Lawrence Kraus delivers an amazing talk on cosmology. He brings us up to date on our latest understanding of the universe -- while getting in a few jabs at God. This is a MUST watch . . . even though it runs over an hour. Absolutely the most informative hour I've spent in my life.
I was transfixed the first time I watched. But I realized I missed something (how we get our universe from nothing), so I watched it again, last night . . . and fell asleep. So, this morning, I watched it again . . . and fell asleep.
Fortunately, I downloaded the entire .FLV file, so I can watch it, without fits and starts, anytime I want. I'll try sitting in an uncomfortable chair the next time I watch it. :-)
I found the following on Wikipedia, at the bottom of the entry for "quantum foam". I have been wondering how quantum fluctuations could lead to the production of PERMANENT particles without violating the First Law. It's the last paragraph, below, that directly addresses the question of permanent particles . . . but does not answer the question of First Law integrity. However, the explanation refers to CP-violation: which I know nothing about. So first, I'll post Wikipedia's description of CP-violation, then follow that up with how quantum fluctuations can lead to permanent particles.
In particle physics, CP violation is a violation of the postulated CP symmetry, the combination of C symmetry and P symmetry. CP symmetry states that the laws of physics should be the same if a particle were interchanged with its antiparticle (C symmetry, or charge conjugation symmetry), and left and right were swapped (P symmetry, or parity symmetry).
In order to conserve the total fermion number of the universe, a fermion cannot be created without also creating its antiparticle; thus many physical processes lead to pair creation. The need for the normal ordering of particle fields in the vacuum can be interpreted by the idea that a pair of virtual particles may briefly "pop into existence", and then annihilate each other a short while later.
Thus, virtual particles are often popularly described as coming in pairs, a particle and antiparticle, which can be of any kind. These pairs exist for an extremely short time, and mutually annihilate in short order. In some cases, however, it is possible to boost the pair apart using external energy so that they avoid annihilation and become real particles.
This may occur in one of two ways. In an accelerating frame of reference, the virtual particles may appear to be real to the accelerating observer; this is known as the Unruh effect. In short, the vacuum of a stationary frame appears, to the accelerated observer, to be a warm gas of real particles in thermodynamic equilibrium. The Unruh effect is a toy model for understanding Hawking radiation, the process by which black holes evaporate.
Another example is pair production in very strong electric fields, sometimes called vacuum decay. If, for example, a pair of atomic nuclei are merged together to very briefly form a nucleus with a charge greater than about 140, (that is, larger than about the inverse of the fine structure constant), the strength of the electric field will be such that it will be energetically favorable to create positron-electron pairs out of the vacuum or Dirac sea, with the electron attracted to the nucleus to annihilate the positive charge. This pair-creation amplitude was first calculated by Julian Schwinger in 1951.
The restriction to particle-antiparticle pairs is actually only necessary if the particles in question carry a conserved quantity, such as electric charge, which is not present in the initial or final state. Otherwise, other situations can arise. For instance, the beta decay of a neutron can happen through the emission of a single virtual, negatively charged W particle that almost immediately decays into a real electron and antineutrino; the neutron turns into a proton when it emits the W particle. The evaporation of a black hole is a process dominated by photons, which are their own antiparticles and are uncharged.
It is sometimes suggested that pair production can be used to explain the origin of matter in the universe. In models of the Big Bang, it is suggested that vacuum fluctuations, or virtual particles, briefly appear. Then, due to effects such as CP-violation, an imbalance between the number of virtual particles and antiparticles is created, leaving a surfeit of particles, thus accounting for the visible matter in the universe.
Lawrence spoke of 3 components of the universe that we’ve yet to confirm actually exist: virtual particles, dark matter and dark energy. Here’s the key concepts about them that (I think) I understand:
#1). Virtual particles come and go so quickly we can’t even detect them (yet).
#2). The Heisenberg Uncertainty Principle mandates that empty space must be unstable and predicts, with confidence, that virtual particles flit in and out of existence at Planck scales of space. [I get an image of effervescence here, like the surface of a freshly poured glass of Coke.] This process is known as quantum fluctuations.
#3). The “sub-particle” Planck scales of space are so small that it includes the “empty space” between quarks within protons and neutrons. Virtual particles pop in and out of these empty spaces exactly as they do throughout the universe: including the vast vacuum voids between galaxies. Space is anything but empty.
#4). Solid objects (like us humans) are comprised of atoms which are mostly empty space. The mass of solid objects, therefor, is mostly derived from virtual particles.
#5). Einstein’s General Relativity was used to “weigh” the universe: specifically, his prediction of “gravitational lensing”. Visible artifacts of gravitational lensing have been found around a distant cluster of galaxies. Using this cluster of galaxies and its gravitational lensing effect on the light from a more distant galaxy 3 billion light-years beyond the cluster, astronomers were able to calculate the weight of the cluster. From this, they then extrapolated the weight of the entire universe (including its empty space).
#6). The weight of the universe was needed in order to determine the curvature (open, closed or flat) of the universe.
#7). Empty space between galaxies in clusters weighs about 50 times more than all the stuff in those galaxies.
#8). Dark matter and dark energy, unlike virtual particles, are permanent but also, as yet, undetected.
#9). The visible portion of the universe makes up less than 1% of its mass.
#10). Dark matter makes up about 30% of the mass of the universe.
#11). Dark energy makes up about 70% of the (unaccounted for) mass of the universe.
#12). Our universe is flat, expands forever, has zero total energy and could have begun from nothing.
What I don’t understand is:
#1). What about The First Law of Thermodynamics (conservations of energy/mass)? If dark matter has gained the advantage over gravity, thus accelerating the universal rate of expansion, doesn’t this violate the First Law?
#2). If the universe has zero energy and, thus, could have sprung from nothing, does this mean it’s impossible NOT to have a universe?
#3). If universal expansion creates space as it expands and the universe sprang from nothing, because nature abhors a void; doesn’t this mean that quantum fluctuations don’t require the presence of a universe to begin with?
#4). If quantum fluctuations don’t require a universe to begin with, doesn’t that mean that quantum fluctuations would be a feature of any and all universes?
No doubt, both my understandings and my questions are flawed. What I’m really hoping for is somebody who truly understands and can explain the scientific concensus on cosmology well enough to clear up my misconceptions.
As to your statement, """ I can agree that it's hard to get one's mind wrapped around the concepts of infinity and eternity but that's not a valid reason to deny them.""" I can hardly believe that this came from an atheist. It is essentially the theist argument for god.
I've only heard that argument used against theism not for it.
I'll have more to say about your comments but, for now, watch the video I just attached to this discussion. As you'll see, you got it bass-ackwards. An eternal universe does not require a Creator God. A universe with a beginning does (or used to . . . until quantum fluctuations).
I've just uploaded a video about quantum fluctuations as an attachment to this discussion. It almost 40 MB, so it will take a little time to download. It's a pretty easy-to-digest video that should help make the notion of quantum fluctuations more clear.
It starts off slow, talking about "The Dark Era" toward the end of the universe, but quickly leads into an interesting discussion of how quantum fluctuations come about.