walker 0 Posted November 9, 2003 (denoir @ Nov. 09 2003,16:10) said: That makes it even more unlikely that anything would happen. The ship is desintegrated and the pellets magically position themselves so that they form a perfect sphere? Not bloody likely. Hi Denoir The author is making it clear that the spheres of plutonium are not in contact. He is arguing that one of those perfect spheres in enough. I dont think the mass is enough myself. Please read it all so you understand his argument that way you wont be dismissing his idea on spurious grounds as you just have done. He is not saying all the spheres get squashed together. He is saying they are seperate. I dont know enough about the physics to make a comment on whether it is possable to get a large fission reaction on the mass of one of those spheres in such a radical environment. Also his argument that terminal velocity at that point is 1km or so seems well thought out. So the compresion would be slow and continuous rather than the suden spike of pressure used to set off a bomb on earth. Other than the size of the mass which has me being sceptical his argument is reasonable. I would like someone to do an analysis of his math on the falling speed and it taking a month to reach sufficient pressure because that looks a little neet. kind Regards Walker Share this post Link to post Share on other sites
denoir 0 Posted November 9, 2003 Ok, Walker I re-read the article and it seems that you are right. The author suggests that the individual pellets imploded, reached critical mass and started a chain reaction. As for calculating the critical mass, it's no simple thing. Critical mass is actually an incorrect term as it involves both mass, density, shape and surroundings (outside materials that act as moderators or reflectors). But, you can do a simple comparison. Bomb grade U-235 requires 15 kg [source] (in addtion to favourable geometry, density and environment) to reach critical mass. Â As the author of the article himself noted U-235 is much more suitable for fission than the Pu-238 used in Galileo. So there would at least have to be 15 kg in each pellet. Furhterhmore he notes that: [b said: Quote[/b] ]As the more fragile parts of the spacecraft disintegrate from the enormous entry temperatures and pressures, its two 4-ft long, 124-lb RTGs ? each containing 72 individual plutonium-238 capsules ? separate from the main spacecraft. Which means 0.8 kg/capsule - not nearly enough to reach critical mass. I'm making a mental note to remember to ask my mother about this (she's a nuclear physicist). Share this post Link to post Share on other sites
SpeedyDonkey 0 Posted November 9, 2003 Pardon my ignorance. But what's the point of this? Why did he write it? Could there have been any negative consequences even if it had been a "nuke" (witch apparently is doubtful... hmpf quack..) Share this post Link to post Share on other sites
walker 0 Posted November 9, 2003 Hi all What we need is the true mass of one of the spheres. I will have another look through the article and its sources. I will say this though. If the initial mass of a sphere is sufficient under such compression and if sphere could survive the entry into Jupiters atmosphere. I would say such an explosion would be a physical certainty. My reasons for saying so: The whole of nuclear bomb trigger technology is designed as you said denoir to create the compression that exists naturaly on Jupiter. Would such a slow build to compression mittigate for or against an explosion? Would there be a small explosion that ripped apart the plutonium sphere first? Would we be able to see it? Hmm not sure; his argument about the chemistry of the soot is intresting but I dont know enough earth chemestry never mind high pressure Jupiter chemestry. For that we need a serious planetary chemist and I have never met one of those The biggest thing against the article is the conspiracy crap but if you want to finish such conspiracy crap you can not use wrong arguments or you strengthen them. Kind Regards Walker Share this post Link to post Share on other sites
denoir 0 Posted November 9, 2003 The best way to get some answers i to check the sci.physics news group Some posts: [b said: Quote[/b] ]There are too many flaws in his "conspiracy" theory to list here. There is no way Pu238 in the RTGs coul initiate a chain reaction because it's bound to oxygen in the oxide so even if it were able to achieve criticality, there are too many oxygen atoms in the package to allow sufficient neutron multiplication. Also, a portion of the Pu238 already decayed since the launch long ago. Secondly, he argues that there is considerable amount of deuterium in the Jovian atmosphere. While that may be the case if you look at the total amount of D on Jupiter, it's the mass concentration that matters. Otherwise, you again have this "poisoning" effect, this time to the resulting fusion reaction. I suspect that deuterium/hydrogen ratio on Jupiter is the same as here on Earth, Â OTOH around 0.7%. So for every D atom you need to cope with thousands of ordinary hydrogen atoms. Even if you had pure deuterium, you hardly could start a self-sustaining thermonuclear reaction because the vast majority of the fusion energy released would be carried away from the reaction zone by photons & very fast neutrons, in effect moderately heating a large surrounding volume instead of depositing the energy in the thin layer of deuterium around the reaction zone, thus allowing self sustaining combustion. Why else do you think it's hard to create a hydrogen bomb? If I recall correctly, you need pressures on the order of 4 gigabars in order to create favorable conditions for a deuterium-deuterium thermonuclear reaction. That's a VERY large pressure. Finally, he says the resulting kiloton range explosion would create a cloud thousands of kilometers across.... Not to mention that he states that in the deeper layers of Jovian atmosphere the probe debris would be falling exceedingly slow, yet when dealing with buoyancy of the alleged resulting bubble he extrapolates off the data from the 1952 Ivy Mike test and gets thousands of miles per hour... [b said: Quote[/b] ]It has lots of fatal flaws. First off, he's wrong about the type of Plutonium on Galileo. It is not bomb-grade material and would not explode. Secondly, the spacecraft no doubt completely vaporized as it plunged into Jupiter's atmosphere at over 100000 MPH, so the plutonium pellets are not around to be compressed to critical density by Jupiter's atmospheric pressure. Thirdly, his description of a nuclear explosion triggering a massive runaway fusion reaction in Jupiter's atmosphere