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I think most people would disagree Isaac Send a noteboard - 13/08/2013 07:09:38 AM

View original postFew human artifacts are older and more widely distributed than statues of bare large-breasted women. In nearly 10,000 years, learning about the birds and the bees is about the ONLY thing accomplished by humans physiologically indistinguishable from us; they did not even manage the most basic metalworking (and I do not mean metallurgy either; even polishing and sharpening copper ore was beyond them.)


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View original post"Cosmology takes GUTs," and explorers are, by definition, the people who traverse regions marked "here there be dragons." I think it was Planck whose college advisors told him to go into something other than physics because all the big questions had been answered and nothing remained but fleshing out the details, but God and the devil both dwell in those details. "Hazy, troublesome, etc." strikes me as another way of saying, "presents fundamental paradoxes that are either currently insoluble, admit no currently verifiable solutions, or both." Again, wave/particle duality was once considered an all but trivial artifact; a century and several new disciplines later we STILL lack a completely satisfactory reconciliation, but have tremendously advanced our understanding of matter, energy and space looking.


View original postA lot of the stories of how scientists thought everything would soon be solved are just that... stories. Sort of a variation on the Columbus/flat Geocentric/stupid concepts mentioned before. I've heard it said that it was said but I've never come across writings of a scientist form turn of the century era that said anything of the sort. I'm not sure who/when considered wave/particle duality a trivial thing either.


View original postWell, if memory serves it was something I heard on PBS years ago; I cannot source it (could not even remember whether Planck was the physicist mentioned.) Yet that was not the first time I heard a reliable reference claim the physics consensus at the turn of the last century was that the science was all but "complete." Wave/particle duality itself was not trivial, but it seems to have been the Higgs of its day, at least until Rutherford, Thompson and the Curies arrived; the problem, as is so often the case in physics, is that discovering the "answer" (to the extent we ever did) just spawned a lot more even more complex questions.

There's a huge amount of stories of every sort in science, as in everything else, which are bullshit or probably bullshit. Like I said, lots of people say there was a consensus science was complete, but always ones who didn't think so themselves, I've never seen (though I'm sure there are some) any writings form respected scientists of that era saying "Yep, science is wrapped up or nearly so"


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View original post"Hazy, troublesome, etc" is just what I said it was, General Relativity covers black holes fine, Quantum Mechanics does so less well, as mentioned Quantum Gravity etc present serious concerns and some apparent paradoxes.


View original postThat was my point: Paradoxes tend to be hazy and troublesome, but their resolutions are often (and understandably) revolutionary. It seems save to say that resolving the contradictions between General Relativity and Quantum Mechanics will be no less earthshattering than resolving the contradictions between the theory of light-as-wave and light-as-particle. Hopefuly we can come up with something a bit more precise and satisfying than "both."

I actually doubt it will be that earthshaking, it would be nice if it was but Olber's Paradox, as mentioned, was not very earthshattering in its resolution. I can name a couple dozen other big ones that were resolved as near footnotes. Duality itself, "It's both", doesn't really bug me anyway, it just is, same as opposite particles repelling, and anti-particle annihilating, we know how, why is probably not something we'll get to find out in the foreseeable future.


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View original postCommentary aside, a follow up question to the follow up question: WHY is Hawking Radiation inversely proportional to mass? Understand, I do not dispute that it is, I am just curious whether the mechanism necessarily requires that if gravitons were produced by a similar mechanism they must be similarly inversely proportional. It often seems to me gravity is at odds with the other fundamental forces, tending to contract what they expand, acting to bring to rest what they set in motion; I strongly suspect it is not so much that there is no such thing as "anti-gravity" so much as that the unification of the other fundamental forces is it. If (and I realize it is a big "if" ) that supposition is valid it seems conceivable that a process minimizing kinetic energy might maximize gravity (in a sense, black holes do just that.)


View original postWhy is Hawking Radiation inversely proportional to the square of mass? I think I called it cube last time, it's lifetime that goes as cube of mass, power is inverse square. It's totally unrelated to gravity except as an ultimate power source for the heat. Anyway, black holes have temperatures, bigger ones are colder. Double a black holes mass and you double its radius, quadruple it surface area, and get 8 times the volume. And skipping some steps, A black hole's temperature is inverse to its own mass. Double Mass, half temperature. You can run through the math on wikipedia, it's mostly algebra.


View original postYeah, I saw that; that is, um, a lot of Greek. I am enough of a layman that saying something is "is Rindler in terms of tau=t/4M and rho=2u" tells me very little. I can see how we end up with an equation where T is equal to a formula with M in the denominator, but that does not explain the mechanics in operation. It only relates to temperature (i.e. elctromagnetic radiation) though, so the same relationship would not necessarily follow for some kind of stimulated graviton emission, which one would expect to be proportional to mass to at least some degree. It was just a spur of the moment notion though, spitballing; I am certainly not married to it, but am curious about the nuts and bolts (even if I may not have the math to follow them.)

