Posted on 01/10/2002 7:18:34 AM PST by JediGirl
In the experiment, the trajectories observed are dependent on, whether or not, the targets have no fluctuations around them, or some other magnitude of fluctuations. The data is compared to what the theoretical calcs say for the proposed conditions.
Ummm, english please?
Typical mumbo-jumbo physics response! ;)
Why are we here? We're not really here at all... We just THINK we're here...
Well, certainly in order to do any science, at some level you have to make the assumption that the fundamental laws of nature are the same all over the universe, and that we aren't in some sort of privileged bubble where general principles cannot be derived.
That being said, your question is a valid one. One of the observable effects of virtual particles is a subtle shifting of atomic spectral lines called the Lamb Shift. We can observe the Lamb Shift in emission lines from the Sun, from distant galaxies, even from absorption lines caused by the interstellar medium, which is typically a harder vacuum than any we can economically create in the laboratory. (It may seem odd that we can see any opacity in a medium so rarefied, but after a hundred thousand light years it adds up.)
I thought that the dielectric constant was determined using a vacuum as a reference (constant of 1, I believe). When you measure the effect of virtual particles, what do you use as a reference? Surely you can't use a vacuum as a reference to measure another vacuum.
Ah, but the number 1 is scale invariant, you'll agree, while the effect of vacuum polarization is not (as I illustrated above in the case of Bhabha scattering).
Again, please translate into english for someone that has only undergraduate physics knowledge and is capable of understanding concepts should they involve familiar terms and/or some further explanation. Fluctuations of what?
Not classically, once you've chosen an inertial frame. And once you claim that you know the energy of a particle, you've chosen an inertial frame.
So there was NO space, NO time, NO matter, and NO temperature. Somebody please explain to me what medium this infinitely dense single point existed in. What was the fabric of the medium this point was floating in? Where was it? When was it? It seems they are saying that NOthing suddenly became everything. What law of physics made this possible? How can there be any laws when nothing, no where, nowhen exists?
The poping of particle pairs out of the vacuum is called the vacuum fluctuation. To understand the experiment consider an electron sitting out in space. Now there's a machine shooter with an electron gun taking shots at it. We use a machine shooter, 'cause he doesn't shake. If there are no fluctuations near the electron you smake the target every time in the same place. You have a pic of the target now. Now if their are particles jumping in and out around the target, the targets going to jump around, because they're all charged. Some will push, some pull. It's going to effect the hits, and a different picture obtains. In this case the shots look scattered on a screen behind the target. You din't need the first experiment, because all the shots hit and there's only one hole in the screen. That's your calc. reference.
In real experiments there are more causes for jitter in both cases, so they both appear scattered, but the results are the same.
Point poop.
" Where was it?"
Everywhere.
When was it?
Before the point flipped it's lid over the stench.
" It seems they are saying that NOthing suddenly became everything."
You don't smell anything do you?
" What law of physics made this possible?
Murphy's law.
I'm not speaking of an idealized subset of objects. I am stating an outcome of physical world in relation to all material objects. If object "A" is "moving" it is "moving" in relation to some other object "B". If it so happens to be stationary in relation to object "C" then "C" is also in "motion" relative to "B". "B" moves in relation to both "A" and "C". All things are "moving". The universe is not inertial.
Hmm.. Maybe stating it philosophically will illustrate my point. If something "moves" the universe is changed. Everything "knows" that the universe is changed. (quantum spookiness)
You're right it is and was. Your post reminded me of an exchange where a turtle held the world on it's back. My apologies, I didn't know you were that serious. Here's some answers.
"So there was NO space, NO time, NO matter, and NO temperature."That's correct. There was only the other place, the vacuum. Folks can't go there, so they only as much of it as they can see from this world.
"Somebody please explain to me what medium this infinitely dense single point existed in. What was the fabric of the medium this point was floating in?"
The single point idea is only used as a mathematical tool at present by the folks in this world to understand things we see in this world. My understanding is that there was not a single point initially, but an occurrence in the other place, the vacuum, out of which this world arose. I don't know the physics of it. Something akin to the developement of a disaster wall in Physicists post #65.
"Where was it?"
As far as I've seen the universe appears to have roughly a crunched spherical shape. You could go back from the edge of the visible universe and locate a spot for where the initial creation happened, but you must realize there was nothing here originaly to say where it was. If you were in the other place, you would have a reference to say it was here.
"When was it?~15 billion years ago.
" It seems they are saying that NOthing suddenly became everything.
Out of the vacuum arose all that we see.
" What law of physics made this possible?
Don't know.
" How can there be any laws when nothing, no where, nowhen exists?
The laws we have in this world arose and are consistent with those in the vacuum. No one can go there to observe, or determine exactly what's there.
Indeed, the concepts are difficult when first encountered.
So perhaps, "In the beginning God.... " is just as apt a way of explaining "it" to a layman as any.
I would suggest that it's the very worst way of explaining it. There are several reasons why:
1. It's not an explanation at all; it's the declaration that it's in inexplicable miracle.
2. When a physical event is declared to be a miracle, it is culturally closed off from all rational inquiry.
3. That sets up an unnecessary conflict between religion and science, which isn't good for either.
4. By linking one's religion so closely to fairy tales about natural events, it is inevitable that one's religion will look silly as science makes progress. Society needs the ethical benefits religion, but these benefits are few when religion is subject to ridicule.
That seems to be what science is doing, since about every other week some cosmologist comes up with a new theory to explain the inexplicable. These theories of course are never proven, just postulated as a possible explanation. When they finally get it down to the final, absolutely final explanation of how it all came about, (And since the existence of God cannot be disproven) "In the beginning God......" will suffice. However, I wish the good luck.
Ever her of the inflationary theory?
Sure. Just read a good article on it in the Economist. It is a descriptive theory of what happened (space increased in size) without explaining how or why it expands. It just says that it does. There is no empirical reason for it to expand--it just fits with observation with no rationale for the motive power behind it that offsets gravity.
Now there are also theories of negative gravity and a fifth force that counteracts it--but no experimental evidence for them.
Space is a vacuum, right? Essentially a large void of nothing between the planets and galaxies. In empty space there is no gas, solid, or liquid. So, how can it be expanding? Gases expand with increased temperature or lower pressure. How can nothing expand?
This just seems to fly in the face of what we know about the physics of gases and vacuums.
The laws applying to gases don't apply to the expansion of space. The expansion of space is required by the general theory of relativity, which states that matter and energy deform and shape space. With the expansion of matter, space also expands. The inflation theory says that space expansion actually drives the spreading of the universe.
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