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Physics: Its Birth in Greek Ionia

This lecture discusses the pioneering physical theories of Thales, Anaximander, Anaximenes, Anaxagoras and Democritus.

The Future of Life on Earth

Although life is probably widespread in the universe, our pale blue dot, Earth, is the only known place harbouring intelligent life. Even if we manage to stave off extinction by climate change, avoid a nuclear apocalypse and the dangers of runaway AI, biological life on our planet will eventually come to an end in about 5 billion years’ time. What are the astrophysical dangers to life on Earth, and the prospects for life’s survival into the distant future?

The Broken Cosmic Distance Ladder

Measuring distances to astronomical objects outside our Galaxy is a surprisingly hard challenge: it wasn't until 1929 that Edwin Hubble obtained proof that Andromeda is indeed a galaxy in its own right. Today, astronomers extend distance measurements in the cosmos to the edge of the visible Universe, building up a 'cosmic distance ladder' made of several rungs. This talk will explore a major conundrum of contemporary astronomy: as observations have become more precise, the distance ladder appears today to be broken.