Tag Archives: Physics

Want a Full Spectrum Love Life? Watch This CD

April 30, 2012 Tim Jones Leave a comment

It’s that candlelit dinner stage of the evening. Soup through nuts, you’ve been your wonderful, genuine, self. And he/she is pretty fantastic too.

spectrum of candle flame by diffraction from CD — Spectrum of candle flame by diffraction in a CD (Photo:Tim Jones)

But why take chances – this is deal clinching time.

With the table cleared, quick as a whippet you pull out your Ethereal Collapse CD, and with a flourish Newton would die for if he wasn’t already dead, guide your beloved’s eye to the spectacular demonstration of spectra by diffraction.

Your friend will by now be in a frenzy of excitement, so this is the moment to push them over the edge.

Rushing through to the restaurant kitchen with a mix of urgency and discord normally reserved for Bond movies, you thrust your CD into the light once again. But now the disc reflects the chef’s fluorescent tube in an almost unbearably different, and extremely interesting way. The smooth continuum of the candle flame is gone! Now superposition bands stand proud, where line discharge spectra from gaseous mercury inside the lamp combine with the continuous spectra emitted from the phosphor coating.

Spectrum of fluorescent lamp by diffraction in a CD (Photo: Tim Jones)

At this point, you’ll almost certainly be offered complimentary Cognacs – if only to leave the kitchen. But by now you’ll both be itching to get off anyway, back to his/her flat to repeat the experiments under controlled conditions. Or maybe play some Scrabble.

Note: Humphry Davy was up for colour ploys (Link to ‘Humphry Davy – Finding Love in the Colourful Age of Romantic Science’)

Book reviews, Books, Physics

Book Review: The Physics Book by Clifford Pickover

April 1, 2012 Tim Jones Leave a comment

Hardcover: 528 pages
Publisher: Sterling (23 Sep 2011)
Language English
ISBN-10: 1402778619
ISBN-13: 978-1402778612
Product Dimensions: 22.1 x 19.6 x 3.7 cm

The Kindle’s supremely convenient, and the iPad’s drop-dead gorgeous. So why do I find Clifford Pickover’s good ol’ fashioned hardback version of The Physics Book so damn attractive. And I do mean physically – so to speak. (It’s on iPad too, but read on.)

Maybe I’m getting all bookish-protective in the month that Encyclopedia Britannica wound up its iconic print edition after 244 years? Or is the tactile slabbiness of The Physics Book a nostalgic reminder of the Purnell’s and Marshall Cavendish encyclopedias of my formative years? Well, it’s the latter of course; I almost feel like jumping into short trousers for a re-read.

But enough of my fetishes already.

The Physics Book isn’t really an encyclopedia, but the word kind of fits given the breadth of topics covered. For each of 250 Milestones in the History of Physics, we’re given enough information to be useful in its own right, but with signposting for further research; it’s a kind of physics taster if you like. And while I’m sure it’s readable in two or three good sessions, I found myself dipping in and returning over a period of weeks. So much for prompt reviews then, but this is an eminently dipinable book.

When I reviewed Tweeting the Universe, I was impressed how the authors tackled the unassuming little task of explaining the whole universe in a series of 140 word ‘tweets’. Pickover’s offering is a different animal with much more meat on it, but he’s still had to work, effectively I think, at getting a coherent story for each item into one page of text and an accompanying photograph. Also, Tweeting the Universe doesn’t weigh 1.5kg!

Appropriately kicking off with the Big Bang 13.7 billion years ago, the chronological journey is otherwise unsegmented. How could it be? Discoveries don’t just pop up in categories to order. But that also means practical, down-to-earth, physics applications – like the engineering truss – can mingle with less tangible concepts like Pauli’s exclusion principle. And while there’s no talking down to the reader – there are even a few equations! – I think the spattering of examples linking underlying physics to everyday objects and experiences keeps us all onboard.

The engineering references in particular show how some devices we think of as modern were discovered and applied ages ago, even if they weren’t at the time properly understood in a scientific sense; it turns out the first electric battery pre-dated Volta by a whole millenium. In other news, we’ve only recently come to grips with why ice is so slippery – and it might not be why you think. We only figured out how the hourglass works in a 1996 physical modelling study at the University of Leicester (as it happens the city I originally hail from and an area of research technique I used to work in). Other apparently simple observations still lack a satisfactory explanation, like the mysterious black drop effect that happens when Venus transits the sun.

A repeating theme is discoveries being made independently by more than one person, like the explanation of rainbows, calculus, and the laws of refraction: a reminder perhaps that we discover scientific knowledge, not make it up depending on who we are, where we are, or which culture we belong to. There are also lessons in the less than intuitive nature of some relationships, like that between fluid volume and pipe size (Poiseuille’s Law).

The popular association of physics with weapons – typically represented by the iconic atom bomb mushroom cloud – is not neglected or shied away from. Indeed, Pickover describes a range of weapons enabled by physics through the centuries. I knew about the boomerang and crossbow, but the prehistoric atlatl technology, exploiting the principle of leverage to kill mammoths and conquistadors with indiscriminating effectiveness, was news to me.

Pickover’s references are diverse, with lots of modern day and ancient quotations from commentators ranging from Aristotle to Einstein, references to fiction and science fiction, and some pan-cultural associations you wouldn’t expect. Who knew Edgar Allen Poe first suggested a solution to Olber’s Paradox “Why is the sky dark at night?”.

Certain pre-eminent individuals like Newton, Einstein, and Hawking, as sources of particular inspiration, get their own pages. William Gilbert De Magnete gets a mention as the first guy to break god’s monopoly on knowledge and start doing proper experiments, as does Eratosthenes for the shear elegance of his Earth circumference calculation from observation and deduction. Talking of experiments, it’s not the main idea, but there are a few prompts to try stuff at home, like breaking candy bars or pulling off lengths of scotch tape in the dark to see the triboluminescence.

If big picture, left-field, even spooky physics are your thing, ideas like Quantum Mechanics (including Quantum Electro-dynamics) and Heisenberg’s Uncertainty principle are generously discussed; also my favourites: Spooky Action at a Distance (Quantum Entanglement, Bell’s Theorem), and stellar nucleosynthesis. It’s a reminder we’re all made of star stuff, and that reality is weird enough without us making up any extra fairy stories. Other entries in this vein border on the philosophical (another discipline gobbled up by physics?), like the totally plausible if challenging thought that we might all be living in a Matrix-style simulation. Then there is Quantum Immortality – the idea that across infinite multiple universes we might live effectively, necessarily, forever. Likelihood is after that lot you’ll only be good for browsing the photos.

So just as well there are lots of them – precisely 50 percent by page area. My favourite – I think I go for shots with people in them – shows observatory staff posing somewhat precariously on the mount of the University of Pittsburgh’s Thaw refracting telescope. I also like the shot of Stanley and Lawrence standing by their cyclotron. Other pictures illustrate applications – good and bad: like the squat ‘Little Boy’ atomic bomb sitting innocently in its cradle: a simple photograph that evokes so many complex thoughts. Or more constructively, a Nuclear Magnetic Resonance (NMR) picture of arteries in the head, for me the ultimate expression of applied, useful, physics. Some pictures are just fun – like Schrodinger’s Cat peeping out of a cardboard box with a “what?” expression on its face.

Moreover, we’re left in no doubt that physics gets everywhere. It’s a bit of a joke across the scientific disciplines, in a sour-grapes sort of way, that all the other sciences are a subset of physics. That’s not the case, but Pickover’s examples for sure underscore physics’ broad reach. I love the way diffusion and Brownian Motion explains the spread of muskrat populations.

So there you go. My impressions and a bit of a content summary of items that stuck with me from The Physics Book. There’s nothing not to like, and despite my reminiscences from childhood, I’m sure readers of all ages and backgrounds will enjoy it – in iPad or ‘real book’ form!

“The truth is stranger than fiction” (Mark Twain and Todd Rundgren)

Other info.

