## Archive for the ‘Astronomy’ Category

### Large meteor over South Wales

Thursday, May 9th, 2013

A meteor was spotted traveling across the night sky by people across many parts of the UK including Cornwall, Hampshire, Lancashire, Worcestershire and South Wales.

Of course, I missed it…

Large meteor spotted in night sky in England and Wales, BBC News

### Lee Smolin in London

Monday, April 22nd, 2013

Lee Smolin is to mark the publication of his new book, “Time Reborn: From the Crisis of Physics to the Future of the Universe” [1] by giving a talk in London, hosted by the Institute of Physics. The talk will he held at the Institute’s offices in London from 6pm, 22 May 2013.

 In his new book Smolin suggests the laws of physics are not fixed, but rather they evolve in time. This hypothesis maybe a way of resolving some of the open questions in physics, such as the nature of the quantum mechanics and its unification with space-time and cosmology.

A poster for the talk can be downloaded from here (opens PDF)

If interested in attending, you need to register online here.

 Lee Smolin is a theoretical physicist who has been since 2001 a founding and senior faculty member at Perimeter Institute for Theoretical Physics. His main contributions have been so far to the quantum theory of gravity, to which he has been a co-inventor and major contributor to two major directions, loop quantum gravity and deformed special relativity Read more at Smolin’s homepage here.

Reference
[1]Lee Smolin, TIME REBORN: From The Crisis in Physics to the Future of the Universe, April 23, 2013

### Einstein’s spooky action at a distance in space.

Wednesday, April 10th, 2013

The International Space Station, image courtesy of NASA

Scheidl, Wille and Ursin [1] have proposed using the International Space Station to test the limits of spooky action at a distance. These experiments could help develop global quantum communication systems.

Part of their plans include a Bell test experiment which probes the theoretical contradiction between quantum mechanics and classical physics. A pair of entangled photons would be generated on the Earth. One of these would then be sent to a detector aboard the International Space Station, while the other photon would be measured locally on the ground for comparison.

According to quantum physics, entanglement is independent of distance. Our proposed Bell-type experiment will show that particles are entangled, over large distances — around 500 km — for the very first time in an experiment…

Professor Ursin

It is also not really known if gravity plays any role in quantum entanglement. These experiments would be the first to really probe the potential effects of gravity.

References
[1] T Scheidl, E Wille and R Ursin, Quantum optics experiments using the International Space Station: a proposal, 2013, New J. Phys. 15 043008 (online here)

“Spooky action at a distance” aboard the ISS IOP News

### Newton lecture 2012: Martin Rees

Wednesday, April 10th, 2013
 The Newton lecture 2012 is now available to watch on the IOP website. Professor Martin Rees, the winner of the 2012 Newton medal, gave the lecture entitled Form Mars to the multiverse.

### Planck backs the ideas of an inflationary epoch

Friday, March 22nd, 2013

The Planck space telescope has produced the most detailed picture yet of the cosmic microwave background radiation (CMBR) [1].

NASA/JPL-Caltech/ESA

Detailed analysis supports the idea that $10^{-32}s$, or there about, the Universe went into a phase of rapid expansion known as inflation. This rapid growth of the Universe explains why the Universe is so big and nearly flat, as well as providing an explanation as to why the CMBR temperature is uniform. More than this, the small anisotropies in the temperature are well explained by tiny quantum fluctuations in the early Universe that get blown-up by the inflationary phase. These small differences seeded the large scale structure of the Universe we see today.

ESA/PLANCK COLLABORATION

Hubble constant
From Planck we also know that the Universe is expanding today at a slightly lower rate than previous estimates have given. The Hubble constant is now revised to 67.3 kilometers per second per megaparsec, which makes the Universe about 80 million years older than WMAP data suggests.

Make up of the Universe
The new data has meant a revision in the proportions of “stuff” in the Universe:

Dark Energy – 68.3%
Dark Matter – 26.8%
Normal matter < 5%

Oddities in the CMBR
WMAP found and Planck has now confirmed, that there is an asymmetry between opposite hemispheres of the sky in the anisotropies of the CMBR. This suggests the rather unnatural possibility that there is a preferred direction in the cosmos. This does rule out some specific models of inflation, but the generic idea is still sound.

The cold spot

The CMBR cold spot is another strange feature that Planck has confirmed. This colder region of the CMBR, 70 µK colder that the average 2.7K was first discovered by WMAP. It is thought a possibility that the cold spot and the asymmetry maybe connected.

Planck telescope peers into the primordial Universe, Nature, 21 March 2013

References
[1] Planck Collaboration, Planck 2013 results. I. Overview of products and results, submitted to Astronomy & Astrophysics, 2013.

### Prof. Martin Rees interviewed by IOP

Friday, March 15th, 2013

Prof. Martin Rees, winner of the 2012 Isaac Newton medal for his “outstanding contributions to relativistic astrophysics and cosmology”, has given an interview for the Institute of Physics. Follow the link below to watch the video.

