Widdekind

Determining the thickness of Europa's ice-crust Even as the below-water height of an earth ice berg, can be determined, from its above-water height (by the ratio of 6/7ths : 1/7th); so, too, the thickness of Europa's ice-crust could be determined, by measurements, of how high that ice rides, up above the water presumably present, in the fissures, in between the ice-crust 'tectonic plates'. For example, if the water, in those fissures, was -1 km below the ice-crust surface, then the ice-crust would be ~7 km thick [modified by the actual ice density ratio, appropriate to Europa's colder climate]. Melt-water must be left inside the melt-shaft, to equalize pressure, at depth Pressure always increases, with depth. So, if a hypothetical human probe melted through Europa's ice-crust, completely vaporizing the water in its wake, so that its melt-shaft was left empty; then, upon penetrating to the high pressure deep water below, pressures would push the probe, upon a 'geyser' of water, back towards the surface -- specifically, ~6/7ths of the way (since ice is 6/7ths of the density of water [at least at terrestrial temperatures]). Thus, such a probe should leave the melt-water in the melt-shaft, to weigh down upon the probe, and impute compensating pressures.

An anti-particle, propagating forward in time, can be considered, as the corresponding particle, propagating backwards in time. Such is seen, quite commonly, in Feynman Diagrams ('back in time' arrows): However, everyone, regardless of 'perceptual opinion', would regard 'the thing' (particle, time forward, to the left -or- antiparticle, time backwards, to the right) as having the same linear momentum (p = m x v 'to the left'). And, the anti-particle, is propagating in the opposite direction, through both time, and space ('to the right') -- yet, it still possesses, unambiguously, momentum 'to the left', to wit, 'backwards' against its own direction of propagation. Thus, w.h.t. [math]m_p \times v = p_{particle} \equiv p_{antiparticle} = m_{ap} \times -v[/math] [math]\therefore m_p \equiv -m_{ap}[/math] Er go, anti-matter, has anti-mass (which 'double reverses' its linear momentum, so that, moving 'to the right', albeit backwards in time, it still has momentum 'to the left') ??

I seem to have been confused. In post 10 & post 11, I cite Gary Zukav, who wrote: According to the HUP, [math]\Delta E \, \Delta t \geq \hbar / 2[/math]. So, the maximum distance that an 'energy borrowed (i.e., virtual)' photon can propagate, away from the emitter, is [math]c \times \Delta t \approx \hbar / \Delta E[/math]. Thus, at greater distances, only weaker 'virtual' photons can be borrowed -- small [math]\Delta E[/math] -- long enough, to reach that remote location. The whole point of 'promotion' appears, then, to merely mean 'repaying energy debt'. If two charged particles can 'repay the debt' on the 'Heisenberg loan', on some 'virtual' photon, then the photon can be 'promoted', 'liberated' from 'debt slavery' [sic] to 'independence'. The fundamental principle, which I did not comprehend, is the Quantum, non-Classical, 'detailed' violation, of strict Energy Conservation, per the HUP.

Galaxies are "anchored by a Super-Massive Black Hole" (SMBH). And, that SMBH can generate a Quasar, when it is "actively-very actively- feeding on surrounding gas". Such occurred, quite commonly, in the early universe, which was much more matter dense. Or, more recently, mergers of galaxies can funnel material into central SMBHs. Now, SMBHs are associated with "intense star formation". Thus, they are associated, and perhaps trigger, "'starburst' galaxies, forming stars at 10 to 15 times the rate we see in the Milky Way today". Such star-burst galaxies were much more common, in the early universe. For example, galaxy HUDF-JD2 "formed the bulk of its stars very rapidly, on time scales less than or equal to 100 Myr, and the subsequent evolution was essentially passive". And, said star-burst period happened "between 350 and 650 Myr" in cosmic time, corresponding to red-shifts "between 10 and 20". Quasars were bright enough, that their light reaches us, even when reflected from surrounding material (leading to a 'light echo').

