Lecture 11: The History of the Earth

What are the main mechanisms of climate regulation and climate change that have operated through Earth's history? The Earth's climate is regulated by a Carbon Dioxide thermostat that is the interaction between the Greenhouse Effect and the CO2 Cycle. I describe the CO2 cycle and ...  Show more

How do we define life? This lecture reviews the six basic criteria for living systems described by biologists: order, reproduction, growth and development, energy utilization, reaction to environment, and evolution that characterize life. The last third of the lecture is an admit ...  Show more

Melvyn Bragg and guests discuss the life cycle of stars. In his poem Bright Star John Keats wrote, "Bright Star, would I were steadfast as thou art". For Keats the stars were symbols of eternity- they were beautiful and ordered and unchanging - but modern astronomy tells a very d ...  Show more

Are we alone in the Universe? This lecture explores the question of how we might go about finding life on planets around other stars. Rather than talking about speculative ideas, like the Drake Equation or SETI, I am instead taking the approach of posing it as a problem of what t ...  Show more

Melvyn Bragg and guests discuss the abrupt transformation of stars after shining brightly for millions or billions of years, once they lack the fuel to counter the force of gravity. Those like our own star, the Sun, become red giants, expanding outwards and consuming nearby plane ...  Show more

Melvyn Bragg and guests discuss the abrupt transformation of stars after shining brightly for millions or billions of years, once they lack the fuel to counter the force of gravity. Those like our own star, the Sun, become red giants, expanding outwards and consuming nearby plane ...  Show more