Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Emc2 on 02/09/2012 07:13:16
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http://www.msnbc.msn.com/id/48863290/ns/technology_and_science-science/#.UEHZK6PNltM
In other words, the photons' near-simultaneous arrival indicates that space-time is smooth as Einstein suggested, rather than pixilated as modern theories require — at least down to slightly below the scale of the Planck length, a smaller scale than has ever been probed previously. The finding "comes close to proving (that space-time is smooth) for some range of parameters," Nemiroff said.
very interesting....hmmm............
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This could indicate a separation of space from matter... Space does not exist in the time dimension. Time is in matter. Even if space could come from matter, it is not matter-energy...
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It's quite interesting, was looking at Damocles theoretical proof of no pixelation of a vacuum just a moment ago and now seeing this :) A really good catch E.
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Quantum mechanics and the Heisenberg uncertainty principle, define a sort of "box" within which we cannot look in detail but only observe the long term results of the "random" processes going on within there.
Many people see this as some fundamental limit on space and time. This does not have to be so. There is no reason why low energy processes related to space and time cannot happen "within the box". The important fact is we can only observe processes which persist long enough to be seen outside of the box.
I can see no reason why interactions should not continue down to a space time scale at least as small again as the planck scale is smaller than the size of our entire visible universe.
We accept without question that we cannot be aware of anything going on outside of the time scale that the big bang allows light to reach us and also that there is probably a lot more of our universe that we cannot see now and probably for ever with increasing expansion rates.
The planck scale derived from the uncertainty principle just puts similar limits on what we can see as a single event on a small scale.
People talk about "mathematical singularities" very glibly. Please bear in mind that if a mathematical singularity exists inside a black hole it is vastly (in fact infinitely) smaller than the Planck dimensions.
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Quite so SoulSurfer, and a nice description. That's my thoughts on what should be a center too, it should not take place over Planck scale and so becoming a enigma in several ways to me. First of all if we assume that it create a 'gravity', as we then also must assume that what we have there is not described by indeterminism or statistics anymore but instead becomes something 'steady' although, possibly, dynamically growing. And then the question what that would mean?
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There's a lot missing from the article. What were the wavelengths of these three gamma rays? Were they a few Planck lengths or a few billion Planck lengths? Were these three the only gamma rays detected during the GRB event? How often are such gamma rays detected from random sources?
The Fermi Gamma Ray Monitor is not a telescope. It has excellent time-scale resolution, but no directionality. It is assumed that these three photons arrived at the same time, within a millisecond, because they originated at the same point source in space-time. Light travels 300 meters in a millisecond. Does anyone know how big a GRB source is? Could two of the photons have traveled 300 meters less distance than the third? What is the duration of a GRB? Do all its gamma rays originate within a millisecond?
The data reported in the article indicate that three photons, presumed to have originated at a single point in space-time, arrived at another point in space-time within a millisecond of each other. If they all travelled the same distance, then their average speed was the same within one part in 3 x 10^19. However, any statistician will tell you that a sample size of three is not statistically significant. The article claims that "... nothing that we know can undisperse gamma-ray photons." That may be true of large numbers of photons, but for a sample of only three, it is not unusual for random dispersion to randomly undisperse. It is possible that these three photons may have taken slightly separate paths, all the same length, dispersing along the way and then converging on the GRB detector.
I would need a lot more information before I could draw any conclusions about the graininess of the aether. And I'm curious why they so carefully avoid using the word "aether", when it is so obvious that is what they're talking about.
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The aether reference is new to me Phractality? If you assume something not grainy but smooth without 'chinks' that you can magnify over and over without ever finding it becoming grainy, would that be a aether? And another thing I'm wondering about. What is the center of a Black Hole consisting of? Energy? What defines the constriction holding that energy. To create a gravity you will need some way of 'trapping' that 'primeval energy' methinks? And somehow those questions belong together in my mind.
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The point I'm wondering about is how we define that energy, and how we expect it to be 'trapped'. One could assume that the event horizon would be the entrapment, but at the center the energy, or mass-energy, is described as 'infinite' and 'concentrated'. How does it work?
And if it is this way then how would 'worm holes' fit that idea?
Any entrapping consist of restrictions in the degrees of freedom something can have, but 'energy' is very ill defined to me, as compared to photons in where we at least have recoil and annihilations.
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A photon has some properties, it express a constant 'c', it will 'bend' to gravity and if that gravity is as 'strong' as assumed for at and inside a event horizon radiation won't have a way to anywhere but that black holes center. So that give us our mass-energy possibly, but it says nothing of how that black hole 'store' it?
