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Not necessarily. Flatness measurements do more to imply an infinite universe but they aren't conclusive. The universe could be finite or infinite.
originally posted by: Phantom423
If the expansion of the universe is due to dark energy and the expansion is faster than the speed of light, does that imply that the expansion of the universe is infinite?
We don't know enough about dark energy to say conclusively. If the zero energy hypothesis of the universe is correct, the increases in dark energy may be offset by the increasing distances between masses, which according to Alan Guth is a form of negative energy.
Space is created as the universe expands – but does dark energy increase in the expansion? Are there any “brakes” in the process or does it just go on ad infinitum?
A generic property of inflation is the balancing of the negative gravitational energy, within the inflating region, with the positive energy of the inflaton field to yield a post-inflationary universe with negligible or zero energy density.[5][6] It is this balancing of the total universal energy budget that enables the open-ended growth possible with inflation; during inflation, energy flows from the gravitational field (or geometry) to the inflaton field—the total gravitational energy decreases (i.e. becomes more negative) and the total inflaton energy increases (becomes more positive). But the respective energy densities remain constant and opposite since the region is inflating. Consequently, inflation explains the otherwise curious cancellation of matter and gravitational energy on cosmological scales, which is consistent with astronomical observations.
I don't think of dark energy as moving, and really I don't even think of the galaxies as "moving" due to inflation, rather, space is expanding. This is my favorite paper on superluminal expansion:
How much faster than the speed of light does dark energy move? Does it vary from place to place or is it uniform?
If you plot where z=1.5 that's roughly a sphere, and generally inside that the recessional velocities will be less than c, outside that recessional velocities will tend to be larger than c, though there may be exceptions due to local motions unrelated to inflation. The further away the greater the recessional velocity, and at larger distances the relationship becomes non-linear. For redshift of z=10 it looks like the average recessional velocity was something like 2.5 times the speed of light, where ~13 billion year old light from galaxies represents a current distance of ~32 billion light years.
The recession velocity of all galaxies with z>∼ 1.5 exceeds the speed of light in all viable cosmological models
Free-lunch interpretation
A generic property of inflation is the balancing of the negative gravitational energy, within the inflating region, with the positive energy of the inflaton field to yield a post-inflationary universe with negligible or zero energy density.[5][6] It is this balancing of the total universal energy budget that enables the open-ended growth possible with inflation; during inflation, energy flows from the gravitational field (or geometry) to the inflaton field—the total gravitational energy decreases (i.e. becomes more negative) and the total inflaton energy increases (becomes more positive). But the respective energy densities remain constant and opposite since the region is inflating. Consequently, inflation explains the otherwise curious cancellation of matter and gravitational energy on cosmological scales, which is consistent with astronomical observations.[7]
OK let's use an analogy. A young man who just graduated from high school has been working a short time and he runs short of money and goes to a payday loan center to ask for $500 so he won't be broke until his next payday.
I was reading this brief explanation, but it doesn't make sense to me, particularly the last sentence about "cancelling matter....)
The standard unit of distance measurement used by astronomers is the "parsec" which is about 3.26 light years.
originally posted by: Phantom423
a reply to: Arbitrageur
Question: what do the terms circled in the jpeg mean? They appear in the Expanding Confusion article but are not defined. Thanks.
originally posted by: Phantom423
I thought that inflation occurred after the Big Bang and at the end of the inflationary period, the universe continued to expand. So Zero point energy means that the energy from inflation was transferred to expansion such that the amount of energy in the universe remains that same?
Inflation energy is supposed to be balanced by the negative gravitational energy. But does that suggest there was some sort of mass generated by inflation? How did they calculate the amount of mass present during the inflationary period? And if it was balanced, why would expansion continue? Wouldn't energy be net zero with no expansion possible?
I was reading this brief explanation, but it doesn't make sense to me, particularly the last sentence about "cancelling matter....)
Free-lunch interpretation
A generic property of inflation is the balancing of the negative gravitational energy, within the inflating region, with the positive energy of the inflaton field to yield a post-inflationary universe with negligible or zero energy density.[5][6] It is this balancing of the total universal energy budget that enables the open-ended growth possible with inflation; during inflation, energy flows from the gravitational field (or geometry) to the inflaton field—the total gravitational energy decreases (i.e. becomes more negative) and the total inflaton energy increases (becomes more positive). But the respective energy densities remain constant and opposite since the region is inflating. Consequently, inflation explains the otherwise curious cancellation of matter and gravitational energy on cosmological scales, which is consistent with astronomical observations.[7]
en.wikipedia.org...
originally posted by: [post=20013468]joelr There is probably some energy in that "zero point field" concept but metaphysics writers have totally taken advantage of it. The way to get energy from that would be to break space-time. We don't know how to do that or even what that means really
originally posted by: Nochzwei
originally posted by: [post=20013468]joelr There is probably some energy in that "zero point field" concept but metaphysics writers have totally taken advantage of it. The way to get energy from that would be to break space-time. We don't know how to do that or even what that means really
Know ye not this has been achieved already
Didn't you have an older thread where that was allegedly confirmed by measuring the pH of two tomatoes, or am I thinking of someone else?
originally posted by: Nochzwei
If you achieve anti gravity effect wrt time, you are progressively breaking space time symmetry wrt time.
