During the 20th century, we came to understand that the essence of all substances - their colour, texture, hardness and so forth - is set by their structure, on scales far smaller even than a microscope can see. Everything on Earth is made of atoms, which are, especially in living things, combined together in intricate molecular assemblages.
Martin ReesI recall a lecture by John Glenn, the first American to go into orbit. When asked what went through his mind while he was crouched in the rocket nose-cone, awaiting blast-off, he replied, "I was thinking that the rocket has 20,000 components, and each was made by the lowest bidder."
Martin ReesI suspect there could be life and intelligence out there in forms we can't conceive. Just as a chimpanzee can't understand quantum theory, it could be there as aspects of reality that are beyond the capacity of our brains They could be staring us in the face and we just Don't recognise them. The problem is that we-re looking for something very much like us, assuming that they at least have something like the same mathematics and technology.
Martin Rees