Hello and welcome to the Oxford University Physics Society (or PhysSoc for short)! This year, we have plenty of events on, including talks, socials, extracurricular classes and much more. This isn’t a society just for physicists; this is a society for anyone who is interested in physics, its applications, and physics-related topics. To find out more, have a look at our Youtube channel, our Facebook page or subscribe to our mailing list.
How do I get involved? Simple. Head over to the How to Join page and follow the instructions there.
Keep it |ψ|!
Trinity 2020 Term Card
The following events are presented from newest to oldest. Upcoming events will be posted here and on our Facebook page on a weekly basis.
Curtis & Spry: “Heat Transfer on Airless Bodies & Exoplanets”
We hope that you enjoyed last week’s talk on many-particle quantum systems. Thank you for the big turnout and all your questions 🙂
This week we will hear from Rowan Curtis and Robert Spry on their research into heat transfer on airless bodies and exoplanets!
Here is the Zoom invite: https://us02web.zoom.us/j/85443050828?pwd=WkIzc1JWR1hMdTFRbitZN3Y1TEM5dz09
Rowan is a DPhil student in AOPP, studying heat transfer on the Moon. In his talk, he will highlight some of the key unanswered questions in lunar science and will talk about how current research at Oxford Physics will contribute to furthering our understanding of the Moon.
Robert Spry is a DPhil student at AOPP, working on ground support for the ARIEL exoplanets mission. In his talk, he will talk about how the ARIEL mission, and other current and future space missions may provide answers to some of the key questions in exoplanets research.
Week 1, Thursday: Professor Fabian Essler: “Many-Particle Quantum Systems and Emergence”
We are back! Yes, lecture halls are closed, but that won’t keep us from bringing you exciting talks from experts in their field.
Here is the Zoom invite: https://us02web.zoom.us/j/84403671957?pwd=ZHZLbnI1UVFremdGbWdZbFgzMHQ3Zz09
Next Thursday (20:00), Fabian Essler will talk to you about the concept of emergence in many-particle quantum theory.
Please note that some basic (≈2nd year) knowledge of quantum mechanics will be useful. Here is a short abstract by the speaker:
In this talk, aimed at UG students, I will discuss the concept of emergence in the context of many-particle Quantum Mechanics. Emergence refers to the collective behaviour of a large number of microscopic constituents that is qualitatively different from that of the individual parts. Using the simple example of lattice vibrations in a crystal, I show how non-relativistic many-particle Quantum Mechanics gives rise to a relativistic Quantum Field Theory. This example shows how Lorentz invariance can emerge (at sufficiently large length scales) from a non-relativistic underlying theory. The example also shows how the fact that the underlying theory is non-relativistic reveals itself if we probe the system at increasingly shorter length scales. I will close with a second example of emergence, namely quantum number fractionalisation. I will show that there are many-particle quantum systems built from electrons (that carry spin 1/2 and charge -e) that support collective excitations that carry charge -e but no spin, and other excitations that carry spin 1/2 but no charge.
Hilary 2020 Term Card
Week 7, Thursday: Professor Todd Huffman: “The Higgs Mechanism Explained”
The Higgs Mechanism explained to anyone who knows Maxwell’s equations for Electro-magnetism (or “How to give the Photon a mass and still achieve Local phase invariance”)
More info on the Facebook event page: https://www.facebook.com/events/1286520078402989/
Week 7, Wednesday: Professor Balazs Szendroi’s class: “Polynomials and Geometry”
Algebraic geometry is the study of geometric objects described by polynomial equations. I will introduce some interesting classes of these objects, such as plane curves and surfaces in three-space. I will show how singularities, symmetries and families of such spaces are also naturally described by objects defined by polynomials. In the end, I will also discuss some applications of these ideas in fields such as robotics and cryptography.
More info on the Facebook event page: https://www.facebook.com/events/2637273576519450/
Week 6, Wednesday: Annual General Meeting!
