Wednesday, 10 December 2008

Anathem

I've just finished reading Neal Stephenson's new novel, Anathem. Previous works by Stephenson have varied from the raw but entertaining Zodiac, through the hilarious Snowcrash (the best opening scenes of a novel ever?) and on into the labyrinthine and erudite yet readable, funny, sexy, gripping 'System of the World' trilogy. In this latest book we are transported to the world of Arbre, fairly similar to Earth but a world where mathematicians/scientists/philosophers live and work in monastery-like buildings, separated from the 'saecular' world. As the story unfolds it becomes clear that this is because of unspeakable things that happened when scientists were able to get their hands on technology.

As the book unfolds it changes nature many times, keeping you fascinated through it's 800+ pages. It's a book about philosophy and you can try matching the famous 'saunts' of Arbre to the philosophers we are familiar with. It's about quantum mechanics and the many universes problem. And it's about meeting aliens. Only the twist here is that it's seen from the Alien's perspective. And I suppose it's a love story, an adventure novel and a lot else besides.

I am amazed at how much Stephenson can get inside a subject like QM or philosophy and produce a stunning novel which incorporates so much of its principles. The last set of novels were all about computing, finance, history and piracy for goodness sake. How much research does he do?

Put it on your Christmas list. A novel for those who enjoy reading, enjoy learning, enjoy thinking.

Wednesday, 10 September 2008

Eschatology

Comment
So the world didn't end. The dog didn't bark in the night and no-one gets sued for blowing up the Earth or swallowing it in a Black Hole. For some reason an old filk song comes to mind:

"Don't start an interstellar war,
It really has no uses.
If someone asks you what it's for,
you'll only make excuses.
If 50 billion folk get hurt,
you'll go to bed without dessert.
Don't start an interstellar war"

Background

Well the doomsayers said that the LHC (Large Hadron Collider, and here) at CERN will create a miniature black hole which will destroy us all. People have even made death threats to the scientists (if you destroy the world we'll come and kill you...). Will it all end in disaster? Hear all about Big Bang Day on the BBC, including a special edition of Torchwood - now that's real science for you!

Why bother? What's the use of such basic science if it doesn't lead to better video games or more food for the needy? This The Times editorial from 8/09/08 attempts to answer that.

You could always go out listening to the LHC Rap.

Did the world end for you? Check this site to see*, or if you're really worried you could look at the live webcams from the Compact Muon Solenoid (CMS)


*View source for the funniest parts...


Saturday, 2 August 2008

Solar Eclipse

Just found this viedo of the recent total solar eclipse, recorded from an airplane. It gives amazing footage of the conical shadow.

Tuesday, 24 June 2008

Homeopathy - nothing to prove

New Scientist reports that Simon Singh and Edzard Ernst have offered a cash prize to anyone who can prove that homeopathy works. Then then report Steve Scrutton of the Alliance of Registered Homeopaths as saying ""We have nothing to prove"

Well I really could not have put it better myself...

Wednesday, 18 June 2008

Zeilinger and Quantum Mechanics

When I listen to good jazz I am temporarily willing to suspend my disbelief in the soul. And the Abram Wilson quartet are good enough not only to have me believe in the soul but to make it get up and dance. Check them out if you like New Orleans swing with a modern twist and trumpet playing that will blow your mind.

I was listening to them at the unlikely venue of the Institute of Physics in London. They were performing as part of a celebration of the first presentation of the Newton Medal, the IoP's new premiere award to any international scientist. The recipient was Anton Zeilinger who has worked on the fundamentals of quantum mechanics in a very productive life. His group in Vienna have made real such dream (thought) experiments as quantum teleportation, quantum cryptography and diffraction of large molecules (azobenzene, 3.2nm long for example).

The talk Zeilinger gave, preceding the concert, was clear and challenging and much of it hinged on the perceived opposite views of Einstein and Bohr. For Einstein the world was real and quantum mechanics had to reflect that - no spooky action at a distance. For Bohr physics was about what could be measured. Einstein "Are you really asserting that when no-one looks at the moon, it isn't there?". Bohr "Can you prove the contrary?".

That quantum mechanics can distinguish between these cases experimentally (so-called Bell's Inequality experiments) is a true wonder: philosophy once again has to stand aside as physics barges in and answers questions pondered for thousands of years.

