists.

Two years in the gym


parkrun logo
parkrun logo (Photo credit: Wikipedia)

This morning, running in the regular 5km “Parkrun” in Finsbury Park (just around the corner) I picked up a (rather sore) thigh strain – so it feels like an odd time to write a piece about how great it is to exercise – but I want to write this piece because I feel I have something important to say.

Two years ago this week, on a foreign assignment, I decided to fill some of the time on a quiet afternoon by going to the hotel gym. I discovered I quite liked it, and kept going back. By the time I got back to the UK, some weeks later, I decided I had to join a gym.

I had been in gyms before – in my mid-20s I worked above – quite literally – Camden council’s “Oasis” gym in Covent Garden and used to go to classes there quite regularly with my work colleague Darra Singh (now a partner at Ernst and Young, having been a senior civil servant). But Darra got a new job, the first on his well-deserved rise, my employers moved office and I stopped going. More than that – I started putting on weight.

But even then I found a way of losing it. My employers’ new offices were in Camden Town and I usually got the bus back home. But one winter’s evening the typical London thing happened – there was a little bit of snow and the public transport system fell into chaos. So I walked the four miles back home. And I liked it, so I kept doing it. By the time the weather got better I was walking back over longer, more challenging routes – up Dartmouth Park Hill to Highgate, or even up Swain’s Lane – and I was both fit and (very) thin.

But then I got another job – my dream job, really – working for the Labour Party. Hours were long, stress was high but it was great fun. But the weight came back on. And it never really went off again. In fact it really kept going back on.

By 2011, many jobs later, I was weighing in at 99 kilos, pretty seriously obese with a BMI of over 33. And fitness was pretty poor – I still liked walking and would regularly walk several miles at a stretch, but if I stopped that for a while then I had to push myself to get back into it. More than that – though I wasn’t fully conscious of doing this at the time – I avoided long or steep staircases and in lots of other ways, reinforced my poor lifestyle.

Today, I am still overweight, but at 79 kilos and a BMI of 26 – 27, it is a lot better. I am pretty fit – I managed that 5k – which involves twice climbing a steep hill – in 25 minutes and 34 seconds, not a personal best, but not awful either. I still have far too big a paunch on the stomach but it is (slowly) reducing: I actually have a “six pack”, it is just that it is floating on top of a lot of subcutaneous fat!

Why am I writing this? Just to show off? OK, I admit I am a little proud of what I have achieved, especially because I have essentially done it by exercise and not through a dieting regime (I eat more healthy now but I am not dieting). But that is not the main reason I am putting this down – instead I want to offer hope and inspiration to others – if I can do it, so can you.

My father died of heart disease when he was 44. For a long time I regarded that as some sort of likely measure of my own lifespan. By 2010 – when I passed it -I began to understand that it need not be that. At the same time, I went back to education, studying for the MSc at Birkbeck and realising that, actually, I wasn’t past it after all.

What was really stopping me was a mental block – nothing physical. Breaking through that because I was bored one afternoon did not feel like much at the time, but it has literally changed my life.

Free software hex editor


I have noticed that my free software hex editor (hexxed) – which is licensed under the GNU GPL – does not really come up in any searches, so here’s another entry to boost it.

It’s a bit crude, but it does some things well (e.g., display unicode and switch endianness) and it will run anywhere you can get Java to work. And as it is free software anyone is free to make it better.

This page tells you all about how to get it and use it.

The Summa Metaphysica and all that


Feynman's prize commemorated on the monument a...
Nobel prize winners commemorated on the monument at the American Museum of Natural History in NYC. (Photo credit: Wikipedia)

Stumbled across a fascinating article in this weekend’s Guardian magazine about David Birnbaum and his “Summa Metaphysica” (this – Q4P2 – Principia Metaphysica (The Birnbaum Summa Metaphysics) – is listed in Amazon and appears to be the work, or a version of it).

Normally I more or less ignore the magazine supplements that come with the weekend’s papers but I was attracted this one by a graphic that mentioned the “Bohr radius” – as I had just been listening to Genius: Richard Feynman and Modern Physics while running in the gym.

To be honest, the article doesn’t do a lot to illuminate what Birnbaum  a New York jeweller who has spent a lot of his own money to promote his ideas – is about. But then, maybe that is because he’s not about very much at all: metaphysics is, after all, literally beyond science and testing.

It does tell us a lot about how Birnbaum has upset quite a few genuine scientists about how he has promoted his claims to have found an ultimate theory to explain existence. He used an imprint – Harvard Matrix – on his self-published books that seems to have left a few people at the university feeling their good name has been misappropriated, while others feel that they were used to give a veneer of credibility to a conference Birnbaum funded at Bard college this past May (though I can only admire – seriously – the Oxford chemist, Peter Atkins, who says he attended because it gave him a chance to get an expenses-paid trip to New York and because he likes a good argument).

Such as they are, Birnbaum’s ideas seem to centre on the concept of “potential” (energy? it’s not clear). It’s not mentioned in the article but, of course, the concept of a multitude of inflationary universes is also, in a sense, related to potential energy (or at least the energy that is freed when the ‘inflation’ changes state). But those ideas are, at least to some degree, testable and potentially falsifiable. By all accounts Birnbaum’s are not.