And it's also so that I presume 'energy' to be a result/expression from transformations? I'm not sure at all what people expect 'energy' to be on its own?
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What about time dilations and 'frames of reference'?
If that is it, is a time dilation then connected to degrees of freedom?
Ouch, 'energy' huh :)
And if you assume that gravity is what constrict that infinite 'energy' then the idea of particles as something 'twisted together' by gravity becomes possible in my mind although that would crave some other type of gravitational interaction than our 'ordinary' gravity constricting that energy into 'particles'. And what about time dilations if it comes to that?
Ouch again.
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The aether reference is new to me Phractality? If you assume something not grainy but smooth without 'chinks' that you can magnify over and over without ever finding it becoming grainy, would that be a aether?
They're talking about a graininess in space-time. How can it be grainy without being a substance? In his Leyden Address (http://www.aetherometry.com/Electronic_Publications/Science/einstein_aether_and_relativity.php), Einstein said, - According to the General Theory of Relativity space without Aether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this Aether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it.
If space-time is grainy, then it must have parts which can be tracked through time.
The OP article does not hint that space-time is infinitely smoothe, only that its graininess is significantly smaller than a Planck length, leaving open the question of whether it is infinitely smoothe. And the data do not even support that conclusion. It is statistically possible that those three photons came from unrelated events in different directions. That's the trouble with a sample size of three.
And another thing I'm wondering about. What is the center of a Black Hole consisting of? Energy? What defines the constriction holding that energy. To create a gravity you will need some way of 'trapping' that 'primeval energy' methinks? And somehow those questions belong together in my mind.
This is too far off topic. Are GRBs related to black holes? Are black holes related to the graininess of space-time? There was no mention of gravity in the OP. There must be other active threads in which to discuss these points, or you could start a new one.
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No, not off topic to me, although far fetched :) The 'graininess' you discuss would need to be 'something' right? some sort of 'grains' delivering the framework for a universe. And there we have that Black Hole center, defined as being ? 'point like' in theory, not having a size at all as I think of it. What defines that point?
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The planck length is not definitive for this reason. The speed that light travels resolves to 1 planck length in 1 planck time. As nothing else can travel at light speed then other particles must move at a fraction of a planck length during 1 planck time interval.
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The planck length is not definitive for this reason. The speed that light travels resolves to 1 planck length in 1 planck time. As nothing else can travel at light speed then other particles must move at a fraction of a planck length during 1 planck time interval.
The slight problem with that elegant use of logic is the heisenburg uncertainty principle - we cannot, even theoretically have particles with the required level of accuracy of momentum and position at those scales. If the universe is truly grainy at the smallest scale then the logic doesn't work really - if we are postulating an entire new idea then you get to make provisions for that sort of hitch.
I don't instinctively agree with quantum foaminess / small scale granularity - but for those that do; to get around your problem one could simply postulate that all matter crosses planck length grains in the planck time but that matter is delayed at boundaries/limits of each grain whereas radiation is not delayed at boundary. ie there is a border transition time for mass that is zero for luxons.
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The planck length is not definitive for this reason. The speed that light travels resolves to 1 planck length in 1 planck time. As nothing else can travel at light speed then other particles must move at a fraction of a planck length during 1 planck time interval.
The slight problem with that elegant use of logic is the heisenburg uncertainty principle - we cannot, even theoretically have particles with the required level of accuracy of momentum and position at those scales. If the universe is truly grainy at the smallest scale then the logic doesn't work really - if we are postulating an entire new idea then you get to make provisions for that sort of hitch.
I don't instinctively agree with quantum foaminess / small scale granularity - but for those that do; to get around your problem one could simply postulate that all matter crosses planck length grains in the planck time but that matter is delayed at boundaries/limits of each grain whereas radiation is not delayed at boundary. ie there is a border transition time for mass that is zero for luxons.
I think the boundary/limit idea is a very elegant solution to the problem. What it also explains is why every reference frame sees light at the same scale as the particle will never move out of its plank position until light has moved to the next one. From the microscopic view point this scales naturally. Time dilation would then be an energy differential needed to catch up with light. The trade-off being a decrease in reaction as the energy input increases. At half light speed light moves two Planck lengths for every one traveled by a mass of ordinary matter. The time dilation equation t = t0/(1-v2/c2)1/2 will then need to be modified in some way to describe microscopic events. I need to think about the modification parameters.
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Quite true Imatfaal. As you say we have HUP throwing a 'cloak' over that scale. And that is also where physics 'ends', so far I know. But Planck scale is a very elegant definition that seems to work.