### National Science and Engineering Week 2013

Thursday, March 7th, 2013

National Science and Engineering Week 2013 in the UK is running from the 15th to the 24th March. The events are coordinated by the British Science Association, though it is other organisations and community groups that actualy run the events and activities. The theme this year is invention and discovery.

For those of you in the UK, follow the link below and get involved in something near you.

National Science & Engineering Week shines the spotlight each March on how the sciences, technology, engineering and maths relate to our everyday lives, and helps to inspire the next generation of scientists and engineers with fun and participative events and activities.

Last year’s National Science and Engineering Week consisted of something like 500 events and activities from thousands of different organisers. More than 2 million people at schools, museums, universities, shopping centres, cafes etc. attended the various events.

Engineering Education Scheme Wales Awards & Presentation Day 2013
Wednesday, March 20, 2013 – 10:00 to 16:00
Celtic Manor Resort, Newport

The British Science Association
The British Science Association is a registered charity that exists works to advance public understanding, accessibility and the accountability of the sciences and engineering in the UK.

Engineering Education Scheme Wales Awards & Presentation Day 2013

### Take that Einstein…I mean, take that cranks!

Sunday, February 17th, 2013

… all of the available constraints on the validity of the founding principles of SR and GR have so far failed to crack any faults in these century-old theories, which thus remains the standard against all competitors so far.

Orfeu Bertolami and Jorge Páramos in [1]

I like the above quote. It is rather an inescapable that Einsteinian relativity works well.

Objections to relativity
I posted, about a year ago now, on the experimental status of Einsteinian relativity, you can read it here.

Whatever the faults with general and special relativity, philosophical or real, today we have no other theory of space, time and gravity that has the experimental success of Einstein’s theories.

Most of the “objections” to special and general relativity stem from not really understanding what the theory is saying, or indeed what a theory really is. Analogies and popular science accounts seem to also be the root of a lot of misunderstandings.

Other good references on the experimental status of relativity include [2,3,4].

The failings of general relativity
It is not true that anyone really expects general relativity to be the final say on gravity. The issues as they stand include:

• The existence of singularities
• The cosmological constant problem
• Incompatibility with standard quantisation methods
• Dark energy

All these problems only really tell us that general relativity is not a complete theory in the sense that there is physics that it cannot accurately explain.  This is not grounds for dismissing general relativity as it is a very accurate model of gravity for a huge range of phenomena.

References
[1] Orfeu Bertolami and Jorge Páramos, The experimental status of Special and General Relativity, arXiv:1212.2177v1 [gr-qc]

[2]Orfeu Bertolami, Jorge Páramos, and Slava G. Turyshev. General theory of relativity: Will it survive the next decade? In Lasers, Clocks, and Drag-Free: Technologies for Future Exploration in Space and Tests of Gravity. Springer Verlag, 2006; gr-qc/0602016.

[3]Clifford M. Will. The confrontation between general relativity and experiment. Living Reviews in Relativity, 9(3), 2006.

[4]Will, Clifford M. (2006). Was Einstein Right? Testing Relativity at the Centenary. Annalen der Physik 15: 19–33

### Professor Dame Jocelyn Bell Burnell is one of the UK’s most powerful women.

Wednesday, February 13th, 2013

BBC Radio 4’s Woman’s Hour announced its list of the 100 most powerful women in the UK on Tuesday 12 February. The list included a number of other high profile scientists and engineers including Professor Bell Burnell.

Prof S Jocelyn Bell Burnell

We’re delighted to see Jocelyn, joined by a range of extraordinary female scientists and engineers, in this inaugural power list. Jocelyn’s contribution to research and as an inspiring figurehead and role model in the fight to overcome gender disparities in science make her a very deserving choice.

Professor Sir Peter Knight, President of IOP

Pulsars
Prof. Bell Burnell is credited with the discovery of the first radio pulsar (PSR B1919+21), while a postgraduate student under the supervision of Antony Hewish. Interestingly, the regular radio signal detected in 1967 that lead to the discovery of the first pulsar was given the designation LGM-1. That stands for “little green men”. The signal was so regular it was initially thought it could not be natural!

We did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds and we had no proof that it was an entirely natural radio emission. It is an interesting problem – if one thinks one may have detected life elsewhere in the universe how does one announce the results responsibly? Who does one tell first?

S. Jocelyn Bell Burnell. “Little Green Men, White Dwarfs or Pulsars?”. Annals of the New York Academy of Science, vol. 302, pages 685-689, Dec., 1977

It took the powerful mind of Fred Hoyle to realise that these signals came from neutron stars with strong magnetic fields.

Controversially, she was not a co-recipient of the 1974 Nobel Prize for Physics along side Antony Hewish and Martin Ryle, which was awarded for pulsar research.

Prof. Bell Burnell was president of the Royal Astronomical Society from 2002-2004 and president of the Institute of Physics from October 2008 until October 2010. She was also interim president following the death of her successor, Marshall Stoneham, in early 2011.