Zeilinger's work is peppered with humour - subtle and sly in most cases. To demonstrate quantum cryptography they chose to transmit an image of the Venus Von Willendorf because, as he put it, it was one of the few images that was distinctly Austrian but nothing to do with war! A cryptographic message across the border to Slovenia on its accession to the EU in 2004 read simply "Welcome back!", a jibe at the country's recent communist past but Austro-Hungarian roots.

Zeilinger reminder us most of all that the pursuit of science is a deeply human act, driven by curiosity and personalities. Long may such strong personalities have their say!

Wednesday, 21 May 2008

MPs and Science...don'cha loveit?

Listening to our MPs debate science issues in the House of Commons is always entertaining. A couple of days ago an MP opened the Human Fertilisation and Embryology debate with the statement that humans should not be mixed with the animal kingdom.

Now, I'm no expert on Linnaen classification but I figure it's already a few hundred million years too late for that.

The abortion upper time limit debate was similarly inept and ill-informed. Clearly the majority of the house think that one can count "one anecdote, two anecdotes, three data". Watching MPs debate scientific issues is like watching a one year old play with the television remote. It may appear to do something almost intelligent. It might even stop at a result which pleases it. But one cannot in any way ascribe intelligence and reason to the process.

Thursday, 15 May 2008

Misconceptions...and exam resits

A friend sent me this story on Tuesday...all true apparently (although a FOAF story...)

This is an account of a conversation overheard in a hospital waiting room this afternoon. There is a misconception here, which you may spot!, which seems to have linguistic origins.

An elderly lady ('granny') was having a scan accompanied by a younger woman ('mother'). As she came out from the scan a teenage girl arrived in a hurry and a little worked-up. 'Just in time' said mother, they were just finished here. The teenager was asked how her exam had gone. Well, she reported, it would have been okay if it had been the examination that she had revised for, and that her teacher had prepared her for. However the examination was not what she had expected.

This was all very loud, and although not deliberately announced to the room there was no attempt to keep the conversation private (so I feel justified in reporting it).

Apparently the girl had gone to the teacher after the exam to complain that she had been misled, and the teacher had offered sympathy for any misunderstanding, but asked why she had not come along to the special revision sessions that had been put on. The girl told her mother and gran that she would have gone to these sessions if she had realised it might help, but had not thought they would be needed.

It transpired that the examination was a resit. She had got a D grade previously, but as she had found the examination easy [I think most examinations are easy if the target is simply to sit the examination, rather than pass it] she had decided to resit. She had paid to get her examination script and I assume a report, and had spent time going through it with her teacher who had advised her on what she would need to write when she re-sat the examination. She had also spent time revising based on this advice so that she knew what to write when she retook the examination.

However, and you may be ahead of me here, when she got into the examination room and opened the paper, she had a nasty shock.
Although she had paid to retake the examination, when she read the paper she was being asked different questions! So she was not (in her
interpretation) getting a chance to resit the examination after all, but being given a new totally different examination. All that hard work going through her mistakes, and seeking advice on what she needed to write when she took the examination again [sic], were wasted because it was not the same examination at all, but a completely different one.

Presumably the young lady was at least 17, and unless she was putting on a very good show she was entirely genuine. So we should perhaps be very careful in using expressions like 'when you take the examination again' as the blatantly obvious may not always be so to all our students.

Wednesday, 7 May 2008

SPS Take on Planet SciCast


This year, instead of Paperclip Physics, Paulines competed in the first ever Planet SciCast video competition. Not quite knowing what to expect, we jumped right in with a dramatic presentation of the wonders and majesty of the inner workings of the rollercoaster.

Confronted with the option of entering the project, our newly formed team, Team Go, consisting of team leader James Ko, Fred Beardmore, Haruka Chambers and James Linehan, decided to use this opportunity to show the world the true greatness of magnets! Having originally thought to show a myriad of magnetic circus tricks, similar to the wondrous Pythagoras switch (google it), our plans were thwarted by Dr. Gardam and Dr. Holmes. And so, we limited our project.

This was the first step of an arduous yet fruitful journey. With the aid of Dr. Gardam and Mr. Holmes, we honed our brainchild into a lean mean competition winning machine (or so we hoped...).

