Reply to topic  [ 66 posts ]  Go to page Previous  1, 2, 3  Next
Evacuate Earth 
Author Message
User avatar

Joined: Sat Mar 05, 2011 6:24 am
Posts: 391
Post Re: Evacuate Earth
An elevator would be one single big piece of infrastructure with hard and rather low limitations on payload volume and mass and number of active climbers. A Lofstrom loop would have similar limitations, while also being a control nightmare and constant power hog, not to mention the safety issues involved in a failure. You need a massive increase in throughput, not a highly specialized launch system that will end up being one big bottleneck. Start mass producing big dumb rockets and build launch sites scattered across the planet...you'll get moving far sooner and be able to launch people and materials as fast as you can build launch vehicles and places to put them.


Thu Dec 03, 2015 4:58 pm
Profile

Joined: Fri Sep 23, 2011 9:33 pm
Posts: 673
Post Re: Evacuate Earth
joestej wrote:
Absalom wrote:
That's not even quite the limit on surviving population: the real limit is determined by the lesser of:
1) the population that the initial load(s) of mining, processing, & construction equipment and workers sent to the moon can build appropriate habitat capacity for, or
2) the population that the evacuation-stage orions can bus up to the habitats built from lunar materials.


Well, that's a bit of a question though. If the coming catastrophe is just going to wipe out Earth, then Lunar/Martian/space colonies are our obvious solution. But if the whole solar system is going to become uninhabitable, our problems are much more dire. I've been assuming that this more extreme threat is the one we'd be dealing with, because it's a more complex problem so there's more to talk about.
Sorry about the lack of clarity, I was assuming the more extreme threat as well, but with the quirk of building the escape ship from lunar materials instead of terrestrial materials, thanks to very early launches of mining equipment to the Moon via Orions. For bulk materials, it strikes me as a pretty good option (certainly better than asteroids, since you can partially use existing technology, and better than the Earth, since you can launch more easier). This wouldn't prevent Earth launches either.


Thu Dec 03, 2015 7:40 pm
Profile

Joined: Thu Mar 12, 2015 5:00 pm
Posts: 327
Post Re: Evacuate Earth
The need to leave earth and the need to leave the solar system are not necessarily the same thing. The scenario used a neutron star but I doubt even that would destroy the whole solar system. As such, priority one is to get out of the way but once that is done, there is little need to hurry. One could lurk around in the solar system for long after a disaster mining stuff and building space habitats. Eventually you have a generation of people raised in those space habitats and they would see an interstellar trip as nothing unusual, apart of even slower connection to the neighbours at home. Indeed the solar system may never really be void of people. Humanity spreads to neighbouring systems with holdouts in the millions still living back home.


Fri Dec 04, 2015 2:47 am
Profile
User avatar

Joined: Wed Nov 04, 2015 1:15 pm
Posts: 43
Post Re: Evacuate Earth
For the sake of argument, suppose the Neutron Star is set to collide with the Sun.


Fri Dec 04, 2015 6:44 am
Profile
User avatar

Joined: Wed Oct 07, 2015 6:47 am
Posts: 179
Location: My own little world...
Post Re: Evacuate Earth
Eluvatar wrote:
For the sake of argument, suppose the Neutron Star is set to collide with the Sun.


This was the option I was assuming as well, though the reason we're leaving is ultimately unimportant. For the purposes of this discussion, all we need to know is that Earth/the whole Solar System will be rendered completely uninhabitable in 70 years so we need to leave.

Absalom wrote:
Sorry about the lack of clarity, I was assuming the more extreme threat as well, but with the quirk of building the escape ship from lunar materials instead of terrestrial materials, thanks to very early launches of mining equipment to the Moon via Orions. For bulk materials, it strikes me as a pretty good option (certainly better than asteroids, since you can partially use existing technology, and better than the Earth, since you can launch more easier). This wouldn't prevent Earth launches either.


