From quantum physics to harvesting energy from stars: reflection on an interview with Freeman Dyson

I’m not sure which is more impressive. Freeman Dyson’s championing of a new era of quantum electrodynamics, or the scale upon which his formidable intellect had an impact.

In his own words, “My most important contribution was the unification of the Feynman-Schwinger-Tomonaga versions of quantum electrodynamics.”, when asked by Vedant Bhargava what he felt was his greatest scientific achievement. Yet his influence spans from fundamental particles like the electron on the scale of roughly 10−18m to a colossal megastructure dubbed a Dyson sphere that would encompass a whole star. Just for reference, the radius of the Sun is on the scale of roughly 108m. That’s something you need a powerful microscope to see right in front of you vs. something you can with your eyes (do not try this at home) 150 million kilometres away. Dyson’s influence is prevalent at every stage.

Not only was he an intellectual behemoth, but he lived through World War II and worked on multiple space-related projects (most notably ‘Orion’). During the war he worked for the Royal Air Force’s bomber command. But, in his own words, his job “had nothing to do with mathematics, either pure or applied”, but this section of his interview is still an interesting read nonetheless. Project Orion intended to create a spacecraft propelled by nuclear power, however, given time to reflect, Dyson now believes “There does not seem to be any type of mission that is well matched to nuclear rockets. Nuclear rockets are too heavy for local missions and too slow for high-velocity missions.”

Something else I noticed that I find particularly amusing, was that the competitiveness between Dyson and his colleagues (Michael Atiyah in this article) appears to have lost none of its vigour despite lasting long over half a century. “Game on”, Dr. Atiyah appears to say as Austin insinuates that Dyson would be double checking Dr. Atiyah’s proof to a million-dollar problem, the Riemann Hypothesis, and solving it in his own right.

Read the full interview coordinated by year 3 student Austin Morris.

Theoretical Physics – reflecting on my MSc studies

With winter graduation ceremonies upon us, we had a chat with Andres Armua who is due to graduate with an MSc in Theoretical Physics, and this is what he told us about his experience here:

Tell us about your most memorable aspects of the degree.

The excellent quality of courses and teaching and the nice atmosphere created by the University staff made the learning process highly satisfying. The teaching staff are very approachable and they are very willing to talk about material. The degree is designed in a very coherent way with good introductory courses and also amazing research level courses. The wide variety of projects offered for the dissertation illustrates the large range of topics in which the School is involved.

What was your research project about?

My research project was on the chaotic properties of turbulence, which involved understanding the background theory of fluids and chaos, then running fluid simulations to analyse data and test certain aspects of the theory.  Before starting the project I knew very little about chaos and I had practically no programming skills so I can say that during this project I largely improved my understanding of the research process as well as my computational skills. At the same time the project was relevant for the research that was being carried out by the Particle Physics Theory Research Group so that was obviously satisfying.

How did you find living in Edinburgh?

The city of Edinburgh is great. It offers a wide variety of activities (sport, cultural and social).  There are also many beautiful towns and places all over Scotland to visit during the weekends. Even though student life can be stressful, I would say that the city helps to make everything more relaxed and enjoyable.

Andres is from Argentina and is currently studying for a PhD in Data Intensive Physics at the University of Edinburgh.

Photo credit: Sergio Parrella.

Maximise your chances of exam success

Your exams are approaching.  You have been planning, revising and studying, so there is little more you can do, right?  Regardless of how much effort you have put in beforehand, your exam performance on the day is also important to help you maximise your chances of exam success.

Here are Dr Ross Galloway’s top ten tips.

1. Read the whole exam paper before doing anything else

It’s the classic exam tip, and with good reason. As the old military maxim says, time spent on reconnaissance is seldom wasted. It will give you an overview of what you’re going to have to do, and your subconscious will start processing the later questions even as you do the early ones.

2. Think about the big picture when choosing which questions to do

Most of your exams will offer you at least some choice of questions to tackle. Don’t pick them just based on which of the opening sub-parts you prefer. Assess the whole question: which ones can you do the greatest amount of?

3. Don’t be put off by unfamiliarity

You read the question. There’s an equation in it that you’ve never seen before. In this situation, lots of people immediately turn the page. Don’t be so hasty! No matter how scary the equation looks, we wouldn’t be asking you to use it if it was unreasonably difficult. Take a moment to assess the question on its merits; don’t immediately reject it just because of an unfamiliar equation.

4. Do the easy questions first

In any exam, there will be some questions you are more confident about. Do them first: it will build your confidence and your momentum, and will give you some marks in the bag before you start thinking about the tougher questions.

5. Stick with the question

If you have a choice of question, select carefully, but then stick with it. One of the most frustrating things we see when marking is when people have a choice of either B.1 or B.2, and they answer both. This is a terrible strategy. Here’s why: suppose you start B.1, and answer 7 marks worth of it. Then you get stuck, have a wobble, and change your mind. You start answering B.2 instead. The first 7 marks of B.2 are completely wasted effort. You are no further forward. It’s only at the eighth mark that you start making any gains at all. That time and effort would be much better spent elsewhere on the paper.

