Archive for August, 2011

More Tim Hunkin Delights

August 31, 2011

The disgusting spectacle - Tim Hunkin's nose-picking machine

My old friend Marijke popped by the other day and reminded me of my student days in Brighton. I seem to remember that I was miserable most of the time and spent a lot of time thinking about physics. A coincidence? Perhaps. Anyway, with Brighton Pier in mind, she sent me a link to Tim Hunkin’s ‘Under the Pier’ Show of delightfully pointless machines. I was especially taken by his very early coin-operated machines which are especially crude, but somehow all the more magical for their simplicty. The video below shows several of the machines in action. Enjoy.

It seems amazing to me that such simple mechanisms can appear so shockingly magical. Perhaps that is a measure of my own ham-fistedness. But this basic awareness of how machines function – the basic engineering principles of reciprocating machines – seems to be something which is not taught anywhere. Perhaps it should be. I can imagine that the young Tim Hunkin learned a fanstastic amount in constructing them. I am in awe.

Cosmic Rays and Climate Change

August 31, 2011
Clouds - condensed water vapour - formed around tiny particles emitted from jet engines

Clouds - condensed water vapour - formed around tiny particles emitted from jet engines. Do cosmic rays give rise to similar 'contrails' that initiate the growth of clouds? Click for larger version

Cosmic rays are the particles (probably protons and not ‘rays’ at all) that are ejected from extreme events throughout our galaxy and beyond, that bombard the Earth from all directions. I discussed the basic phenomenology and the fantastic satellite recently launched to study them here. This article is about recent stories reporting a link between cosmic ray flux and the formation of water droplets in the atmosphere -clouds. Various articles describing the research can be found here:

Water molecules in the atmosphere have quite different effects depending on whether they are present as droplets – i.e. in a cloud – or as isolated molecules i.e. water vapour. In either form they have roughly similar effects on infra red light emitted by the Earth, but as we all know, clouds block visible light. The process by which droplets form has been the object of extensive study for more than a century – one of the major effects affecting the stability of droplets is called the Kelvin effect – and yet still we do not collectively understand how water vapour condenses in the atmosphere to form cloud droplets.

Of course we don’t know nothing, but even though the process of droplet formation is ubiquitous and important, the process is complex. The most significant fact is that even when there is more than enough water vapour in the air to form liquid droplets (so-called super-saturated air) they just don’t form by themselves. The chance of the water molecules clumping together by chance is infinitesimal. In practice, they need a ‘seed’ of some kind which allows water molecules to stick to it and which forms the ‘nucleus’ of a droplet which can grow.

CERN's Illustration of the process of droplet formation

CERN's Illustration of the process of droplet formation. Click for larger version. Courtesy CERN

The research from CERN (who can generate proton beams very easily) evaluated the effect of cosmic rays (i.e. fast protons) on the formation of the smallest droplets under different simulated atmospheric conditions and in the presence of different impurities. The results were complex, but can be divided into two parts:

  • When simulating the atmosphere at an altitude of 1 kilometer (3000 feet) where the temperature is approximately -10 °C (prime cloud forming temperature) , they were surprised to find that the rate of droplet formation was only one thousandth of  that observed in the real atmosphere, with or without the ‘cosmic ray’ bombardment.
  • When simulating the atmosphere at an altitude of 5 kilometers (16000 feet) where the temperature is approximately -25 °C – they found that ‘cosmic ray’ bombardment enhanced the rate of tiny droplet formation by a factor 10.
So the results indicate that droplet formation is even more complex than had been previously considered. But as many reports were at pains to point out, this is not really news because nobody ever thought they understood the process in the first place! And the droplets formed in the experiment were still too small to grow into cloud droplets and scatter light. Small droplets – perhaps 10 nanometers (50 atoms) do not necessarily grow to be large 1 micron size droplets typically found in clouds. Small droplets tend to evaporate faster than larger droplets and so when there is a mix of droplet sizes, small droplets tend to shrink and larger ones tend to grow – that is a manifestation of the Kelvin effect I mentioned above. However, no doubt we will eventually figure out how the process works.
However, I would like to single out the disingenuous Andrew Orlowski who writes for the Register for special castigation. Mr. Orlowski is an iconoclast who enjoys mocking the achievements of others. From reading his articles it is cleat that Mr. Orlowski objects to the idea that anthropogenic carbon dioxide emissions could conceivably be affecting the climate. So Mr Orlowski loves the idea that Cosmic Rays could be affecting the climate because they are ‘not our fault’ and we can just ignore the ‘liberal whingers’ calling for controls on energy usage. I don’t know why he so persistently rejects the idea that carbon dioxide emissions could be affecting the climate, because its a pretty sound idea with quite a lot of evidential and theoretical support. But every report he writes on the subject focuses on the things which people can’t explain and implies that the whole concept is thought up by a liberal/authortarian elite who – unlike the free-thinking Mr Orlowski – are unwilling to accept new data. However he never has the honesty to state what he actually thinks. So, for example,  he ends his article with a quote implying that the lead author thinks that previous climate studies are bunkum.
When Dr Kirkby first described the theory in 1998, he suggested cosmic rays “will probably be able to account for somewhere between a half and the whole of the increase in the Earth’s temperature that we have seen in the last century.”
But in fact the actual results of Dr. Kirkby’s work are completely inconclusive – telling us only what we knew before – that we don’t understand the basic process of cloud formation.
As new research fills in the gaps in our knowledge of the many complex factors that affect our climate, many media sources invite us to view the work in an essentially confrontational light. The question they ask is whether this report strengthens the views of climate change ‘skeptics’ or climate change ‘supportors'(!). Frequently one voice from each camp will be quoted to further this sense of antagonism. But in fact there will always remain many areas of uncertainty and we – you and I and scientists and governments – have to cope with this uncertainty. We have to make our Climate Models as best we can even though we don’t understand all the elements: We have to make decisions about energy usage and generation (Wind turbines, Electricity pylons, banned light bulbs) in the face of this uncertainty. These decisions  are difficult enough in themselves and we would all do better without this kind of tribal response to each new piece of information.

What I learned from the Financial Times

August 18, 2011

Regular readers will know that I am not really a Financial Times type of person, but my favourite cafe in Teddington is Cafe Mimmo. What? Well the food and service at Cafe Mimmo are excellent but they have a choice of just two newspapers: the Daily Mail or the Financial Times. Well, which would you choose?

And to my surprise I have learned that the Financial Times is full of something that many other news papers shy away from: News. Their web site is still open to all, but you do need to register.

So today I read about The Thawing Arctic (free but registration required). The article described the opportunities for business and trade that are likely to open up when [my italics] the summer melting of sea-ice extends further over the coming decades. There was no real discussion about the reality of climate change. They simply showed a graph…

Graph from financial Times

The summer minimum of sea-ice extent in millions of square kilometres versus year. Can you spot the trend? Graph from FT.com and data from NSIDC

…and let their numerate readers draw their own conclusions. This is much more dramatic that the headline graphs at the NSIDC news centre!

Back on August 12th I read,  Doubts raised over UK energy investments (free but registration required), an insightful article reviewing the financial situation of RWE and Eon, and the extent to which the financial returns available to these German companies would affect their choice to invest, or not, in the UK’s energy infrastructure. In my head I had previously imagined that somehow our government made these decisions, but that is not how Financial Times sees it.

And today I read that  Young Britons [are] opting to study sciences which is good news in my book. And I know it must be true because the story is also covered on the BBC who ask inanely:

Well as anyone who reads this blog knows, physics has always been cool, and it always will be.

All in all, my perspective on the Financial Times has changed. Although I don’t feel part of the Financial Times ‘tribe’, neither do I feel comfortable as part of any newspaper tribe. But the Financial Times seems to be the only newspaper which is still focussed on reporting ‘actual facts about things that matter’. It’s a novel idea for a newspaper: perhaps it will catch on.

Radioactivity the Musical

August 16, 2011
Screenshot from an application which turns radioactive decay into music.

Screenshot from an application which turns radioactive decay into music.

With the exception certain inspired individuals, radioactivity is rarely considered a subject for home experimentation. But my colleague Clare Lee just sent me a delightful link to a Flash application which turns radioactive decay into music. One selects up to 5 radioactive elements and the application turns their decays into music by scaling the energy of the gamma radiation to a musical tone.