Past-president makes Woman’s Hour power list IOP News

The power list BBC Radio 4’s Woman’s Hour

### An interview with Dr Paul G. Abel

Friday, February 8th, 2013
 Dr Paul G. Abel is a British astronomer, mathematician and writer. He is now a regular face on the BBC’s The Sky at Night. Paul has written for many popular astronomy magazines promoting amateur astronomy and the science that amateurs can contribute to the field.

Science and Popularisation

What first got you involved in science, and in particular astronomy?

It was a combination of things actually. In 1989 Voyager 2 got to Neptune and sent back some wonderful pictures of this blue planet. This was also the first time I encountered Patrick Moore. He was obviously different from the toher scientists who spoke- his words conveyed such a passion for astronomy, and even with the results of the great Voyager 2 spacecraft, he emphasized the good work amateurs could do. So, I started reading his books and watching The Sky at Night. I got a small telescope and I remember the first thing I saw was Saturn. The sight of this magnificent alien world, with its surreal looking ring system and family of moons hooked me. From that moment onwards, I knew I would never do anything else but astronomy.

My first ‘proper’ telescope was a wonderful Russian thing- a Tal-1 Mizar 4.5 inch Newtonian reflector on equatorial mount. Looking back on it now, it was like being given the keys to your first low powered spaceship. I observed all of the planets I could, and sought out many of the objects on the Messier catalogue. I also made my own star charts and became reasonably familiar with the constellations which populate the UK night skies.

How did you get involved in the BBC’s Sky at Night?

Quite by chance- indeed I had no plans to do tv at all! It was all Patrick’s idea. He had asked if I had wanted to do one (I had been in correspondence with him since the age of 12). But I had declined. So he organized one without me I was going to be in it- until I arrived on the day!!! It was the event a few years ago now when four of Saturn’s moons passed in front of the planet. Both Patrick and our producer Jane fletcher thought I was OK and I joined the team as a co-presenter.

What is your favorite astronomical object, and why?

It’s what ever I’m looking at- yes I am that fickle! To be honest, it is only the Moon and planets which interest me as an amateur astronomer. I am a visual observer so I don’t image, I make coloured drawings of what I have observed. Indeed, it was the art of visual observing, and keeping good astronomical log books which Patrick taught me to do, and he himself was taught this by the wonderful astronomer W. S Franks. I do wonder how many hours I have spent at the eyepiece of a telescope, and I have quite a few log books now with drawings and observations of the Moon and planets.

Which medium do you think is the most effective at popularising science?

I don’t think it is the medium, I think it is the person doing the communicating. If you have a passion for astronomy and science, you can convey it anyway open to you!

What, in your opinion, should be the ultimate goal of science popularisation?

I think it should be two-fold. First it should re-familiarise people with why science is a wonderful thing, why objective rational thought and the scientific method has improved all of our lives. Not only do we have it to thank for giving us the technology of our civilization but it has allowed to tame the dark, we no longer burn witches for example! As Carl Sagan once rightly pointed out, science is the candle in the darkness. The second thing it can do is encourage people who want to make a contribution in their own way. Amateur astronomy is a thriving subject in this country, and I would hope that people feel compelled to do more than just point there telescope at some of the wonderful objects in the Universe, they might start to make their own systematic observations and contribute to the wonderful scientific work amateur organizations like the British Astronomical Association have been doing for over a 100 years. In short: get involved!!!!

Research

Indeed. My research is concerned with using a quantum Langevin approach to Hawking radiation. I am also interested in the Unruh effect. The Davies-Fulling-Unruh effect (to give it its fall name!) is the idea that constantly accelerating observers in Minkowski (flat) spacetime see a thermal spectrum of particle in an area of spacetime called the Rindler wedge. I think it is clear that recent work has showed that although energy from say a harmonic oscillator on such a trajectory would radiate, that energy would be absorbed by the field so overall there is no energy flux. This has applications to Hawking radiation.

Which one of your papers are you most proud of, and why?

I believe I have yet to write this paper! Who wants their greatest work to be behind them?!

In your opinion, what is the biggest stumbling block to finding a quantum theory of gravity?

Well perhaps the greatest stumbling block is ourselves. At present there are two approaches, one is the approach adopted by String theory which is, in essence to describe the basic particles of matter in terms of 1D energy filaments- strings. A big part of String theory is super-symmetry the evidence for which is in-direct. In order for a theory to have physical significance it must be testable. Alas many of the predictions for string theory require energies far greater than human being can produce here at this time.

The other candidate is Loop Quantum Gravity which seeks to use general relativity and quantum mechanics but again this approach has many problems and at the time of writing, LQG is not testable either.

For me personally, I don’t think either String Theory or Loop Quantum Gravity is radical enough. They doesn’t feel like they are presenting a radical shift in fundamental philosophy what we got when Newtonian gravity moved over for General Relativity. Of course it may be that the answer to the problem of a quantum description of gravity does not need such a profound rethink, but until either of these theories can provide experimental evidence to support their claims, I would regard them as nice excursions into mathematics. Physics, should be testable. It may be the case that it takes another ‘Einstein’ to shake up our views of space, time and matter and point us in a new direction