Unfortunately there are a lot of things in physics that require a lot of math to understand. I try to explain without it when I can, I'll even fudge reality a bit to fit a decent analogy, but there's not an obvious one to me for this that wouldn't be 'too wrong' to offer. From a practical standpoint just assume larger black holes are cooler because they have considerably more volume increase then mass increases, and emit less light because of that, same as a blackbody. Fill two objects, one twice the size of the other, with a cup of boiling water and dump them into the void and the bigger one will give off less background radiation. Same basic concept but the math is different, for instance you've got redshift of light as a huge factor for something outside a black hole's event horizon but still very under its gravitational influence.


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View original postI do not propose black holes could emit gravitons IDENTICALLY to the way they emit Hawking Radiation (which, as I understand it, is an oversimplification anyway; consuming one product of virtual particle decay before it can recombine with the more distant product is not "emission," per se.) I have in mind tidal forces shredding objects, down to the subatomic, subnuclear, level, until destroying the very particles with which gravitons interact, leaving gravitons nowhere to go except into the black hole or out to space seeking some other purchase. Since their interaction is unlimited and always attractive, it would effectively draw objects toward the black hole, and the larger the black hole the greater the number of objects tidal forces would destroy, expelling more gravitons (again, from the objects, not the black hole itself.)


View original postWell virtually particles don't get blocked the way you're thinking, if they got absorbed by interaction that way then having an object between you and them should mean less gravity then if nothing was in the way which obviously isn't the case.


View original postI was not thinking of them being blocked so much as the possibility dissolution of a (relatively) larger object (not necessarily by the black holes action) might generate gravitons the same way pair production yields electrons/positrons and the like: It is not that photons are COMPOSED of either or both, but the energy lost cannot truly be "lost" and is sufficient to produce the pair, so it goes there. Although, when I think about it that way (i.e. in quantum and thermodynamic terms) it amounts to indirectly positing antigravity, and since that seems literal science "fiction" I do not want to go there.


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View original postThe whole concept of gravitons perplexes me, since I always took it for granted all matter exerts gravity: Does that include gravitons themselves? If so, what is the medium? Obviously not a graviton, unless it is self propagating like I have suggested photons may be. Not to mention the fact gravitons are every bit as necessary and hypothetical as the Higgs boson is (or was,) but practically impossible to detect with the LHC or anything else. They seem far more deserving of the "God particle" title, especially since the Higgs was only the Standard Models last unverified particle because the Standard Model deliberately excludes gravity from consideration. It is a bit like a cartographer declaring, "I have mapped the entire universe," on the grounds of defining everything outside the Solar system as "not part of the universe."


View original postGravitons perplex everyone, I wouldn't worry over it much. We don't know if they exert gravity, photons do since electrical fields can, anything containing energy probably does but gravitons may be an exception.


View original postAs long as it is not an arbitrary one. It is very odd to think of matter without gravity though; anything, really, given equivalency. Gravity seems fundamental in a way that goes much deeper than either Newton or Einstein. It certainly intrigues me more than the Higgs "completing" the Standard Model; a Standard Model without a graviton does not feel all that complete, just another reminder quantum and relativity remain unreconciled.

Since the SM doesn't include Dark Matter particles at all I'm not exactly worrying about the gravitons absence making the model not 100% complete and proven.


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View original postIf reduced to Brownian motion though that would also tend to resolve the paradox: Intervening matter struck by incoming photons is also struck by OUTGOING photons so the latter effectively reflect the former (even if it is technically a case of intervening matter absorbing both and emitting new photons with velocities opposite that of the first two.) Of course, for that to work energy emission from and toward the center must be equal, which it obviously would not be in our uniformly distributed onion, but otherwise the far greater incoming energy would not be offset by outgoing energy and the intervening matter would have a net momentum preventing some incoming energys transmission to the core: No core radiation bombardment.


View original postI'm not entirely sure what you're saying.


View original postEssentially that even Brownian motion would not hold intervening particles at or even near kinetic equilibrium, because our hypothetical onions volume dictates "rimward" energy sources will always greatly outnumber "coreward" ones. Therefore the intervening matter could and would absorb the difference and move about, rather than being locked in place and reemitting it toward the core. It will still radiate the difference "minus whatever small amount is going into momentum," but that "small amount" ought to be relatively LARGE for low densities (like, say, the interstellar medium.) The low mass and surface area does not allow much energy absortion per unit volume in the first place, and the low mass and negligible drag means it does not take much of it to get them moving, and every erg going to motion is not re-emitted. There is no core radiation bombardment because the exces all goes to motion, if only motion of very rarefied matter.

I'm sorry I'm still not clear what you're trying to say here, as I said any system is almost bound to have a gradient (net direction of force that is non-zero after almost everything cancels out), it doesn't matter for our purposes, it's minimal, and in an infinite universe it just average out anyway but even if it didn't, remember that a particle flying away form us redshifts and gets dimmer, and toward us blue shifts and gets brighter, kinetic energy still contributes to an objects brightness.

If you're asking if a net outward motion would decrease the brightness then yeah, and if it were sufficient enough we'd have a dark sky... that's the point, everything has a major outward motion from us, expanding Universe, no paradox.