We will host an annual general meeting where we will recap the progress the society has made over the past year. We will also give the opportunity for anyone to bring up any questions or concerns they have about the society as well as any suggestions for the future. Finally, we will host elections for the new committee. Hope to see you all there!
Additionally, any member who attends and votes is eligible for a 50% discount on the annual Physsoc formal dinner!
More info on the Facebook event page: https://www.facebook.com/events/637731100371389/
Week 6, Wednesday: Professor Steven Rose’s class: “Observing the linear Breit-Wheeler process for the first time”
As the inverse of Dirac annihilation, the Breit-Wheeler process , the production of an electron-positron pair in the collision of two photons, is the simplest mechanism by which light can be transformed into matter. It is also of fundamental importance in high-energy astrophysics, both in the context of the dense radiation fields of compact objects  and the absorption of high-energy gamma-rays travelling intergalactic distances . However, in the 85 years since its theoretical prediction, this process has never been observed. Here we describe a recent experiment conducted at the Rutherford Appleton Laboratory in the UK that has attempted to detect this process by which light is transformed directly into matter .
You only need second-year quantum mechanics and first-year relativity to understand this lecture. It not only deals with physics but also looks at press reporting of science and touches on how to involve the wider community in real scientific research. Of the four papers referenced,  is the one to read first.
 G. Breit and J.A. Wheeler, Phys. Rev. 46, 1087 (1934)
 S. Bonometto and M.J. Rees, MNRAS 152, 21 (1971)
 A.I. Nikishov, Sov. Phys. JETP 14, 393 (1962)
 O.J. Pike et al, Nature Photon. 8, 434 (2014)
More info on the Facebook event page: https://www.facebook.com/events/586303258617274/
Week 5, Wednesday: Professor John Chalker’s class: “Random Matrices and Quantum Chaos”
Undergraduate quantum mechanics courses are highly misleading (even at Oxford, and even if I am the lecturer!). The courses are misleading in the sense that they focus on problems that we know how to solve, such as a particle in a box, the quantum harmonic oscillator, or the hydrogen atom. The features that make these problems solvable also make their behaviour different from the behaviour of systems that we might call generic or typical. This raises the question: how can we find out about the behaviour of generic systems, for which we cannot solve the Schroedinger equation? As I will explain, one approach to answering this question is to study matrices whose entries are random numbers. The talk will use some ideas from second-year quantum mechanics and mathematics, but I hope most of it will be understandable with the background knowledge of a first-year physicist.
More info on the Facebook event page: https://www.facebook.com/events/477031119848596/
Week 4, Wednesday: PhysSoc Crewdate
Come study projectile motion by throwing pennies in each other’s drinks at our first social of Hilary! Buying a ticket on FIXR is required, coming prepared with good sconces is also recommended but harder to enforce. BYOB.
Time: 7pm – 9pm
Location: Angrid Thai
Admission: £12 PhysSoc member tickets on FIXR (£10 lifetime membership available at event). FIXR ticket link: https://fixr.co/event/319669210
More info on the Facebook event page: https://www.facebook.com/events/186653222407083/
Week 4, Wednesday: Professor Hang Zhou’s class: “Quantum Bird – Quantum entanglement inside avian magnetic compass”
Although it has been known for almost half a century that migratory birds can detect the direction of the Earth’s magnetic field, the primary sensory mechanism behind this remarkable feat is still unclear. The leading hypothesis centers on a pair of entangled radicals—magnetically sensitive chemical intermediates formed by photoexcitation of cryptochrome proteins in the retina. Low as 50 μT, the earth magnetic fields could influence the singlet- triplet interconversion as part of the radical pair photocycle, therefore change the reaction yield. I will briefly explain the quantum spin dynamics of this photo-induced radical pair system works theoretically, and show our various spectroscopic experiments. Note that some knowledge about quantum mechanics should be required to follow my lecture.
