Archive for Physics

Controlled Nuclear Fusion: Forget about it

Posted in The Universe and Stuff with tags , , , on October 20, 2014 by telescoper

telescoper:

You’ve probably heard that Lockheed Martin has generated a lot of excitement with a recent announcement about a “breakthrough” in nuclear fusion technology. Here’s a pessimistic post from last year. I wonder if it will be proved wrong?

Originally posted on Protons for Breakfast Blog:

Man or woman doing a technical thing with a thingy told with laser induced nuclear fusion.

Man or woman adjusting the ‘target positioner’ (I think) within the target chamber of the US Lawrence Livermore National Laboratory.

The future is very difficult to predict. But I am prepared to put on record my belief that controlled nuclear fusion as a source of power on Earth will never be achieved.

This is not something I want to believe. And the intermittent drip of news stories about ‘progress‘ and ‘breakthroughs‘ might make one think that the technique would eventually yield to humanity’s collective ingenuity.

But  in fact that just isn’t going to happen. Let me explain just some of the problems and you can judge for yourself whether you think it will ever work.

One option for controlled fusion is called Inertial Fusion Energy, and the centre of research is the US National Ignition Facility. Here the most powerful laser…

View original 601 more words

A Problem of Wires on the Rails

Posted in Cute Problems with tags , , , on October 5, 2014 by telescoper

It’s been a long time since I posted a cute physics problem so here’s one about magnetism for your edification and/or amusement.

Two long wires are laid flat on a pair of parallel rails perpendicular to the wires. The spacing d between the rails is large compared with x, the distance between the wires. Both wires and rails are made of material which has a resistance ρ per unit length. A magnetic flux density B is applied perpendicular to the rectangle formed by the rails and the wires. One wire is moved along the rails with uniform speed v while the other is held stationary. Derive a formula to show how the force on the stationary wire varies with x and use it to show that the force vanishes for a value of x approximately equal to μ0v/4πρ.

Give a physical interpretation of this result.

HINT: Think about the current induced in the wires…

 

Newcastle Joins the Resurgence of UK Physics

Posted in Education, Science Politics, The Universe and Stuff with tags , , , on August 17, 2014 by telescoper

I’ve posted a couple of times about how Physics seems to undergoing a considerable resurgence in popularity at undergraduate level across the United Kingdom, with e.g. Lincoln University setting up a new programme. Now there’s further evidence in that Newcastle University has now decided to re-open its Physics course for 2015 entry.

The University of Newcastle had an undergraduate course in Physics until 2004 when it decided to close it down, apparently owing to lack of demand. They did carry on doing some physics research (in nanoscience, biophysics, optics and astronomy) but not within a standalone physics department. The mid-2000s were tough for UK physics,  and many departments were on the brink at that time. Reading, for example, closed its Physics department in 2006; there is talk that they might be starting again too.

The background to the Newcastle decision is that admissions to physics departments across the country are growing at a healthy rate, a fact that could not have been imagined just ten years ago. Times were tough here at Sussex until relatively recently, but now we’re expanding on the back of increased student numbers and research successes. Indeed having just been through a very busy clearing and confirmation period at Sussex University, it is notable that its the science Schools that have generally done best.  Sussex has traditionally been viewed as basically a Liberal Arts College with some science departments; over 70% of the students here at present are not studying science subjects. With Mathematics this year overtaking English as the most popular A-level choice, this may well change the complexion of Sussex University relatively rapidly.

I’ve always felt that it’s a scandal that there are only around 40 UK “universities” with physics departments Call me old-fashioned, but I think a university without a physics department is not a university at all; it’s particularly strange that a Russell Group university such as Newcastle should not offer a physics degree. I believe in the value of physics for its own sake as well as for the numerous wider benefits it offers society in terms of new technologies and skills. Although the opening of a new physics department will create more competition for the rest of us, I think it’s a very good thing for the subject and for the Higher Education sector general.

That said, it won’t be an easy task to restart an undergraduate physics programme in Newcastle, especially if it is intended to have as large an intake as most successful existing departments (i.e. well over 100 each year). Students will be applying in late 2014 or early 2015 for entry in September 2015. The problem is that the new course won’t figure in any of the league tables on which most potential students based their choice of university. They won’t have an NSS score either. Also their courses  will probably need some time before it can be accredited by the Institute of Physics (as most UK physics courses are).