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View original postIt was my understanding that is essentially the Second Law of Thermodynamics' consequence: Gradual but inevitable conversion of kinetic energy to potential energy until universal heat death. There the graviton again rears its ugly hypothetical head, forcing us to consider whether that produces a truly static universe or the graviton somehow transcends the Second Law in a Big Crunch. Accelerated expansions Dark Energy only complicates rather than resolves that question.


View original postNo, the type of energy is basically irrelevant, but 'heat' is essentially random kinetic energy not potential and that includes photons from blackbody radiation occurring at or under the Universe's temperature. It's the gradual but inevitable conversion of patterned objects into unpatterned ones, or that form which no work can be extracted.


View original postRight, the kinetic energy is practically (if not technically) nil, because so diffuse nothing can be done with it. Sorry, I sloppily said, "potential energy," instead of "matter," but of course the potential energy of matter at that point will be ACTUALLY rather than PRACTICALLY zero (that is kind of the point.)

In a heat-dead universe all energy is kinetic, its just all random with no pockets of greater or lesser to work with. That's entropy.


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View original postThe thing is, science, especially prior to the modern era, rarely addresses truly novel questions, or those for which no potential answer has been proposed: It usually addresses long standing questions by exposing the deficiencies of accepted answers and proposing new ones that remove those deficiencies.


View original postGranted that is less so in the century or so since science found so many rigorous, verified and widely accepted answers to so many old questions; today it is increasingly tasked with resolving the conflicts and failings of its own improved answers rather than previous ones of older disciplines. Yet the process remains unchanged; we can explore no region before aware of its existence. Science has simply progressed from correcting/clarifying errors of other disciplines to correcting/clarifying its own. It is more often refinement and verification than true discovery; Plancks advisors had that part right, but vastly underestimated its import.


View original postI took roughly 400 years to answer Olber's Paradox, more than half of them passing before it even got named that. One less than a century old isn't one I'm going to elevate to unsolvable, it's not something like


View original post"Is there a God?" or "Is this all a dream?" where one can not conceive of a means of answering the question with certainty and we've not been beating on the problem very long.




View original postI never said it was insoluble, only that the solution is apt to be revolutionary, the more so the longer it eludes us, since we can only find it by continually increasing our understanding. Our understandings expansion is only possible in its paradoxes and frontiers. Maybe that is why we can never answer all questions: We could no longer ask them if we did.

Very Zen. Also kinda meaningless, which is typical of such I suppose. Like I said, I don't know if there are a finite number of questions or if they are all solvable, I've never seen any evidence indicating that was or wasn't so, I know the questions we currently have and I'd like them answered if they can be, some may spawn more questions, some may not, I worry about those if and when they appear because otherwise it amounts, IMO, to a sort of fatalism.

The intuitive mind is a sacred gift and the rational mind is a faithful servant. We have created a society that honors the servant and has forgotten the gift.
- Albert Einstein

King of Cairhien 20-7-2
Chancellor of the Landsraad, Archduke of Is'Mod
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Bored and irritated rumination on Olber's Paradox - 28/07/2013 03:21:37 AM 704 Views
I initially read that as "urinated." - 28/07/2013 04:17:47 AM 435 Views
It's tied to the Copernican Principle - 28/07/2013 05:09:58 AM 500 Views
That makes sense. Thanks, Issac! *NM* - 28/07/2013 03:54:54 PM 211 Views
Expansion's a bitch, innit? *NM* - 28/07/2013 04:37:26 AM 228 Views
I'm not saying it's aliens ... - 28/07/2013 06:03:25 AM 508 Views
Re: I'm not saying it's aliens ... - 28/07/2013 10:27:54 PM 1000 Views
Well - 28/07/2013 04:49:06 PM 567 Views
Re: Well - 28/07/2013 10:28:22 PM 597 Views
I always wonder about the magic solution to fix the math - 29/07/2013 01:30:23 PM 405 Views
Sure, that's basically what Dark Energy is - 29/07/2013 07:30:00 PM 449 Views
I, in turn, always wondered how black holes would permit gravitons to function. - 11/08/2013 09:37:39 PM 516 Views
They don't, yet they obviously do, that's the whole problem - 11/08/2013 11:08:35 PM 525 Views
Probably the first and last time "man on the moon" was put on par with "plentiful free online porn." - 12/08/2013 02:09:36 AM 490 Views
The latter is admittedly a far greater accomplishment - 12/08/2013 05:06:17 AM 623 Views
Meh, porn predates civilization; its novelty has faded. - 13/08/2013 06:36:13 AM 457 Views
I think most people would disagree - 13/08/2013 07:09:38 AM 1992 Views
Re: I think most people would disagree - 14/08/2013 09:05:32 AM 551 Views
Interesting Read - 30/07/2013 02:24:31 AM 391 Views
Re: Interesting Read - 30/07/2013 04:19:34 AM 402 Views
Fair enough - 30/07/2013 12:15:15 PM 434 Views
What if the universe is more like a sea urchin? - 30/07/2013 04:04:56 PM 459 Views
Re: What if the universe is more like a sea urchin? - 30/07/2013 11:04:49 PM 448 Views

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