More info on the Facebook event page: https://www.facebook.com/events/206927360493588/
Week 3, Thursday: Professor Steve Balbus: “Accretion discs around black holes”
Until the advent of gravitational wave astronomy, the only way to study black holes was to examine the effect they had on the gas that surrounds them. This matter generally takes the form of an accreting disc. Accretion discs have become the central objects of study in high energy astrophysics. In this lecture, I will review both the history and the physics of black hole accretion discs, and discuss recent work done my group on the evolution of time-dependent accretion discs that form when an entire star is disrupted by an encounter with a supermassive black hole at the centre of a galaxy.
More info on the Facebook event page: https://www.facebook.com/events/578573199540266/
Week 3, Wednesday: Professor Andre Lukas’s class: “Symmetries and Particles”
I will introduce some basics of (Lie) groups and their linear representations. This Mathematics will then be applied to the problem of classifying particles in physics. The first step involves the groups SU(2)/SO(3), their representations and the relation to spin/angular momentum. Representations of the Lorentz group lead to the types of particles which appear in the relativistic world. These particles have additional quantum numbers, for example electro-magnetic charge or colour, which are specified by representation of the standard model group SU(3)xSU(2)xU(1). Finally, I discuss some aspects of unification based on the group SU(5).
More info on the Facebook event page: https://www.facebook.com/events/576349083212371/
Week 2, Wednesday: Professor Adam Ingram’s class: “All about black hole X-ray binary systems”
Black holes are the result of compete gravitational collapse. They are so dense that, inside of the event horizon, not even light can escape. There are thought to be ~100,000 black holes in our Galaxy, formed by the collapse in supernova explosions of massive stars. However, it is very difficult to see black holes precisely because they are black! I will talk about black hole X-ray binary systems, whereby a black hole is in a close binary system with a normal star and material from the companion is falling on to the black hole. As the material spirals towards the black hole, it is heated to such high temperatures that it glows brightly in X-rays – giving us a rare glimpse of the regions close to a black hole event horizon through X-ray telescopes. I will explain what we know observationally about these systems, and what we can and cannot explain theoretically. No advanced knowledge should be required to follow my lecture, only basic A-level / early degree level physics.
More info on the Facebook event page: https://www.facebook.com/events/632577534211747/
Week 1, Wednesday: Professor James Binney’s class: “Statistical Mechanics of Self-gravitating Systems”
A star cluster poses a basic problem in statistical physics, but violates basic assumptions of classical theory. The problem arises already when considering a ball of massive gas. At a basic level the problem is that self-gravitating systems have negative specific heats. At a more technical level they have access to states of unbounded entropy. If time allows, I’ll cover the extension of entropy to black holes.
More info on the Facebook event page: https://www.facebook.com/events/674384269968690/
Michaelmas 2019 Term Card
Here’s a list of events we have prepared for Michaelmas 2019!
Julien Devriendt: “From Supernovae to Supermassive Black Holes”
|Week||2||Wednesday||Max Abitbol: “Cosmic Microwave Background”|
|Paul Fendley: “Lattice, Symmetry and Topological Computations”|
Halloween Pub Social
Andrew Boothroyd: “Topology: a New Twist to Electrons in Quantum Materials”
|Crewdate with PhilSoc|
David Marshall: “Physical Oceanography Part 1”
|Bob Coecke: “Quantum Linguistics”|
Simon Clark event
|Week||6||Thursday||Hans Kraus: “Dark Matter Direct Detection Experiments”|
|Pub crawl with Invariants|
David Marshall: “Physical Oceanography Part 2”
Tony Bell: “Astrophysics at the Highest Energies”
Baron Ho: “Magnetic and Condenser Physics”
Todd Huffman: “The Higgs Mechanism Explained”
Week 8, Thursday: Professor Todd Huffman: “The Higgs Mechanism Explained”
The Higgs Mechanism explained to anyone who knows Maxwell’s equations for Electro-magnetism (or “How to give the Photon a mass and still achieve Local phase invariance”)
More info on the Facebook event page: https://www.facebook.com/events/588617898619951/
Week 8, Wednesday: Professor Baron Ho’s class: “Fundamental Theories behind an Electron Microscope”
Did you remember what thing you saw by using an optical microscope in the secondary school? Do you know what scale can be seen by humans? Light microscopes let us look at objects as long as a millimetre and as small as 0.2 micrometres, whereas the most powerful electron microscopes allow us to see objects as small as an atom (about one ten-millionth of a millimetre or 1 angstrom). Even within the microscopic scale, there are immense variations in the size of objects. After all, a millimetre is 10 million times larger than one angstrom – that is a difference in scale equivalent to the size of Earth versus the size of a beach ball!