Cliff Pickover’s page on The Physics Book (includes photos)

Preview of electronic version on US iTunes site

Disclosure: I’m grateful to Clifford Pickover for sending me a complimentary copy of The Physics Book

Biography, NoAd, Physics

Richard Feynman’s Grave

December 12, 2011 Tim Jones 4 Comments

Today I paid my respects at the grave of physicist Richard Feynman, interred with his wife Gweneth at the Mountain View Cemetery in Altadena, California. Feynman died of cancer in 1988 and his wife died the following year.

The grave is marked by a very simple plaque, which my wife and I would never have found without the help of the cemetery staff. Even then, until we brushed it off, the plaque was barely visible among the leaves and twigs – fallout from the Santa ana winds that have just ripped through the region.

Richard_Feynman_-_Fermilab — Richard Feynman at Fermilab. Image in public domain and available via Wikicommons

Today was calm and sunny though, and the cemetery is a beautiful spot to find yourself. Lots of trees with birds and squirrels running about, the whole overlooked by the San Gabriel Mountains and Mount Wilson (of 100 inch telescope fame).

Feynman researched and taught as Professor of Physics at the nearby California Institute of Technology in Pasadena from 1950 until his death.

Here are some more photos at the cemetery:

If you don’t know about Richard Feynman, I recommend in addition to his Wikipedia page you check out the biographies Genius by James Gleick, and Quantum Man by Lawrence Krauss. I also enjoy failing to completely understand (note the word order) Feynman’s 1979 Douglas Robb Memorial Lectures on Quantum Electro-dynamics (QED).

More recently, here’s physicist Leonard Susskind’s personal insight on the man in his January 2011 TED talk ‘My friend Richard Feynman’

and the BBC Horizon ‘No Ordinary Genius’:

Astrobiology, astronomy, events, Physics, science communication

Lawrence Krauss Sprinkles Stardust at the School of Life

October 18, 2011 Tim Jones 2 Comments

I’d heard of Alain de Botton’s School of Life and its “good ideas for everyday living“; I just hadn’t been to one of their ‘Sunday Sermons’.

Lawrence Krauss at Conway Hall 16th October 2011. Photo by Tim Jones — Krauss 2.0 ?

So arriving at Conway Hall yesterday to hear theoretical physicist and all-round science communicator Professor Lawrence Krauss talk about Cosmic Connections, it was an unexpected but not disagreeable surprise to find David Bowie and a seven foot spandex-clad devil stirred into the mix. I for one can’t think of a better preparation for contemplating one’s insignificance in a miserable futureless universe than a good singalong to Space Oddity.

On the face of it, Krauss’s ultimate message is a bit grim: that our expanding, accelerating, universe will eventually dilate into cold, empty, blackness. But, more positively, he’s saying we should take all that as read and concentrate on our perspective: understand what we really are and how we connect with the universe. Then the journey to oblivion doesn’t look so miserable afterall; it looks fascinating – even poetic.

Krauss’s consciousness-raising / cheer-up therapy centred around three less than obvious connections we have with the cosmos:

First off – we are the universe. We’re made of stars. The heavy elements that make us up could only have been made in stars, and they could only end up as part of us if they were blasted out of exploding stars: the supernovae.

Call me a romantic, but I like the imagery. Bits of me: hands and feet, arms, legs, head, brain – they didn’t just pop up a few decades ago, but have been flying around for billions of years and will be around for billions more. I’ve been inside an exploding supernova – several most likely.

Lawrence Krauss and the Devil. Photo by Tim Jones — Straight on at purgatory, then right at the second circle….

Next came the connectedness of life, with a nice story of Krauss sitting to write a physics paper, aware he’s breathing the very atoms breathed by Einstein as he formulated his own theories (inspired inhalation?). We’ve all got a bit of Julius Caesar in us it seems – literally. And on the larger scale of the solar system, the exchange of possible life-bearing rocks between the Earth and other planets, including Mars, could mean we’re all extra-terrestrials without even knowing it.

