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| Thread: Einstein's Blunder | |
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yogi
Promising
Famous Hero
of picnics
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posted September 18, 2016 05:38 PM |
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Maurice
Hero of Order
Part of the furniture
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posted September 18, 2016 11:07 PM |
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What I always consider funny about those considerations is that space is taken as a constant. While considering the expansion of the universe, this implies that space itself increases (i.e. the volumetric content of the universe increases).
But what if that's not the case? Einstein was right in proposing the concept of "zero-energy" (i.e. the energy of an empty volume of space) as well as the relation between matter, energy and space ... but isn't it the logical conclusion then that space itself isn't a constant? We know that gravitational lensing occurs and it's being said that it's the cause of photons having a non-zero rest mass, while it's often also said they're mass-less. Basically, a particle following a trajectory will follow the path of least resistance, with the lowest energy potential. But what if space itself is actually compacted around mass concentrations, such as galaxy clusters?
Think of this as chewing gum or a sheet of elastic material. Fasten it at its edges and then peel at the center, twisting it around so the material is getting stretched across the surface, except at the center where it coalesces. At the center it will heap up as a result, while in the rest of the sheet, it will be stretched thin. Translate this to the picture of the universe, where each mass concentration is such a center being wound up, while the near-void areas between them are where space is being stretched (very) thin. This immediately means that distances aren't a constant either when comparing them in different areas of gravitational pull, when determining just how much space was covered. Essentially you could define this as the "density of space". Think of it as foam with concentrations of small bubbles where you'd have mass concentrations and large bubbles everywhere in between, surrounding those clusters.
I didn't actually do the numbers, but for all I know it could very well explain stuff like dark matter, which was "invented" to explain the rapid rotational speed in the outer areas of galactic discs. If space there is simply more stretched due to having less mass, the observed distance travelled is simply larger than expected - which is precisely what we're seeing. It also explains gravitational lensing as a passive effect, since the trajectory travelled by photons is more or less like with a vehicle being on a hard road with the wheels on one side and a soft bed on the other side; that other side will be dragged along and the vehicle has the tendency to steer towards the soft bed. For a photon travelling, it will find space on one side to be *slightly* (owing to the extremely small side of a photon) denser than on the other side, experiencing a slight course deviation towards that denser region every moment it's travelling past it (and actually, also towards and away from it).
I don't know what such a "space density" implies for red- and blueshifts though, as they're the ones they use to determine spacial velocities.
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Stevie
Responsible
Undefeatable Hero
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posted September 18, 2016 11:32 PM |
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I'm just gonna rest my fascination at the fact that the universe is accelerating its expansion, not even slowing down due to gravity's pull. Why would that be? There's obviously a force at play, but the reason for its being is not apparent.
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Guide to a Great Heroes Game
The Young Traveler
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yogi
Promising
Famous Hero
of picnics
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posted September 20, 2016 05:02 AM |
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Edited by yogi at 05:05, 20 Sep 2016.
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you would seem to be in the quintessence crowd Maurice.
Stevie said:
I'm just gonna rest my fascination at the fact that the universe is accelerating its expansion, not even slowing down due to gravity's pull. Why would that be? There's obviously a force at play, but the reason for its being is not apparent.
time.
"Quintessence differs from the cosmological constant explanation of dark energy in that it is dynamic, that is, it changes over time, unlike the cosmological constant which always stays constant. It is suggested that quintessence can be either attractive or repulsive depending on the ratio of its kinetic and potential energy. Those working with this postulate believe that quintessence became repulsive about ten billion years ago, about 3.5 billion years after the Big Bang."
"Within the framework of general relativity, an accelerating expansion can be accounted for by a positive value of the cosmological constant Λ, equivalent to the presence of a positive vacuum energy, dubbed "dark energy"."
https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe
http://phys.org/news/2015-02-fast-universe.html
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yogi - class: monk | status: healthy
"Lol we are HC'ers.. The same tribe.. Guy!" ~Ghost
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yogi
Promising
Famous Hero
of picnics
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posted September 20, 2016 05:33 AM |
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Edited by yogi at 05:33, 20 Sep 2016.
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