There’s a lot of ground to make up, and my guess is that it will take some years to built up a significant intake.The University bosses will therefore have to be patient and be prepared to invest heavily in this initiative until it can break even. The decision a decade ago to cut physics doesn’t exactly inspire confidence that they will be prepared to do this, but times have changed and so have the people at the helm so maybe that’s an unfair comment.

There are also difficulties on the research side (which is also vital for a proper undergraduate teaching programme), there are also difficulties. Grant funding is already spread very thin, and there is little sign of any improvement for the foreseeable future  in the “flat cash” situation we’re currently in. There’s also the stifling effect of theResearch Excellence Framework I’ve blogged about before. I don’t know whether Newcastle University intends to expand its staff numbers in Physics or just to rearrange existing staff into a new department, but if they do the former they will have to succeed against well-established competitors in an increasingly tight funding regime. A great deal of thought will have to go into deciding which areas of research to develop, especially as their main regional competitor, Durham University, is very strong in physics.

On the other hand, there are some positives, not least of which is that Newcastle is and has always been a very popular city for students (being of course the finest city in the whole world). These days funding follows students, so that could be a very powerful card if played wisely.

Anyway, these are all problems for other people to deal with. What I really wanted to do was to wish this new venture well and to congratulate Newcastle on rejoining the ranks of proper universities (i.e. ones with physics departments). Any others thinking of joining the club?

Sussex and the World Premier League of Physics

Posted in Education, The Universe and Stuff with tags , , , , , on August 16, 2014 by telescoper

In the office again busy finishing off a few things before flying off for another conference (of which more anon).

Anyway, I thought I’d take a short break for a cup of tea and a go on the blog.

Today is the first day of the new Premiership season and , coincidentally, last week saw some good news about the Department of Physics and Astronomy at the University of Sussex in a different kind of league table.

The latest (2014) Academic Rankings of World Universities (often called the “Shanghai Rankings”) are out so, as I suspect many of my colleagues also did, I drilled down to look at the rankings of Physics departments.

Not surprisingly the top six (Berkeley, Princeton, MIT, Harvard, Caltech, & Stanford) are all based in the USA. The top British university is, also not surprisingly, Cambridge in 9th place. That’s the only UK university in the top ten for Physics. The other leading UK physics departments are: Manchester (13th), Imperial (15th), Edinburgh (20th), Durham (28th), Oxford (39th) and UCL (47th). I don’t think there will be any surprise that these all made it into the top 50 departments worldwide.

Just outside the top 50 in joint 51st place in the world is the Department of Physics & Astronomy at the University of Sussex. For a relatively small department in a relatively small university this is a truly outstanding result. It puts the Department  clear in 8th place in the UK, ahead of Birmingham, Bristol, Leicester, Queen Mary, Nottingham, Southampton,  St Andrews, Lancaster, Glasgow, Sheffield and Warwick, all of whom made the top 200 in the world.

Incidentally, two of the other departments tied in 51st place are at Nagoya University in Japan (where I visited in January) and Copenhagen University in Denmark (where I’m going next week).

Although I have deep reservations about the usefulness of league tables, I’m not at all averse to using them as an excuse for a celebration and to help raise the profile of Physics and Astronomy at Sussex generally.  I’d therefore like to take the opportunity to offer hearty congratulations to the wonderful staff of the Department of Physics & Astronomy on their achievement. 

With the recent investments we’ve had and further plans for growth I hope over the next few years we can move even further up the rankings. Unless of course the methodology changes or we’re subect to a “random” (ie downward) fluctuation…

 

 

 

Combining Research and Teaching in Physics & Astronomy

Posted in Education, The Universe and Stuff with tags , , , , , on August 7, 2014 by telescoper

Among the distinctive things we do here in the School of Mathematical and Physical Sciences at the University of Sussex are our degree programmes that involve a Research Placement (RP). Students on these courses take the normal lectures, laboratory classes and workshops during the academic year, but they spend the summer vacation doing (paid) work with research groups in the School to get an experience of what the world of research is really like. Various combinations of Physics and Astronomy with a Research Placement have been around for some time. These courses have been so popular and successful that we’ve extended the idea to Mathematics for 2015 entry. We have also started extending the RP scheme to include placements in laboratories elsewhere, either in industry or in a university abroad; we even have two students currently doing their placements in China.