Krauss’s final illustration challenges our perception that aspects of reality we normally consider outlandish and irrelevant to our day-to-day life do indeed have a direct influence on us. The mundane activity in question is navigation by Global Positioning System (GPS), where the consquences of not correcting for satellite speed (Special Relativity), and height above the Earth (gravity effect/General Relativity), on measurement of the requisite nano-second scale signal transit times, would in only a day be sufficient to put ground track navigation out by several kilometres.

David Bowie tribute band absolutebowie.net Photo Tim Jones — “Ground control to Major Tom”

I really like this GPS example and the way Krauss presented it. There was no such thing as GPS when I was at school, so all we got were stories of atomic clocks losing time when they were shot round the world on fast planes, or hypothetical astronauts of the future going on fictional journeys. To be able to relate relativistic effects to a very real navigational error that normal folk can recognise and care about is brilliant.

Who’d have thought Sunday sermons could be such fun?

Lawrence Krauss and Tim Jones Photo Sven Klinge — It’s important to help struggling authors….

Photographs copyright Tim Jones.

Final photo: Thanks Sven Klinge.

Update 4th Dec. 2011 Video of the event:

Lawrence Krauss on Cosmic Connections from The School of Life on Vimeo.

Also of interest? – Lawrence Krauss recently on Materials World with Quentin Cooper (about 15 mins in)

Biography, education, Physics

Of Physics, Firearms, and Fireworks

September 23, 2010 Tim Jones 4 Comments

I learnt only recently, while researching the early use of computers in schools, that my physics teacher from the late seventies, John Page, had died during 2009.

Better known by his nickname ‘Bumble’ (possibly after the Dickens character), he was certainly a character himself. He was also a teacher who encouraged me to think.

bumblememorial — Reproduced from the Gateway Magazine

For sure, Bumble covered the official syllabus: wheeling out worthy but ultimately plain vanilla physics kit like air pucks, weights, and springs. But the most interesting discussions – the ones that have stuck with me – followed some of his more off-the-wall demonstrations.

For example, as an introduction to Newton’s Laws of Motion and the Gas Laws, Bumble kicked off one lesson by discharging a black powder pistol at the front of the classroom.

The lesson started in the usual way, Bumble making his signature ponderous walk to the laboratory’s front desk, eyes looking at the floor.

Entirely normal so far, except today he carried a long-barrelled revolver in his hand, one chamber of which he proceeded to load, methodically inserting pieces of cloth, then gunpowder, then cloth again (no bullet thankfully), before compressing the package with a small ram rod. We watched in stunned silence.

Gateway Grammar School Leicester — Gateway Grammar School, Leicester (Photo: Tim Jones)

Remember, this was all way before the Dunblane massacre or other school shootings, so I guess we felt a sense of intrigue rather than fear. This was Bumble anyhow – he did weird stuff. With a copper percussion cap in place, the gun was pointed in the general direction of the laboratory wall. And fired.

Within seconds of the most enormous bang echoing through the now smoke-filled laboratory, the Head of Physics, Mr Gill, closely followed by the Head of Chemistry, Mr Scottow, tumbled into the lab looking suitably alarmed. They’d clearly not been pre-briefed, and I still remember their expressions changing from shock to relief – and a glance of resignation between them – as the gunman stepped out of the smoke.

Stunts like Bumble’s Colt Navy revolver demo were attention grabbing and fun, but also an introduction to typically stretching discussions.

In this case, Bumble got us thinking about how long a gun barrel would have to be before the bullet changed direction and went back the other way. Imagine the thought processes needed for that. First off, there’s the non-intuitive realisation that a projectile in a tube can change direction if the pressure behind it falls sufficiently relative to the pressure in front of it – which theoretically can happen in a long enough gun barrel. Then there’s the skill of mentally extrapolating the familiar (relatively short barrel) to unfamiliar extremes (hugely long barrel). Thinking in abstraction and at scales beyond normal experience is useful, for scientists and non-scientists alike, in appreciating the scales relevant to fields as diverse as evolutionary biology and cosmology (and presumably also super-gun design).

