Thursday, March 21, 2013
Martin Rees - Royal Philosophical Society of Glasgow
The lecture ranged from Man's future in space, to the possibilities of life elsewhere in the universe to the age, origin, size, future of the universe and to the multiverse. I was impressed not so much on what he said, which I generally agreed with, but of his willingness to say how much we simply don't know.
"Space flight exposes the difference between what could be done and what has been" - we could be settling Mars now if the political will had been there - supersonic transport is another example.
It is Saturn eclipsing the Sun.
With each advance in robotics the technical argument for human beings in space grows weaker. However the philosophical one remains overwhelming.
"It is better to read first rate science fiction than 2nd rate science"
There are arguments over the theories that life must be common or that we really are alone in the universe. We do not yet have enough information to hold a sensible view, but it could be that we are alone as intelligent life.
Perhaps the difficult step is not from non-life but to intelligence. Intelligence may be an evolutionary dead end.
We are currently about 40% of the way through the life of the Earth. Whatever exists by then may be as far removed from us as we are from microbes, perhaps moreso since we can now take charge of our own evolution.
"Not one living species will transmit its unaltered likeness to a distant futurity" quoting Darwin
"99.9% of the population have one thing in common - they live their lives on Earth. The rest are astronomers."
"Fred Hoyle my predecessor at Cambridge"
"We are the ashes of long dead stars" (ie carbon, oxygen and the other complex atoms were all formed in stars)
We now know that most stars have planets.
Some of these planets have been found by private citizens using data online.
We will probably send fleets of robotic fabricators ahead before we travel to other star systems.
Beyond the range of what our telescopes can see (ie more than 13 billion light years away) there will be billions of galaxies.
There may be a multiverse of other Big Bang bubbles with their own universes.
I asked a question - You mentioned that the European Extremely Large Telescope [(real name :-) ] with a 30 metre mirror will be able to see planets in nearby star systems, if only as dots. This is about the maximum that can work on Earth because of the atmosphere and more importantly because of the gravity field. Like you I believe humanity will have a spacegoing civilisation, though it may well be Chinese. Are there any limits to the possible size of telescopes we will be able to make when we have such a civilisation.
"The E-ELT uses magnetism to hold the mirror stable. Gravity much more than the atmosphere is the limiting factor. I think we will build such telescopes in orbit rather than on the Moon and I know of no limits to their potential size."
I said I looked forward to seeing the day when we would have telescopes a kilometre across and could see extrasolar planets in detail and he said we would need longevity for that. I hope he is wrong on the last, but that entirely depends on the politicians allowing us to start doing what is technologically possible. But he seemed unfazed - this guy thinks in billions of years.