The link in question analyzes the possibility of creating a doomsday weapon that could launch a projectile that would destroy all life on another earth sized planet remotely. That is a far more difficult task than just destroying life on the planet the bomb is on. The limiting factor in question is also fission materials to serve as triggers for the primary explosion in each of hundreds of thousands of shaped thermonuclear explosions. The massive numbers of distinct explosions are needed to progressively accelerate the Orion device but for a single explosion the ration of fissile trigger to fusion material need not be the same.
Mind you the Orion weapon is just intended to obliterate all life. That task becomes comparitively trivial when you aren’t trying to do it across space via projectile. But if Multipartite literally wants to smash the earth into pieces I suspect he is out of luck for now!
He wants something which would crack the planet’s crust; you’re not going to get that with widely dispersed efficient-life-killing thermonuclear strikes (leaving aside the obvious question ‘what do you do about the vents and spores etc’). To do that, you need a lot of energy, whether it’s a kinetic projectile or a fireball & shockwave. A Project Orion kinetic strike would probably be more efficient than a pile of gigaton nukes since each explosion can be smaller and more energy extracted than it.
you’re not going to get that with widely dispersed efficient-life-killing thermonuclear strikes (leaving aside the obvious question ‘what do you do about the vents and spores etc’).
Where on earth did widely dispersed efficient-life-killing thermonuclear strikes come into it? Multi was considering a bomb (or cluster thereof) at a single location. The closest to ‘dispersion’ was when you brought Orion into it, with it’s chain of bombs spread out over the launch distance.
A Project Orion kinetic strike would probably be more efficient than a pile of gigaton nukes since each explosion can be smaller and more energy extracted than it.
Or, alternately, it would be overwhelmingly inefficient because the projectile is aimed away from the planet—or at best along the surface of it.
I incidentally dispute your efficiency claim anyway. I’d be willing to bet that if you collect every one of the bombs you were using for your Orion weapon and place them in single location then it would be more capable of slippiting the planet than the projectile would have been. Even if you managed to make it target the earth directly. If necessary you would of course use several years worth of the entire earth’s production of steel (and maybe lead, gold and anything else hard or heavy) and use it to cover the bomb and keep the energy around a tad longer.
Why does it need to be aim along the planet? Use orbital mechanics: Send your spacecraft on an orbit such that it hits the planet it launched from at the fast point of a very long elliptical orbit. Or even just at the far side of the current planet’s orbit, whatever. It can’t be that hard to get an impact at whatever angle you’d prefer with most of the Orion vehicle’s energy, launching direction barely seems to matter.
No particular reason. It’s just that the arbitrary task of planetary self destruction that Multipartite specified happens to be that of destroying the planet with a bomb on the surface. If you were just trying to destroy the planet then doing so from the surface seems like a terrible idea.
(For thoroughness, noting that the other approach was also wondered about a little earlier. Surface action is an alternative to look at if projectile-launching would definitely be ineffective, but if the projectile approach would in fact be better then there’d no reason not to focus on it instead.)
I incidentally dispute your efficiency claim anyway. I’d be willing to bet that if you collect every one of the bombs you were using for your Orion weapon and place them in single location then it would be more capable of slippiting the planet than the projectile would have been. Even if you managed to make it target the earth directly. If necessary you would of course use several years worth of the entire earth’s production of steel (and maybe lead, gold and anything else hard or heavy) and use it to cover the bomb and keep the energy around a tad longer.
As I already said, the scaling laws mean the larger the bomb, the less efficient it becomes. Piling together 200 bombs just means you get inefficiency and possible fratricide from the explosion themselves or neutron emission. (Looking briefly at my old notes, underwater explosions have an exponent of tonnage raised to 2⁄3 for the resultant overpressure wave.)
I’m the one who has read in detail about basic equational descriptions of nukes by their tonnage, targeting concerns, the engineering involved in going to megatonnage or gigatonnage range, etc. (I wanted to make a nuke simulation game), so you’ll pardon me if I put more weight on my opinion than yours.
so you’ll pardon me if I put more weight on my opinion than yours.
And you must pardon me if I find that:
Your reference work pertains to an entirely different problem—one of interstellar planetary destruction.
Your reference work pertains to killing a population not destroying the planet itself.
The limiting factor that you appeal to is the lack of fissile material. This is an artifact of the tactic you have adopted of making many moderately sized nukes. If someone was optimizing the total amount of explosion they could make from a given amount of fission material they quite obviously would change the design. For example they would include a third stage of fusion fuel. Most bombs that been constructed thus far (with the hypothesized exception of Tsar Bomba) have not bothered to do so because, well, what would be the point?
You haven’t even seemed to acknowledge that there is a problem making your projectile effectively destroy the earth when it has been accelerated across the surface of the earth and so is pointing in totally the wrong direction.
Whatever mass of theoretical expertise you may have behind you, you most decidedly haven’t applied it coherently here. To the extent that if you had just made an assertion and appealed to your own authority I may have believed you but given that you explained details that are clearly wrong I have to dismiss it out of hand.
The scale factors don’t refer to killing populations.
The more stages you have, the worse the instabilities become. 3 stages is doable, but any more than that? Seriously questionable.
Is that seriously an objection? Why on earth does it have to be accelerated across the Earth’s surface? You’re being really lazy here in not even thinking of any alternatives.
The more stages you have, the worse the instabilities become. 3 stages is doable, but any more than that? Seriously questionable.
Three is more than sufficient to undermine your proof of concept “not enough fissiles” declaration.
Is that seriously an objection? Why on earth does it have to be accelerated across the Earth’s surface? You’re being really lazy here in not even thinking of any alternatives.
What the? Don’t be absurd. “Bomb on the planet’s surface.” was exactly the problem specification. If I wanted to destroy the earth I would obviously not try to do so with a bomb on the planet’s surface.
Any interstellar method is a fortiori a terrestrial method as well.
Three is more than sufficient to undermine your proof of concept “not enough fissiles” declaration.
In what respect? The Tsar Bomba gives us an estimate on what the third state buys one, let’s be generous roughly an order of magnitude (6mt to 60mt). The analysis I linked concluded that the existing nuclear stockpile was at least 100x too small to power an Orion, so a 10x increase is useful but not enough (and where’s the plutonium for 65k stage threes coming from?). If we go with the link’s world-wide estimate of 300,000 years of production and blindly apply the 10x estimate, that still leaves us 30,000 years short.
“Bomb on the planet’s surface.” was exactly the problem specification.
And where does the Orion vehicle hit?
(Would an ICBM be excluded as an answer because it enters space?)
Any interstellar method is a fortiori a terrestrial method as well.
It’s a task with entirely different challenges and to which entirely different tactics are optimal. It is just plain not the case that all interstellar methods are a fortiori terrestrial methods—since the very method your declaration of impossibility assumes is sufficiently optimal to rule out any possibility is one that doesn’t work when launched from the surface of the target planet.
The Tsar Bomba gives us an estimate on what the third state buys one, let’s be generous roughly an order of magnitude (6mt to 60mt).
The Tsar Bomba was deliberately crippled from it’s original specifications so as to reduce fallout while still being a sufficiently excessive explosion (although this was only on the order of a twofold reduction). Regardless I am almost as willing to accept the Tsar Bomba as the theoretical best (or worst) case for what humankind can do with a three stage thermonuclear device as I am to declare that ‘Little Boy’ the most potent fissile device that humans could make.
Simply taking the calculations used for hypothesizing about Orion weapons and applying them to surface based doomsday device is a gross error. The approach taken and the limiting factors would be entirely different.
This is not to say that I believe we currently have the technology to destroy the planet itself. To the best of my knowledge we do not. I simply reject the notions that an Orion device would be the way to go about it and hence that the fission limitation found when hypothesizing about Orion still applies at the levels calculated. I don’t present an alternate hypothesis that because these limitations no longer apply as calculated that we must be able to do the destruction—that would be reversing stupidity.
And where does the Orion vehicle hit?
Not at the location where the bombs go off—that’s exactly the problem.
(Would an ICBM be excluded as an answer because it enters space?)
I suppose Multi would allow it provided in returns and detonates at or near enough to the surface. My initial speculations about using Orion for self destruction speculated at finding a gravity well sufficient to slingshot it back to us—but that engineering feat strikes me as a tad difficult.
It is just plain not the case that all interstellar methods are a fortiori terrestrial methods
I’ll rephrase it, then: any method planet A can use to attack planet B can also be used by planet A to attack planet A. In the case of an Orion object, some large hyperbolic orbit which intersects the Earth seems possible, but if not, it could always be slowly launched out to whatever distance necessary and turn around.
The Tsar Bomba was deliberately crippled from it’s original specifications so as to reduce fallout while still being a sufficiently excessive explosion (although this was only on the order of a twofold reduction).
No doubt that’s part of the explanation, but is it the whole explanation? From one of Wikipedia’s refs:
Every aspect of the development was rushed. The mathematical analysis normally conducted by the Soviet weapon scientists for a new thermonuclear weapon design was skipped, substituting estimates and approximations of various kinds. This created uncertainties about the system performance that cropped up late in the preparations—leading to eleventh hour doubts, and last minute design modifications even while assembly was underway.
Another part of the ref mentions those modifications were made due to bitter arguments about whether it would work at all. (A quote from a report to the Soviet politicians says the design allowed for bombs of ‘unlimited power’ - which given the context, is as trustworthy as a $3 bill.)
Reducing the yield and eliminating an entire tamper sounds like something one might do if one is not sure the instabilities have been dealt with. Finally, to quote from one of the rival Soviet bomb-makers:
“At the beginning of 1961 we, who worked in the Urals, had word that our competitors in Arzamas-16 had thought of a new super-bomb. Pretty soon it turned out that it was not some super-discovery, but merely an increase in weight and size. Did that make sense? Building up yields in this simple fashion looked to us both trivial and useless. In those days, we were obsessed with a very different idea—miniaturization, which I have already described. At the same time (and I must honestly confess this) the fuss over the super-bomb idea could not leave us untouched. We were professionally jealous. We looked into the problem and at once spotted two weaknesses in our competitor’s design: their product would be too complicated and too heavy. It could not be squeezed into any of the delivery vehicles—already existing or those still on the drawing boards. Today, I can say quite definitely that we were right. All big bombs followed our way, while the 100-megaton giant—the pride of Arzamas-16 - was made only once—for the test. There was also a replica for the museum.”
(Unfortunately he doesn’t say whether the complexity and size were solely an issue for delivery or intrinsic to scaling, but it’s suggestive.)
Simply taking the calculations used for hypothesizing about Orion weapons and applying them to surface based doomsday device is a gross error. The approach taken and the limiting factors would be entirely different.
Yes, it is a gross error. An Orion vehicle is probably more efficient than a giant nuke or set of nukes, so the lower bounds aren’t going to be tight.
The link in question analyzes the possibility of creating a doomsday weapon that could launch a projectile that would destroy all life on another earth sized planet remotely. That is a far more difficult task than just destroying life on the planet the bomb is on. The limiting factor in question is also fission materials to serve as triggers for the primary explosion in each of hundreds of thousands of shaped thermonuclear explosions. The massive numbers of distinct explosions are needed to progressively accelerate the Orion device but for a single explosion the ration of fissile trigger to fusion material need not be the same.
Mind you the Orion weapon is just intended to obliterate all life. That task becomes comparitively trivial when you aren’t trying to do it across space via projectile. But if Multipartite literally wants to smash the earth into pieces I suspect he is out of luck for now!
He wants something which would crack the planet’s crust; you’re not going to get that with widely dispersed efficient-life-killing thermonuclear strikes (leaving aside the obvious question ‘what do you do about the vents and spores etc’). To do that, you need a lot of energy, whether it’s a kinetic projectile or a fireball & shockwave. A Project Orion kinetic strike would probably be more efficient than a pile of gigaton nukes since each explosion can be smaller and more energy extracted than it.
Where on earth did widely dispersed efficient-life-killing thermonuclear strikes come into it? Multi was considering a bomb (or cluster thereof) at a single location. The closest to ‘dispersion’ was when you brought Orion into it, with it’s chain of bombs spread out over the launch distance.
Or, alternately, it would be overwhelmingly inefficient because the projectile is aimed away from the planet—or at best along the surface of it.
I incidentally dispute your efficiency claim anyway. I’d be willing to bet that if you collect every one of the bombs you were using for your Orion weapon and place them in single location then it would be more capable of slippiting the planet than the projectile would have been. Even if you managed to make it target the earth directly. If necessary you would of course use several years worth of the entire earth’s production of steel (and maybe lead, gold and anything else hard or heavy) and use it to cover the bomb and keep the energy around a tad longer.
Why does it need to be aim along the planet? Use orbital mechanics: Send your spacecraft on an orbit such that it hits the planet it launched from at the fast point of a very long elliptical orbit. Or even just at the far side of the current planet’s orbit, whatever. It can’t be that hard to get an impact at whatever angle you’d prefer with most of the Orion vehicle’s energy, launching direction barely seems to matter.
No particular reason. It’s just that the arbitrary task of planetary self destruction that Multipartite specified happens to be that of destroying the planet with a bomb on the surface. If you were just trying to destroy the planet then doing so from the surface seems like a terrible idea.
(For thoroughness, noting that the other approach was also wondered about a little earlier. Surface action is an alternative to look at if projectile-launching would definitely be ineffective, but if the projectile approach would in fact be better then there’d no reason not to focus on it instead.)
As I already said, the scaling laws mean the larger the bomb, the less efficient it becomes. Piling together 200 bombs just means you get inefficiency and possible fratricide from the explosion themselves or neutron emission. (Looking briefly at my old notes, underwater explosions have an exponent of tonnage raised to 2⁄3 for the resultant overpressure wave.)
If we had some convenient test planets handy I would bet against you when it came to optimal planetary suicide methods.
Orion’s is a great idea for a different task but just not the solution to this problem.
/shrug
I’m the one who has read in detail about basic equational descriptions of nukes by their tonnage, targeting concerns, the engineering involved in going to megatonnage or gigatonnage range, etc. (I wanted to make a nuke simulation game), so you’ll pardon me if I put more weight on my opinion than yours.
And you must pardon me if I find that:
Your reference work pertains to an entirely different problem—one of interstellar planetary destruction.
Your reference work pertains to killing a population not destroying the planet itself.
The limiting factor that you appeal to is the lack of fissile material. This is an artifact of the tactic you have adopted of making many moderately sized nukes. If someone was optimizing the total amount of explosion they could make from a given amount of fission material they quite obviously would change the design. For example they would include a third stage of fusion fuel. Most bombs that been constructed thus far (with the hypothesized exception of Tsar Bomba) have not bothered to do so because, well, what would be the point?
You haven’t even seemed to acknowledge that there is a problem making your projectile effectively destroy the earth when it has been accelerated across the surface of the earth and so is pointing in totally the wrong direction.
Whatever mass of theoretical expertise you may have behind you, you most decidedly haven’t applied it coherently here. To the extent that if you had just made an assertion and appealed to your own authority I may have believed you but given that you explained details that are clearly wrong I have to dismiss it out of hand.
They’re the same thing.
The scale factors don’t refer to killing populations.
The more stages you have, the worse the instabilities become. 3 stages is doable, but any more than that? Seriously questionable.
Is that seriously an objection? Why on earth does it have to be accelerated across the Earth’s surface? You’re being really lazy here in not even thinking of any alternatives.
No they aren’t.
Three is more than sufficient to undermine your proof of concept “not enough fissiles” declaration.
What the? Don’t be absurd. “Bomb on the planet’s surface.” was exactly the problem specification. If I wanted to destroy the earth I would obviously not try to do so with a bomb on the planet’s surface.
Any interstellar method is a fortiori a terrestrial method as well.
In what respect? The Tsar Bomba gives us an estimate on what the third state buys one, let’s be generous roughly an order of magnitude (6mt to 60mt). The analysis I linked concluded that the existing nuclear stockpile was at least 100x too small to power an Orion, so a 10x increase is useful but not enough (and where’s the plutonium for 65k stage threes coming from?). If we go with the link’s world-wide estimate of 300,000 years of production and blindly apply the 10x estimate, that still leaves us 30,000 years short.
And where does the Orion vehicle hit?
(Would an ICBM be excluded as an answer because it enters space?)
It’s a task with entirely different challenges and to which entirely different tactics are optimal. It is just plain not the case that all interstellar methods are a fortiori terrestrial methods—since the very method your declaration of impossibility assumes is sufficiently optimal to rule out any possibility is one that doesn’t work when launched from the surface of the target planet.
The Tsar Bomba was deliberately crippled from it’s original specifications so as to reduce fallout while still being a sufficiently excessive explosion (although this was only on the order of a twofold reduction). Regardless I am almost as willing to accept the Tsar Bomba as the theoretical best (or worst) case for what humankind can do with a three stage thermonuclear device as I am to declare that ‘Little Boy’ the most potent fissile device that humans could make.
Simply taking the calculations used for hypothesizing about Orion weapons and applying them to surface based doomsday device is a gross error. The approach taken and the limiting factors would be entirely different.
This is not to say that I believe we currently have the technology to destroy the planet itself. To the best of my knowledge we do not. I simply reject the notions that an Orion device would be the way to go about it and hence that the fission limitation found when hypothesizing about Orion still applies at the levels calculated. I don’t present an alternate hypothesis that because these limitations no longer apply as calculated that we must be able to do the destruction—that would be reversing stupidity.
Not at the location where the bombs go off—that’s exactly the problem.
I suppose Multi would allow it provided in returns and detonates at or near enough to the surface. My initial speculations about using Orion for self destruction speculated at finding a gravity well sufficient to slingshot it back to us—but that engineering feat strikes me as a tad difficult.
I’ll rephrase it, then: any method planet A can use to attack planet B can also be used by planet A to attack planet A. In the case of an Orion object, some large hyperbolic orbit which intersects the Earth seems possible, but if not, it could always be slowly launched out to whatever distance necessary and turn around.
No doubt that’s part of the explanation, but is it the whole explanation? From one of Wikipedia’s refs:
Another part of the ref mentions those modifications were made due to bitter arguments about whether it would work at all. (A quote from a report to the Soviet politicians says the design allowed for bombs of ‘unlimited power’ - which given the context, is as trustworthy as a $3 bill.)
Reducing the yield and eliminating an entire tamper sounds like something one might do if one is not sure the instabilities have been dealt with. Finally, to quote from one of the rival Soviet bomb-makers:
(Unfortunately he doesn’t say whether the complexity and size were solely an issue for delivery or intrinsic to scaling, but it’s suggestive.)
Yes, it is a gross error. An Orion vehicle is probably more efficient than a giant nuke or set of nukes, so the lower bounds aren’t going to be tight.
That sounds rather a lot more plausible than the story they may prefer to be believed.