Darwin showed that we are the outcome of four billion years of evolution. What astronomers try to do is go back before this time. We can trace things back to the time of the bang, but we don’t know what banged, and why it banged. That’s a challenge for 21st century astronomy.
The ultimate challenge of science is a theory of everything – that is a theory which unifies the very large and the very small. At the beginning of our universe, it was just an atom, and until we understand this single theory, we cannot understand what happened at that time.
One idea – albeit a speculative one – is that our big bang was not the only one. We may not be aware of another dimension, like two sheets of paper, with ants on, and not being away that above the paper exists more ants on that sheet. There could be another universe just a millimetre away from us, but we’re not aware of it because we only know about our three dimensions, and there is actually a fourth dimension available.
Human beings, and our basic character and structure has not changed for thousands of years. But it may change this century. Because of targeted drugs, implants into the brain, and so on. The human impact on the environment is also unprecedented. Both of these things present new challenges for us.
If you represent the Earth’s lifespan in a year, the 21st Century would be a quarter of a second in June. A tiny fragment of time. But, our century is very special, we’ve achieved more change to our being, and to our planet, than in all of our history. The next one hundred years will determine the future of our planet, and indeed of our species.
(Part of TED a day for June)