Sections of Big Babylon at Fort Nelson, Portsmouth — Sections of the ‘Big Babylon’ Iraqi super-gun at the Royal Armouries, Fort Nelson, Portsmouth (Photo: Tim Jones)

Then comes the actual physics and chemistry: mechanics, thermodynamics, kinetics, friction, shock-wave propagation – not to mention the mathematical tools needed (I don’t remember if we came up with an actual quantitative answer, and suspect an analytical solution is only possible with major simplification. ) The follow-on lesson might cover ballistics: catching up with the bullet after it leaves the gun.

In a similar vein, my introduction to fluid flow through constrictions and Bernoulli’s principle took the form of the largest firework rocket I’d ever seen being launched from the school playground. In the lesson afterwards, we talked about rocket nozzle design. It turned out Bumble was licensed to make fireworks and had designed and cast his own ceramic nozzles. I still marvel that the thing came down ‘safely’ in the confines of the school yard.

So that’s how I remember Bumble. We might at times have got distracted from the strict letter of the course syllabus; but that’s the nature of real-world problems if they’re studied with sufficient rigor. And arguably as the antithesis of spoon-fed exam training, Bumble’s teaching style may not have suited all students. But personally, I love the attitude and approach to education John Page represented, and very much hope we haven’t seen the last of the Bumbles.

Books, Philosophy of Science, religion

Run Over From Behind By A Bus

January 28, 2009 Tim Jones 2 Comments

Run over from behind by a bus. That’s how physicist and skeptic Professor Robert Park wants to go when his time is up.

Professor Robert 'Bob' Park and Jo Marchant, NewScientist (Photo Sven Klinge) — Professor Robert 'Bob' Park and Jo Marchant, NewScientist at the Royal Institution this evening (Photo Sven Klinge)

I joined Bob Park at the Royal Institution this evening to hear him talk about his new book – ‘Superstition: belief in the age of science’.

To be candid, I’m not sure we got much of an insight into the book, and with a good showing of the ‘usual suspects’ (purely based on my memory of familiar faces – National Secular Society, British Humanist Association, Brights, and atheists of other flavours no doubt – not to mention scientists) in the audience, this was pretty much preaching to the converted. But it didn’t matter; Bob came across as a great guy – gentle and sharp at the same time; but most of all – human.

Following an introduction by Jo Marchant from New Scientist, Bob launched straight into the tale of how two catholic priests had given him the last rites, having stumbled across him, unconscious, under a fallen giant oak. He had photographs to prove it, and that pretty much set the tone for the evening.

We, Bob explained, as homo-sapiens, had only been around for 35,000 years when he was a lad; but today we were 160,000 years old. How come? There’s just more evidence today – we have the 160k skull. And as we’ve only been civilised (read post-hunter/gatherer) for 10,000 years of that, it’s fair to say our brains aren’t exactly wired to watch TV, never mind cancel the irritating offer of a wi-fi connection that repeatedly popped up throughout Bob’s PC presentation. Yet despite our brains being rigged to escape tigers and seek out elusive berry bushes, those same brains do a pretty good job of enjoying concertos, fine art, and solving complex differential equations. So we are somehow managing to get along with less than fit-for-purpose equipment. The secret now is to understand it (the brain) sufficiently so that we can explain and counter some of its more noisome excesses – like war for example.

But getting on to superstition now, Bob explained that as early as 585 BC, Thales of Melitus had understood how solar eclipses came about, if not how to predict them. And yet armed with this and doubtless many other supportive evidences for causation, we failed to declare the rational age of man, but rather continued, as we still do, to be superstitious.

Religion is a superstition, Bob maintained. And with 90% of the global population subscribing to some form of religion, doesn’t that make most of us superstitious? In Bob’s reckoning, that should be a concern.

There followed a variety of God-Delusionesque arguments around the illogical multiplicity of christian and other religions, what I thought was a somewhat confused description and use of the anthropic principle, and a potted history of John Templeton and the Templeton prize. The prize is given to individuals who do research that advances ‘spiritual discovery’ – and is big bucks; the last one was £820,000 to Michael Heller – a cosmologist and catholic priest. We learnt that Templeton’s only dictate on value of the prize was that it should always exceed whatever Nobel is offering. Bob shared the results of a Templeton funded study that must be seen as an own goal in some quarters: a controlled trial to assess the value of prayer on the recovery rates of coronary bypass patients. No effect was found. Interestingly, there was a negative impact on the health of a sub-group of patients who were told up-front they would be receiving prayers.

