Originally posted by swan001
Quantum Jitter IS vacuum energy.
So your statement, that "The most popular hypothesis seems to be that (dark energy) it's the result of vacuum energy", is the same thing as me saying
that dark energy is the result of quantum jitter. Vacuum energy and quantum jitter is the same thing: only quantum predicts energy in total vacuum.
I asked for a source yet you provide none.
I'm not cranky Swan, I just like to clarify misconceptions and here is another one. The cosmological constant in relativity specifies the the effect
of vacuum energy, and there is no quantum jitter in relativity. In fact relativity doesn't address of mesh with quantum mechanics at all, yet it is is
Einstein who is credited with the "cosmological constant" which can mathematically describe the effect we see from dark energy. Since you didn't
provide a source, I will:
What is dark energy
One explanation for dark energy is that it is a property of space. Albert Einstein was the first person to realize that empty space is not
nothing. Space has amazing properties, many of which are just beginning to be understood. The first property that Einstein discovered is that it is
possible for more space to come into existence. Then one version of Einstein's gravity theory, the version that contains a cosmological constant,
makes a second prediction: "empty space" can possess its own energy. Because this energy is a property of space itself, it would not be diluted as
space expands. As more space comes into existence, more of this energy-of-space would appear. As a result, this form of energy would cause the
Universe to expand faster and faster. Unfortunately, no one understands why the cosmological constant should even be there, much less why it would
have exactly the right value to cause the observed acceleration of the Universe.
So that's one possibility from Einstein's work.
Now I'm not sure if this is what you are calling quantum jitter or not, but it's the alternate explanation offered by NASA, and they don't call it
that (nobody does as far as I can tell, as quantum jitter refers to something else):
Another explanation for how space acquires energy comes from the quantum theory of matter. In this theory, "empty space" is actually full of
temporary ("virtual") particles that continually form and then disappear. But when physicists tried to calculate how much energy this would give empty
space, the answer came out wrong - wrong by a lot. The number came out 10^120 times too big. That's a 1 with 120 zeros after it. It's hard to get an
answer that bad. So the mystery continues.
And NASA offers more possibilities:
Another explanation for dark energy is that it is a new kind of dynamical energy fluid or field, something that fills all of space but something
whose effect on the expansion of the Universe is the opposite of that of matter and normal energy. Some theorists have named this "quintessence,"
after the fifth element of the Greek philosophers. But, if quintessence is the answer, we still don't know what it is like, what it interacts with, or
why it exists. So the mystery continues.
A last possibility is that Einstein's theory of gravity is not correct. That would not only affect the expansion of the Universe, but it would also
affect the way that normal matter in galaxies and clusters of galaxies behaved. This fact would provide a way to decide if the solution to the dark
energy problem is a new gravity theory or not: we could observe how galaxies come together in clusters. But if it does turn out that a new theory of
gravity is needed, what kind of theory would it be?...
The thing that is needed to decide between dark energy possibilities - a property of space, a new dynamic fluid, or a new theory of gravity - is more
data, better data.
So it's a complex mystery and nowhere is quantum jitter mentioned.
So what is quantum jitter if not vacuum energy? I found one reputable source defining the term and even that source put the term in quotes:
`quantum jitter': the value of quantities characterizing the system fluctuate
Fluctuating values of a quantum system can apply to
which is not the same concept as vacuum energy:
quantum foam can be used as a qualitative description of subatomic spacetime turbulence at extremely small distances (on the order of the Planck
length). At such small scales of time and space, the Heisenberg uncertainty principle allows energy to briefly decay into particles and antiparticles
and then annihilate without violating physical conservation laws. As the scale of time and space being discussed shrinks, the energy of the virtual
particles increases. According to Einstein's theory of general relativity, energy curves spacetime. This suggests that—at sufficiently small
scales—the energy of these fluctuations would be large enough to cause significant departures from the smooth spacetime seen at larger scales,
giving spacetime a "foamy" character.
With an incomplete theory of quantum gravity, it is impossible to be certain what spacetime would look like at these small scales, because existing
theories of gravity do not give accurate predictions in that regime.
so would you agree that quantum foam is a product of quantum jitter and that
quantum foam is a different concept than vacuum energy?
edit on 20-11-2012 by Arbitrageur because: clarification