What's that all about then?

But don't foget we only know limited stuff about our own galaxy, there could well be other entire galaxies out there that we are just not aware of.

Although, I would agree that if we haven't found them yet, or they us, for that matter then the likelihood does somewhat diminish.

We know very little about the universe. I came across some probability talk ages ago (sorry, can't remember where) which said that the universe is SO HUGE that there is a high probability of there being life elsewhere in it. But it is also SO HUGE that there are innumerable places where the existence of life is not at all likely (low to zero probability). So far we've only come across those places. But we haven't been able to look very far yet. We're only apes with limited brain power and limited technology, so that isn't even the teeniest bit surprising.

Should have added a [cold-blooded-mathematical-approach emoticon]

What came before the Big Bang?

Depends if you believe in God. If you do then God was there and if you don't then nothing was there. I don't know how the Big Bang happened.

That's what physicists are trying to work out, flick. Meanwhile, the answer is "dunno". I'm happy with that.

I think physicists say that the question what came before the Big Bang has no meaning because there isn't a before the Big Bang. I know – it's hard to get the head round.

I have stong suspicions that my sister is from another planet, in another universe.

Attenborough's retrospective programme the other day was a lot about evolution. He referred to the fact that in the biochemical soup of the Yellowstone geysers (shot of murky bubbling pool) there are unicellular organisms which are similar to the ones that started it all off. Is there evidence that these organisms are in a process of evolving? And why are so many of the creatures and plants farther back in the evolutionary tree still around? Why is one tree shrew still a tree shrew and another evolved? And the coelacanth? Really want to know!

There are hundreds of billions of galaxies in the universe. I think it would be too strange to be the only life form in the universe.

I am buying my eldest grandchildren a telescope each for Christmas. I love looking at the night sky and want them to get interested too. There is a lunar eclipse happening right now and I am waiting patiently.

Not every one out of each species joined the fast lane. some of them stayed as they were, unevolved, while the ones who had changed moved on, rather like people who have never learnt how to use a computer, but have not become extinct.

They just keep going alongside the savvy whizzkids, and survive perfectly well unless conditions alter so far that the ones who adapted have too great an advantage over them and outnumber and outbreed them. If enough of them survive to keep a viable breeding group, they hang in there until times are OK for them to expand their population again.

Maybe when computers become unusable for some reason, those people who still know how to do long division and look things up in a book ("What was a book, mummy? what did you do with it?") will be in the ascendent again.

I agree with Bags - and all the other stars are many light years away. So unless they come looking for us - why would we know?!!! [scared emoticon]
Everything is evolving lilygran just some things are evolving more quickly and obviously than others. If something is perfectly adapted to an ecological niche and that niche is very stable, then change is unlikely to be rapid. There are no "evolutionary pressures".
An example of something that probably changed quickly:
When humans migrated north from Africa, with their dark skins, and started wearing clothes, then they will have become susceptible to vitamin D deficiency and hence, rickets. This will have led to adult women with deformed pelvises - unable to give birth - mother and baby dies. Result would have been huge evolutionary pressure to develop paler skin, and do so quickly, so that they could generate Vitamin D more rapidly. Big advantage to having paler skin in northern latitude = more successful mothers.

Species which find a niche where they can reproduce without too much competition have less 'need' to evolve, so mutations that might lead to adaptations are simply irrelevant because they confer no reproductive or survival advantage.

Crossed posts, jess, saying the same thing about evolutionary pressure, or lack of it.

Nanadog Wed 28-Nov-12 12:29:22

"I have stong suspicions that my sister is from another planet, in another universe."

Sometimes I'm bloody sure I am, when I see how people behave on this one. You know, like Strictly Come Dancing and all that...

Mathematically it's said to be unlikely that with so many millions of galaxies, with each containing so many billions of stars, many of which will have planets, life should only have got started here. Yet I wouldn't be surprised if it turned out to be a unique occurrence.

What does get me is the assumption that if one day we should encounter alien life it would be sufficiently similar in its development to allow useful communication - after all, imagine trying to converse with a Neanderthal, or even one of Boudicca's tribe... imagine trying to explain digital TV to Jane Austen!

You'd probably have as hard a job explaining it to me, feetle! (That's not a reflection on you, btw).

Why should it be anything like human life anyway? Just because humans are top dog, as it were, on this rock, doesn't mean some species that we are completely unable to imagine isn't top dog on another rock with completely different characteristics. I know that certain conditions seem to be necessary for "life" to happen but I suspect that they are nothing like so clear cut as suggested. Think, for example, of those recently discovered marine creatures living at immense depths with very high temperatures and apparently in a solution of life-destroying chemicals – yet flourishing very happily thank you very much.

There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.

I think with the vastness of space and the number of stars and planets we have yet to discover it would be extremely egotistical of us to assume ours is the only intelligent lifeform.

For all we know beings much more advanced than us may have already "discovered" us and are waiting for us to catch up before making contact.

The human race is very egotistical. There are even scientists – albeit not evolutionary biologists – who slip into the error of suggesting that evolution developed more and more complex creatures until it reached its pinnacle with the human race.

vpq I don't think anyone knows how the BB happened and absent I went to a series of lectures on a 'Brief History of the Earth' some time ago and the lecturer (scientist - geologist) said that it was as if all the ingredients were there (to make it all happen, to create life) but no one knows 'who or what turned on the oven'. I wasn't suggesting that we are the only life form or that other life forms may be like us, so I quite like the idea that maybe we still have to catch up with other advanced life forms. I just wonder how come we have never, ever found anything else - but perhaps its the vastness of it all and our limited search that explains that. I'll keep pondering.

shd be 'searches that explains that'. This darn PC keeps hanging.

Thank you for the explanations.

I'd love to meet a Neanderthal. They were humans almost identical to us, but tougher in the cold of N Europe. I would like to know their customs and hear their language.
DG accused of having Neanderthal genes - he has a wide, flaring ribcage for instance which was much more typical of Ns than of Sapiens.
I saw a european scientist in some TV prog recently and he really really did look like a neanderthal.
I would also love to go back in time to NZ before the Maori got there - a mini continent full of ferns and wonderful birds, now extinct (no mammals other than bats and seals) including the huge Moa. I wonder what colours they were? Oh, and because NZ birds have little or no fear of predation you could probably walk up and pat them.

My 3 year old GS came today and the first thing he said was: "Do you know, I think that there is a galaxy with our world in it, then there is another one with another world in it, and another and another - I think there are loads of them" Frankly I can't keep up with him!
So if you've got any questions I am happy to pass them on to him!