Hi Peter
I did not know there were problems understanding "how a bike works", if I had realised I would have worked it out for them years ago.
But apparently great minds are engaged so I will leave it to them.
As to why humans need sleep ..that's easy...because they get tired.
Money makes the world go round and commands many motivations so what we see is is apparent corruption of what should be. Nevertheless the system manages
to produce usable results.
NASA are working on a "warp drive" that exciting, although I am suspicious that they really have anything, that must count as exciting and if it can be made work may change everything.g
I certainly get the impression science is like a religion but I think that view comes from behaviours exhibited on science forums who frankly have very few real scientists
participating.
I think the most important area is to find a quantum gravity theory.
I of course have worked it out but I want the others to work it out.
