Category Archives: General

Astronomy, Interviews, Physics

An interview with Dr Paul G. Abel

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Paul

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.

He agreed to answer a few question I had.

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.

What was your first telescope?

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

Can you say a few words about your research? (GR, Hawking radiation and semi-classical gravity?)

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

About Paul

Paul is based in the Centre for Interdisciplinary Science in the department of Physics & Astronomy at the University of Leicester where he teaches Mathematics. His research is focused on black hole thermodynamics with Prof. Derek Raine.

You can find out more about Paul on his website and The Sky at Night website.

 Paul
Astronomy, General, Physics

Is the UK ready for a massive solar storm?

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A report published on the 07 February 2013 by the Royal Academy of Engineering examines this question.

 

sun
Image courtesy of NASA

UK must plan now to defend itself against extreme solar weather events

The UK should plan now to mitigate the effects of a rare but potentially serious solar superstorm, according to a report published today by the Royal Academy of Engineering. Although the UK is better prepared than many countries, there are areas where we need to improve our resilience.

http://www.raeng.org.uk/news/releases/shownews.htm?NewsID=825

The report Extreme space weather: impacts on engineered systems and infrastructure, was drawn up with the help of a diverse range of experts. This is the first report of its kind.

Areas highlighted

  • Electricity grid: six super grid transformers in England and Wales and a further seven grid transformers in Scotland could be damaged in the worse case scenario. The time to repair would be between weeks and months. However, local disruption is only expected to be hours as nodes have more than one transformer available.
  • Satellites: up to 10% of satellites could experience temporary outages lasting hours to days as a result of an extreme solar event.
  • Aircraft passenger and crew safety: increased cancer risk of 1 in 1,000 for each person exposed, although this must be considered in the context of the lifetime risk of cancer, which is about 30%.
  • Ground and avionic device technology: the estimate is that during a solar superstorm the avionic risk will be ~1,200 times higher than the quiescent background risk level and this could increase pilot workload.
  • Global navigation satellite systems (GNSS): a solar superstorm might render GNSS partially or completely inoperable for between one and three days.
  • Cellular and emergency communications: the UK’s commercial cellular communications networks are much more resilient to the effects of a solar superstorm than those deployed in a number of other countries since they are not reliant on GNSS timing. The emergency communications network is dependent on GNSS and mitigation strategies are already in place.
  • High frequency (HF) communications: HF communications is likely to be rendered inoperable for several days during a solar superstorm.
  • Mobile satellite communications: L-band (~1.5GHz) satellite
    communications might be unavailable, or provide a poor quality
    of service, for between one and three days.
  • Terrestrial broadcasting: vulnerable to secondary effects,
    such as loss of power and GNSS timing.

The take home message

Our message is: Don’t panic, but do prepare – a solar superstorm will happen one day and we need to be ready for it. Many steps have already been taken to minimise the impact of solar superstorms on current technology and by following the recommendations in the report we anticipate that the UK can further minimise the impact.

Professor Paul Cannon FREng, Chair of the Academy’s working group on extreme solar weather

Links
UK must plan now to defend itself against extreme solar weather events

Extreme space weather: impacts on engineered systems and infrastructure (opens pdf)

General, Physics

The Higgs Prize

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An annual prize, named after Professor Peter Higgs, has been launched by Scotland’s First Minister Alex Salmond.

The prize offers outstanding young physicists the chance to win a trip to CERN and see the cutting-edge of international physics.

 higgs
Mathematisches Institut Oberwolfach (MFO)

We’re delighted that the Government intends to introduce this prize. With £8.5 billion of the Scottish economy created by physics-based businesses, the prize is recognition of the vital importance of the subject.

Professor Sir Peter Knight, President of IOP

Link
Higgs Prize to recognise outstanding young physicists in Scotland IOP News

General

Proposed tax on sugary soft drinks

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60 organisations, including the Royal College of Paediatrics and Child Healthare are calling for a 20p-per-litre tax on soft drinks to be included in this year’s Budget. This could raise up to £1bn a year in duty, which could be used to fund free fruit and healthy meals in schools. The tax could drive people towards no added sugar drinks.

pop
Image courtesy of Simon Cousins

A 330-millilitre can of sugary pop typically contains something like 35g of sugar, that is nine lumps. There are about 4 calories per gram of sugar, so that is 140 calories per can of sugary pop.

The Guideline Daily Amount (GDA) for sugar is 90 grams. That is less than three cans of sugary pop, which is in “old money” is a pint and a half.

Link
Call for soft drink sugar tax in Budget BBC News

Education, General, Physics

How quantum physics democratised music, a lecture by lecture by Professor Sir Michael Berry

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How quantum physics democratised music

Date: Monday 4th March 2013
Venue: Institute of Physics, 76 Portland Place, London, W1B 1NT
Time: 18.30 (registration from 18.00)

sir berry
Professor Sir Michael Berry

“Connections between physics, technological invention, and aspects of human life that seem far from science, are both unexpected and unexpectedly common. And rather than flowing one way – from physics to gadgets – the connections form an intricate and subtle web, linking all aspects of human culture in a way that eludes our convenient intellectual categories.”