Performing most of our magnificent feats in the atrium one bank holiday Monday, we collected most of footage required for the final product, with the exception of the final scene, shot on a staircase after many takes of the same temperamental setup.

With the data collected, we were faced with over an hour’s worth of bloopers, and almost exactly two and a half minutes’ worth of useful footage (the maximum length the video was allowed to be), which we managed to salvage from the great mass of useless material.

We congregated on the day before the video deadline and to cut a long story short, we made the film as it is seen today.

The next thing we knew we were sent invites to the award ceremony with two nominations – for Best Technical and Artistic Achievement and for Best Engineering Film.

The judges were overcome by the sheer magnitude of our magnets (yes, we did just say that) and we won the Best Engineering Film award with our “pretty cool” (as Dan Cosser described it) model.

By Fred Beardmore and James Ko

Wednesday, 30 April 2008

Which science books would you recommend?

A friend of mine just linked to 20 Science Books Every Scifi Fan (and Writer) Should Read. (By the way, I found his link not on his weblog or via an email but from his del.icio.us bookmarks. If you don't know del.icio.us, check it out: it's a great way of sharing web pages and blog posts that strike you as important — social bookmarking.)

Which science books would be on your 'must read' list? Post suggestions here in the comments and also consider cross-posting to the SPS Book Forum.

Monday, 21 April 2008

Exclusivity and Demand

I was talking to a Professor of physics from Imperial College the other day and he mentioned that a few years ago they increased their 'standard offer' of A level grades required to get in from AAB to AAA. The effect on applicants was a marked increase*.

It's an example of the exclusivity effect - you can make something more desirable simply by pricing it higher. I first thought about it when motorcycle touring in America in the 90's. Sitting in a cafe in Sturgis during a huge rally (quarter of a million bikes in the area for the week) I found myself chatting to a typical Harley-Davidson owner. Typical of the time that it - mid 40's, overweight and a gynecologist. In order to buy a new Harley you had to put down the full cost (about $28000 back then) in advance and then wait 18 months for the factory to build your bike. Second hand bikes were more expensive than new! This approach had turned around an ailing company playing out the last chords of a sad threnody and started a whole new movement of a whole new symphony. Harleys were cool, desirable and hard to get hold of.

Obviously it's a dangerous line to tread - annoy your customers by not delivering and you're dead. But it worked there and it has worked for Imperial.

We've seen it again recently with the Ford Mondeo vs the BMW 3 series. Obviously the main objection to the Mondeo is that they are everywhere - everyone drives one. So it'd probably do BMW's sales no good at all if people found out that the BMW 3 series now outsells the Mondeo...

I see something of an analogy here with physics. Make a subject accessible to all and you risk driving away students and teachers who value it for its lack of appeal to all - not a snobbish exclusivity, not a "I'm in the physics club you're not" but a simple pride in being able to solve problems and work in a way which others cannot, and so make a genuine contribution to society and the economy. Do we really want Ford Mondeo physics? Or BMW physics? And is it possible that, if we offer BMW physics, it might actually appeal more widely?

* His claim, which is anecdotal, was that applications doubled.

Thursday, 17 April 2008

Engineering at University

On Wednesaday (16th April) I was at a meeting organised by the Education Group of the Institute of Physics. The purpose was to inform physics teachers about what engineering and materials science courses are like and what the universities are looking for. After all, most physics teachers studied physics, not engineering (with some noteworthy exceptions!) so don't really know what engineers are looking for.

The answer appears to be three things:
  1. Maths
  2. Teamwork
  3. Problem solving
If engineering could be summed up in a nutshell (it can't, nothing can except perhaps the kernels of nuts) it would be that it is about developing adequate models of systems given insufficient information and the possibility that the maths is not solvable. The model has to do the job of being sufficiently applicable to the real world to solve a real problem.

What the lecturer from Oxford pointed out was that engineering is not plumbing, wiring and tinkering with motors. Nor is it repairing TVs or operating lathes. It's a profession. And if there's a problem with A levels at the moment it is that the link between maths and physics has disappeared - and physics has become too hand waving.

Engineers are clearly vital for our future and unemployment amongst them is near enough the square root of diddlysquat but we cannot fulfill the need without teachers knowing what universities are looking for.

