vegevore - Physics Page 4: Other notes: 1. (from: 06 April 1999) Recent reports (e.g., "Science", New Focus, 13 Nov. 1998, P.1249) suggest the existence of a non-zero cosmological constant. Searching for the density of particle-antiparticle pairs in the vacuum (or by an analogy from chemistry: What is the 'pH' of space-time?) leads to the question of what is the vacuum energy density? Were this infinite, we could use an analogy from mechanical engineering to suggest otherwise: The strength of a material is given by Young's modulus but this has units of an energy density. Were this infinite for space-time then starlight would not be seen to deflect. Continuing the analogy, one could ask what is the stiffness of space-time, but one finds that only a specific stiffness (Young's modulus per unit density) is easily obtained, which is c2. But in looking further, we see that Newton's constant of gravitation, G, has within it a density, thus: density = 1 / G t2 Then, inserting t's of significance (the age of the universe at about 12 billion years or the Planck t at 1.35E-43 seconds), we find either a density consistent with that of the suggested cosmological constant or the Planck density (respectively) with the ratio between the two of about 120 orders of magnitude. 2. (from: date?) In superconductivity, a spin-spin coupling between two particles of spin 1/2 gives the properties of a spin 1 particle (and one of spin 0). e-[1/2] + e-[-1/2] <==> X[0] + Y[1] Can we by analogy apply this to a spin-spin coupling between two spin 1 particles to form a spin 0 particle and a spin 2 particle? photon[1] + photon[-1] <==> [0] + [2] Can this then tell us something about the Higgs and the graviton?? 3. (from: date?) Electromagnetic energies (photons) beyond about 1 MeV can produce real electron-positron pairs. Can energies near or above about the visible produce real neutrino-antineutrino pairs? 4. A question: For Electromagnetism (in Special Relativity): ai = Fij uj where: Fij = eija Ea + bija Ba where the eija are generators of the boosts (translations) and the bija are generators of the rotation symmetries. For General Relativity: ai = Gijk uj uk we want to know what the infinitesimal 'symmetries' are. Supposedly, the connection coefficients are composed of components like expansion, torsion, etc.??? 5. Acceleration: One of the things about neutrinos is that they interact so "weakly" with matter that they can pass thru it more easily than light can. If indeed light can produce pairs of virtual neutrinos, then the neutrinos may be able to effectively expand the universe faster than light can. Thus, they can lead to an accelerating expansion. Yes? 6. Random thoughts (2004 Aug 10): Dirac envisioned a semi-infinite sea of virtual particles: knocking one out of the sea resulted in a particle with the resultant hole seen as an antiparticle. Maybe not coincidently, a Scientific American article ("The Classical Vacuum", 1985 August) discussed an idea that the vacuum energy is an infinite zero-point radiation with such a spectrum as to be relativistically invariant (thus "invisible"). Thermal processes are not invariant. I have been suggesting that thermal processes have mass but that the vacuum energy does not (elsewhere here: that only bound energy has mass; that is, bound to a process, which hints at observables in QM and whether something exists (does Shrodinger's cat die?) if unobserved (does the entropy change? but entropy is a discrete conception while QM is continuous, sort of, a wave that crosses states?; GR is a distortion of the zero-point field by the mass associated with the thermal process associated with a local phenomenon)). It is no coincidence that the wave equation of quantum mechanics looks like a thermal diffusion process. And I propose that it is more initimate than that: any process that distorts the vacuum energy creates mass through a thermal process reflected in the wave equation (pun intended).