6. Use the clues

Many (though not necessarily all) of the longer exam questions have a running theme: later parts make use of results obtained in the earlier parts. Very often we see students successfully solve part (a) but then apparently reboot their brains and start again from scratch with part (b). When tackling a sub-part in a long question, think to yourself, are any of the previous parts relevant to what I am doing? Can I use those results as a shortcut to help me out now?

7. Be marks-smart

Related to the previous tip, there should be a sensible relationship between the number of marks available for a part, and how much you have to do to earn them. If you’re writing two pages of algebra for a 2-mark part, think to yourself, have I made a slip early on? Have I missed a trick? Is there an easier alternative way to solve this? On the other hand, don’t be too formulaic in how you interpret the allocated marks: 5 marks for a sub-part doesn’t necessarily mean that you have to write 5 individual ‘things’. Questions that require deeper thought can be worth more marks, even if you don’t have to write so much.

8. Look for the back door

Another piece of exam question structuring: many (though again not necessarily all) long questions will be structured with an alternative entry point later in the question, so that you can still tackle the later parts even if you can’t solve the first parts. A classic hallmark of this is being asked to ‘show that’ a given result is true in the early parts of a question. There’s a good chance you can use that result to help with solving the later parts. Keep an eye open for these back doors.

9. Don’t get freaked out by the ‘sting in the tail’

Long exam questions aren’t of uniform difficulty, by design. Very often, the last part(s) will be disproportionately challenging. This is called the ‘sting in the tail’, and is intentionally very difficult, to provide some way to separate out the very highest performing students. If you get to the end of a question and have no clue what to do, don’t let it knock your confidence, and don’t waste large amounts of time struggling with it. Move on, and come back at the end if you have time.

10. Replace then erase

Suppose you make a false start to a question, and change your mind about how you’re going to solve it. Write out your new solution, and only score out the old one after you have finished replacing it: if you run out of time, you may get some marks for the working in your first attempt, so don’t scribble it out prematurely.

Don’t forget: Read the rubric

This won’t directly affect your marks, but is still important. All exam papers have instructions on the front, called the rubric. Read the rubric, and follow it. In particular, if it asks you to write different sections of the exam in separate script books, please do this. If you don’t, it makes the marking process much more laborious (I won’t bore you with why, just trust me on this). Also, that grid on the front of the script book that asks you to fill in which question numbers you have done? Please actually do that. You might not always think it, but the markers are endeavouring to give you as many marks as we can; don’t make our task any harder than it needs to be. Having said that, if you have a memory blank then suddenly realise you have written an answer in the wrong book, just press on. Don’t spend any time re-writing it in the correct book; this is a huge waste of your precious time. We might grumble a bit about it, but we will work around the issue when marking.

Also: Leave yourself some space

If you get stuck, leave space to answer the rest of the question so that you can come back and fill in the gap later on. The order of the questions doesn’t matter and we’ll mark everything in the script (that hasn’t been crossed out), but it’s much easier to navigate script books when the answers to all of the parts of a question are together. Also, the single most confusing thing you can do is split the answer to a question over multiple script books; please don’t do this. If you run out of space in your book, ask an invigilator for spare sheets of paper to fasten into it.

Good luck!

Who are the Modern Physics quiz whizzes?

For the second year running, the Modern Physics course held a mid-semester pub quiz. Kind of like a normal pub quiz, but for physics geeks. With rounds on physics, astrophysics, science film quotes, Nobel prizes, a picture quiz, and general knowledge (admittedly, mainly general knowledge related to physics…).

Questions ranged from “What is the Banana Equivalent Unit a measurement of?” to “How many cups of tea do we drink each year in the UK?”, which had a clue in that answers would be accepted to the nearest 5 billion!

Well done to the 10 competing teams, and congratulations to runners up ‘Buckfast’s at Tiffany’s’ and the winning team ‘Drawing a Planck’.

Now, let’s check out your knowledge… What country is located just north of Lake Turkana, at a point bordering Kenya, Ethiopia, Uganda, and South Sudan?  No one at the quiz got this right.  Do you know the answer?


Diversity in physics is a multifaceted challenge

Many staff and students are keen on sharing their interest in science with the public.  Sarah-Jane Lonsdale has combined this interest while promoting the diversity of those studying and working in science.

“It was my gap year experience at the Royal Institution as a ‘Year in Industry’ student which was the main influence for my science communication and public engagement work.”

This experience led to her working with Pride in STEM, a charitable trust that works to promote and support those who identify as LGBTQ+ (Lesbian, Gay, Bisexual, Transgender, Queer and other sexual and gender minorities) in Science, Technology, Engineering and Mathematics (STEM) careers. Sarah has been active in promoting the first international day celebrating LGBTQ+ people in STEM earlier this year.

Sarah was also nominated for the Jocelyn Bell Burnell Medal and Prize in recognition of her contribution to physics and work to support and encourage others in the field.

Sarah is a postgraduate student within the Institute for Particle and Nuclear Physics at the School of Physics and Astronomy, where she is investigating the neutron-induced destruction of Aluminium-26 in massive stars. She won a prestigious Principal’s Career Development Scholarship to pursue her studies at Edinburgh. Prior to this, she completed an MPhys research in Nuclear Astrophysics at the Oak Ridge National Laboratory in Tennessee, USA.