The data I've been able to find on Lunar minerals suggests that the most common resources would be anorthite (which can be refined into aluminum), iron, calcium (as a byproduct of anorthite refinement), and ilmenite (a resource that can be purified into titanium). Of those four, only the ilmenite and anorthite would be really useful as titanium and aluminum both have high strength for their mass and aluminum is used as fuel for some chemical rockets. Either way the mining will be much easier than the refining and forging. It'll take quite a bit of infrastructure before we can make moon-mines viable, but it still might be a good idea.

_________________
"Sometimes it's better to light a flamethrower than to curse the darkness."


Fri Dec 04, 2015 7:26 am
Profile WWW

Joined: Thu Mar 24, 2011 8:46 pm
Posts: 165
Post Re: Evacuate Earth
Eluvatar wrote:
For the sake of argument, suppose the Neutron Star is set to collide with the Sun.



Then we are screwed. There is no way we could get -any- ship far enough out of the solar system to survive the energetic event that will happen to the sun after a neutron star smacks into it. Not without a warp, hyper or jump drive. Not to mention, don't neutron stars put out a LOT of radiation? Moreso than our sun? If so, the 70 year escape time frame is likely going to have some years snipped off the end.


Fri Dec 04, 2015 8:33 am
Profile
User avatar

Joined: Sat Mar 05, 2011 1:35 pm
Posts: 917
Location: Middle of Nowhere
Post Re: Evacuate Earth
hi hi

For a stellar collision scenario, the best chances for survival would probably be building bunkers deep underground and waiting out the collision. Then, once the charred, airless world is in the middle of turning into a frozen hellscape, people in space suits can leave their underground bunkers and start building ships to go to another world.

I suppose if the colliding star is big enough, one might want to consider building giant bunkers deep underground on Mars, or one of the more distant solar bodies, but the important thing is probably avoiding the nova/gamma ray burst that is likely to result.


Fri Dec 04, 2015 10:02 am
Profile WWW
Site Admin
User avatar

Joined: Fri Mar 04, 2011 9:19 pm
Posts: 2308
Location: San Jose, CA
Post Re: Evacuate Earth
Eluvatar wrote:
For the sake of argument, suppose the Neutron Star is set to collide with the Sun.

That would be bad. :D

_________________
Outsider


Fri Dec 04, 2015 10:11 am
Profile WWW
User avatar

Joined: Wed Oct 07, 2015 6:47 am
Posts: 179
Location: My own little world...
Post Re: Evacuate Earth
Zakharra wrote:
Eluvatar wrote:
For the sake of argument, suppose the Neutron Star is set to collide with the Sun.



Then we are screwed. There is no way we could get -any- ship far enough out of the solar system to survive the energetic event that will happen to the sun after a neutron star smacks into it. Not without a warp, hyper or jump drive. Not to mention, don't neutron stars put out a LOT of radiation? Moreso than our sun? If so, the 70 year escape time frame is likely going to have some years snipped off the end.


icekatze wrote:
For a stellar collision scenario, the best chances for survival would probably be building bunkers deep underground and waiting out the collision. Then, once the charred, airless world is in the middle of turning into a frozen hellscape, people in space suits can leave their underground bunkers and start building ships to go to another world.

I suppose if the colliding star is big enough, one might want to consider building giant bunkers deep underground on Mars, or one of the more distant solar bodies, but the important thing is probably avoiding the nova/gamma ray burst that is likely to result.


Arioch wrote:
Eluvatar wrote:
For the sake of argument, suppose the Neutron Star is set to collide with the Sun.

That would be bad. :D


After some quick research, it seems Zakharra and Arioch are quite correct. According to Wikipedia a stellar collision within a hundred light years of Sol would probably end all life on Earth. Sorry icekatze, I don't think anyone can make bunkers deep enough to survive if our own star exploded like that.

Still, Plan Vault-Tec wouldn't be a horrible idea to survive a nearby Neutron Star hit. I question why we'd ever want to come back up at all though if we were living fine down there before. We can mine and process stuff underground, and we'd be growing our own food down there anyway. It's not perfect, but still a lot safer than leaving for alien worlds on SLT Generation Ships.

_________________
"Sometimes it's better to light a flamethrower than to curse the darkness."


Fri Dec 04, 2015 10:26 am
Profile WWW
User avatar

Joined: Sat Mar 05, 2011 1:35 pm
Posts: 917
Location: Middle of Nowhere
Post Re: Evacuate Earth
hi hi

First of all, the result of the collision is going to depend on the velocity and the angle of the collision. If the collision velocity exceeds the escape velocity, then you'll likely get a nova. If the collision velocity is lower than the escape velocity, it could potentially just form a Thorne-Zytkow object

Second of all, if you read the work by Dimitri Veras or John Debes, it may be very possible for planets to survive being ejected from the system during a post-main phase event.

The sun is certainly not 7 to 10 times the mass of the sun.


Fri Dec 04, 2015 11:15 am
Profile WWW
User avatar

Joined: Sun Mar 06, 2011 10:10 am
Posts: 269
Post Re: Evacuate Earth
Hm, that's actually an interesting question. Being further out in the system would cut down on the intensity of any solar problems, but you're also better off the more mass you can put between you and the sun, and earth is the biggest rock around. Maybe the best bet would be to set up stations in jupiter orbit, timed so that they're behind jupiter when the first shockwave hits. Then you've got the whole jovian system to exploit afterwards, so that'd be nice. You'd want to be pretty spot on with that timing, though.

_________________
Homeworld Fulcrum, a Homeworld 2/RM Mod


Fri Dec 04, 2015 1:40 pm
Profile
Site Admin
User avatar

Joined: Fri Mar 04, 2011 9:19 pm
Posts: 2308
Location: San Jose, CA
Post Re: Evacuate Earth
I doubt very much that you would be able to accurately predict the exact path of a neutron star through our solar system 70 years in advance of the encounter. I don't think it's possible to know the mass of the object to a close enough precision to be able to say with certainty what would happen. The slightest perturbation would significantly alter the interaction of the system, and such perturbations could be introduced deliberately.

If it's possible to predict a disaster with absolute certainty 70 years in advance, there is probably going to be something that can be done in those 70 years to prevent or ameliorate the disaster that is much more practical than evacuating the entire planet. If what you're interested in is the evacuation scenario, then it's probably best not to worry at all about what the disaster is, because inventing such a disaster is probably more work than inventing the evacuation scenario.

_________________
Outsider


Fri Dec 04, 2015 1:47 pm
Profile WWW
User avatar

Joined: Wed Oct 07, 2015 6:47 am
Posts: 179
Location: My own little world...
Post Re: Evacuate Earth
Arioch wrote:
If what you're interested in is the evacuation scenario, then it's probably best not to worry at all about what the disaster is, because inventing such a disaster is probably more work than inventing the evacuation scenario.


My thoughts exactly. Not that coming up with interesting ways to vaporize the planet wouldn't be fun, but this was originally supposed to be about how to evacuate Earth. We should probably stick with that.

Speaking of which, I think the biggest problem we're going to have now is that the nearest planet with any chance of being habitable is Tau Ceti e, 11.9 light years away. Even if we could build something like a Starwisp to check it out for us, it'll take 60 years to get there. Even if it can just go halfway and send us something back, we'll still be up the metaphorical creek if Tau Ceti e is useless (as it likely is).

I think our best shot is just building some space colonies with engines on them, pointing at the nearest star and going. So long as they can mine enough stuff to keep their reactors going and repair anything that breaks, they can just float around Alpha Centauri or any other star indefinitely. Not life as we knew it, but a lot better than taking a shot in the dark that there MIGHT be an Earth-like planet where ever we're going.

_________________
"Sometimes it's better to light a flamethrower than to curse the darkness."


Fri Dec 04, 2015 2:23 pm
Profile WWW
User avatar

Joined: Sat Mar 05, 2011 6:24 am
Posts: 391
Post Re: Evacuate Earth
Arioch wrote:
I doubt very much that you would be able to accurately predict the exact path of a neutron star through our solar system 70 years in advance of the encounter. I don't think it's possible to know the mass of the object to a close enough precision to be able to say with certainty what would happen. The slightest perturbation would significantly alter the interaction of the system, and such perturbations could be introduced deliberately.


A neutron star may only be 20-some km across, but the minimum mass is about 1.4 solar masses, about 1500 times the mass of Jupiter. If you're dealing with an opponent that can meaningfully perturb an object that outmasses the entire solar system, your best bet is to very humbly ask them for forgiveness for whatever it is you did that displeased them so much, since running away or hiding probably isn't going to work.

Otherwise, I really don't see a problem in working out the orbit necessary to place yourself on the far side of Jupiter from the most energetic of the events. The gravitation of the sun is well known, the gravitation of the incoming star is in a fairly narrow range, and probes could easily make precision measurements if there are no conveniently nearby Oort cloud/Kuiper belt objects to observe as they interact with the invader. You also don't have to put the stations in their final orbit 70 years in advance.


Fri Dec 04, 2015 3:32 pm
Profile
User avatar

Joined: Sat Mar 05, 2011 6:24 am
Posts: 391
Post Re: Evacuate Earth
icekatze wrote:
hi hi

First of all, the result of the collision is going to depend on the velocity and the angle of the collision. If the collision velocity exceeds the escape velocity, then you'll likely get a nova. If the collision velocity is lower than the escape velocity, it could potentially just form a Thorne-Zytkow object


It would have to be traveling at escape velocity, unless it had a close interaction with a third star that was also making a close pass of the solar system. I think it would initially go right through the sun...the sun doesn't have the mass to stop it, and that mass is too spread out. Whether they exchange enough momentum for the sun to be captured and eventually merge with the neutron star to form a Thorne-Zytkow object probably doesn't matter to us, since the sun and the rest of the solar system would most likely be parting ways. You probably wouldn't be able to recognize the sun anymore anyway.

I would expect the neutron star to emerge mid-nova as it fuses newly-gained hydrogen on its surface.


Fri Dec 04, 2015 3:57 pm
Profile
User avatar

Joined: Wed Oct 07, 2015 6:47 am
Posts: 179
Location: My own little world...
Post Re: Evacuate Earth
Mjolnir wrote:
Arioch wrote:
I doubt very much that you would be able to accurately predict the exact path of a neutron star through our solar system 70 years in advance of the encounter. I don't think it's possible to know the mass of the object to a close enough precision to be able to say with certainty what would happen. The slightest perturbation would significantly alter the interaction of the system, and such perturbations could be introduced deliberately.


A neutron star may only be 20-some km across, but the minimum mass is about 1.4 solar masses, about 1500 times the mass of Jupiter. If you're dealing with an opponent that can meaningfully perturb an object that outmasses the entire solar system, your best bet is to very humbly ask them for forgiveness for whatever it is you did that displeased them so much, since running away or hiding probably isn't going to work.

Otherwise, I really don't see a problem in working out the orbit necessary to place yourself on the far side of Jupiter from the most energetic of the events. The gravitation of the sun is well known, the gravitation of the incoming star is in a fairly narrow range, and probes could easily make precision measurements if there are no conveniently nearby Oort cloud/Kuiper belt objects to observe as they interact with the invader. You also don't have to put the stations in their final orbit 70 years in advance.



...you may have missed the second part of that comment, where Arioch pointed out that the cause of the catastrophe wasn't relevant to the discussion at hand?

_________________
"Sometimes it's better to light a flamethrower than to curse the darkness."


Fri Dec 04, 2015 4:02 pm
Profile WWW
User avatar

Joined: Sat Mar 05, 2011 1:35 pm
Posts: 917
Location: Middle of Nowhere
Post Re: Evacuate Earth
hi hi

Well, depending on the cause of the disaster, you could potentially use the disaster to your benefit. A nova could provide a lot of delta V if you had an appropriately shaped pusher plate. :)


Fri Dec 04, 2015 4:24 pm
Profile WWW
User avatar

Joined: Wed Nov 04, 2015 1:15 pm
Posts: 43
Post Re: Evacuate Earth
icekatze wrote:
Well, depending on the cause of the disaster, you could potentially use the disaster to your benefit. A nova could provide a lot of delta V if you had an appropriately shaped pusher plate. :)

That is good lateral thinking. I approve.

That said, such a pusher plate might be more expensive than launching a more conventional craft a few years or even decades earlier.


Fri Dec 04, 2015 4:48 pm
Profile

Joined: Fri Sep 23, 2011 9:33 pm
Posts: 673
Post Re: Evacuate Earth
joestej wrote:
Absalom wrote:
Sorry about the lack of clarity, I was assuming the more extreme threat as well, but with the quirk of building the escape ship from lunar materials instead of terrestrial materials, thanks to very early launches of mining equipment to the Moon via Orions. For bulk materials, it strikes me as a pretty good option (certainly better than asteroids, since you can partially use existing technology, and better than the Earth, since you can launch more easier). This wouldn't prevent Earth launches either.


The data I've been able to find on Lunar minerals suggests that the most common resources would be anorthite (which can be refined into aluminum), iron, calcium (as a byproduct of anorthite refinement), and ilmenite (a resource that can be purified into titanium). Of those four, only the ilmenite and anorthite would be really useful as titanium and aluminum both have high strength for their mass and aluminum is used as fuel for some chemical rockets. Either way the mining will be much easier than the refining and forging. It'll take quite a bit of infrastructure before we can make moon-mines viable, but it still might be a good idea.
The numbers I've seen place oxygen, silicon, and aluminum, in that order, as the most common constituencies of the entire Moon, or at least the visible surface. I don't know that silicon is all that usable as a structural material, but aluminum conceptually is. That having been said, aluminum supposedly has no way to not loose strength over time, so I'd be more inclined to use it for internal components, launch fuel, and initial facilities construction. The "good stuff" is the iron and titanium (primary structural components, until you get time to hunt down a carbon-rich asteroid), generalized regolith (ablative armor), etc. Still, depending on time required, perhaps the aluminum would be the right way to go.

Eluvatar wrote:
icekatze wrote:
Well, depending on the cause of the disaster, you could potentially use the disaster to your benefit. A nova could provide a lot of delta V if you had an appropriately shaped pusher plate. :)

That is good lateral thinking. I approve.

That said, such a pusher plate might be more expensive than launching a more conventional craft a few years or even decades earlier.
The mounting system, too.


Fri Dec 04, 2015 6:43 pm
Profile

Joined: Thu Mar 24, 2011 8:46 pm
Posts: 165
Post Re: Evacuate Earth
Eluvatar wrote:
icekatze wrote:
Well, depending on the cause of the disaster, you could potentially use the disaster to your benefit. A nova could provide a lot of delta V if you had an appropriately shaped pusher plate. :)

That is good lateral thinking. I approve.

That said, such a pusher plate might be more expensive than launching a more conventional craft a few years or even decades earlier.



Unless you have damned good shielding systems and cooling systems all over the ship, you're still dead. The radiation and heat will go around the pusher plate and will fry and cook/burn anything in the ship. Remember you'll be inside the nova AoE when it goes off. It's being, literally, in the middle of a fusion explosion many orders of magnitude stronger than the most powerful nuclear weapon humanity has ever made.


Sat Dec 05, 2015 1:02 am
Profile
User avatar

Joined: Sat Mar 05, 2011 6:24 am
Posts: 391
Post Re: Evacuate Earth
Absalom wrote:
joestej wrote:
Absalom wrote:
Sorry about the lack of clarity, I was assuming the more extreme threat as well, but with the quirk of building the escape ship from lunar materials instead of terrestrial materials, thanks to very early launches of mining equipment to the Moon via Orions. For bulk materials, it strikes me as a pretty good option (certainly better than asteroids, since you can partially use existing technology, and better than the Earth, since you can launch more easier). This wouldn't prevent Earth launches either.


The data I've been able to find on Lunar minerals suggests that the most common resources would be anorthite (which can be refined into aluminum), iron, calcium (as a byproduct of anorthite refinement), and ilmenite (a resource that can be purified into titanium). Of those four, only the ilmenite and anorthite would be really useful as titanium and aluminum both have high strength for their mass and aluminum is used as fuel for some chemical rockets. Either way the mining will be much easier than the refining and forging. It'll take quite a bit of infrastructure before we can make moon-mines viable, but it still might be a good idea.
The numbers I've seen place oxygen, silicon, and aluminum, in that order, as the most common constituencies of the entire Moon, or at least the visible surface. I don't know that silicon is all that usable as a structural material, but aluminum conceptually is. That having been said, aluminum supposedly has no way to not loose strength over time, so I'd be more inclined to use it for internal components, launch fuel, and initial facilities construction. The "good stuff" is the iron and titanium (primary structural components, until you get time to hunt down a carbon-rich asteroid), generalized regolith (ablative armor), etc. Still, depending on time required, perhaps the aluminum would be the right way to go.


Silicon + oxygen = silica, the primary component of glass fiber. In fact, plain basalt can be spun into fiber that can be used in reasonably high performance composites. Elemental silicon fiber would probably also be pretty good, but I don't know if its strength to weight would be higher than silica. And it's not like you need the oxygen for something else...there's only so much you can breathe.

Calcium's too reactive to use on Earth, but would make a good electrical conductor in vacuum, and alloys might be good structural metals (it's the lightest of the alkali earth metals, lighter than magnesium). You would need a thicker wire gauge than copper to achieve the same conductivity, but IIRC, the mass would be lower. Calcium and oxygen are also components of many ceramics, particularly high-temperature ones.

Waste oxygen could be a useful propellant, if you can keep it from oxidizing your rocket engine. Silicon could be a low-performance but cheap fuel to use with it.


Sat Dec 05, 2015 7:37 am
Profile
User avatar

Joined: Wed Nov 04, 2015 1:15 pm
Posts: 43
Post Re: Evacuate Earth
Zakharra wrote:
Eluvatar wrote:
icekatze wrote:
Well, depending on the cause of the disaster, you could potentially use the disaster to your benefit. A nova could provide a lot of delta V if you had an appropriately shaped pusher plate. :)

That is good lateral thinking. I approve.

That said, such a pusher plate might be more expensive than launching a more conventional craft a few years or even decades earlier.



Unless you have damned good shielding systems and cooling systems all over the ship, you're still dead. The radiation and heat will go around the pusher plate and will fry and cook/burn anything in the ship. Remember you'll be inside the nova AoE when it goes off. It's being, literally, in the middle of a fusion explosion many orders of magnitude stronger than the most powerful nuclear weapon humanity has ever made.

Inverse r^2 shrinks pretty fast, to be fair.


Sat Dec 05, 2015 8:06 am
Profile

Joined: Fri Sep 23, 2011 9:33 pm
Posts: 673
Post Re: Evacuate Earth
Mjolnir wrote:
Absalom wrote:
joestej wrote:
The data I've been able to find on Lunar minerals suggests that the most common resources would be anorthite (which can be refined into aluminum), iron, calcium (as a byproduct of anorthite refinement), and ilmenite (a resource that can be purified into titanium). Of those four, only the ilmenite and anorthite would be really useful as titanium and aluminum both have high strength for their mass and aluminum is used as fuel for some chemical rockets. Either way the mining will be much easier than the refining and forging. It'll take quite a bit of infrastructure before we can make moon-mines viable, but it still might be a good idea.
The numbers I've seen place oxygen, silicon, and aluminum, in that order, as the most common constituencies of the entire Moon, or at least the visible surface. I don't know that silicon is all that usable as a structural material, but aluminum conceptually is. That having been said, aluminum supposedly has no way to not loose strength over time, so I'd be more inclined to use it for internal components, launch fuel, and initial facilities construction. The "good stuff" is the iron and titanium (primary structural components, until you get time to hunt down a carbon-rich asteroid), generalized regolith (ablative armor), etc. Still, depending on time required, perhaps the aluminum would be the right way to go.


Silicon + oxygen = silica, the primary component of glass fiber. In fact, plain basalt can be spun into fiber that can be used in reasonably high performance composites. Elemental silicon fiber would probably also be pretty good, but I don't know if its strength to weight would be higher than silica. And it's not like you need the oxygen for something else...there's only so much you can breathe.
I don't see mention of a binder anywhere in this. I hope you're not proposing iron (melting point) or aluminum (arguing against it due to unavoidable stress-related degradation was the point of that part of the post).

Mjolnir wrote:
Calcium's too reactive to use on Earth, but would make a good electrical conductor in vacuum, and alloys might be good structural metals (it's the lightest of the alkali earth metals, lighter than magnesium). You would need a thicker wire gauge than copper to achieve the same conductivity, but IIRC, the mass would be lower. Calcium and oxygen are also components of many ceramics, particularly high-temperature ones.

Waste oxygen could be a useful propellant, if you can keep it from oxidizing your rocket engine. Silicon could be a low-performance but cheap fuel to use with it.
I already mentioned "etc.", though I hadn't considered silicon as a propellant fuel: good idea that answers how to launch from the moon pre-semiconductor purities.


Sun Dec 06, 2015 1:01 am
Profile
User avatar

Joined: Sat Mar 05, 2011 6:24 am
Posts: 391
Post Re: Evacuate Earth
Absalom wrote:
I don't see mention of a binder anywhere in this. I hope you're not proposing iron (melting point) or aluminum (arguing against it due to unavoidable stress-related degradation was the point of that part of the post).


No, I was thinking of something more conventional. You need very little binder compared to the amount of reinforcement fiber, you could import it (or the hydrocarbons needed to produce a silicone binder) and still achieve a large gain. Cloth and cables can also be useful without any binder.


Sun Dec 06, 2015 7:21 am
Profile

Joined: Thu Mar 24, 2011 8:46 pm
Posts: 165
Post Re: Evacuate Earth
icekatze wrote:
Well, depending on the cause of the disaster, you could potentially use the disaster to your benefit. A nova could provide a lot of delta V if you had an appropriately shaped pusher plate. :)

Eluvatar wrote:
Zakharra wrote:
Eluvatar wrote:
That is good lateral thinking. I approve.

That said, such a pusher plate might be more expensive than launching a more conventional craft a few years or even decades earlier.



Unless you have damned good shielding systems and cooling systems all over the ship, you're still dead. The radiation and heat will go around the pusher plate and will fry and cook/burn anything in the ship. Remember you'll be inside the nova AoE when it goes off. It's being, literally, in the middle of a fusion explosion many orders of magnitude stronger than the most powerful nuclear weapon humanity has ever made.

Inverse r^2 shrinks pretty fast, to be fair.



Very likely, but not when you're IN the system when the sun goes nova. At that point everything in the system is destroyed. Especially since a nova and supernova will affect systems that are several lightyears away.

And I realized that digging deep bunkers in a planet or moon isn't likely to work either. The shockwave and succeeding waves of the explosion of the sun will shatter the planets (at the least strip away any atmosphere and cause massive earthquakes of 50 or higher on the Richter scale. The outer gas giants are likely to have their atmospheres stripped away and their moons blown out into space or shattered. I cannot see how anything can survive being in system when a sun goes boom. Or a ship(s) surviving it.


Mon Dec 07, 2015 7:43 am
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 66 posts ]  Go to page Previous  1, 2, 3  Next

Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by STSoftware for PTF.