Space

[legios]

Depends on your yardstick really doesn't it? Long and short are really only relative terms - something is not long in isolation, it becomes so because other things are not as long. Measured against geological time then a billion years looks a lot shorter than it does when measured against a human lifetime, or even the timeframe of recorded history. I'd call it a matter of perspective - but that's just my relatively untraining opinion.

Karl

[Shockprowl]

I think you're right. In cosmic terms, though, I was kinda thinking in terms of is 13 to 15 billion years long enough to actually get stuff done? Is it actually enough time for all the galaxies etc to be formed? Current popular theory is that our Solar System gradually condensed from a large cloud of material left over following another star's death in a nova or super nova. If the Sun and our system are 5 billion years old, and the star preceading our star had a 'normal' solar life span of 5 to 10 billion years, depending on what kind of star it was, that's more or less used up a good chunk of the 13 to 15 billion years that the Universe is supposed to have existed. Can all the galaxies of the Universe really have formed in only 13 to 15 billion years?

[The Doctor]

I'll pop back in the TARDIS and have a look.

-The Doctor

[Shockprowl]

Ta.

[The Doctor]

DALEKS!

-The Doctor

[Shockprowl]

Aaaargh!!!

[The Doctor]

DAVROS!

-The Doctor

[Fortmax2020]

shockprowl said:

I think you're right. In cosmic terms, though, I was kinda thinking in terms of is 13 to 15 billion years long enough to actually get stuff done? Is it actually enough time for all the galaxies etc to be formed? Current popular theory is that our Solar System gradually condensed from a large cloud of material left over following another star's death in a nova or super nova. If the Sun and our system are 5 billion years old, and the star preceading our star had a 'normal' solar life span of 5 to 10 billion years, depending on what kind of star it was, that's more or less used up a good chunk of the 13 to 15 billion years that the Universe is supposed to have existed. Can all the galaxies of the Universe really have formed in only 13 to 15 billion years?

Plenty of time. The first generation of stars would've been big blighters and the bigger a star is the faster it burns and goes boom.

Our Sun being a somewhat relative lightweight burns slowly and so can last billions of years compared to the millions of years for the 1st generation. Our Sun is either 2nd or 3rd generation (prob 3rd) and whatever the size of the star(s) it is now made from would make little difference to the Sun itself.

Rocky planets such as Earth could not have formed until heavy elements were formed in at least the first generation of stars so it is unsurprising that we are only here now at this point in the Universes history.

[Shockprowl]

Wow, that's really interesting. When you put it like that. With heavy elements only being around for a relatively short time, we could be very much alone in the Universe, or one of very few races out there.

(at 0731, that's heavy going this early!)

[kayevcee]

Well, there was a programme on one of the Discovery channel where a bunch of dudes from NASA tried to work out all the factors involved in the development of life on an Earth-like planet- a second/third gen star with plenty of heavy elements kicking about to make planets in the first place, a big ol' gas giant to mop up most of the apocalypse-sized space rocks, at least one large moon to keep the core churning and generate a magnetic field to protect against the solar wind and so forth. They came out reckoning that only one in every 2,000,000 stars in our galaxy was likely to be capable of sustaining Earth-like life. That's still 50,000 inhabited planets in our galaxy, though. If we ever get the whole faster-than-light thing sorted out we'll have a job on our hands finding other races, but we're off to a good start with all the Planetfinder systems on and above Earth.

-Nick

[The Doctor]

I've been watching a lot of Doctor Who recently and can confirm the universe is full of habitable planets.

-Ralph

[Fortmax2020]

I was reading a recent paper the other day and in it was an extremely pessimistic calculation for the number of civilisations throughout the universe and even that churned out a few billion or so... spread out of hugely contact prohibitive distances, but still as Nick points out we just need to finish cracking the FTL problem...

[Grand Moff Muffin]

I have no time for 'expert' calculations of how many inhabited planets might be out there. It's easy to come up with something no-one can disprove, but you might as well use a random number generator.

The truth is, every planet in the Solar System that we've explored has turned out to be very different from what scientists had been expecting based on prior experience. Unlike doing research into things found on Earth, theorising about the nature of other planets is extremely unreliable because we have so little data to form patterns/experience from.