In any case I doubt there is much relation between them and inflationary cosmology either, but as cosmology/particle physics becomes more complex, then the scope for the naive (a category into which, being kind, I will place Birnbaum) as well as the exploitative – wait for the next batch of psuedo-science in the Daily Mail – grows larger.

Many scientists in these advanced fields are unhappy about the core of the “standard model” – in that it posits a very large number of supposedly “fundamental” particles. There has been disappointment as well as joy over how well the model has stood up to the LHCs explorations – a triumph of the scientific method as great as Le Verrier’s prediction of Neptune, but also a confirmation of a model that looks less than fundamental after all. If, and until, we solve some of those seeming contradictions then we are just going to have to live with the interstices of physics being filled with ideas from strange people – especially rich ones who want to be taken seriously.

(Incidentally, the Bohr radius graphic was actually a reference to an idea promoted by Jim Carter who denies the truth of quantum mechanics.)

Reasoning about a NoC


Thinking about a Network-on-Chip system and what its system software needs to do…

  • Parallelisation is essential to efficiency – in a NoC there are a multitude of cores, but each core has only the fraction of the computational power a “traditional” unicore might be expected to have – therefore it is essential that, where possible, code is parallelised across as many cores as possible;
  • Each core needs to be able to access operating system services (via system calls or some other mechanism), but it is not necessarily the case that each core has to run a full or even a partial operating system – thus RPC or some other mechanism can be used to ‘remotely’ provide system services;
  • Application programmers want, above all, a single address space.

 

Astrology: the anti-science acceptable to the educated élite?


Man Booker Prize
Man Booker Prize (Photo credit: Wikipedia)

Imagine if, in the US, a new novel that celebrated creationism was awarded the greatest of all literary prizes, topped the local best seller lists, gained five star reviews in the papers and was recommended to school pupils by their teachers. Typical American idiocy, eh?

Then imagine in the rest of the English-speaking world a new novel that celebrated astrology was awarded… well you don’t have to imagine, because it has already happened with the award of the Man Booker Prize to The Luminaries – a book the plot of which revolves (literally, apparently) around astrology.

Now, you might argue, the fact that a character in the plot, or even the plot itself, focused on astrology is hardly that shocking – this is the world of the imagination after all. But that ignores the fact that the author, Eleanor Catton, noted that it was 28 years since a New Zealander had last won the prize and that this was of astrological significance – because it was the orbital period of Saturn? Frankly, if I was a Booker judge, I’d be tempted to sue over the suggestion that my decision to award the prize was based on something other than rational thought!

It seems no one has batted an eye-lid about the astrological theme. Astrology is the anti-science that our arts degree holding élite find completely acceptable – it’s just a bit of fun, after all, isn’t it?

No, it’s not. It ought to be a matter of national shame that our children know far more about this rubbish than any true cosmology.

In fact my view is that astrology is the “gateway drug” to all sorts of far more pernicious anti-science ideas. It needs to be confronted not tolerated.

As you might have guessed I have no intention of reading Ms Catton’s book. So, maybe I am being unfair – a bit like those prudes of years gone by who denounced Monty Python’s Life Of Brian without ever bothering to watch it. That’s a risk I am taking writing this, I admit. But the evidence I can see suggests Ms Catton takes astrology more than semi-seriously:

Is Catton trying to legitimize astrology for our modern age, perhaps rescue it from newspapers’ back pages?

“I do feel like I have a special fondness for any school of thought that is not fashionable,” she says with a shy laugh. “It’s just kind of a rebellious streak in me, and certainly astrology does not command a great deal of intellectual respect.”

The zodiac, she explains, “is incredibly psychologically complex, I think. As a sequence, it makes a great deal of harmonic sense: You know, the 12 signs from Aries through to Pisces really are a 12-part story, and each sign kind of rejects the principles of the sign that precedes it. And reacts against them, in a funny kind of way.”

As an example, she cites Aries, “which is understood as the objective principle; Taurus, the subjective, which is a reaction against the objective; and then Gemini, which is a kind of synthesis of objective and subjective, and moves freely between them. And so on and so forth, all the way around.

“So, yeah, I think I do find astrology really interesting as a kind of primitive or naive version of psychology, really. Or, like, a psychological schema.”

(From The Globe and Mail – here)

She’s entitled to her view, no matter how plain stupid it makes her look. The Booker Judges aren’t entitled to give it credibility without being open to ridicule though.

Third time lucky?


Last time we met, my PhD supervisor told me to expect to spend a long time making things that didn’t work: it

Crashed payphone -- Linux kernel panic
Crashed payphone — Linux kernel panic (Photo credit: sethschoen)

certainly feels like that right now.

My current task is to build a logical model of a working memory allocation scheme for a NoC.

I started with some Groovy, then realised that was going nowhere – how could I test these Groovy classes? I could write a DSL, but that felt like I’d be putting all the effort into the wrong thing.

My next thought was – write some new system calls for an experimental Linux kernel. Well, that has proved to be a pain – writing system calls is a bit of a faff (and nowhere does it seem to be fully documented – for a current kernel as opposed to a 2.2 one! – presumably because nobody should really be writing new Linux system calls anyway and so its knowledge best confined to the high priests of the cult) and testing it is proving to be even more difficult: it’s inside a VM or nothing.

Then I thought this afternoon – why bother with the kernel anyway – if I wrote a userland replacement for malloc that allocated from a fixed pool that should work just as well – so that is what I am about to try.