Cancer Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! Like we haven't all done that at one time or another. If you were to add "or wish we had" I'd go for that. The biggest thing I've launched is water balloons (and fruit) with a three-man slingshot. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 27, 2011 Author Report Share Posted December 27, 2011 Re: More space news! Pluto's surface may contain organic molecules Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 27, 2011 Author Report Share Posted December 27, 2011 Re: More space news! Twin probes to study Moon's gravity field Quote Link to comment Share on other sites More sharing options...
Lucius Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! Afaik gravity does not really weakens over distance the way most radiation does. If it did not - if the gravitic attraction generated by, say, a black hole, were the same at any given distance as it is in proximity - There'd be only one black hole in the universe, and we'd be inside it. Lucius Alexander The palindromedary says that still doesn't make a dyson sphere practical Quote Link to comment Share on other sites More sharing options...
John T Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! Pluto's surface may contain organic molecules. You double-stacked the http:// there. Quote Link to comment Share on other sites More sharing options...
John T Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! There'd be only one black hole in the universe' date=' and we'd be inside it.[/quote'] There isn't?.. We're not?.. Damn, there goes my whole religious cosmology... Quote Link to comment Share on other sites More sharing options...
SteveZilla Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! If it did not - if the gravitic attraction generated by, say, a black hole, were the same at any given distance as it is in proximity - There'd be only one black hole in the universe, and we'd be inside it. Lucius Alexander The palindromedary says that still doesn't make a dyson sphere practical If I remember correctly (haven't checked, and don't remember where I heard it), radiation weakens with the cube of the distance, while gravity weakens with the square of the distance. Quote Link to comment Share on other sites More sharing options...
Sociotard Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! Nope. both follow an inverse square law. gravity light intensity It also works for electrical forces and sound. I'd imagine the Strong and Weak forces would too, but they just don't act on a scale where it would be relevant. Quote Link to comment Share on other sites More sharing options...
SteveZilla Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! Nope. both follow an inverse square law. gravity light intensity It also works for electrical forces and sound. I'd imagine the Strong and Weak forces would too, but they just don't act on a scale where it would be relevant. Yeah, I was somewhat skeptical of what I had heard, but just never got around to do the research. Thanks for the formulas! Quote Link to comment Share on other sites More sharing options...
Tom Carman Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! Nope. both follow an inverse square law. gravity light intensity It also works for electrical forces and sound. I'd imagine the Strong and Weak forces would too, but they just don't act on a scale where it would be relevant. I suddenly flashed on an old Doctor Who show "The Time Monsters" (Jon Pertwee, 3rd Doctor). The Master was working a problem and musing aloud "E equals MC cubed..." Professor: "Oh I say, old fellow, I think you mean 'MC squared'." The Master: "Not! In! Hyperspace!" Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 27, 2011 Author Report Share Posted December 27, 2011 Re: More space news! You double-stacked the http:// there. Fixed. Sorry about that; the website was giving me problems when I was trying to edit my original post. That's why I posted the lunar probes link separately. Quote Link to comment Share on other sites More sharing options...
McCoy Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! Nope. both follow an inverse square law. gravity light intensity It also works for electrical forces and sound. I'd imagine the Strong and Weak forces would too, but they just don't act on a scale where it would be relevant. I'm thinking "no" on the nuclear forces. They have to get stronger faster at very small dstances or else there would be nothing but hydrogen and deuterium in the universe. Quick check if a couple of web sites suggest the range of gravity and EM is infinite, but the nuclear forces have a very definite limited range. That doesn't sound like they follow the same law. Quote Link to comment Share on other sites More sharing options...
Cancer Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! No, the nuclear forces definitely have something other than an inverse square law dependence. Quote Link to comment Share on other sites More sharing options...
dmjalund Posted December 27, 2011 Report Share Posted December 27, 2011 Re: More space news! it's magnetism which is inverse cubed Quote Link to comment Share on other sites More sharing options...