You're exaggerating the difference between relativity and Newtonian mechanics, because at non-relativistic conditions they make approximately the same predictions. The Roche limit was calculated in 1848 and nobody needed to re-calculate that when General Relativity appeared in 1915 though one could apply GR corrections if they were significant, but I think in typical applications of the Roche limit they're not significant.
originally posted by: greenreflections
Right, the rubber ball will lose it round form and become elongated, distorted.
From GR perspective how this could be explained?
If that wasn't you then you have a doppelganger who makes exactly the same claims about relativity having time dilation backwards, and who similarly presents flawed evidence in support of that claim. Even the writing style was similar to yours. If that wasn't you (I suspect it probably was) then you should hook up with that guy so you'll finally have someone who can agree with your anti-relativity claims. I think he went by AngelicResurrection or something like that.
originally posted by: Nochzwei
No I am still referring to the Ark Video
a reply to: Arbitrageur
The shape of the Hubble sphere is a sphere, and the geometry of the universe appears to be flat though there are of course caveats to this such as the citation below and others.
originally posted by: Phantom423
a reply to: Arbitrageur
If the universe is flat, isn't the Hubble sphere really an ellipse or a curve on a plane? The volume of the Hubble sphere is calculated as c/Ho. Volume for an ordinary sphere is v =4/3 pi r(cubed). Is "sphere" a misrepresentation of what the shape is - or maybe we don't know the shape?
However, the term is also frequently (but mistakenly) used as a synonym for the observable universe; the latter is larger than the Hubble volume.
In a perfectly flat universe, two laser beams aimed parallel to each other would remain parallel forever. If the universe were not flat, then the laser beams would eventually diverge or converge...
We see evidence of this flatness in the cosmic microwave background (CMB). Overall, the temperature of the CMB is very uniform. There are small variations in its temperature, but those small variations average out. This is exactly what we would expect with if the universe is (on average) flat....
But recently we've found that there is a bit of an anomaly in the CMB. ...
While many proposals to explain this anomaly invoke exotic ideas such as multiverses, a recent paper in Physical Review Letters shows that the anomaly could be explained entirely by cosmic curvature. The team has demonstrated that the observed anomalies (if real) can be accounted for by a universe with a saddle shaped universe, seen as the left figure in the image above.
a reply to: Arbitrageur
If the universe has "flat geometry" we would expect two parallel laser beams to remain parallel forever. Geometry in this context refers to four-dimensional space-time so if you try to visualize it in three dimensions, you don't get the concept. We can't really visualize this type of four-dimensional curvature accurately, but we can measure and calculate it.
I said we can't visualize it accurately, I didn't say we can't visualize it at all. With the shape of the universe we only need to take a 2D surface of the Earth versus 3D volume of the Earth, which we can visualize, and add one more dimension. We know if we take two points on the Earth's equator 90 degrees apart, and a third point at the north pole and draw a triangle, that all three 90 degree angles add up to 270 degrees, not 180 degrees like a triangle would on a flat surface, so this shows the Earth's surface is curved. Likewise if triangles in space have angles that add up to less or more than 180 degrees we know space isn't flat. If the angles add up to exactly 180 degrees it's flat.
originally posted by: Phantom423
Yes, I can't say I understand, but I get the point. But to say that you can't visualize something, but yet you can measure and calculate it leaves me somewhat puzzled. It's probably a poor analogy, but I can't imagine synthesizing a chemical compound or isolating an unknown compound without being able to measure it, calculate bond energies, determine its chemical structure, etc.
I thought the CMB example was straightforward, you're just comparing one part of the sky to other parts of the sky to see if it looks the same everywhere, or if you see distortions. Of course the accuracy of measurements can be in question and they certainly are in the article I cited. We're not sure if that's even a real anomaly and even if it is, we're not sure if it's caused by the curvature of the geometry of the universe or something else.
A thousand questions like how do you know the measurements are accurate - what are the standards that you compare them to?
For multiple-particle systems like the electrons of the hydrogen molecule, showing the magnitude of the wave function as grey tones no longer works since it is a function in six-dimensional space. You cannot visualize six-dimensional space.
originally posted by: Nochzwei
Lo as I recall we were on about breaking space time symmetry and you cherry picked one line from that post to go into wild speculationn. Besides any engineer in this world worth his salt will phoo phoo GR and actually feel like drumming those who embrace it
a reply to: Arbitrageur