The Energy-Loss Magnetic Circular Dichroism (EMCD) technique can be used to record signal of circular dichroism with high spatial resolution as a result of the short wavelength of high-energy transmitted electrons. EMCD was first proposed in 2003, demonstrated experimentally in 2006 and developed rapidly in recent years. In his studies, they measured spin and orbital magnetic moments quantitatively, with the spatial resolution determined by the probe size used under convergent beam illumination conditions. Here, I will introduce the theoretical fundamentals, mathematical interpretations and how this technique provides an improved understanding of structure-property relationships of molecules.
More info on the Facebook event page: https://www.facebook.com/events/483375865632774/
Week 8, Monday: Christmas Social
It’s the last week of term, and also our last social of 2019! Come celebrate the end of Michaelmas with free food, drinks, and other physicists.
More info on the Facebook event page: https://www.facebook.com/events/414622502826574/
Week 7, Thursday: Professor Tony Bell: “Astrophysics at The Highest Energies”
The origin of cosmic ray nuclei, some with an energy (>1020eV) exceeding that of a well-hit tennis ball, is one of the outstanding mysteries in astrophysics. I will describe the various places in and beyond our Galaxy where cosmic rays are or might be accelerated, review the observational evidence, and explain the theory of how they get their energy.
More info on the Facebook event page: https://www.facebook.com/events/427021554656036/
Week 7, Wednesday: Professor David Marshall’s class: “Physical Oceanography Part 2”
I stumbled into physical oceanography by chance, having been set on becoming a theoretical particle physicist. This serendipitous decision is one of the best I ever made! In these two lectures, I’ll explain how I stumbled into oceanography, why there is so much work for a physicist in the Earth sciences (and no doubt many other interesting areas of science), and how many of my apprehensions about moving away from “mainstream physics” proved completely unfounded. I will attempt to illustrate some of ways in which a physicist can contribute to understanding the circulation of the oceans through a few of the problems I’ve worked on: exploiting simple theoretical models, numerical models and observations, but always with the mindset of a physicist.The second lecture will focus on a curious tale of turbulent ocean eddies and their counterintuitive impact on the Antarctic Circumpolar Current. While my lectures will contain mathematics, you should not need any background knowledge beyond that of a starting first year physicist.
More info on the Facebook event page: https://www.facebook.com/events/436998840556757/
Week 7, Tuesday: PhysSoc/Invariants Joint Bar Crawl
Join Physics Society and the Invariants on a joint social exploring different college bars! We’ll try to stick to the schedule, but you can join at any point.
St Peter’s College Bar 7:30-8:30
Balliol College Bar 8:30-9:30
Hertford College Bar 9:30-10:15
St Catz College Bar 10:15-11:00
More info on the Facebook event page: https://www.facebook.com/events/978835482491445/
Week 6, Thursday: Professor Hans Kraus: “Dark Matter Direct Detection Experiments”
“Dark matter in the universe is a hot topic in research and several collaborations attempt to detect dark matter particles with terrestrial detectors. Significant progress has been made over the past two decades regarding increase of detector sensitivity but no confirmed detection has been made so far. I will review the motivation for dark matter, discuss current instruments and detection technologies, and give an outlook on new developments in the field.”
NOTE: We are in the Lindemann this week, NOT the Martin Wood. Reception will however be at the same location.