The lecture is free to attend and is open to all, physicists and non-physicists alike. You need to register at http://publiclectures2013.iop.org

The poster for the lecture can be found here (opens a PDF).

Note
The original message is from
Angela Townsend
Development Administration & HE Curriculum Support
Institute of Physics

Education, General, General Mathematics

2013 Mathematical Art Exhibition Awards

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The Mathematical Art Exhibition Award “for aesthetically pleasing works that combine mathematics and art” was established in 2008 through an endowment provided to the American Mathematical Society by an anonymous donor who wishes to acknowledge those whose works demonstrate the beauty and elegance of mathematics expressed in a visual art form. The awards are US$400 for Best photograph, painting, or print; $400 for Best textile, sculpture, or other medium; and $200 for Honorable Mention. The Mathematical Art Exhibition of juried works in various media is held at the annual Joint Mathematics Meetings of the American Mathematical Society (AMS) and Mathematical Association of America (MAA).

http://www.ams.org/news?news_id=1753

Here are the winners for this year.

circles
“Bended Circle Limit III,” by Vladimir Bulatov was awarded Best photograph, painting, or print.

boxes
“Inlaid Wooden Boxes of Makoto Nakamura’s Tessellations,” by Kevin Lee, Normandale Community College, Saint Paul, MN, was awarded Best textile, sculpture, or other medium.

necklace
“Tessellation Evolution,” by Susan Goldstine, St. Mary’s College of Maryland, received Honorable Mention.

For larger pictures and further details follow the link below.

Link
2013 Mathematical Art Exhibition Awards (Tuesday January 15th 2013 )

General, Research work

Odd Jacobi manifolds and Loday-Poisson brackets

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I have a new preprint posted on the arXiv; “Odd Jacobi manifolds and Loday-Poisson brackets”. It is a continuation of my studies of odd Jacobi structures on supermanifolds.

Odd Jacobi manifolds and Loday-Poisson brackets
Andrew James Bruce
(Submitted on 21 Jan 2013)
arXiv:1301.4799 [math-ph]

In this paper we construct a non-skewsymmetric version of a Poisson bracket on the algebra of smooth functions on an odd Jacobi supermanifold. We refer to such Poisson-like brackets as Loday-Poisson brackets. We examine the relations between the Hamiltonian vector fields with respect to both the odd Jacobi structure and the Loday-Poisson structure. Interestingly, these relations are identical to the Cartan identities.

———————————————————–

There are some subtle differences between even and odd structures and this preprint discusses one such difference. In particular, one can use the derived bracket formalism [3] to construct a Poisson-like bracket on the supermanifold mod the skewsymmetry.

The Loday-Poisson bracket

An odd Jacobi manifold is a supermanifold equipped with an almost Schouten structure and a homological vector field that satisfy some relations. The relations are not important for this discussion. See [1] for details.

From this data one can construct an odd Jacobi bracket, that is an odd version of a Poisson bracket with a modified Leibniz rule. The adjoint operator is a first order differential operator as opposed to a vector field.

Furthermore, by using the fact that the homological vector field is a Jacobi vector, that is it a “derivation over the odd Jacobi bracket” one can construct an even bracket using the derived bracket construction.

The resulting bracket satisfies a version of the Jacobi identity, but is not skewsymmetric. It also satisfies the Leibniz rule (from the left). Lie brackets mod the skewsymmetry were first examined by Loday, and so I call Loday brackets + Leibniz rule “Loday-Poisson brackets”.

This is in contrast to classical manifolds, where due to the work of Grabowski and Marmo [2], we know that the Jacobi identity and the Leibniz rule force the skewsymmetry. On supermanifolds we have nilpotent functions and this invalidates the assumptions of Grabowski and Marmo.

Furthermore, on an even Jacobi supermanifold there is no canonical choice of homological vector field to use, if one exists at all.

In the preprint I present several relations between the Hamiltonian vector fields with respect to the initial odd Jacobi structure and the derived Loday-Poisson structure. I note the similarity with the standard Cartan calculus.

The derived product

I have discussed the derived product on a Q-manifold here. As odd Jacobi manifolds come with a homological vector field as part of the structure, they are also Q-manifolds and have a derived product.

Interestingly, the Loday-Poisson bracket not only satisfies the Leibniz rule (from the left) for the usual product of functions on a supermanifold, but also the derived product.

That is we have a kind on non-skewsymmetric bracket that satisfies a version of the Jacobi identity and a version of the Leibniz rule over a Grassmann odd noncommutative form of multiplication. To my knowledge, these kinds of noncommutative Poisson algebras have not been studied.

References
[1] Andrew James Bruce. Odd Jacobi manifolds: general theory and applications to generalised Lie algebroids. Extracta Math. 27(1) (2012), 91-123

[2] J. Grabowski and G. Marmo. Non-antisymmetric versions of Nambu-Poisson and Lie algebroid brackets. J. Phys. A: Math. Gen. 34 (2001), 3803–3809.

[3] Yvette Kosmann–Schwarzbach. Derived brackets. Lett. Math. Phys., 69 (2004), 61-87.