In another talk it was pointed out than in Birmingham alone there are 151 different schemes about engineering for school kids. How are you meant to sort, select and know which are useful?

Saturday, 12 April 2008

The Strange Case of the BumbleBee which Flew

This is a piece I wrote about 12 years ago for a science writing competition (it won first prize). I thought about editing it up and correcting some bits but feel it should just stand as it was, for posterity.

I get many strange reactions from people when I tell them I am a scientist. Frequently I'll be told by my new acquaintance that they were hopeless at science at school, or I'll be asked if I make atom bombs. People, it seems, are frightened of science, so they take every opportunity to belittle it. They'd like to believe that science is all very well in the lab, and for making bombs, but it doesn't apply to "real life". Michael Flanders summed it up beautifully when he said that he cannot understand scientists and they cannot understand anyone else; they must be spoken to in their own language: "H2SO4 Professor! Don't synthesise anything I wouldn't synthesise! And the reciprocal of pi to your good wife!". Like most great humour, painfully close to the truth.
One favourite subject people raise is the old line about scientists having proved that the bumble bee cannot fly, a much-beloved piece of urban folklore. There it is, the humble Bombus Terristris, plainly flying around us all through the summer and those crazy know-all scientists with their noses in their test-tubes say it cannot possibly fly. What utter nonsense! It is obvious to any scientist that the bumble bee can fly as experiment proves it. So what is this business about proving bees cannot fly? And who started it?
First let's look at the physics behind the story. If you are asked about flight the first thing you do is to use the equations which describe how much lift an object has. You compare the lift to the weight of the object. If the lift is greater than weight then the thing can fly. Bumble bees are pretty big, weighing almost a gram, and have a wing area of about a square centimetre. Tot up all the figures and you find that it cannot generate enough lift at its typical flying speed of about one meter per second. But that doesn't prove bees cannot fly. It proves that bees with smooth, rigid wings cannot glide. Experiment has proven this too. With the aid of dead bees and a little lacquer it is easy to show that they really cannot glide.
So how do they fly? Actually that turns out to be a very interesting question and one that reveals a lot of physics. Why do bees flap while jumbo jets have fixed wings? It is a question of size and this is revealed in a figure called the Reynolds Number. Osborne Reynolds was a Victorian engineer who was interested in what happens when you place an object in a stream of liquid or gas. The number named after him is a ratio which tells us, for a particular object, how much lift you get compared to how much drag or resistance you get. A low Reynolds number means little lift for a lot of drag and a large Reynolds number means a lot of lift. The Reynolds Number depends on the size of the wing. Bigger wings give bigger Reynolds numbers. Now if, again, you put in all the numbers you find that bees work at very low Reynolds Numbers (1000 or so for a honeybee, as little as 15 for the aphid-eating chalcid wasp). This means that their flight is very inefficient because as a wing starts to move to create lift the drag holds it back. It is fairly straightforward to show that birds can generate enough lift to fly once they are in motion with air flowing smoothly over their wings, but many of them would have great difficulty taking off. Small insects, according to this model, cannot fly at all. Of course, all this proves is that the model is incomplete.
Some brilliant work by Torkel Weis-Fogh has shown us how small insects do fly and it has led to some rather neat insights into nature's cunning. If you are small and want to fly you have a problem. The Reynolds Number is against you so you cannot glide and flapping is very hard work. A wing is a device which encourages the air to flow over it so that when it leaves the rear wing edge, the air moves downwards. That produces a thrust upwards on the wing. A smoke-filled wind tunnel shows this beautifully with curling eddies of smoke flicking off the wing edges. Unfortunately to make a good eddy takes time. The wing has to move a few times its own length to get things started. This makes it tricky if you are going to flap as the maximum travel of a wing is about its own length and very little lift is generated for most of the stroke. Nature has come up with a number of interesting solutions to this problem of which the "clap-fling" is a good example. When a small bird or insect wants to take off it needs a lot of lift. What it does is bring its wings together above its back so they clap, expelling air from between them. As the wings are separated, air is drawn quickly in to fill the void. The wings are flung apart and lift is generated immediately as the air is already in motion in the correct way. You can hear the clap. The characteristic whirring of a pheasant taking off is caused by its wings clapping. Almost 2000 years ago Virgil recorded in The Aeneid that a rock dove claps its wings as it takes off - a passage he stole from Homer but he added the bit about the clapping.
So in asking how bees fly we find that they are remarkably clever about it. Aircraft can generate enough lift that they do not need such tricks, but they do need long runways. Birds get enough lift to fly but for take-off need a boost. Just the poor old bee and about a million different species of winged insect need some extra trickery to stay aloft. But how did it all start? Where does the story date back to? J.H.Mcmasters states that the story was prevalent in the German technical universities in the 1930's, starting with the students of the aerodynamicist Ludwig Prandtl at Göttingen. The story he tells is that a noted Swiss aerodynamicist, whom he does not name, was talking to a biologist at dinner. The biologist asked about the flight of bees and the Swiss gentleman did a back-of-the-napkin calculation of the kind I described. Assume a rigid, smooth wing and so on. Of course, he found that there was insufficient lift and went away to find out the correct answer. In the meantime the biologist put the word around, presumably to show that nature was greater than engineering, and the media picked it up. The truth, as now, wasn't newsworthy so a correction has never been publicised. The man on the Clapham omnibus, therefore, continues to tell me that science is a load of crock because it once proved that bumble bees cannot fly. And he will not hear otherwise, especially not from a scientist. Perhaps if I became a journalist he might listen?