We haven't even ruled out life existing elsewhere in the Solar System yet (e.g. below the ice surface of Jupiter's moon Europa), so how people can calculate the proportion of other stars containing life (not knowing the range of forms of life that may be possible, and how far they might spread with a few million year's head-start on us) is beyond me.

Martin

[kayevcee]

Every factor involved in the calculation was a wild guess, and even the scientists involved said so. We haven't adequately explored even our own solar system firsthand enough to say with any kind of authority what is required for life to develop in the first place. So... never mind. Considering some of the weird places on Earth that life can flourish (ocean trenches with no light, no oxygen and skeleton-pulverising pressure, deep ice cores, deep subterranean rock strata and suchlike) I reckon their estimate is pretty pessimistic.

-Nick

[The Doctor]

kayevcee said:

Considering some of the weird places on Earth that life can flourish
-Nick

True. I've always been doubtful life flourished naturally in my old secondary school of doom.

-Ralph

[Grand Moff Muffin]

Nov 18, 2007 10:53:16 GMT The Doctor said:

He's wrong! Planet!

PLANET!

Damn it, it is a bloody planet! Pluto is a planet! It is not a dwarf, nor a smurf, nor a minor! It's a planet! It's written on the side! Can no-one see?!

P!
L!
A!
N!
E!
T!

P is for Pluto! P is for planet!

I hope that settles that.

-Ralph

Apparently not.

P is for plutoid.

Alan Stern, a former Nasa space sciences chief, however, declares: "Plutoids or haemorrhoids, whatever they call it. This is irrelevant."

I'm sure having plutoids is more painful than having haemorrhoids.

Martin

[Fortmax2020]

Alan Stern should stop throwing a hissy fit over whether Pluto is a planet, plutoid or bodily condition. He has got a probe going there no matter what its called despite NASA's best efforts otherwise!

[The Doctor]

I agree 100% with him!

""It's just some people in a smoke-filled room who dreamed it up," he told the Associated Press. "Plutoids or haemorrhoids, whatever they call it. This is irrelevant.""

-Ralph

[Grand Moff Muffin]

It shouldn't even be called Pluto.

Yes, the Romans called the planets they could see with the naked eye after their Olympian gods, Venus, Jupiter, Mars (and Saturn aka Cronos, their dad). But I doubt they'd have called one of them Pluto, since Pluto (Hades) lives in the Underworld, not the sky.

Martin

[legios]

True, but I think that astronomers were running through the important members of the Pantheon when they got to Pluto rather than thinking about it too heavily. I think they should have moved on to some of the second tier Greco-Roman deities. That way it could have been called Nike, Alecto, Nemesis or Tisiphone or something like that.

Karl

[The Doctor]

I want a planet Sausage, damn it.

-Ralph

[Grand Moff Muffin]

Jun 12, 2008 19:47:02 GMT The Doctor said:

I want a planet Sausage, damn it.

So be it.

Google is scary.

Martin

[The Doctor]

Good lord!

-Ralph

[kayevcee]

You know, Nasa could get themselves some mighty sponsorship deals if they found a new planet/plutoid/really big space rock and named it Planet Nike.

-Nick

[legios]

Jun 12, 2008 20:38:59 GMT kayevcee said:

You know, Nasa could get themselves some mighty sponsorship deals if they found a new planet/plutoid/really big space rock and named it Planet Nike.

-Nick

I am under the impression that there is already an asteroid named for Nike. (I don't think the sports shoe company has any claim on it though)

Karl

[karla]

There was a woman on the radio, saying she was too scared to go into space incase the "things" from Star Wars or...

MEGATRON

would get her.
She followed by saying that these ideas come from somewhere!

[kayevcee]

Yeah. George Lucas and Bob Budiansky, respectively.

-Nick

[karla]

no....no she didn't mean that...she was implying they we're real

yay!!!

[legios]

news.bbc.co.uk/1/hi/sci/tech/7891132.stm

In honesty this seems to be a case of a scientist plucking some numbers out of his head for purposes of livening up a presentation. But it is a thought that I find rather inspiring. The idea that there might be many, many opportunities for sapience to arise, and that we might not necessarily be unique is one that I find rather comforting.

Karl

[karla]

Planet Tharg