The Schwarzschild solution, whose low-mass limit is Newtonian Gravity, assumes an infinite, flat, spacetime, which is then perturbed by the addition of a spherically symmetric mass. In analogy, it assumes an infinite flat trampoline, or infinite flat rubber sheet. Now, that assumption is not inaccurate, in our current Cosmos, whose Radius of Curvature is 10s Gly's, so that space is almost flat. But, what about shortly after the Big Bang, when spacetime was highly curved ? If spacetime is cosmically closed, into a 3D hypherspherical shell, then, in the early universe, deviations of spacetime, from 'infinite & flat', could have caused deviations, from Schwarzschild-Newtonian Gravity, yes?

Would that be at absolute zero temperature? With thermal oscillations, in the nucleus, and more binding energy-per-nucleon available, w/ an iron structure, would such a decay occur, given astronomical time scales?

Big bright stars do not produce planetary systems. For, And, this break may imply the presence of planetary systems, which covertly cache the missing angular momentum (Carroll & Ostlie. Intro. Mod. Astrophys., p.891). Sturrock. Physics of the Sun, p.172 (annotated). Now, metal poor stars also do not produce planetary systems (Majestic Universe (Scientific American), p.). Such suggests that metallic dust may 'seed' the planet production process. CONCLUSION (?): Even metal-rich massive stars do not produce planets. Er go, even when metals are present in their collapsing proto-stellar clouds, those metals do not nucleate into dust grains (which would, then, 'seed' planetesimal aggregations). Might that mean, that more massive stars' raging radiation perpetually prevents metal grains from collecting (and so seeding planet accumulation) ? break in 'Kraft' curve caused by onset of CNO fusion ? The break in behavior, between spectral-classes F & A, segregating small, slowly-spinning stars, from big rapidly-rotating stars, Lewis. Physics & Chemistry of the Solar System, p.28. coincides with the occurrence of convection, in the star's outer envelope, and ensuing star-spot cycles: And, those surface convective zones, preserved in the atmospheres of small stars, through onto the Main Sequence, are present initially, in all proto-stars: This transition, in turn, coincides with the occurrence of core convection, in more massive stars: Green & Jones. Introduction to the Sun & Stars, p.181. Perhaps, then, a different 'flavor' of fusion, in more massive stars, restructures them internally, whilst externally emitting harsher radiation, which rips apart nascent nucleating metallic dust grains in their collapsing cloud, and disk, thereby preventing planets from forming. In turn, the quenching of planet formation apparently permits more mass, and angular momentum, to transfer through the circum-stellar disk, and deposit into the central star. Indeed, planets apparently compete, with the central star, to accrete disk matter, which fact limits the largest size attainable, by 'Brown Dwarf' super-planets ([math]m < 0.01 \, M_{\odot} \approx 12 \, m_J \approx 4000 \, m_{\oplus}[/math]), to the amount of matter resident in such disks (and explaining why Jupiter possesses almost all of the Sun's 'missing angular momentum'). In sum, initially "[star] formation works the same for all stars, regardless of mass", modified only by the onset of various forms of fusion, at First Light, of the central star, which would affect the spatial extent, of the "dust-free region between [the central star] and the surrounding disk [where] the star's energy had evaporated the dust molecules closest to it", apparently pushing the 'molten metallic droplet / dust-grain condensation distance' out beyond the effective edge of the disk.

In crossing the cosmos, could photons ever encounter fleetingly ephemeral particles-antiparticle pairs, which happened to 'pop' into existence in their path? If so, would such scatterings accumulate, over cosmic time scales? What would be the effect (tired light) ?

Gary Zukav says charged particles are 'always emitting & absorbing' virtual particles, during interactions. Now, first, if virtual photons had energy, then, since [math]\Delta E \Delta t \approx \hbar / 2[/math], the energetic virtual photon would have a finite lifetime, and, hence, a finite range. So, since the EM force is potentially infinite range, such cannot be the case. And, second, real particles constantly emitting & absorbing virtual photons would constantly lose/gain energy. Such seemingly suggests, that virtual photons carry momentum, but no energy -- as 'force carriers', they're all force-momentum, no energy. If attractive interactions involve pairs of virtual photons, then, perhaps the deconstructive interference, of two opposite virtual photons, amounting to a DC null photon (E=p=0), which is 'on mass shell', is the point of entry, of that pair, from virtuality, into birthed reality?? (A 'promoter' virtual photon detector, would need to 'match' the incident virtual photon, with an appropriately opposite pair.)

