**When? Where?**

Talks are held at **8:15pm on Thursday evenings** (unless otherwise stated) in the Lindemann Lecture Theatre of the Clarendon Laboratory

Cost: **Free for members**, £2 for non-members

Life Membership £8

**What’s on this term?**

**Thursday 1st Week – Domenico Di Giacomo**

*“Earthquake Magnitude: meaning and open problems”*

The earthquake magnitude is a fundamental parameter to measure the earthquake strength and the related damage potential. From numerous media reports on recent natural calamities we hear the words “earthquake magnitude on a Richter scale” all the time. However, since Richter’s magnitude other earthquake magnitude scales have been introduced, especially to better measure the size of large earthquakes. This talk is intended to show the meaning of the magnitude concept, the recent developments in standard seismological practice and answer to the questions: 1) how can we best describe the earthquake source properties in terms of tectonic effects and released energy? 2) can a single magnitude be enough to assess an earthquake’s impact?

**Thursday 2nd Week – Dr Rob Gilbert**

*“Biophysics Used to Dissect Biomolecular Machines: Examples from Studies of Protein Synthesis and Membrane Pore Formation”*

Biophysics’ broadly encompasses a great number of techniques but prominent among them are X-ray crystallography, cryo-electron microscopy and hydrodynamics. The way in which these techniques can be used in combination to determine the mechanical basis of biological processes enacted by ‘macromolecular machines’ will be discussed with a particular emphasis on studies of pore formation and protein synthesis by the ribosome.

**Thursday 3rd Week – Prof. Vlatko Vedral**

*“Quantum Physics in the Macroscopic World”*

I will discuss the quantum superposition principle, what evidence we have for it and what we believe its limitations might be. Two domains are thought to limit the superposition principle: the macroscopic domain (e.g. dead and alive cats are never observed) and the domain of gravitational phenomena (the two domains are, of course, not unrelated). As far as the former, I will discuss the current prevailing opinion as to how the classical world emerges from the quantum one (without ever leading to any contradictions with the superposition principle). When it comes to gravity, however, matters are more subtle and, at the end of my talk, I would like to briefly mention an emerging view (considered somewhat controversial) on how to reconcile it with the superposition principle.

**Thursday 4th Week – James Holloway**

*“Scientific Techniques Applied to Finance”*

A scientific education equips you with many powerful analytical tools and, most importantly, an understanding of when to use them. In the world of finance where there are no fixed rules, success and failure are governed by your ability to distinguish between having faith in your models (and overruling your emotions) and recognising when your models are obsolete. I shall talk a bit about some of the techniques we use at Winton, and touch on the dangers of blindly applying mathematics without fully understanding your assumptions.

**Thursday 5th Week – Prof Mike Charlton**

*“Trapped Antihydrogen”*

Over the last decades it has become routine to form beams of positrons and antiprotons to produce trapped samples of both species for a variety of purposes. Positrons can

captured efficiently and in such quantities to form dense, single component plasmas useful for antihydrogen formation. The latter was made possible by developing techniques for dynamically capturing and then cooling antiprotons ejected from the Antiproton Decelerator at CERN.

This talk will review recent advances which have included the first demonstration of the trapping of antihydrogen. Trapping, which is thought to be a pre-requisite for spectroscopic comparisons of antihydrogen with hydrogen, causes extra complications by introducing a magnetic minimum neutral atom trap in the same region that the antiparticles are held. We will describe how clouds of antiprotons can be compressed and evaporatively cooled in preparation for antihydrogen formation in such an environment, and how this allows a small fraction of the anti-atoms we create to be held in the trap.

We will discuss the physics motivations for undertaking such difficult experiments.

**TUESDAY 6th Week – Prof. Harvey Brown – Co-hosted with Invariants**

*“Emmy Nöther”*

Amalie Emmy Nöther, was an influential German mathematician known for her groundbreaking contributions to abstract algebra and theoretical physics. She has been described by David Hilbert, Albert Einstein and others as the most important woman in the history of mathematics. Tonight we will explore her work in physics.

Harvey Brown is Professor of Philosophy of Physics, his research includes the foundations of quantum mechanics, relativity theory and thermal physics, the philosophy of space and time, and the role of symmetry principles in physics.

**Thursday 6th Week -Dr Jean Clavel**

*“What’s Going on in Space Science in Europe today?”*

The current ESA (European Space Agency) programme in space science, which ranges from cosmology through astrophysics to solar system exploration and solar-terrestrial interactions, will be reviewed including the new joint US-European plan for exploring Mars. Although with much lower budget than the US, Europe has increasingly taken a pivotal role in world space science and astronomy. Why this is so will be discussed.

**Thursday 7th Week – Dr Mike Towler**

*“The Quantum Theory of de Broglie and Bohm: A Challenge to Orthodox Quantum Mechanics”*

De Broglie-Bohm theory is a ‘hidden variables’ formulation of quantum mechanics initially developed by Louis de Broglie from 1923-1927 and clarified and extended by American physicist David Bohm beginning in 1952. Just by the simple expedient of refusing to believe that particles cease to exist if you stop looking at them, it is easy to show that – contrary to popular belief – quantum mechanics can be interpreted as a dynamical theory of particle trajectories rather than as a statistical theory of observation. In such a formalism the standard paradoxes related to measurement, observation and wave function collapse (Schroedinger’s cat, and so on) largely evaporate. The classical limit does not have to be presupposed and emerges from the theory in a relatively clear way. All the ‘talk’ is replaced by sharply-defined mathematics, it becomes possible to ‘visualize’ the reality of most quantum events, and – most importantly – the theory is completely consistent with the full range of QM predictive-observational data. The theory also gives rise to the possibility of new physics – and of new mathematical and philosophical ideas – and is currently undergoing a major resurgence. In this talk I review the structure of the theory and its consequences, and present some recent non-equilibrium trajectory calculations which demonstrate the origin of the Born rule and may hold the key to possible experimental tests of the de Broglie-Bohm framework.

**Wednesday 7th Week – AGM + Elections**

We will be having our AGM on Wednesday night in the Sainsbury Common Room at Worcester College from

**7pm**. In the meeting we will also hold our Committee elections for 2011/2012.

**Thursday 8th Week – Prof Katherine Blundell**

*“Black holes and Spin Offs”*