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Hello, at the end of the last century, H.G. Wells imagined and traveling through time in the time

machine. The palpitation of night and day merged into one continuous

grainous. The sky took on a wonderful deepness of blue, a splendid luminous

color like that of early twilight. The jerking sun became a streak of fire, a brilliant

arch in space. When he was writing, we thought time was unbending and universal and

counted out by Newton's clock. A hundred years later we have Einstein in

relativity, quantum theory and atomic clocks, but as we stand on the cusp of the third millennium, is mankind

any closer to understanding what time really is? With me is the theoretical physicist

Dr Neil Johnson from the Clarendon Laboratory at Oxford University.

He's this year's Royal Institution Christmas Lecturer on the Subject of Time.

I'm also joined by the Cosmologist Lee Smolin, Professor of Physics at Pennsylvania State

University, who's currently on a year sabbatical at Imperial College.

He's the author of The Life of the Cosmos.

Neil Johnson, what's the best way of characterizing Newtonian time? It's really a clock in the sky for all to see very much like in

the birth of the railroad when there was one clock in the center of the station

which set the time for the town in which the station was. It was a

universal time. The Newton idea is that there's a clock in the sky for everybody

in the universe to see. Everybody agrees on that time no matter how far they are away

and no matter what they're doing at the particular moment when they look at the clock.

So the big clocks in the sky is regulating life on earth but is it independent of it?

...