So, quantum reality is 'bi-cameral', composed of (1) real particles, mathematically modeled with wave-functions; and (2a) (swarms of) virtual particles, associated to real particles, and (collectively) accounting for real particles' interactions; and (2b) a 'background ethereal sea' of virtual particles (perpetually [re-]appearing & disappearing) ? [math]\hat{E} \Psi= \hat{H} \Psi[/math] [math]i \hbar \partial_t \Psi(\vec{x}) = - \frac{\hbar^2 \, \nabla^2}{2 m} \Psi(\vec{x}) + V(\vec{x}) \Psi(\vec{x})[/math] [math]\nearrow \; \; \; \; \; \; \; \; \; \; \; \; \nwarrow[/math] virtual particles.......real particles By definition, virtual particles are unobserved, & unobservable, directly (except, e.g., by 'promotion', of virtual photons, into real photons, during bindings, of oppositely charged particles*) ? Instead, their presence is only inferred, from influences affecting (the wave functions of) real particles ? * Perhaps it is possible to build a virtual particle 'ghost detector' -- the "goes-into" is a virtual photon; the "comes-out-of" is a promoted, real photon ? If so, then every time a (presumably promoted) real photon was emitted by the device, the (previous) presence, of a virtual photon, could be correctly inferred.

According to Zukov (PP), when particles interact, electromagnetically, each particle is absorbing virtual photons, from the other particle's entrained cloud, of virtual photons. And, when oppositely charged particles bind together, virtual photons, from the interaction, are 'promoted', into real, actual, actualized photons -- which promptly carry away the binding energy / momentum. And more, the afore-cited link seems to say, that a pair of equal-but-oppositely directed virtual photons, are involved in electrostatic interactions (of attraction). Does that mean, that one pair of virtual photons, one initially associated to each interacting particle, 'merge' & 'meld', 'forging', from two virtual photons, one real photon ?? (In a crude, qualitative-only, mathematical analogy, the sum of two imaginary numbers/functions, can yield a single real number/function.) And if so, by reversibility, an impinging, ionizing real photon, upon liberating the once-bound electron, 'splits', into a pair of 'equal-but-opposite' virtual photons, one associated to each free charged particle ??

(thanks for the replies) What about the apparent violation, of global (pan-cosmic), energy conservation, w/ photons, whose energy dependence decays, per theory, as a(t)-4 ?

If some surface absorbs photons, and becomes warm, it could be used for -- and, so, could be construed as -- the heat reservoir, of a heat engine. Thus, natural non-living systems could be said to create fuel, yes?

Thanks again for the link. I understand, that charged particles are always 'emanating' or 'spinning out' virtual photon fields, 'out to infinity'. So, charge particles in interaction are immersed fully within their partner's 'far flung virtual photon field'. And so, even if the partner particle is 'in front', that partner particle's virtual photons can impinge upon the other particle 'from the back'. Could you consider point particles, to 'emanate' spherical waves -- [math]e^{i k r} / r[/math] -- of both 'incoming' & 'outgoing' ([math]\pm k[/math]) varieties ?? (With a finite aged universe, would, technically, virtual photon fields have 'had time to establish' themselves, beyond their local Hubble Volume ??)

Thus, [math]a \approx \frac{p}{m\Delta t} = \frac{ E_{transition} }{m c \, \Delta t} \approx \frac{ E_{transition} \, \Delta E_{state}}{m c \hbar / 2}[/math] If so, then 'sharp' excited states, with well defined energy values (small [math]\Delta E[/math]), which last longer, would accelerate less. Yet, 'intuitively', why wouldn't more sharply defined energy states, suffer 'sharper' transitions, back down to the ground state, and so accelerate more on emission, even if emission was a long time in coming (lower overall avg. accel.)?