Here is the ‘sound of’ Bromine-76 Tin-118 Bismuth-201 and a couple of other elements I forgot to make note of.

Now the music is – to my ears – delightfully non-repetitive, but what I like most about this application is its openness. It shows ALL the radioactive isotopes and immediately makes it clear that there is a world of these isotopes out there. And it shows information that most people won’t look at, but which you can look at if you want to. The application allows people to engage with a complex and frightening topic in an accessible and engaging way.

P.S. The music will drive you nuts after a while – about 10 minutes in my case 🙂

Clouds-updated

August 16, 2011
Sun Dog

Sun Dog viewed from Street Somerset. Click for larger version

During my recent holiday I became even more obsessed than usual with clouds. Somehow I found my focus repeatedly drifting upwards throughout the day. I found myself a witness to events of colossal beauty and subtlety. And often nobody else seemed to be noticing: perhaps I will have to join the Cloud Appreciation Society.

The picture above shows a ‘Sun dog‘ a rainbow-like pattern caused by hexagonal ice crystals in high cirrus clouds. Sun dogs appear about 22 ° on either side of the Sun – use the wiki page or Google to see more spectacular pictures. But actually I am quite proud of this picture not least because after Stephanie spotted it – I think I infected her with cloud-fever – I had the gumption to stop the car and take a picture. The picture below shows a close up:

Close up of the Sun Dog

Close up of the Sun Dog: Click for a larger version

But I also took literally hundreds of photographs of other non-specific but – to me at least – breathtakingly beautiful cloud scenes. The images show a complexity and a subtlety that astounds me. For instance this evening I walked out the front door and took this picture showing delicate linear cloud structures.

Above Church Road Teddington - Notice the filigree layers of cloud

Above Church Road Teddington - Notice the filigree layers of cloud: Click for larger version

Or this one – again taken this evening – showing cirrus clouds formed from contrails.

Cirrus clouds formed by aircraft contrails

Cirrus clouds formed by aircraft contrails: Click for larger version.

Seeing these celestial events reminds me of just what a breathtakingly beautiful world we are living in. And how it is possible to live most of a lifetime focussed on the ‘down to earth’ and to fail to notice even the grandest events taking place just above our eye-line.

UPDATE

I was e-mailed by the amazing Nick Day who suggested making a lifetime ‘I Spy’ list of celestial phenomena. Nick has seen all these:

  • Secondary rainbow
  • Supernumary rainbows
  • Polarisation of rainbow
  • Heidinger’s brushes
  • Rainbow at sunset (very red biased)
  • Alexander’s dark band
  • Moonbow
  • Corona
  • Irisation
  • 22-degree halo (sun)
  • 22-degree halo (moon)
  • Parhelic circle
  • Circumzenithal arc (quite common but oft-overlooked as overhead)
But has yet to see
  • 46-degree halo (moon)
  • Upper tangent arc (22-degree)
  • Liljequist parhelion
  • Aurora
  • 46-degree halo (sun)
  • Antihelic arcs of various descriptions
  • Parry arcs

Now I need to find out what all these are!

 

Holidays

August 4, 2011
Who needs holidays?

Who needs holidays?

As I write this, I am exhausted in every dimension in which exhaustion is possible. Physical, spiritual, emotional and mental. And I am off on holiday for  a few days. I have to admit that one part of me still thinks that holidays are for wimps. And one part of me is secretly thinking that a holiday is the just the time I need to get some work done. PhD Comics sums it up perfectly.

PhD Comics deals with holidays

PhD Comics deals with holidays: click for site link.

But in truth I know that I desperately need a break. I have actually been getting more and more run down in recent weeks, and consequently less and less able to blog. And so the list of topics about which I am bursting to blog has got longer and longer. When I get back I hope to have time to comment on

  • The completion of the Boltzmann project – the most accurate temperature measurement in the world. Ever!
  • NASA
  • The ‘Slow Science’ movement
and a whole shedload of climate and temperature related topics.
Anyway, for now, I hope you all have a lovely summer. And please don’t worry about whether it is abnormally hot. Or cold. Or dry. And I will try not worry about it either.

%d bloggers like this: