Free diving world record

The guy - William Trubridge - dives 88m in 3:30 min with no fins!

Freediving World Record - 88m without fins from william trubridge on Vimeo.

Was Spacetime a Glorious Historical Accident?

Julian Barbour

Exactly half a century after Minkowski’s justly famous lecture, Dirac’s efforts to quantize gravity led him “to doubt how fundamental the four-dimensional requirement in physics is”. Dirac does not appear to have explored this doubt further, but I shall argue that it needs to be considered seriously. The fact is that Einstein and Minkowski fused space and time into a four-dimensional continuum but never directly posed the two most fundamental questions in dynamics: What is time? What is motion? It was an historical accident that Einstein attempted to implement Mach’s principle after he had created special relativity; otherwise he would have been forced to address these questions, which have never been properly considered. I shall show how they can be answered and suggest that: 1) time and space are utterly different; 2) the dynamical law of the universe may define absolute simultaneity in a manner that is still consistent with local validity of Minkowski’s marvellous notion of spacetime.

This is Julian Barbour presenting his beautiful theory at the Perimeter Institute.

It is a flash file so you should have the latest Flash version in your computer to be able to watch it.

You should watch this!