Below are some popular-level astronomy talks that I have given. Some can also be found on my YouTube channel.

Philosophy of Cosmology UK/US Conference

My lecture, "A Beginner's Guide to Cosmological Speculation", on Bayesian probability theory, typicality and the multiverse. Presented at the Philosophy of Cosmology UK/US Conference (2014).

A full list of the lectures given with videos and slides can be found here.

Black Hole Q & A

I was sent a series of questions about black holes for a school project, and thought I'd make this video rather than writing a long email. Here are the questions:

UCSC Summer School for the Philosophy of Cosmology

Two lectures on the fine-tuning of the universe for intelligent life. Delivered at the 2013 UCSC Summer School for the Philosophy of Cosmology.

A full list of the lectures given with videos and slides can be found here. There are some outstanding lectures on a range of topics related to cosmology.

Part 2 is here.

The Universe, Multiverse and Fine-Tuning

Four one-hour lectures on the fine-tuning of the universe for intelligent life. Delivered at the 2011 St. Thomas Summer Seminar in Philosophy of Religion.

The first and second lectures outline the laws and constants of nature, and give an overview of the history of the universe from its earliest stages to galaxy, star and planet formation.

The third lecture considers what would happen if we changed the laws of nature. In particular, we find that in many cases, the universe would not be able to evolve and sustain complex, intelligent life.

The fourth lecture discusses the multiverse - the idea that the universe that we observe is just one of many, each different. I discuss the most popular multiverse today - the inflationary multiverse - and the challenges that the multiverse faces.

Getting your brain around the universe

How big is the universe? Can the human mind comprehend it? Let's give it a go ...

This is a talk given at the Institute of Astronomy, University of Cambridge in November 2008. It was part of the institute's open nights - every Wednesday throughout winter, all welcome.

The talk is in 5 parts. Here's the first one. The links for the rest are below:

Life in a fine-tuned universe

Let's make a new universe. Let's make it slightly different from the one that we are familiar with. We could change the laws of nature, just a little bit. We could change how the universe begins, or make it four-dimensional. In the last 30 years, scientists have discovered something astounding: the vast majority of these changes are disastrous. We end up with a universe containing no galaxies, no stars, no planets, no atoms, no molecules, and most importantly, no intelligent life-forms wondering what went wrong. This fact is called the fine-tuning of the universe for life. After explaining the science of what happens when you change the way our universe works, we will ask: what does all this mean?

This is a talk given at the Institute of Astronomy, University of Cambridge in March 2009. It was part of the institute's open nights - every Wednesday throughout winter, all welcome.

The talk is in 5 parts. Here's the first one. The links for the rest are below: