THE LUCIFER PROJECT ::: T-minus 6 days and counting..

reply to post by Essan


yeah but earths atmosphere is oxygen, which is way way harder to fuse than hydrogen and its also under a lot less pressure.

I get the feeling from trying to find answers that this is an area where "all bets are off" so to speak, ie we just dont know enough about it to say for certain that the triggered ignition of jupiter is not possible, all we know is that the spontaneous ignition of planets that size is not possible, according to our models.

also I found this re D-T vs normal H-H (proton proton) fusion:

hyperphysics.phy-astr.gsu.edu...

apparently less than 15 million degrees is sufficient, which could be achieved by a fairly large fission blast
I'm still in the same boat as some of the original proponents of this CT: its unlikely but not impossible (Especially if it is a deliberate test/attempt therefore other slight improvements could have been made to ensure higher yields, further sinking before phase change etc)

Originally posted by diablomonic


ie the phase change is ENTIRELY relevant to the critical mass as it affects the density...

Only in that anything that affects the density affects the density. In this case, it's the external pressure that's the prime cause. The phase changes cause non-linearities in the density/pressure curve, but they are not the root cause of the density changes.

as far as I remember reading the pellets themselves, in there separate extremely tough containers, had enough mass to got super critical after the phase change. having more of the pellets round just increased the likely hood that one would collapse due the phase change quick enough to actually have a half decent yield (which is related to how over critical it can get before exploding, which is related to how quick it collapses, as Im sure you already know)

They're not that large. An individual GPHS-RTG (as used in Cassini) pellet is something like 150g and cylindrical. Were they using a different RTG for Galileo?

Not to mention that they're not metallic - they're 238PuO2, which is going to increase the required mass due to the absorption cross-section of the oxygen.

here it is "http://www.rinf.com/news/nov05/lucifer-project.html"

There's your first problem - RINF is as trustworthy as India Times or Weekly World News. Maybe not as much so as Pravda Online.

well the temperature is provided by the fission blast, which can reach millions of degrees, and then kept up by the subsequent fusion reactions. As to pressure, I dont know whats required, but jupiters pressure reaches ~4000 GPa and this would obviously be raised considerably locally by the explosion.

In a standard Teller-Ulam secondary, you have to have a fission primary putting out a ton of x-ray and gamma rays, which drive a compression wave that compresses the 6LiD fuel around a plutonium bar. The plutonium is eventually compressed sufficiently to cause a fission explosion in the center. So it basically takes the neutron flux (for the Li conversion to T), heat and pressure created by a fission explosion in the center of the fuel, combined with the ongoing physical and radiation pressure exerted by an external primary trigger. It's really rough to get this to work any other way.

You also only get that pressure you quote at the core of the planet, which you would not have been anywhere near.

As for calculations, go dig up the Lawson criterion, it will at least give you a clue about how to calculate initial ignition temperatures and pressures. It gets to be a bit more difficult to work out the sustainability once it ignites, since you're going to be losing heat in several ways, primarily through radiation, and the explosion will cause a pressure wave through the atmosphere. That usually takes a long numerical solution, there's several models for it, and you have to figure out why they diverge which they almost always do. But you can get a nice rule of thumb by just assuming a constant pressure and no heat loss. If it can't meet that, it won't ignite anyway.

As far as H-H being more difficult than D-T, there's a couple of reasons. First and worst is the fact that H-H -> He is not a single stage reaction. It requires several steps and time. First, you have to fuse two protons (about 10E7 degrees to get that one to go), and that has to have time to decay to deuterium by emitting a positron and a neutrino. This is admittedly not long, but it does take time during which your density is dropping as the reaction begins to expand. Then you have to corral two of those deuterium atoms and fuse them, with a critical ignition temp of about 4E8 degrees. That's not so straightforward. There's an even worse chain where you fuse the deuterium with another proton to make He3, then fuse the two He3's in yet a third reaction. That's the more likely one in terms of energy requirements, but it takes three separate fusion events, all of which are of low orders of probability.

It's why we use hydrogen isotopes with neutrons already in there like tritium and deuterium. You don't have to wait to make two neutrons by positron emission. Having to manage fusions twice per reaction (or three, even worse) also craps all over your requirements for density and time, because you have multiplied two (or three) small probabilities together. That's why H-H generally only happens in the cores of stars where you have hellish densities and very long confinement times.

"The question you should ask yourself is - how many Hiroshimas was the impact of Shoemaker-Levy? It hit with an amazing amount of energy."

irrelevant. whats relevant is whether the impact energy was concentrated enough at any place to achieve the required temperatures and pressures... which it obviously wasn't and that doesn't surprise me. Also that impact was to the outside of the planet, therefore the energy was mainly released in the upper atmosphere, where the pressure is not so high. These pellets sink quite deep to a point where the pressure may indeed be high enough to help sustain ignition (at least, its a lot more likely than at the surface)

Incorrect. The impact energy was concentrated in the leading edge of the impacting objects, an area where a huge amount of compression is also ongoing, as I'm sure you'd agree. There were several impactors that were quite large. The total impact energy, by the way, was estimated at 50,000,000 Hiroshimas - not insubstantial.

For fun - Lawson's original paper. Warning - pdf. Here's lots of info and I don't have to get off my lazy arse and fire up mathcad to do the equations. You can't do much of a job on one of these boards with math, so I end up having to fire up mathcad to make equation jpg's you can post. It's a pain, and no-one much understands it anyway, I quit doing it long ago.

on the page I linked, it is mentioned that:

2003 (July) Geographer, J.C. Goliathan publishes a report stating that a nuclear reaction is slightly possible if Galileo goes into Jupiter.

25 2003 (early Sept) Physicist, Jacco van der Worp publishes a report warning of what could happen if Galileo plunges into Jupiter citing Goliathan's report and actually crunching the numbers to prove it. Jacco sites the low probability, but believes the risk is high enough to warrant a warning.

I can't find that Goliathan has ever published. That doesn't necessarily mean anything, but in one of these cases it generally makes me want to verify he has the academic credentials he claims.

Looking at van der Worp, he's sort of tied up into this Planet X/Nibiru/free energy/YOWUSA bullcrap, and sells CT books. He's also a MSc, which I will be too sometime next year, but I won't call myself a physicist with a masters'.

You might look around, you said you'd had some physics classes? van der Worp says that a magnet stuck to the underside of a metal plate is doing work. What would you say? Do you think it is? (note to other ATS'ers, "work" in physics is not the same as "effort" in English)

At any rate, Galileo hit in September of 2003, no new sun.

[edit on 3-11-2007 by Tom Bedlam]

Originally posted by Essan
Reminds me a bit of the 1950s (or was it 40s?) when some scientists thought nuclear tests would set off a chain reaction in Earth's atmosphere ......

Anyway, I guess when nothing happens we'll know the plan failed

Dr Teller was afraid that the blast would produce sufficient energy to start a Bethe cycle (solar phoenix) between CO2, nitrogen and water vapor. It turns out that not even the Sun is large enough to use the Bethe cycle, but it took them some time to decide it couldn't happen.

Supposedly Fermi was taking bets at the Trinity site as to whether or not they'd got the maths right.

Originally posted by Tom Bedlam
Only in that anything that affects the density affects the density. In this case, it's the external pressure that's the prime cause.

not going to argue on the semantics of it, you are correct that the external pressure causes the density changes, but the fact that there is a phase change to a higher density state and that this "collapse" could occur quite quickly (though I doubt anything like as quick as a shaped charge crushing a spherical shell) means to me that there is at least a slight possibility of a decent yield explosion

They're not that large. An individual GPHS-RTG (as used in Cassini) pellet is something like 150g and cylindrical.

as far as I know this is correct. (just noticed cylyndrical so even more unlikely to be super critical) According one of document I read (with no in depth verifying calculations...) this may be sufficient for this particular isotope mix in the higher density phase. Feel free to show how this is incorrect, I'm not convinced either way. another option was for some of them to be forced together during descent (even more unlikely, UNLESS deliberately designed to occur...)

There's your first problem - RINF is as trustworthy as ...

never heard of it (rinf) previously myself, please read it anyway and address the argument not the source.

In a standard Teller-Ulam secondary
.... It's really rough to get this to work any other way.

fair enough, not gonna argue, but this is not really applicable (Li transmutation/product fusion vs H-H fusion.. see later sun comment)

You also only get that pressure you quote at the core of the planet...

you are correct. I should look up what pressure the phase change actually happens at. This number was more to do with IF (and yes its a big if) the fusion was triggered and managed to "find its way" to the center of jupiter, could it sustain itself there?

As for calculations, go dig up the Lawson criterion, ...

you sound like you may be able to actually DO these calculations.. love to see them done for this particular situation (that was a complement not sarcasm). I'm having a look through the document you linked.

As far as H-H being more difficult than D-T, there's a couple of reasons. First and worst is the fact that H-H -> He is not a single stage reaction. It requires several steps ...

yeah I was looking at that while checking up for my last post.

It all came down to this though: the sun manages to achieve this process at sub 15 million degrees.

Obviously the greater pressure helps, as probably does the fact that it has already reached some degree of, erm, "pressure equilibrium" between inward and outward forces, Im just curious if this is a NECESSARY part of it, or if jupiters pressure suffices (even for a short non stable reaction)

as to your work question: no, I would not say that, work requires a force to be applied over a distance ( and results in a change in kinetic energy of the object to which the work is done, so the direction of the force also matters to whether work is done or not: ie object in orbit: force, distance but no work, object falling out of orbit: work). if the magnet is not moving in relation to the plate, it cannot do any work on it.

to answer your real question: basic physics and physics concepts were never a problem to me, I did extremely well, HOWEVER This is beyond my knowledge base (and what I do know is from long ago so hazy) therefore I can only comment in general terms (unless I bother to get right back into it and work out the maths, which is probably not gonna happen).
what Im really trying to do is show that in general terms, its not quite as nuts as to be immediately dismissed without even looking at it, only very unlikely, and hoping someone WILL do the required calcs to prove it either way.
(and yes, if he said that, it disturbs me a little)

reply to post by Tom Bedlam

Incorrect. The impact energy was concentrated in the leading edge of the impacting objects, an area where a huge amount of compression is also ongoing, as I'm sure you'd agree. There were several impactors that were quite large. The total impact energy, by the way, was estimated at 50,000,000 Hiroshimas - not insubstantial.

yes but what was the maximum temperature involved, and how deep (ie at what surrounding pressure) was this achieved? my intuition (which obviously could be wrong) tells me it didnt reach 15+ million degrees and especially not at a considerable depth/pressure (relative to the sinking rtg pellets) this ties into another of your comments:

At any rate, Galileo hit in September of 2003, no new sun.

about the ONLY reason I give this theory any time at all is because of what happened a month or two later, perhaps in response to it:

www.space.com...

a huge black spot appeared.

apparently it would take roughly a month for the rtg pellets to reach the depths required fo the phase change to occur (this calculation, if it was even done properly, is obviously going to have some very big error bars on it since it involves the structure of Jupiter's atmosphere (largely unknown) and the aerodynamics of the falling rtg (also largely unknown))

THAT is the thing that makes me pause and go hmmm... I dont think so but...maybe?

(the theory being that after falling to this depth, one or more of the pellets "went off" in a fission explosion but failed to create a sustained fusion reaction

Dr Teller was afraid that the blast would produce sufficient energy to start a Bethe cycle (solar phoenix) between CO2, nitrogen and water vapor. It turns out that not even the Sun is large enough to use the Bethe cycle, but it took them some time to decide it couldn't happen.

Supposedly Fermi was taking bets at the Trinity site as to whether or not they'd got the maths right.

pretty safe bet I guess (assuming he bet against it happening), not like he'd be around to care if he lost... wonder what the odds were?

Originally posted by DaRAGE
It's not going to happen. Why?

When those metoer/comets? LEvy shoemaker, hit into jupiter did they cause an explosion? yes. Did jupiter lite up? no.

They would have caused explosions of the nuclear size..but they didn't ignite Jupiter.

Plutonium wont ignite jupiter either.

The explosion, if memory serves me was the size of Earth its self. Had the comet hit as, we would have... literally been dust.

But also, I had never heard that Jupiter was made of combustible gases before??

Originally posted by DaRAGE
It's not going to happen. Why?
When those metoer/comets? LEvy shoemaker, hit into jupiter did they cause an explosion? yes. Did jupiter lite up? no.

The comet was a ball of ice (so they say) not a plutonium laden spacecraft... I do not see a comet initiating a fission or fusion reaction

Originally posted by Rockpuck/i]
The explosion, if memory serves me was the size of Earth its self. Had the comet hit as, we would have... literally been dust.

Its curious how liitle FUSS has been made about the current comet that is now over 10 times the size of Jupiter and can be seen with binoculars (17P/Holmes)

But also, I had never heard that Jupiter was made of combustible gases before??

Jupiter has methane for one... methanr burns pretty good last time I checked my gas stove...

Saturn on the other hand is approx 75% Hydrogen, 25% helium, (very similar to the sun... Hydrogen burns very well (IE Hindenberg, Shuttle Launches etc) And Hydrogen fusion is what powers the sun..

Can they ignite Saturn? I doubt it...

At least I certainly HOPE not..

But dropping it into the hole at the pole... and having 72 pounds of plutonium, (compared to 17 in Galileo) seems really stupid to me...

Its a planned delibert mission... Project Lucifer? I don't know...

But so far no one has answered me WHY ARE THEY EVEN DOING THIS