Eleven members of Burnham U3A attended these three lectures on 5^thOctober, and all agreed that it was an afternoon well spent.

The first lecturer, Prof. Fay Dowker, presented Einstein’s general relativity to us in a very original way. She tried to get us to see (with some success) that Einstein’s ideas are easier to grasp intuitively than Newton’s. Even a small child can understand the sequence of things happening in time (pyjamas – teeth – story – bed), but clock and calendar time are much harder to grasp. In general relativity there is no universal time, only the sequence of events for each observer. Similarly there is no gravitational force, although we were taught about it in school. So if you jump out of a 5^th floor window, you do not experience a downward force, you are simply floating freely in spacetime. Unfortunately spacetime is warped by the great mass of the Earth and so you collide with said Earth with (probably) fatal results!

Having had our minds boggled by Prof. Dowker, we were then presented with a complete change of focus by Prof. Judith Mank, who spent 45 minutes talking about sex. She discussed the variety of ways it has evolved in different species and the strange tastes which some creatures exhibit when choosing their partners.

Humans, beetles and flies have X and Y chromosomes to determine their sex. Birds, butterflies and moths have W and Z chromosomes which work in a similar way. The sex of turtles and crocodiles is determined by the temperature at which their eggs are incubated, and some fish can change sex at the drop of a hat (or a fin). Bees and ants are a law unto themselves, and aphids reproduce without sex until the very end of the summer.

Refreshed by tea and biscuits, we returned to the lecture theatre (which will be familiar to any of you who have watched the Christmas Lectures on the BBC) to hear Nick Hawes pouring scorn on the very idea that robots might take over the world – the stuff of science fiction, he said. Nick works on artificial intelligence and the development of autonomous robots which can work with and for humans. He described how difficult it is to design a robot to do quite simple tasks. We saw a film of a German robot which can make pancakes, but only with pre-prepared pancake mix and a flat electric hotplate. No beating of eggs or tossing the pancake from a frying pan! And it can’t make a cup of tea; or walk upstairs; or play chess; or feed the baby; or ….;   or ….;   or …. And this was his point. A robot which could do everything a human can do is in the impossibly distant future.

All three lectures will shortly be available at YouTube.com/Royal Institution.

Jill Taylor