Earth evacuation

jeff findley wrote in message ...
Doug Haxton writes:
OTOH, if it's much bigger than 15-20 miles in diameter, it *is* game
over for the human species...not to mention every other megafauna.

Why? We're really good at harnessing energy sources other than solar
energy. Unless you obliterate all power plants all over the planet,
we'll still have some power to harness. Grow light production will
surely increase in order to produce food in artificially lit
greenhouses.

If a 20 mile diameter asteroid struck the Earth, the impact would have
(calculating off the top of my head) about 30 times the energy of the
Dinosaur killer of 65 MYA. It would have a 3 in 4 chance of striking
in the ocean; the resultant waves would destroy virtually every
coastal city on Earth, and many inland ones. The crater would be
around 400(!) miles wide. The blast alone would probably kill anyone
within a couple of thousand miles. When the ejecta from the impact
rained down, it would be the equivelant of a global thermonuclear
war...and then some. Every fault line on Earth will probably go off.

And that's just in the first day.

Good luck running a nuclear power plant under those conditions...

The following website:
http://www1.tpgi.com.au/users/tps-se...#tsunamiimpact

estimates the casualties from a 2 km wide asteroid impact at 1.5
billion. If it was 100 times more massive? As I said...game over.

Doug

On 15 Sep 2003 14:02:59 GMT, (TKalbfus) wrote:

Still game over, in all likelihood. The only chance we'd have would
be to build a self-sustaining base on the Moon. I just don't see how
we could design & build enough vehicles in only 5 years to do that.

If we had 10 or 20 years...maybe. If we had a century, certainly.

Too hard a problem! Its easier to build an asteroid shelter for many more
people, that it would to build a spaceship for escape. An asteroid shelter
could protect 100 million people even from a dinosaur killer. What did most of
the killing for the dinosaurs was the asteroids effect on the atmosphere. With
a properly built shelter, human beings could survive that.

What, exactly, is an "asteroid shelter"?

Doug

Doug Haxton wrote:
If a dinosaur-killer just hit us, forget it. Game over.

Let's assume it's not an asteroid. Maybe a mass increase in volcanism around
the world that starts doing what happened to Venus? I think shelters
wouldn't help then.

David

--
Engineers aren't boring people, we just get excited about boring things.

What, exactly, is an "asteroid shelter"?

Doug


An underground bunker far enough away from the point of impact and able to
shield against secondary effects. It contains all the stuff Humanity needs to
start over again once the atmosphere clears.

Tom

On 16 Sep 2003 04:18:18 GMT, (TKalbfus) wrote:

What, exactly, is an "asteroid shelter"?

Doug


An underground bunker far enough away from the point of impact and able to
shield against secondary effects. It contains all the stuff Humanity needs to
start over again once the atmosphere clears.

You said that this bunker could protect 100 *million* people. Was
that a typo on your part, or do you think that we could actually build
such a structure?

Doug

On Tue, 16 Sep 2003 14:02:39 +1000, David Findlay
wrote:

Doug Haxton wrote:
If a dinosaur-killer just hit us, forget it. Game over.

Let's assume it's not an asteroid. Maybe a mass increase in volcanism around
the world that starts doing what happened to Venus? I think shelters
wouldn't help then.

Any increase in vulcanism sufficient to render the Earth uninhabitable
in only 5 years would disrupt society to the degree that launching
anything of significance into space would be impossible.

Doug

jeff findley wrote:

Doug Haxton writes:
OTOH, if it's much bigger than 15-20 miles in diameter, it *is* game
over for the human species...not to mention every other megafauna.

Why? We're really good at harnessing energy sources other than solar
energy. Unless you obliterate all power plants all over the planet,
we'll still have some power to harness. Grow light production will
surely increase in order to produce food in artificially lit
greenhouses.

Jeff

I think he means, would any of us even survive the first *day* under
those circumstances?

Let's assume it's not an asteroid. Maybe a mass increase in volcanism around
the world that starts doing what happened to Venus? I think shelters
wouldn't help then.

David

An unlikely event considering that it didn't even happen to Venus. Venus is
heated by the Greenhouse effect and its closer proximity to the sun, not by
volcanism. Volcanism didn't cause Venus to be the way it is. For Volcanism to
make the Earth as hot as Venus, the volcanoes would have to release an equal
amount of heat as the Earth already receives from the sun, and it must release
this heat over a long period of time. An equally likely scenario is for Mars to
suddenly become hypervolcanic and begin outgassing, tremendously thickening its
atmosphere and heating its surface to hospitable levels.

Tom

You said that this bunker could protect 100 *million* people. Was
that a typo on your part, or do you think that we could actually build
such a structure?

Doug

Sure, why not? 100 million is 1/60th the World's current population. I'm sure 6
billion people can build and stock a shelter for 100 million. That would be 60
people building living quarters for every individual. A lottery would be drawn
with each person having a 1 in 60 chance of winning. The main thing is to
produce and store enough supplies to last through the darkness. 60 years should
be enough time for the skies to clear up. We have no chance at all of building
a spaceship that can carry 100 million people. Maybe a few thousand, but
getting into space is expensive with our current technology, the resources
would be better spend to save 100 million lives on Earth than a few thousand in
space. Also if we are capable of lifting so many people into space we could
probably also divert the asteroid. Asking about a 200 km asteroid on a
collision with Earth is kind of silly as its unlikely to happen.

Tom

David Findlay wrote:
Doug Haxton wrote:
If a dinosaur-killer just hit us, forget it. Game over.

Let's assume it's not an asteroid. Maybe a mass increase in volcanism around
the world that starts doing what happened to Venus? I think shelters
wouldn't help then.

Butthat is a very long term thing and countering (artifical high
speed equvalents of fossilisation, etc) might be possible. The longer
it takes, the easier it is to counter.


David


--
Sander

+++ Out of cheese error +++