Sunday, 6 April 2008

Computing Post

So we all know Physics is cool, and lots of nice photos demonstrating interesting phenomena always makes for good blog reading, but I thought I'd throw in my hand as a proponent of the interesting world of Computing with a link to this article from Neatorama, basically outlining some of the history of early computers, dating right back to about 33000BC!
So it may not be as pretty as a green sunset, but I still reckon it's pretty interesting.
Check out the link if you want to find out more.

Oh and just to keep it colourful, here's a photo of the Antikythera Mechanism. Made in around 100BC it is thought to be part of a system for calculating the motion of the sun and the moon.

Wednesday, 2 April 2008

A physicist on holiday

Well, a typical physicist on holiday - a week in the Maldives scuba diving and what do I take photos of (apart from fish, turtles, rays, sharks and coral)?


A glory, a rising red moon, the green flash and vertically-pointing satellite dishes. The first image is of a glory or anthelion. This one was taken from a seaplane, looking down onto the clouds. In the centre you can see the shadow of the plane and surrounding it are coloured rings. These arise from the sunlight being scattered back from the water droplets and, like in a rainbow, the refraction of the light through the water splits it into colours.

The second image is of the setting sun. Actually the sun set a moment before. Alright, about eight and a half minutes before if you're being fussy. As the sun drops below the horizon you occasionally see a green flash of light. Here I was lucky enough to catch it on ccd. (Damn that doesn't sound right, but it wasn't captured on film so what doyou say?). The atmosphere scatters the blue end of the spectrum (which is why the setting sun looks redder) but the red light is refracted least. After the sun is actually below the horizon you can still see it because the atmosphere acts like a lens, curving the light of the sun towards us. Red is curved less than blue so the red sun disappears before the blue. But blue is scattered more than red so blue is blocked by the atmosphere. That leaves green as the last light you see. It's meant to mean good luck if seen from Ireland or Scotland - either Celtic legend or wry acceptance of the chances of clear weather and a calm, flat sea...


Here the rising moon appears quite red. No I didn't photoshop it! It has only just cleared the horizon and, as it is fairly full (waning gibbous) it rose not long after sunset. The first reflected light to hit it is the red light of the sun - red because of the path back and forth through our atmosphere scatters so much of the bluer light. As it gets higher, it gets whiter. I've never seen this before - not been around on a clear enough moon rise I guess, sufficiently far from light pollution.












This last picture is of the various satellite dishes on the island. Being just a few degrees north of the equator, the two dishes pointing to geostationary satellites are, of course, nearly vertical. If you walk down pretty much any street you'll see arrays of satellite dishes for TV, all pointing the same way. In the UK it'll be pretty close to south because of the position of the relevant satellite. Here you can tell your latitude by the angle of the dish. I thought it was worth recording, but perhaps I'm easily amused...
If you want to know more about glories, sunrises and a huge range of optical phenomena then you couldn't do better than Marcel Minnaert's "Light and Colour in the Outdoors".

KPZ