More info on the Facebook event page: https://www.facebook.com/events/769992543470200/
Week 5, Thursday: Simon Clark: “Why You Should Care About The Stratosphere”
The stratosphere is a fascinating place; a lid on the turbulent lower atmosphere, a realm of alien dynamics that defy our everyday experiences, and home to the most violent events in the entire atmosphere. Every now and again the stratosphere reaches down and completely changes the weather we experience on the surface. It may well play a key role in the single most dangerous experiment humanity ever attempts. So, in short, you really should understand a bit more about what’s going on up there.
In this talk I will give an introduction to the key features, dynamics, and impacts of the stratosphere. In particular I’ll be discussing sudden stratospheric warmings and their impacts on surface weather, the subject of my PhD, and also the potential use of the stratosphere in geoengineering.
More info on the Facebook event page: https://www.facebook.com/events/545243432960578/
Week 5, Wednesday: Professor Bob Coecke’s class: “Quantum compilation and natural language processing in one picture”
For well over a decade, we developed an entirely pictorial (and of course, formally rigorous) presentation of quantum theory , and it was recently shown that graphical reasoning by means of ZX-calculus can reproduce all equational reasoning in Hilbert space [2a, 2b]. In practical terms, it is currently for example being used as the core of quantum compilation , as it allows for easy translation between different computational models, allows for automation, and has outperformed any other method for circuit reduction. At the present, experiments are also being setup aimed at establishing the age at which children could effectively learn quantum theory in this manner. Meanwhile, the pictorial language has also been successful in the study of natural language  which induces new quantum algorithms , and we have started to apply it to model cognition, where we employ GPT-alike models . In a recent development we are able to assign meaning to entire texts, which then looks like a quantum circuit, that reduces to a ZX-like diagram.
More info on the Facebook event page: https://www.facebook.com/events/439075810139369/
Week 4, Wednesday: Professor David Marshall’s class: “Physical Oceanography Part 1”
I stumbled into physical oceanography by chance, having been set on becoming a theoretical particle physicist. This serendipitous decision is one of the best I ever made! In these two lectures, I’ll explain how I stumbled into oceanography, why there is so much work for a physicist in the Earth sciences (and no doubt many other interesting areas of science), and how many of my apprehensions about moving away from “mainstream physics” proved completely unfounded. I will attempt to illustrate some of ways in which a physicist can contribute to understanding the circulation of the oceans through a few of the problems I’ve worked on: exploiting simple theoretical models, numerical models and observations, but always with the mindset of a physicist. The first lecture will focus on the Atlantic overturning circulation (or, as the media likes to portray it, “Will the Gulf Stream shut down?) The second lecture will focus on a curious tale of turbulent ocean eddies and their counterintuitive impact on the Antarctic Circumpolar Current. While my lectures will contain mathematics, you should not need any background knowledge beyond that of a starting first year physicist.
More info on the Facebook event page: https://www.facebook.com/events/723803104791019/
– Week 4, Tuesday: PhysSoc x PhilSoc Crewdate
If you drink a bottle of wine but nobody is there to see it, are you still drunk?
That’s a really lame philosophical question, and also one you don’t need to find out the answer to – bring your wine (and sconces, and shoes) to Jamal’s and drink with lots of other physicists and philosophers instead! £12 PhysSoc member entry
Link for PhysSoc tickets: https://fixr.co/event/740190293
More info on the Facebook event page: https://www.facebook.com/events/671768969980258/
– Week 3, Thursday: Professor Andrew Boothroyd: “Topology: a new twist to electrons in quantum materials”
Topology is a branch of mathematics which deals with whether shapes can or cannot be smoothly deformed into one another. In the last decade, solids called topological quantum materials have become a hot topic in physics following the discovery of electronic states which are topologically distinct from those of electrons in free space. In this lecture, I will explain how topology is changing the way physicists think about electrons in solids, and describe how notions of topology can help us understand the existence and behaviour of exotic electronic states such as skyrmions, topological insulators, and Weyl fermions.
