My science stuff isn't up to much, but I thought that scientists hadn't even seen a black hole yet, just hypothesised their existence based on...stuff. And yet you're saying that they also know about roving black stars? How are they charting these? Through our magical space sensors?

"In the distant future, our lovely planet will be incinerated and blown apart by the sun. If we live on Mars, we will buy additional time to leave the system before this world is, too, destroyed."

Time it'll take us (if we really got our arses into gear) to colonise Mars: Less than 200 years (300 if you want to be generous).

Time it'll take for the sun to explode: A few million.

quote:

---

Er, so if Alpha Centuri exploded, we'd die? How exactly?

---

Yes, and rather horribly, I'm afraid. A supernova puts out enough radiation to essentially sterilize any inhabited body out to a distance of many tens of lightyears.

Of course, none of the stars in the Centauri system are going to go supernova tomorrow, or ever. And I don't _think_ there are any stars on the verge of exploding that are close enough to worry about.

Still, that's today. We are moving around, after all. Could wind up in a bad neighborhood.

Anyway, I'm actually all in favor of people living on Mars, though my reasons are a bit more abstract. I think, if it's resources we're looking for, asteroids make much more sense.

Oh, and a supernova near enough to kill us will kill us no matter which planet we're on in this system, unless we're in the center of one, and maybe not even then, depending on distance. We're talking about a LOT of radiation.

So to survive such an event, we'd need to spread across a larger region of space than could be irradiated by a single supernova. This is no mean feat.

Of course, to steal from that guy who wrote Survivor, on a long enough timeline, the survival rate of everything in the universe drops to zero. Can't get away from heat death.

quote:

---

First, everything is already there. Carbon, Oxygen, Hydrogen (we think). We can make air, fuel, water, grow plants, make bricks and cement, even make plastic using shit already on Mars! Compare that to lifting a 10,000 person habitat into orbit that has to be built from scratch.

For the love of all that is empirical and scientific read "The Case for Mars" and if so inclined, "Entering Space". Debating from ignorance is no debate at all.

---

"You mean we've only got 30,000 years left to start colonising?"

Well, the last time it happened was a while ago. So we'd have less than 30 000 years (assuming that's the right number). It would be like saying "Well, the lifetime of a star like our sun is nine billion years, so we don't have to worry about it for nine billion years". That would, of course, ignore the fact that we've already used up half that time.

Earlier, a poster asked if black holes are invisible, how can we spot them? Quasars. Extremely strong radiation. These are two examples. The simplest analogy-you may not see the predator that killed the deer, but you can see the evidence of the predator on the deer and around the deer.

[ November 02, 2001: Message edited by: targetemployee ]

[ November 02, 2001: Message edited by: Mojo Jojo ]

quote:

---

The simplest analogy-you may not see the predator that killed the deer, but you can see the evidence of the predator on the deer and around the deer.

---

Oh, Jesus H. Christ, now Target Employee is developing a sense of humor. The world is coming to an end.

Hmmm.

quote:

---

under normal terrestrial conditions i.e. with gravity

---

On an asteroid? In space? First of all, to get one suitable you'd have to go beyond Mars in the first place, and an operation as complex as changing the orbit of an asteroid WOULD require people - at least at our level of technology anyway. And again, why would you go so far as to build a world from scratch (or with an asteroid, 90% or so from scratch) when there is a world in which you can set up one piece of machinery and create your fuel, air, and water from it. It's called the Sabatier reaction, and is 19th century industrial chemistry.

And how much energy do you think it would take, not only to make an asteroid into some semblance of habitable, but to spin it at such a rate that it produced a 1G environment? A lot. An experiment has been run - as a preliminary to a further experiment - testing the ability of mice to live and reproduce at 25 rpms. This experiment was done to make sure the Coriolis Force wouldn't be an obstacle in the successful execution of the Translife Project, which will test the ability of mice to live and reproduce in an artificial gravity enivronment (and with any luck, I will be a part of). If successful, it will show the validity of artificial gravity as a means of combating the negative effects of zero g in space travel but it will also empirically show (though I haven't heard any scientist dispute the claim yet) that animals and people can live just fine in .38G.

I have yet to see why Mars would be a better candidate for MINING (which is what I thought we'd started off talking about) than a Near-Earth Asteroid (which, incidentally, you don't have to go beyond Mars to find... there's estimated to be something like 10,000 that approach or cross the Earth's orbit.)

One would think that several aspects of mining would be easier in microG's. Certainly all the activity would help prevent deterioration like it does on the Station -- if we used humans at all. There'd be a much shorter trip down from Earth Orbit ('Roid capture being feasable with mass-driver technology), and no Martian gravity well to lift resources out of.

Now, if we're talking human colonization, then Mars is probably the place to be, followed by Titan and maybe Europa or a terraformed Venus (though I expect that one would be darned hard.)

quote:

---

Originally posted by First of Two:
...you'll still need 'Roid-grabbing technology, for water ice.

---

[ November 02, 2001: Message edited by: Mojo Jojo ]

You know the Earth's magnetic poles flip every few thousand years, right? We're due for that any moment now. Goodbye cosmic ray shielding (i.e. magnetosphere). Goodbye all electronics. Goodbye modern mankind.