I guess I'm just saying that an asteroid impact that's small enough to be survivable by a good fraction of the complex species could be rendered unsurvivable by any species if the asteroid were pulverized (and nearly all fragments still hit).
> Now, if we can find a way to grind to asteroid into a fine powder, then we are all safe...
Nope. Think about the Leonids. They're a very very diffuse cloud of dust fragments, and they give us a nice light show. I don't know the numbers, but it couldn't be more than a few hundred kilograms of matter. The amount of matter from a 1-km asteroid is many orders of magnitude greater. Think of there being 1000 times as many meteors as in a leonid storm. Then multiply that enough times for the amount of light to be about the same as daylight. Then go another thousand times that. That's probably what we're talking about; I'd wager it's enough to fry everything.
To think of it another way, think of 1 billion 1-meter objects airbursting within a similarly short time frame. Think of how much heat would be dissipated.
Here's another angle:
> Now, take the second cannon and load it with nice finly ground sand. Fire the sand at the car. You wind up needing a new paint job, and probably a nice dent...
What if all you cared about was the paint (equiv. to the life on the surface of the earth)? One big cannon ball makes a big hole, but most of the surface, while disturbed, is still there. The sand blast would scrape off everything, even though the interior would be relatively unscathed. But there's no life in the interior of the earth; it can take a punch.
> Relatively, 1000 1-meter rocks are better than 1 1-km rock.
Make that 1 billion 1-meter rocks ( 1 cubic km = 1000*1000*1000 meters).
> In order for any explosive asteroid deterrant system to work well, you still have to make sure that the asteroid will be sufficiently vaporized to be eaten up in the atmosphere.
Actually, that's even worse. If we break it up enough for the atmosphere to dissipate all the energy, that just means we're making sure the *surface* of the earth gets *all* the energy. Read: equivalent to nuclear armaggedon (actually probably a lot more energy than that). If it was in one big piece, the interior of the planet will receive a big chunk of the energy, and dissipate it as heat.
The only way breaking it up would be better is if the dust is dissapated widely enough that only a tiny fraction of it impacts the earth (per orbital pass).
> Relatively, 1000 1-meter rocks are better than 1 1-km rock.
Make that 1 billion 1-meter rocks ( 1 cubic km = 1000*1000*1000 meters).
> In order for any explosive asteroid deterrant system to work well, you still have to make sure that the asteroid will be sufficiently vaporized to be eaten up in the atmosphere.
Actually, that's even worse. If we break it up enough for the atmosphere to dissipate all the energy, that just means we're making sure the *surface* of the earth gets *all* the energy. Read: equivalent to nuclear armaggedon (actually probably a lot more energy than that). If it was in one big piece, the interior of the planet will take on a big chunk of the energy, and dissipate it as heat.
But what if the interior of the rabbit were inert; if it's life depended only on its surface? Then a bullet would make a big mark, but just one mark. Peppering it with buckshot would cause more damage.
The earth is like that -- the interior can take a beating; there's no life there; the propagating shockwaves simply dissipate the energy as heat, and there's a lot of heat there already. If we break the asteroid up, the *surface* of the earth takes *all* the energy. We're talking many many times the energy of all the nukes that we humans have pointing at each other.
> Yes, I'd rather be hit with a bail of hay than of a bullet carrying the same kenetic energy. Neither would be pleasant, but I'll take the distributed forces any day.
But what if the bale of hay were traveling at Mach 2; the bullet at, oh I dunno, mach 20? The bullet would pierce through you, with some shockwave effects, but the bale of hay would atomize you. Which one gives you a better chance of survival?
Not only is it not effective, but breaking up an asteroid into smaller pieces would actually make things *worse*.
Think about it: a cubic kilometer contains 1 billion cubic meters. At the velocities we're talking about, a 1-cubic-meter asteroid will likely cause a pretty decent airburst when gets to a sufficiently dense level of the atmosphere. I'd guess it'd be an explosion that's a significant fraction of a kiloton in size -- let's say 100 tons of explosive force. We then do the math: 100 * 1 billion = 100 billion tons -- that's equivalent to 100,000 one-megaton nuclear weapons going off in the atmosphere.
Even if I'm being pessimistic by a factor of 100, that's still a thousand nukes' worth. At any rate, it'd pretty easily be worse than any nuclear armageddon we might unleash upon ourselves. And remember I'm only talking about a 1-km asteroid here.
If the asteroid were intact, however, a very large fraction of the energy would be delivered directly into the body of the earth, where it will be dissapated as heat internally. Yes, the site of impact is atomized, with global earthquakes and potential tsunamis, raining debris, etc, but life in general -- even complex life -- would still have a good chance. 100,000 nukes going off in the atmosphere would fry *everything* on the surface, and would only spare the interior of the earth, which is the one thing that can take it.
>BMRT was closed source but free, and now it's > dead, gone for good as well as Entropy.
I'm holding out the (perhaps naieve) hope that this IP will make its way into one of NVidia's chips. That *would* be cool, actually, if you could have BMRT/Entropy-quality renderers implemented in *hardware*.
And if someday it's integrated into a handheld device, you'd have a real "renderman". (Which, by the way is the idea that spawned that name.)
Slashdot Mirror
I guess I'm just saying that an asteroid impact that's small enough to be survivable by a good fraction of the complex species could be rendered unsurvivable by any species if the asteroid were pulverized (and nearly all fragments still hit).