We moved on to a debunking of the ten commandments as the basis for our moral code, and an appeal instead to the Golden Rule of ‘do unto others as you would have them do unto you’ , which Bob put down to sensible evolutionary development rather than any biblical dictate. (As it happens, A.C.Grayling challenged the attractiveness of the Golden Rule earlier this week – but that’s another story….).

On the role of science, Bob believes that if there is one thing science has to offer over everything else, it’s openness – a reference to open data sharing and peer review.

So what are we left with? A questioner from the audience asked what we all wonder now and again – ‘does life have any meaning?’

But Bob had already answered the question in his slides. There is no plan, and if there’s no plan, there’s no purpose beyond that we give to life ourselves. But, as Bob continued, “that doesn’t mean that we can’t have good lives, enjoyable lives, and part of doing that is the way we treat other people”. There’s nothing more to say.

Also of Interest

Professor Robert Park interview at the Guardian HERE

education, News, Politics

Dumb Dee Dumb Dee Dumb

November 27, 2008 Tim Jones 2 Comments

Okay – in September I made this little joke about the dumbing down of education standards in the UK; a tension reliever from the continuous and often anecdotal murmur around grade stats going up while exam difficulty goes down.

But the issue is dead serious, as we are reminded today by the Royal Society of Chemistry‘s publication: A wake-up call for science education?

The report describes what happened recently when 1,300 of the nation’s brighter 16 year olds were tested on chemistry exam questions taken from over the last 50 years. The selected questions were of the more mathematical type that test a pupil’s ability to analyse and understand the fundamentals (I think the word ‘hard’ has become politically incorrect), as these are the more useful skills critics say have been fogged out in contemporary tests weighted towards memory.

The report is here, but in a nutshell: the authors say there has been a real and significant reduction in the difficulty of numerical or analytical type questions moving from the 1980’s to the 1990’s, which corresponds to a change in the exam system. UK readers will recognise this transition as the move from a combination of O-Levels (for the ‘brighter’ kids) and CSEs (for the others) to the single GCSE system. Things have stabilised a bit since the transition but, as the authors observe, there are fewer of the analytical type question in the new regime.

What’s more, the average test score on these more analytical questions was only 25%, causing the RSC to call for an urgent increase in this type of question in today’s papers.

Consistent with the authors’ thesis, pupils did least well on multi-step maths oriented problems where there was no prompting of what to do next. Even problems requiring basic maths presented difficulties. Part of the explanation -although its arguably nothing to be proud of – is that some of the more complex content is no longer taught at this level.

In a double whammy that will have the sociologists wetting themselves: the study found that pupils from independent schools (that means private, where typically middle class professional parents pay for their kids’ education ) did significantly better than the state educated pupils; also that boys did better than girls on the hard maths problems. The independent school result is put down in part to the tendency for these schools to teach science as separate subjects – physics, chemistry, biology – and to them having more specialised science teachers (of which there is a chronic national shortage). The authors consider the gender result ‘unusual’.

The final conclusion was that the current system doesn’t recognise the most exceptional students with a wider knowledge of the subject. I think that reflects a tendency to ask only questions the routine solution for which has been taught. Essentially, we have gone from a situation where the teacher gave you a knife with instructions how to carve, to one where the standard tool is a pastry cutter.

What the government will make of this latest grenade lobbed into the mire of UK education policy, we will have to wait and see.

The mainstream press on this story:

Also interesting:

This at Amused Cynicism.

And in Telegraph, June 14 2011, this on ‘Pupils Should Study Maths to 18‘

education, Physics

A-Levels Dumbing Down?

August 22, 2008 Tim Jones 2 Comments

There’s been some debate, but for sure, kids today get nothing like this question from my 1980 Physics paper (reproduced from memory, so there may be some insignificant errors).

Communicate Science