Now in its fourth year the Astronomy Photographer of the year competition winners for 2012 have been announced. The competition is run by The Royal Observatory, Greenwich in partnership with The Sky at Night magazine.
Pleiades Cluster by Jacob von Chorus (Canada), aged 15
I am quiet impressed with the under-16s winner Jacob von Chorus and his picture of the Pleiades Cluster.
I congratulate all the winners and urge everyone to view the pictures, which can be found here.
Links
Galileo Galilei was an Italian physicist, mathematician, astronomer, and philosopher who shaped modern scientific thinking. Galileo has been called the “the Father of Modern Science”.
Galileo’s wider “claim to fame” was his persecution at the hands of the then very powerful and politically influential Catholic Church. (We seem to get reminded of this quite a lot be disgruntled “amateurs”. )
An educational film dramatising the life of Galileo and his scientific discoveries can be found on the IOP website here.
The chapters are as follows
2:15 – Scene 1: Of Mice and Pendulums. Pisa Cathedral, Italy, 1583
7:50 – Scene 2: The Feather and the Weights. The Leaning Tower of Pisa, 1590
14:55 – Scene 3: The Spyglass. Optician’s Shop, Holland, 1608
21:15 – Scene 4: Galileo’s Star Party. Galileo’s Garden, Padua, Italy. 1609
36:10 – Scene 5: A Visit From the Pope. Galileo’s Garden, Florence, Italy, 1633
51:00 – Epilogue: The Space Probes. A student’s room, Lancaster University, 2009
It appears that a similar situation to the English GCSE has occurred in the Science GCSE. The grade boundaries were changed part-way through the year.
Apparently, year 10 pupils who sat the AQA board chemistry and biology modules this January needed up to 11 more marks to get an A* grade than those who sat the same modules in June.
Link
A team of researchers at Cambridge used liquid crystals in place of standard printer ink to print tiny dots on a surface covered with a special coating [1]. When the coating dried, the dots on the surface become lasers.
This is the first time that anyone has been able to print lasers and opens up a host of potential applications. Including various displays, lighting effects and motion sensors.
Image courtesy of the University of Cambridge.
Lasers
A laser is a device that emits light of a high degree of spatial and temporal coherence (i.e. “very uniform”) via a process of optical amplification based on the stimulated emission. This process was predicted by Einstein and is a direct consequence of quantum mechanics. Laser is an acronym for “light amplification by stimulated emission of radiation”.
Stimulated Emission
One of the important consequences of quantum mechanics is that electrons surrounding an atom of molecule can only sit in specified discrete energy levels. Electrons can jump up to excited states (if they are free) by the absorption of a photon. Similarly, an electron in an excited state can fall back into a lower energy state by the emission of photon. Note that such transitions are necessarily between the discrete energy levels. This leads to the phenomena of spectral lines.
An electron in an excited state will not sit there forever. An electron in an excited state will decay to a lower energy state, which is not occupied by another electron, after some time which characterises that particular transition. This is known as “spontaneous emission”. The phase associated with the photon that is emitted is random and the radiation is emitted in all directions. For example, florescence and thermal emission are of this kind.
An external photon with the energy associated with a transition can affect the quantum mechanical state of electrons. In particular the probability of the electron making a transition is greatly increased. The rate of transitions between two states is can be much greater than that due to spontaneous emission. A transition from a higher to a lower energy state, produces two photon; this is the process of “stimulated emission”.
The key point is that the photons generated by stimulated emission is almost the same as the input photons in terms of wavelength, phase, and polarisation. This gives laser light its rather uniform properties, including direction of emission.
References
[1] D. J. Gardiner , W.-K. Hsiao , S. M. Morris , P. J. W. Hands , T. D. Wilkinson , I. M. Hutchings and H. J. Coles. Printed photonic arrays from self-organized chiral nematic liquid crystals. Soft Matter, 2012, Advance Article DOI: 10.1039/C2SM26479J
When people tell me that Mathematica isn’t fast enough, I usually ask to see the offending code and often find that the problem isn’t a lack in Mathematica‘s performance, but sub-optimal use of Mathematica. I thought I would share the list of things that I look for first when trying to optimize Mathematica code.
I have found these tips very useful.
The mere formulation of a problem is far more essential than its solution, which may be merely a matter of mathematical or experimental skills. To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks real advances in science.
I strongly agree with this. Quite often a problem is not important in itself, but rather the tools developed in its solution are pivotal to science.
Mathematics
Great mathematical examples here are lemmas that go on to be more important than their original application.
One great example that springs to mind is the Poincaré lemma: “All closed differential k-forms (k > 0) are locally exact”.
Plenty of other examples exist. The point is, although initially the lemmas seem very technical and narrow, they turn out to be of independent interest and very powerful in unexpected ways.
Particle physics and space science
Possibly a better example is that of spin-off technologies from particle physics and space exploration. For example experimental particle physics has brought us, sterilisation methods, non-destructive testing, cancer treatments, medical imaging techniques and so on.
Wider society and culture
Something that should not be overlooked is the impact of science and mathematics on culture. Advances in mathematics and science can change our outlook on the Universe and shape what we are. To quote Robert R. Wilson, who was the first director of Fermilab, when asked to justify the cost of the experiments to the Congressional Joint Committee on Atomic Energy, said
It has only to do with the respect with which we regard one another, the dignity of men, our love of culture. It has to do with: Are we good painters, good sculptors, great poets? I mean all the things we really venerate in our country and are patriotic about. It has nothing to do directly with defending our country except to make it worth defending.
Simon Singh has displayed on his website some mathematics cartoons. All are quite funny.
You can find them here.
A new study published today (Friday 14 September) in Environmental Research Letters, compares the latest seasonal forecast system to the one previously used [1]. The conclusion is that the latest models can better warn the UK of extreme winter weather conditions.
The winter of 2009–2010 was known as “The Big Freeze” here in the UK and was part of the severe winter weather in Europe. It was the coldest winter since 1978-79, with a mean temperature of 1.5 °C.
Picture of the UK taken on the 7th January 2010.
The new model takes into account sudden stratospheric warmings (SSWs), which are known to be responsible for cold surface conditions. SSWs happen when the polar vortex of westerly (eastward) winds in the winter hemisphere suddenly slows down or even reverses direction, accompanied by a rise of stratospheric temperature by several tens of kelvins.
References
[1] D R Fereday, A Maidens, A Arribas, A A Scaife and J R Knight. Seasonal forecasts of northern hemisphere winter 2009/10. (2012) Environ. Res. Lett. 7 034031
Links
Apparently about a quarter the UK Russell Group Universities still have undergraduate student places, as the new tuition fees regime comes in.
…it is likely fewer people will go to university this year.
Higher Education Minister David Willetts
UCAS say that there are more than 26,000 university courses with empty places, compared with 20,000 at this time last year.
Links
A team at IBM in Zurich have used a variant of a technique called atomic force microscopy to produce single-molecule images [1]. These are so detailed that the type of atomic bonds can be seen.
Here are some of those pictures. They belong to IBM and can be found on the BBC website.
The bonds at centre are shorter than those at the edges, as they involve more electrons.
The same team imaged olympicene.
References
[1] Gross et al. Bond-Order Discrimination by Atomic Force Microscopy. Science 14 September 2012:
Vol. 337 no. 6100 pp. 1326-1329
