Moon May Have Formed in Natural Nuclear Explosion

[RexMundi]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Not really. All an explosion IS, is a reaction. Just faster and a little more energetic.

 

~Rex

[Kristopher]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Not really. All an explosion IS' date=' is a reaction. Just faster and a little more energetic.[/quote']

 

Um... a little?

 

While the fundamental physics of the fission chain reaction in a nuclear weapon is similar to the physics of a controlled nuclear reactor, the two types of device must be engineered quite differently (see nuclear reactor physics). It is impossible to convert a nuclear reactor to cause a true nuclear explosion[citation needed], or for a nuclear reactor to explode the way a nuclear explosive does, (though partial fuel meltdowns and steam explosions have occurred).

[Old Man]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Not really. All an explosion IS, is a reaction. Just faster and a little more energetic.

 

~Rex

 

Yes, but as I pointed out earlier, in order to get a detonation you have to bring the fissile material together very, very quickly, so that it goes supercritical. I can think of only one natural phenomenon that might accomplish that on this scale...

 

...an impact.

[McCoy]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Yes, but as I pointed out earlier, in order to get a detonation you have to bring the fissile material together very, very quickly, so that it goes supercritical. I can think of only one natural phenomenon that might accomplish that on this scale...

 

...an impact.

Humm, IIRC, the reason it has to be brought together "very, very quickly" is that it's going to release energy, creat heat, and force itself apart. If you had enough force compressing it, say, several subcritical masses suspended in the molten core of a planet, could they not be squeezed together more slowly? As long as the compressive force was greater than the force tearing them apart?

[Cancer]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

But how did you assemble those subcritical masses quickly against the compressive force that was holding them where they were? The number of kilograms in a critical mass is an unavoidable upper limit into how big the pre-bang masses of fissile stuff can be before the blast, because if you assemble a bigger mass than that, by definition it blow up and expends all the nuclear potential energy you could get out ot it.

 

When a mass goes critical, the timescale for nuclear reactions is entirely different from the timescale for the forces that assembled the critical mass. If you don't bring ALL the going-to-go-critical masses together at the same time (and that time interval has to be no longer than a few minutes, since while little bangs will blow stuff into the air the stuff will fall back down again and lose all that nice kinetic energy you got out of the bang, so the next little bang has to start more or less from scratch in trying to blow the chunks into orbit), then they each make separate little firecracker pops that won't blow the huge 1/80 of the planet out into space. They WILL disrupt the surface a lot, but you won't get anything out into orbit. And in those firecracker pops you expend most of the fissile nuclei, breaking them into fission products that can no longer go bang in any way, shape or form.

 

You get one chance at a big-enough fission blast, and it all has to go bang at once. UNLESS you somehow channel most of the energy out of each little blast into propelling one small bit of matter to high veolcities straight up. And there is no such mechanism: as we HERO-system power designers surely know, the Explosion modifier on a Blast means the blast expends its energy in a symmetric way around the blast origin.

[Zeropoint]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

This is where we cross-link to the Orion Drive thread.

[NuSoardGraphite]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

It seems to me that if you combine both theories (fissionable material on the surface exploding and Extra-terrestrial body slamming into the earth) it makes a great deal more sense.

 

Imagine an extraterrestrial body (asteroid most likely) partially made of fissionable material, slamming into the earth at a location containing a large concentration of said material. Would that bring the material together fast enough to incite the proper reaction?

[Kristopher]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

It seems to me that if you combine both theories (fissionable material on the surface exploding and Extra-terrestrial body slamming into the earth) it makes a great deal more sense.

 

Imagine an extraterrestrial body (asteroid most likely) partially made of fissionable material, slamming into the earth at a location containing a large concentration of said material. Would that bring the material together fast enough to incite the proper reaction?

 

In such a highly unlikely scenario, you might get an explosive reaction out of that, if all the variables were just right -- variables that are hard to get right when you're trying to make it happen.

 

Problem 1: you get a reaction at masses far less than the mass needed to "blow the moon off".

Problem 2: if you have a collistion anyway, the explosion is superfluous.

[RexMundi]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

I think there's a lot of things that happen in nature all by themselves, that we can't even come close to simulating much less actually make happen, so therefore to keep using the terminology of Can't, Never, Unlikely, and Impossible as the main rebuttal, doesn't make much sense to me.

 

I kind of like the big fissionable + Impact idea. Far more "unlikely" things have happened all over the place then that. The thing that I would consider, is, if you're looking at impact, then you have to gauge it by, How hard can it be hit, and still end up as two relatively round pieces, instead of a small asteroid belt? It seems to be easier, to get the Two pieces, if something is Expelled from the larger whole, as opposed to smashed off it with a fast moving rock.

 

That, or David Weber is right, and the moon, is just the previous Galactic Empires Flagship Battle Cruiser, waitng for a new Captain to tell it what to do.

 

~Rex

[Zeropoint]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Having the globs come out round is no trick at all: at the scale of the earth and moon, they can't be any other shape because no naturally occurring material (i.e. rock) is strong enough to support any other shape against gravity.

[Kristopher]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

I think there's a lot of things that happen in nature all by themselves' date=' that we can't even come close to simulating much less actually make happen, so therefore to keep using the terminology of Can't, Never, Unlikely, and Impossible as the main rebuttal, doesn't make much sense to me.[/quote']

 

Let me put it another way, then. There's an obstacle course of unlikely events all that all have to come together to make this scenario happen, to the point that it's so unlikely as to be functionally impossible.

 

Have you ever heard of a Rube Goldberg machine?

[RexMundi]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Let me put it another way' date=' then. [b']There's an obstacle course of unlikely events all that all have to come together to make this scenario happen, to the point that it's so unlikely as to be functionally impossible.

[/b]

Have you ever heard of a Rube Goldberg machine?

 

Ah. Kind of like, the creation of the Universe and Life, not to mention intelligent life then? As for the Rube Goldberg Machine. of Course, I to, once stayed in a Holiday Inn Express.

 

Watched Chitty Chitty bang bang there to. Always wanted the breakfast machine. We could all learn a thing or three from Caractacus Potts.

 

~Rex

[Kristopher]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Ah. Kind of like' date=' the creation of the Universe and Life, not to mention intelligent life then? [/quote']

 

No, not like those things. We don't know how likely or unlikely those things are -- our data set is still too small.

 

We do know what it would take for a fission detonation large enough to kick off the mass of the moon to occur, and it is vanishingly unlikely. We've been over many of the hurdles on this thread.

[Shinobi Killfis]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

Ah. Kind of like, the creation of the Universe and Life, not to mention intelligent life then? As for the Rube Goldberg Machine. of Course, I to, once stayed in a Holiday Inn Express.

 

Watched Chitty Chitty bang bang there to. Always wanted the breakfast machine. We could all learn a thing or three from Caractacus Potts.

 

~Rex

 

What is the bizare chain of events that came about to create intelligent life?? I mean everyone knows Santa Claus who always was and always will be was making a bunch of toys with his elves, but they had no one to give them to. Then Blitzen came up with a great idea, make intelligent self replicating toys that like to play with toys. Santa loved the idea and made a man and a woman. And that is how mankind came about.

[RexMundi]

Re: Moon May Have Formed in Natural Nuclear Explosion

 

You know, THAT, actually has potential for a Convention Event. I can see it now, heh.

 

~Rex