Eva Silverstein | Horizon Physics: Cosmology, Black Holes, and String Theory – 1 of 2

Black hole and cosmological horizons — from which nothing can escape according to classical gravity — play a crucial role in physics. They are central to our understanding of the origin of structure in the universe, but also lead to fascinating and persistent theoretical puzzles. They have become accessible observationally to a remarkable degree, albeit indirectly. These lectures will start by introducing horizons and how they arise in classical gravity (Einstein’s general relativity). In the early universe, the uncertainty principle of quantum mechanics in the presence of a horizon introduced by accelerated expansion (inflation) leads to a beautifully simple, and empirically tested, theory of the origin of structure. Its effects reach us in tiny fluctuations in the background radiation we observe from the time when atoms first formed.

This theory, and the observations, are sensitive to very high energy physics, including effects expected from a quantum theory of gravity such as string theory. Modeling the early universe within that framework helps us better understand the inflationary process and its observational signatures. Analyzing the `big data’ from the early universe — which continues to pour in — is a major effort. This provides concrete tests of theoretical models of degrees of freedom and interactions happening almost 14 billion years ago.

Our understanding breaks down if we push further back in time, or into black hole horizons. This challenges us to determine more precisely how and why our existing theories fail. I will explain these basic puzzles, and conclude with some of the latest results on this question in string theory, which exhibits interesting new effects near black hole horizons.


Schrödinger lecture 2014: Professor Serge Haroche – Shedding new light on Schrödinger’s cat

Quantum theory has allowed scientists to understand better the subatomic world, and led to revolutionary technologies including computers, lasers and atomic clocks. In spite of its successes, quantum physics can seem strange and counterintuitive. It describes a world in which the concepts of waves and particles are deeply intertwined; and has led to the bizarre notions of superposition, which allows particles to exist in many concurrent states until observed, and entanglement, whereby particles control the state of distant and seemingly unconnected partners within a system.
2012 Physics Nobel Laureate Professor Serge Haroche delivers the annual Schrödinger Lecture

Quantum theory: it’s unreal

How to construct a better narrative over what really goes on in the subatomic world. Inaugural lecture of Professor Terry Rudolph. recorded on 29 October 2014

Class 01 Reading Marx’s Capital Vol I with David Harvey

Class 01 Reading Marx’s Capital Vol I with David Harvey
Class 1 Introduction. An open course consisting of a close reading of the text of Volume I of Marx’s Capital in 13 video lectures by Professor David Harvey. The page numbers Professor Harvey refers to are valid for both the Penguin Classics and Vintage Books editions of Capital.

Antimatter: Why the anti-world matters

Tara Shears – Antimatter: Why the anti-world matters
Antimatter, an identical, oppositely charged version of normal matter, is one of the most mysterious substances in the Universe and very little of it survives today. Tara Shears examines the progress being made towards understanding this elusive version of matter, and explains the latest results from LHCb and elsewhere.

Quantum Fields: The Real Building Blocks of the Universe

David Tong – Quantum Fields: The Real Building Blocks of the Universe
According to our best theories of physics, the fundamental building blocks of matter are not particles, but continuous fluid-like substances known as ‘quantum fields’. David Tong explains what we know about these fields, and how they fit into our understanding of the Universe.