More info on the Facebook event page: https://www.facebook.com/events/2186642148295044/
– Week 3, Wednesday: Halloween Pub Night
Since we’ll all be spending October 31st at this week’s Physics Society talk, celebrate Halloween with us at the Chequers pub a day early!
Have any good physics-related Halloween costume ideas? The first 40 PhysSoc members in costume at the pub (who bring or buy a PhysSoc membership) will have their first drink paid for by the society.
(In addition to buying membership, bring money if you want to buy stash!)
More info on the Facebook event page: https://www.facebook.com/events/698180477369190/
– Week 3, Wednesday: Professor Paul Fendley’s class: “Splitting an electron (effectively)”
A fundamentally weird characteristic of quantum mechanics is that it makes sense to add different states together. As a consequence, striking and counterintuitive phenomena can occur in quantum many-body systems. For example, certain systems comprised entirely of electrons have an emergent degree of freedom whose charge is a fraction of the electron’s. I’ll explain how such behaviour happens in systems with topological order, and how this feature might lead to a form of quantum computation resistant to errors.
You won’t need to know quantum mechanics beyond that the spin of an electron forms a two-state system — I’ll explain the rest.
More info on the Facebook event page: https://www.facebook.com/events/2429807657103117/
– Week 2, Wednesday: Professor Max Abitol’s class: “The First Second: how observations of the cosmic microwave background reveal physics of the early Universe”
The cosmic microwave background (CMB) is radiation remnant from the Big Bang. Observations of the CMB result in a picture of the Universe from nearly 14 billion years ago when it was only 380,000 years old. Combined with our understanding of General Relativity, these observations allow us to infer large scale properties of the Universe, such as the total amount of energy in baryonic matter, dark matter and dark energy, with percent level precision. The next decade of CMB observations will push our understanding of cosmology even further, to the first fraction of a second. Inflation is a process thought to have created the initial conditions of the Universe through an exponential expansion of space at the beginning of time. Gravitational waves generated by inflation leave an observable imprint in the CMB, called B-modes. A detection of primordial B-modes would provide strong evidence for inflation and mark a breakthrough in modern cosmology.
In this lecture, I will introduce the theoretical background and observational history of the CMB that have been fundamental in developing the standard cosmological model. I will then discuss current experimental and data analysis methods, with a focus on B-mode measurements. To conclude, I will talk about remaining tensions, questions and future prospects in CMB cosmology.
More info on the Facebook event page: https://www.facebook.com/events/423137384887064/
– Week 1, Thursday: Professor Julien Devriendt: “From supernovae to supermassive black holes: how to reconcile the standard Big Bang model with observed galaxy properties”
The standard Big Bang model has proven incredibly successful in describing our Universe on super galactic scales with just a handful of numbers. However, it does require that (fairly) cold dark matter, as opposed to the normal matter of which we are made of, be the dominant form of matter in the Universe. This simple albeit quite extraordinary requirement has dramatic consequences for the formation and evolution of galaxies such as our own Milky Way, as it makes very robust predictions regarding the abundance and structure of the dark matter halos which host these galaxies. In particular, it forecasts the existence of many more dwarf dark matter halos than observed dwarf galaxies, and at the other end of the mass spectrum, stipulates that extremely massive galaxies should be populating the most massive dark matter halos. In this talk, I will describe current efforts to reconcile these discrepancies by modelling the most energetic events in the Universe, namely supermassive black hole jets and supernovae explosions, within cosmological hydrodynamics simulations.
More info on the Facebook event page: https://www.facebook.com/events/434099957486159/
– Week 1, Wednesday: Freshers’ Social
Pizza! Drinks! Games!
A chance to buy (and WIN) Oxford University Physics Society stash (more details below)!
Whether you’re a physics student or passionate about physics, come down to the annual freshers’ social! Meet people who share your interests or just show up and have a good time. We have food, drinks, and games for everybody!
More info on the Facebook event page: https://www.facebook.com/events/1412544752234009/