When I portrayed myself as a worm, you were surprised that I included by boyhood and old age. But to think of a man without his duration is just as a… - Arthur Eddington

Neither matter, nor energy, nor anything capable of being used as a signal can travel faster than the speed of light. This limitation of the speed signalling to 299,796 kilometres a second seems a rather arbitrary decree of Nature.

When we encounter unexpected obstacles in finding out something which we wish to know, there are two possible courses to take. It may be that the right course is to treat the obstacle as a spur to further efforts; but there is a second possibility - that we have been trying to find something which does not exist. You will remember that that was how the relativity theory accounted for the apparent concealment of our velocity through the aether.

I think that science would never have achieved much progress if it had always imagined unknown obstacles hidden round every corner. At least we may peer gingerly round the corner, and perhaps we shall find there is nothing very formidable after all.