Yes, but what about 10 billion Bruce Willis's?
> Now, if we can find a way to grind to asteroid into a fine powder, then we are all safe...
Nope. Think about the Leonids. They're a very very diffuse cloud of dust fragments, and they give us a nice light show. I don't know the numbers, but it couldn't be more than a few hundred kilograms of matter. The amount of matter from a 1-km asteroid is many orders of magnitude greater. Think of there being 1000 times as many meteors as in a leonid storm. Then multiply that enough times for the amount of light to be about the same as daylight. Then go another thousand times that. That's probably what we're talking about; I'd wager it's enough to fry everything.
To think of it another way, think of 1 billion 1-meter objects airbursting within a similarly short time frame. Think of how much heat would be dissipated.
Here's another angle:
> Now, take the second cannon and load it with nice finly ground sand. Fire the sand at the car. You wind up needing a new paint job, and probably a nice dent...
What if all you cared about was the paint (equiv. to the life on the surface of the earth)? One big cannon ball makes a big hole, but most of the surface, while disturbed, is still there. The sand blast would scrape off everything, even though the interior would be relatively unscathed. But there's no life in the interior of the earth; it can take a punch.
(whoops, my previous post was formatted wrong)
> Relatively, 1000 1-meter rocks are better than 1 1-km rock.
Make that 1 billion 1-meter rocks ( 1 cubic km = 1000*1000*1000 meters).
> In order for any explosive asteroid deterrant system to work well, you still have to make sure that the asteroid will be sufficiently vaporized to be eaten up in the atmosphere.
Actually, that's even worse. If we break it up enough for the atmosphere to dissipate all the energy, that just means we're making sure the *surface* of the earth gets *all* the energy. Read: equivalent to nuclear armaggedon (actually probably a lot more energy than that). If it was in one big piece, the interior of the planet will receive a big chunk of the energy, and dissipate it as heat.
The only way breaking it up would be better is if the dust is dissapated widely enough that only a tiny fraction of it impacts the earth (per orbital pass).
> Relatively, 1000 1-meter rocks are better than 1 1-km rock. Make that 1 billion 1-meter rocks ( 1 cubic km = 1000*1000*1000 meters). > In order for any explosive asteroid deterrant system to work well, you still have to make sure that the asteroid will be sufficiently vaporized to be eaten up in the atmosphere. Actually, that's even worse. If we break it up enough for the atmosphere to dissipate all the energy, that just means we're making sure the *surface* of the earth gets *all* the energy. Read: equivalent to nuclear armaggedon (actually probably a lot more energy than that). If it was in one big piece, the interior of the planet will take on a big chunk of the energy, and dissipate it as heat.
But what if the interior of the rabbit were inert; if it's life depended only on its surface? Then a bullet would make a big mark, but just one mark. Peppering it with buckshot would cause more damage. The earth is like that -- the interior can take a beating; there's no life there; the propagating shockwaves simply dissipate the energy as heat, and there's a lot of heat there already. If we break the asteroid up, the *surface* of the earth takes *all* the energy. We're talking many many times the energy of all the nukes that we humans have pointing at each other.
> Yes, I'd rather be hit with a bail of hay than of a bullet carrying the same kenetic energy. Neither would be pleasant, but I'll take the distributed forces any day.
But what if the bale of hay were traveling at Mach 2; the bullet at, oh I dunno, mach 20? The bullet would pierce through you, with some shockwave effects, but the bale of hay would atomize you. Which one gives you a better chance of survival?
Not only is it not effective, but breaking up an asteroid into smaller pieces would actually make things *worse*.
Think about it: a cubic kilometer contains 1 billion cubic meters. At the velocities we're talking about, a 1-cubic-meter asteroid will likely cause a pretty decent airburst when gets to a sufficiently dense level of the atmosphere. I'd guess it'd be an explosion that's a significant fraction of a kiloton in size -- let's say 100 tons of explosive force. We then do the math: 100 * 1 billion = 100 billion tons -- that's equivalent to 100,000 one-megaton nuclear weapons going off in the atmosphere.
Even if I'm being pessimistic by a factor of 100, that's still a thousand nukes' worth. At any rate, it'd pretty easily be worse than any nuclear armageddon we might unleash upon ourselves. And remember I'm only talking about a 1-km asteroid here.
If the asteroid were intact, however, a very large fraction of the energy would be delivered directly into the body of the earth, where it will be dissapated as heat internally. Yes, the site of impact is atomized, with global earthquakes and potential tsunamis, raining debris, etc, but life in general -- even complex life -- would still have a good chance. 100,000 nukes going off in the atmosphere would fry *everything* on the surface, and would only spare the interior of the earth, which is the one thing that can take it.
>BMRT was closed source but free, and now it's
> dead, gone for good as well as Entropy.
I'm holding out the (perhaps naieve) hope that this IP will make its way into one of NVidia's chips. That *would* be cool, actually, if you could have BMRT/Entropy-quality renderers implemented in *hardware*.
And if someday it's integrated into a handheld device, you'd have a real "renderman". (Which, by the way is the idea that spawned that name.)
... to build a thousand 100-km rail guns
to launch cargoes into any orbit you want,
IN PARALLEL, rather than a single, 100,000km
serial cable?