How the Universe can come from Nothing. Vacuum Fluctuations and Virtual Particles

[mcgheetech79]

Hello everybody im new here. this is a great website and look forward to great conversations. For a while ive been doing research on vacuum fluctuations and virtual particles From what I understand it is the process that when a vacumn is created lots of 'virtual particles' will be created. These are made by the vacumn borrowing energy from the future and using it to create an antimatter particle and a usual particle. These then collide creating the energy used to pay back the 'future'. If i am way of the mark can someone tell me because i am pretty new at this.

[trinitree88]

Hello everybody im new here. this is a great website and look forward to great conversations. For a while ive been doing research on vacuum fluctuations and virtual particles From what I understand it is the process that when a vacumn is created lots of 'virtual particles' will be created. These are made by the vacumn borrowing energy from the future and using it to create an antimatter particle and a usual particle. These then collide creating the energy used to pay back the 'future'. If i am way of the mark can someone tell me because i am pretty new at this.

mcgheetech79. Welcome to the forum. Curiosity killed the cat but drives the scientist. Stay curious. First let me steer you to the hyperphysics site for a rapid self-teaching tour on mainstream physics...here:http://hyperphysics.phy-astr.gsu.edu/hbase/HFrame.html

notice that the Heisenberg Uncertainty Principle applies to a pre=existing particle. This is an object that exists in real space-time, has a real rest mass and occupies some volume in that spacetime. It does not apply to an "empty" vacuum.
For our real particle, we may attempt to find it's position, and it's momentum. Unfortunately, to "see" it we need to hit it with a photon that reflects to our eyes. That photon carries momentum, delivers some to the particle in question, and changes the particle's momentum. The object is located within the width of the photon, plus or minus a bit...that's inherent uncertainty. The momentum is uncertain because of the quantity added or subtracted...in seeing it. The product of the two uncertainties is constant. = or > than h/2 pi.

Einstein rearranged the quantities implying that over short time intervals the particle, not empty space, had an uncertainty in it's energy. Over long intervals the uncertainty is small but over short intervals it can be relatively large. This "transient energy excess" can be used like Cinderella's coach to make a particle/antiparticle pair, as long as the excess disappears within the time constraints. This is not a vacuum doing this. The vacuum has no momentum, no rest mass. It is a known particle doing this.
So the idea that the empty vacuum is swarming with virtual particles is wrong. If instead you have a low density gas of particles....say neutrons...the volume around the neutrons can have an ephemeral visitation by particle/antiparticle pairs, but they must annihilate within the constraints of the time interval in the equation (delta E) times(delta T) = or > than h/2 pi. That leaves the mass/energy of the neutron in question constant within our experimental limits. Unfortunately, unlike calculations done with poor use of significant figures....there actually is a limit on the number of decimal places a good experimentalist can place on any scientific value. When I was a kid, 4 or 5 sig figs was pretty good. Modern apparatus sometimes produces 8 or more, but you aren't going to find one that produces 23....or 88.



pete

[gzhpcu]

Welcome to BAUT.

The Heisenberg uncertainty principle implies that virtual particles can come into existence for short periods of time even when there is not enough energy to create them. In effect, they are created from uncertainties in energy. One could say that they briefly "borrow" the energy required for their creation, and then, a short time later, they pay the "debt" back and disappear again


Some speculate that in the very beginning, there was a void, a curious form of vacuum, a nothingness containing no space, no time, no matter, no light, no sound. Yet the laws of nature were in place and this curious vacuum held potential.. A vacuum fluctuation then triggered the Big Bang...

[trinitree88]

Welcome to BAUT.

The Heisenberg uncertainty principle implies that virtual particles can come into existence for short periods of time even when there is not enough energy to create them. In effect, they are created from uncertainties in energy. One could say that they briefly "borrow" the energy required for their creation, and then, a short time later, they pay the "debt" back and disappear again


Some speculate that in the very beginning, there was a void, a curious form of vacuum, a nothingness containing no space, no time, no matter, no light, no sound. Yet the laws of nature were in place and this curious vacuum held potential.. A vacuum fluctuation then triggered the Big Bang...

gzhpcu. Not true...."Another common misconception is that the energy-time uncertainty principle says that the conservation of energy can be temporarily violated - energy can be "borrowed" from the Universe as long as it is "returned" within a short amount of time.[15"...
There has to be an object with an energy level to fluctuate, such as a proton, electron or neutron. Empty space has no object...therefor no fluctuation accomodated by HUP. There remains as yet no known reason for the universe to exist with it's observed asymmetry in Matter over Antimatter. None. No lab result. No astrophysical result. No theoretical result. It remains one of the most fundamental unabridged questions in physics still. It does not explain the Big Bang.
Perhaps one of the missing hyperons from the top/bottom family, or strange/charm family will show an asymmetry in it's decay. But so far, every conservation law known says the universe ain't so, and can't be. But it is. pete

[Cougar]

...it is the process that when a vacumn is created...

I'm not sure what you mean here. Our universe has a so-called vacuum, within which all the action takes place. Apparently our vacuum was "created" at some point long ago, along with the rest of the universe. Of course, we know little about this very initial state. It may have just been a transformation from one state to the one we now observe.

[Cougar]

There has to be an object with an energy level to fluctuate, such as a proton, electron or neutron. Empty space has no object...therefor no fluctuation accomodated by HUP.

I don't know, Pete. I've read a lot of treatments that contradict what you say, that it's not necessarily the energy level of an existing particle that fluctuates, but observed on the smallest of scales, it's the geometry of the vacuum itself that begins to fluctuate wildly.

And even devoid of particles, our vacuum apparently contains some very low level of energy. Heisenberg Uncertainty pertains only to conjugate pairs, e.g., position-momentum. As the accuracy of the observation of one goes up, the other must go down. Energy-time is apparently another conjugate pair. As you try to cram one into a smaller and smaller box, the other becomes more and more.... uncertain.

[DrWho]

I don't know, Pete. I've read a lot of treatments that contradict what you say, that it's not necessarily the energy level of an existing particle that fluctuates, but observed on the smallest of scales, it's the geometry of the vacuum itself that begins to fluctuate wildly.

And even devoid of particles, our vacuum apparently contains some very low level of energy. Heisenberg Uncertainty pertains only to conjugate pairs, e.g., position-momentum. As the accuracy of the observation of one goes up, the other must go down. Energy-time is apparently another conjugate pair. As you try to cram one into a smaller and smaller box, the other becomes more and more.... uncertain.

That is also my understanding.

[trinitree88]

My limited point of view is that (delta E)(delta T) means a large energy fluctuation is allowed briefly, but not permanently, and over a large time interval,say 13 billion years, the energy content of the universe (which noone knows) is ~ constant, meaning the change in it is zero.
The interlinking of time considerations and quantum fluctuations was more elegantly put by the authors in the new Casimir thread a while back. Both blackbody radiation and the Casimir effect are rooted in boundary conditions for the experiment. It doesn't seem to validate a universe popping into existence from nothing, which as a staunch defender of conservation laws (it's the chemist in me),,,I find hard to swallow. But, I'm listening. pete

SEE:http://www.bautforum.com/science-tec...ir-effect.html nice job by Palova, Chandra & Coleman


also SEE:http://en.wikipedia.org/wiki/Uncertainty_principle
no mention of volume and energy content...

[mcgheetech79]

thanks everyone for your great responses. Also I just learned that in particle and antiparticle annihilation Reactions such as e− + e+ → γ + γ (the two-photon annihilation of an electron-positron pair) is an example. The single-photon annihilation of an electron-positron pair, e− + e+ → γ cannot occur because it is impossible to conserve energy and momentum together in this process. The reverse reaction is also impossible for this reason. However, in quantum field theory this process is allowed as an intermediate quantum state for times short enough that the violation of energy conservation can be accommodated by the uncertainty principle. This opens the way for virtual pair production or annihilation in which a one particle quantum state may fluctuate into a two particle state and back. These processes are important in the vacuum state and renormalization of a quantum field theory. It also opens the way for neutral particle mixing.

[trinitree88]

thanks everyone for your great responses. Also I just learned that in particle and antiparticle annihilation Reactions such as e− + e+ → γ + γ (the two-photon annihilation of an electron-positron pair) is an example. The single-photon annihilation of an electron-positron pair, e− + e+ → γ cannot occur because it is impossible to conserve energy and momentum together in this process. The reverse reaction is also impossible for this reason. However, in quantum field theory this process is allowed as an intermediate quantum state for times short enough that the violation of energy conservation can be accommodated by the uncertainty principle. This opens the way for virtual pair production or annihilation in which a one particle quantum state may fluctuate into a two particle state and back. These processes are important in the vacuum state and renormalization of a quantum field theory. It also opens the way for neutral particle mixing.

mcgheetech79; You're welcome. pete

EDIT for Dr. Who and Cougar. Here's my rationale.
1.According to Heisenberg Uncertainty, either the product of the uncertainty in momentum times the uncertainty in the position of a/an system/object....or...according to Einstein....the product of the uncertainty in the energy times the uncertainty in the time of the measurement of same is equal to or less than h-bar where h = Planck's constant and h-bar is that divided by two.

2. From Weinstein's physics page...h-bar is 1.0546 times 10^-27erg*sec. Since an erg =~6.24 times 10⁵Mev...that reduces to ~ 6.58 X 10^-22Mev*sec. This is what Yukawa used to find the ~ mass of the exchange particle in the nucleus.

3. Let's take the mass of the universe as ~ 10⁷⁹ protons. A single proton has a mass of ~ 938 Mev/c². Multiplying, we get ~ 10⁸⁰Mev/c².

4. we'll let your cosmologist have the energy "fluctuate" to create a matter universe, and an antimatter universe simultaneously. That means 2 times 10⁸⁰ Mev/c², for the uncertainty in the mass/energy part.

5. So, ( 2 X 10⁸⁰Mev/c² )( Delta T)=~ 6.58 X 10^-22Mev*sec.

6. Solving for Delta T, the time for which this quasi-state may exist by HUP...yields


it exists for =~ 3.29 X 10^-102seconds. Then it disappears, both the matter version and the antimatter version together. Heisenberg's Uncertainty Principle never said an "empty vacuum" could fluctuate into the universe we see. Hopefully these physicists didn't work part time in the stock market over the last decade ... this is ~ 10^-58 Planck-times...absurd.

What is still required by all the experimental data, is for equal creation and annihilation conserving Conservation Laws at all points. ... pete