Here are a couple of videos we’ve made featuring two RP students who have been working in the Department of Physics & Astronomy this summer.

This is Ross Callaghan:

And this is Nathaniel Wiesendanger Shaw:

Both these students are in between their 2nd and 3rd years of a 4-year MPhys programme. As it happens, both survived the experience of being in my Theoretical Physics class last term too!

It’s an ongoing frustration of mine that so many influential people think that teaching and research are separate functions of a university and should not be mixed. I believe that the two go hand-in-hand and that you can’t really claim to be getting a real university education if it’s not informed by the latest developments in research. Moreover, some also imply that research-led teaching only happens in the Russell Group, which is not the case at all. In fact, I think we provide a much better environment for this in Sussex than either of the Russell Group universities in which I’ve previously worked.

Many Departments talk about how important it is that their teaching is based on state-of-the-art research, but here at Sussex we don’t just talk about research to undergraduates – we let them do it!

Talking About Undergraduate Physics Research…

Posted in Education, The Universe and Stuff with tags , , , , , , , on July 2, 2014 by telescoper

One of the courses we offer in the School of Physics & Astronomy here at the University of Sussex is the integrated Masters in Physics with a Research Placement. Aimed at high-flying students with ambitions to become research physicists, this programme includes a paid research placement as a Junior Research Associate each summer vacation for the duration of the course; that means between Years 1 & 2, Years 2 & 3 and Years 3 & 4 . This course has proved extremely attractive to a large number of very talented students and it exemplifies the way the Department of Physics & Astronomy integrates world-class research with its teaching in a uniquely successful and imaginative way.

Some time ago I blogged about  some very good news about one of our undergraduate researchers, Talitha Bromwich, who is about to graduate from her MPhys degree, after which she will be heading to Oxford to start her PhD DPhil; she is pictured below with her supervisor Dr Simon Peeters:

Talitha Bromwich with her JRA supervisor Dr Simon Peeters at 'Posters in Parliament' event 25 Feb 14

Talitha spent last summer working on the DEAP3600 dark-matter detector after being selected for the University’s Junior Research Associate scheme. Her project won first prize at the University’s JRA poster exhibition last October, and she was then chosen to present her findings – alongside undergraduate researchers from 22 other universities – in Westminster yesterday as part of the annual Posters in Parliament exhibition, organized under the auspices of the British Conference of Undergraduate Research (BCUR).

A judging panel – consisting of Ben Wallace MP, Conservative MP for Wyre and Preston North; Sean Coughlan, Education Correspondent for the BBC; and Professor Julio Rivera, President of the US Council of Undergraduate Research; and Katherine Harrington of the Higher Education Academy – decided to award Talitha’s project First Prize in this extremely prestigious competition.

We held a small drinks party in the School of Mathematical and Physical Sciences to congratulate Talitha on her success. Here are a couple of pictures of that occasion:

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From left to right you see Simon Peeters, myself, Talitha and Prof. Michael Farthing (the Vice Chancellor of the University of Sussex); the winning poster is in the background. Here’s me presenting a little gift:

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More recently still, the MPS Elves have made a little video featuring Talitha talking about her research placement:

We take undergraduate research very seriously here at the University of Sussex, and are now extending the Research Placement scheme to Mathematics. Many Departments talk about how important it is that their teaching is based on state-of-the-art research, but here at Sussex we don’t just talk about research to undergraduates – we let them do it!

 

The Cake Equation

Posted in The Universe and Stuff with tags , , , on May 31, 2014 by telescoper

Yesterday being the last Friday of the month of May it was time for another tea-and-cake event in the School of Mathematical and Physical Sciences. These provide an opportunity for staff to get together and chat while demolishing a specially-themed cake. The cakes themselves are organized by the inestimable Miss Lemon and I never know what the theme is before the goods arrive, so I have to ad lib a short introduction (for just a minute, without repetition, hesitation, deviation or repetition) before cutting the cake.

As you will observe, this time the (Lemon Drizzle) cake was decorated with the Dirac Equation (which I consider to be the most beautiful equation in physics)..

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