Image of Keck ObservatoryI've been thinking about sentient life in the Universe (as you do) and realised that, while I had all the facts in my brain,I had never really put them together in any meaningful way before.
Our planet sits in her orbit at a perfect distance from her sun, which is a perfect example of a star configured to give rise to - well - us.
I nearly said 'intelligent life' there for a minute.
There is a finite number of such stars in our galaxy and we are unaware for the most part whether they have attendant planets or not. But I don't see why they shouldn't have, so let's go with that assumption for the moment.
OK then- star in the Main Sequence of the Hertzsprung-Russel diagram, not too hot nor too cold (one of the G-sequences), not too young (life took about 4.5 billion years to arise here) , a T-type planet orbiting in the right zone not to fry or freeze life, having sufficient mass to retain an atmosphere (Mars and the moon are a tad too small).
It's not beyond the bounds of possibility that several planets with these precise specs exist, somewhere.
But consider- 65 million years ago, a bloody great comet sweeps in from the outer reaches of the solar system and boom all higher life forms are extinguished. Which at that time were the dinosaurs.
The chances are good that the Earth would be hit by such a massive comet or asteroid every few hundred thousand years if not for the presence of two large gaseous planets- Jupiter and Saturn.
That's right. The Emperor and the Grandfather are directly responsible for allowing our kind of life to arise upon the Earth. Thank you, Your Majesty. Thanks, Gramps.
But now take that thought and add this fact to it: large gaseous planets of the J-type are incredibly difficult to form from the disk of a growing star. Much more tricky than the little T-types,such as Mercury, Venus, Mars and Us.
So - are we a very uncommon phenomenon, rather than the norm?
Are there in fact no wiser races inhabiting the galaxy or even the universe?
Are we perhaps all alone?
I admit to finding this thought more than a little terrifying.
It's one thing to wonder how we'd shape up in some Galactic Council among more advanced races and another altogether to contemplate the possibility that there's no one out there at all.
Just us, alone in this huge universe.
What a responsibility.
Do you have a reference for gas giants being difficult to form? I've never heard that, and find it a bit difficult to believe since we've found hundreds of extrasolar planets, pretty much all of which seem to be Jovian gas giants. And that's with only the relatively modest methods we have on hand now.
ReplyDeleteBrought up, as we are, with the concept of "boundaries" (backyards, fences, territorial lines on a map) - human beings always have a problem with comprehending the concept of "infinity" (distance) and "eternity" (time)..
ReplyDeleteSelf can't really see a problem with thinking that there is a "matching" planet, out there, somewhere...
Hi Bill,
ReplyDeleteWell, the latest thinking seems to be that the gas giants form early in the star's life, or not at all. They are formed not by accretion of matter (as the T-type planets are) but by being pulled off the cooling gaseous matter of the forming system,probably by passing stars. They must cool and form quickly, or remain a part of the sun.
I know we've found mostly gas giants around other stars-that's because the pertubations they cause and their sheer size and mass make them easier to spot.
I'm not sure what your standard of science is, so I found this link for you.
Hi Davo,
ReplyDeleteI don't have a problem with imagining a planet with our attributes and our kind of life either-I've been imagining it most of my life.
It's the other scenario which gives me problems, where we're alone in it all.
Love,
Terri
Well, but you're missing the point-- that the size of gas giants makes them easier to spot than terrestrial planets makes no difference to the fact that we have abundant evidence that gas giants are not rare.
ReplyDeleteThe new theory of formation is interesting, but doesn't change the evidence that we already have for the frequency of Jovian planets.
Hello again Bill,
ReplyDeleteNo, not rare, but more difficult to make.
If the gas giant doesn't form within the first few million years it doesn't form at all.
By this model, T-type planets, of which the Earth is one, should be far more abundant than the J-type.
I predict (and this is just my blog, not my field of speciality, although I do hold a degree in Astronomy as well as in Theoretical Physics) that when and if we get to enumerate the solar systems in this galaxy, we'll find the J-type much more rare than the T-type.
Love,
Terri in Joburg
Okay, I get where you're coming from now. Thank you.
ReplyDeleteI hope that we both live long enough to see whether your prediction holds true :-)
Apologies,Bill- I didn't realise until just now who you are. :)
ReplyDeleteI don't normally take such a damn lecturing tome with people I "know", so forgive me.
Love,
Terri feeling a bit silly in Joburg
Hey, no problem, I thought your tone was fine. Besides, sometimes I don't know who I am either ;-)
ReplyDeleteI contend that there is no other life out there like us, been out there and searched it all, not even close to being like us out there. Life here is a miracle for sure.
ReplyDeleteAnd yes, it is a big responsibility, one that mankind isn't taking seriously enough.
Becoming a better cook in Port Angeles. Terri wanna brownie? :-)
This planet was a giant gas ball at one time also, but this part of the cosmos is very old and more or less stable now so I'm not much worried about it getting hit by things like it has in the past.
ReplyDeleteAll of that new creation out there is very unstable and it will be millions of years before this kind of life can form on it, if in fact that ever does happen.
For now, what you see is what you have. And it is all we have.
Besides, if there was other life out there we would be finding out if it was part of the food chain. Or it would be finding out if we are part of the food chain.
I suggest that you just be thankful that there isn't other life out there. Hugs.
"human beings always have a problem with comprehending the concept of "infinity" (distance) and "eternity" (time).."
ReplyDeleteNot me, it's amazing out there, but devoid of interesting life. That is what makes this planet so interesting. And so touchy feely, yup, this is the spirits touchy feely place.
Reach out, reach out and touch someone. Hugs