shows a remarkable ignorance of the conditions required to sustain a fusion reaction. It also completely ignores the fact that the cometary impacts witnessed back in 94 were many orders of magnitude more powerful than a mere nuclear explosion, but they did not trigger any runaway fusion reaction. Fourthly, the marking seen on Jupiter is far too large to have been caused by Galileo. [b said: Quote[/b] ]The web-site provides an informative and useful (to those who study fringe group sociology) stream-of-consciousness narration of how a crack-pot "theory" is formulated from distorted and half-understood pieces of information. In this discourse "plutonium-238 dioxide ceramics" are equated to "plutonium alloy" (is salt a sodium "alloy"?), and a fact that specifically applies only to a particular type of alloy (one in the delta phase) is slapped on to an entirely different material. Pu-238 is an intense neutron emitter. Agradual compression process, as occurs Galileo falls through the atmosphere could not produce a significant explosion (even all of this guys other silly claims were granted) due to predetonation. His description of his "explosion process" is utterly devoid of any physical reasoning, its just stringing words together hoping to creat the impression of a credible process: "At this point, one of the capsules randomly implodes . and initiates, via the resulting shockwave and intense neutron shower, a runaway nuclear chain reaction in all the other surviving capsules, now spread in a spherical falling "cloud" a few tens of miles across ~700 miles below Jupiter's visible "surface." The resulting cascade nuclear detonation of all the surviving capsules totals several tens of kilotons .. The simultaneous detonation of over 40 lbs of plutonium-238, over 700 miles below Jupiter's cloud tops, instantly creates a superheated "bubble" of "million-degree plasma" deep inside Jupiter, tens miles across." This is just physical gibberish with fake numbers pulled out of a hat. Share this post Link to post Share on other sites
walker 0 Posted November 9, 2003 (SpeedyDonkey @ Nov. 09 2003,19:19) said: Pardon my ignorance. But what's the point of this? Why did he write it? Could there have been any negative consequences even if it had been a "nuke" (witch apparently is doubtful... hmpf quack..) Hi SpeedyDonkey Two reasons Remote posibility of turning Jupiter into a sun Intelectual curriosity. Kind Regards Walker Share this post Link to post Share on other sites
denoir 0 Posted November 9, 2003 (walker @ Nov. 09 2003,19:34) said: Hi allWhat we need is the true mass of one of the spheres. I will have another look through the article and its sources. Check my previous post. 0.8 kg per capsule according to the article. [b said: Quote[/b] ]If the initial mass of a sphere is sufficient under such compression and if sphere could survive the entry into Jupiters atmosphere. I would say such an explosion would be a physical certainty. Hardly since it also very much depends on the material. Also having a compression is not enough, there's a time frame involved as well. As was pointed out in one of the usenet posts above there is a very big difference between a compression that occurs within microseconds in a nuclear bomb and a compression that takes a month. Also unclear is the effects that the external environment would have. The surrounding materials of the nuclear core are essential as well. Share this post Link to post Share on other sites
walker 0 Posted November 9, 2003 Hi Denoir (denoir @ Nov. 09 2003,19:40) said: Check my previous post. 0.8 kg per capsule according to the article. Yeh but it is a salt of plutonium plus a mix of decay particles some of the decay particles are radioactive. There are allso some neutron producers. Add in the the wierd high pressure chemestry and things get very confusing. (denoir @ Nov. 09 2003,19:40) said: Hardly since it also very much depends on the material. Also having a compression is not enough, there's a time frame involved as well. As was pointed out in one of the usenet posts above there is a very big difference between a compression that occurs within microseconds in a nuclear bomb and a compression that takes a month. Also unclear is the effects that the external environment would have. The surrounding materials of the nuclear core are essential as well. I think the point in one of your quotes about pre explosions is the most telling. Kind regards Walker Share this post Link to post Share on other sites
Acecombat 0 Posted November 9, 2003 Damn you guys lost me after denoirs post answering my question Ok after all chit chat what relevance is that Black spot even off? Even the author if hes correct of the NUKE explosion causing the black scar , whats the danger now? It certainly isnt expanding or anything like he stated ... he himself describes its shut down in the atmosphere after it reaches its extreme height , it isnt a run-away sort a bomb or is it? Share this post Link to post Share on other sites
walker 0 Posted November 9, 2003 Hi Acecombat Read my earlier post in reply to SpeedyDonkey. It is a black spot on Jupiter we have whole books written about the red spot. Why would we not want to know what caused it? We are human beings we got were we are by asking things like: What makes things burn? Why do the cattle eat grass? What happens when I press this? Of course occasionaly pressing this can lead to lots of us dieing. Think how many got killed when people started say what happens if you split an atom? Intelectual Curiosity heh? Get you every time. My cat died ages back, guess yours still has a few lives. Kind Regards Walker Share this post Link to post Share on other sites
Oligo 1 Posted November 11, 2003 Does it really matter whether the Galileo fuel canisters went nuclear or not? I'm sure nothing as small as a nuke would cause any trouble for Jupiter, which shrugged off a huge cometary impact by Shoemaker-Levy. A nuke is but a small fart compared to the impact of each of the 1-2 kilometer fragments of Shoemaker-Levy. The biggest impact by Shoemaker-Levy fragment G released energy equivalent to 6 million megatons of TNT, which is roughly 600 times the estimated arsenal of the world. The biggest nukes tested on Earth were in the 100 megaton range. So if Jupiter did not go sun from that impact, why would a small nuke cause that? Share this post Link to post Share on other sites
walker 0 Posted November 11, 2003 Hi Oligo Guess your cat still has plenty of lives too. Like I said mine used up the last oh way back now it is just that bad smell behind the book shelf. Kind Regards Walker Share this post Link to post Share on other sites