SteveZilla Posted December 28, 2011 Report Share Posted December 28, 2011 Re: More space news! it's magnetism which is inverse cubed Ah! Thanks. Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted December 28, 2011 Report Share Posted December 28, 2011 Re: More space news! No, the nuclear forces definitely have something other than an inverse square law dependence. Entirely correct--the nuclear forces don't even reach all the way across a large nucleus. That's why elements with larger atomic numbers are unstable: protons can only be attracted by so many other particles (the ones that fit in the strong nuclear force radius), but there's no limit to how many other protons can repel it electrically. Quote Link to comment Share on other sites More sharing options...
John T Posted December 28, 2011 Report Share Posted December 28, 2011 Re: More space news! ...but there's no limit to how many other protons can repel it electrically. Sounds like my ex-wife... Quote Link to comment Share on other sites More sharing options...
Sociotard Posted December 28, 2011 Report Share Posted December 28, 2011 Re: More space news! it's magnetism which is inverse cubed I don't think so. It is weirder than electrical charge, though. Trying to read about the Strong and Weak forces now. Wow! That is some weird stuff. Quote Link to comment Share on other sites More sharing options...
Christopher Posted December 28, 2011 Report Share Posted December 28, 2011 Re: More space news! I'm thinking "no" on the nuclear forces. They hve to get stronger faster at very small dstances or else there would be nothing but hydrogen and deuterium in the universe. Quick check if a couple of web sites suggest the range of gravity and EM is infinite' date=' but the nuclear forces have a very definite limited range. That doesn't sound like they follow the same law.[/quote'] I was mistaken by a small sentence in the description of Gravity stating "it can theoretically work over infinite distances". So when you are in one point of the universe you would still feel the gravitational pull of a grain of Sand on the other end. Granted it would be considerably weak pull so it propably won't have much effect but the effect is still there. Entirely correct--the nuclear forces don't even reach all the way across a large nucleus. That's why elements with larger atomic numbers are unstable: protons can only be attracted by so many other particles (the ones that fit in the strong nuclear force radius)' date=' but there's no limit to how many other protons can repel it electrically.[/quote'] Afaik the elemental forces in an atom are so strong, that radioactive decay would be impossible - only Quantum Tunneling allows "decay" as we observe it. Quote Link to comment Share on other sites More sharing options...
McCoy Posted December 28, 2011 Report Share Posted December 28, 2011 Re: More space news! Afaik the elemental forces in an atom are so strong' date=' that radioactive decay would be impossible - only Quantum Tunneling allows "decay" as we observe it. Again, I'm going to say "no." Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 29, 2011 Author Report Share Posted December 29, 2011 Re: More space news! Lunar Probes to Reach Moon by New Year Planets that Survived Their Sun's Death? Quote Link to comment Share on other sites More sharing options...
Christopher Posted December 29, 2011 Report Share Posted December 29, 2011 Re: More space news! Again' date=' I'm going to say "no."[/quote'] At least for Fusion I could find some explanations: And I am pretty sure the same thing is true for Fission as well. Quote Link to comment Share on other sites More sharing options...
McCoy Posted December 30, 2011 Report Share Posted December 30, 2011 Re: More space news! Afaik the elemental forces in an atom are so strong' date=' that radioactive decay would be impossible - only Quantum Tunneling allows "decay" as we observe it. Again' date=' I'm going to say "no."[/quote'] At least for Fusion I could find some explanations: [snip] And I am pretty sure the same thing is true for Fission as well. Um, were that so, there would be no unstable isotopes lighter than iron. There are, so again, no. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted December 31, 2011 Author Report Share Posted December 31, 2011 Re: More space news! China's space plans up to 2016 Quote Link to comment Share on other sites More sharing options...
Narf the Mouse Posted January 3, 2012 Report Share Posted January 3, 2012 Re: More space news! http://spectrum.ieee.org/biomedical/bionics/goodbye-wheelchair-hello-exoskeleton - Cybernetics helping people walk again. Quote Link to comment Share on other sites More sharing options...
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