Chemistry involves the transfer of charge (electrons, protons), and is, therefore, an Electro-Magnetic (EM) process, fundamentally related to photons. However, the EM forces, which coax charges, between atoms & molecules, are mediated by 'virtual' photons, bound to the matter from which they 'emanate' (even as the EM fields, associated with matter, are bound to the same). Thus, the "Life magick" in bio-chemistry, depends upon 'virtual photons', of 'virtual light' (which transfer energy & momentum, between atoms & molecules, accounting for the forces between them). Perhaps, living chemical systems 'emanate' modified virtual photons, when interacting, with other living chemical systems (thereby, generating un-conventional EM force fields -- "Life forces", perhaps giving guidance, to bio-chemical compounds, 'directing traffic', in a non-random 'match-maker' way, to 'organize' the bio-chemical reactions more efficiently) ???

According to the HHMI DVD Life Matrix (lecture 2), the formation of the 'Cleavage Furrow', during cell division, is implemented, by myocin-2 & anillin proteins, which cluster around the middle of the as-yet-undivided cell, even as the chromosomes are pulled to opposite poles. The lecturer, Dr. Stuart Schreiber, seemed to say, that no-one as yet knows what triggers the Cleavage Furrow to form, or pinch off. And yet, Dr. Schreiber showed, that 'Small Molecules' can bind to Proteins, activating or de-activating them. Could it be, that once the chromosomes are in position, they send out some sort of 'we're in position, sir' signal ?? That chemical signal, then, could hypothetically activate the cytoskeleton proteins, to start the Cleavage Furrow forming, and fissioning.

Thanks for that clarification. According to Wiki: Does such suggest, that aaRS's had only recently evolved, and were in 'unfinalized form', c.4 Gya, during the days of 'proto-Life' (LUCA) ? What about more advanced pre-Life (advanced RNA-world) ? Pure RNA does not self-assemble, into strands, longer than 50-100 base-pairs (bp) (Lane. Life Ascending, p.50~). However, the basal bacteria, on the earth phylogenetic tree, all have >1.5 Mbp. And, the simplest bacteria, Pelagiobacter ubique, has ~1.2 Mbp. Such suggests, that the Last Universal Common Ancestor (LUCA), of all earth microbes, had ~1 Mbp in its DNA ring. So, pre-Life, in the RNA-world, had ~100 bp ("log 2"); whereas, proto-Life, LUCA, had ~1 Mbp ("log 6"): pre-Life (RNA-world): ~100 bp ("log 2") ... proto-Life (LUCA): ~1 Mbp ("log 6") Now, RNA can combine with Proteins, into RNP complexes. And, 'stabilizer Proteins' can strengthen those structures (Scientific American [April 2011], p.73). And more, RNA has been interacting with Proteins, from the first efforts, of earth life. So, such suggests, that, before DNA evolved, as a "durable deep storage" biochemical 'upgrade' of RNA, protein-stabilized RNPs could have accommodated increasingly complex genetic codes, for increasingly complex bio-chemical life, before the evolution of full-fledged cells, like LUCA, at ~1 Mbp. So, interpolating, between pre-Life & proto-Life, perhaps 'advanced pre-Life' had genomes of ~10 kbp ("log 4"), stored in stabilized RNP complexes. And, genomes of such length, are reminiscent of archaic RNA retro-viruses. And more, a retro-virus 'virion' super-complex, as a (colossal) combination of RNA & Proteins, is, technically, an RNP. Perhaps, then, advanced pre-Life, was (retro-)viral, employing Protein 'plate armor' protected retro-virional-like RNP super-complexes, to stably store their genetic codes, which were then thousands & tens of thousands of bp long. pre-Life (RNA-world): ~100 bp ("log 2") advanced pre-Life (retro-virions): ~10 kbp ("log 4") proto-Life (LUCA): ~1 Mbp ("log 6") The retro-virional RNP super-complexes would have functioned only as genetic code, and would have relied on a surrounding bio-chemical system of pathways, to access and translate said code. If the RNA-world was housed, in the pores of undersea hydrothermal vents, then that bio-chemical 'support system', would have been housed, in those undersea vents.

http://www.physorg.com/news204298215.html

Early earth life lacked bio-catalysts, which speed up the assembly, of protein poly-peptides: Now, chemical reactions can occur, without catalysts -- even as one can 'walk to work', without taking the turbo-charged car. And, pre-Life, upon this planet, was surely simple and 'stripped down', to the maximal minimum. Could early earth pre-Life, then, have been 'slow life', which 'walked unaided', ponderously pursuing bio-chemical reactions, which are rather rapid today, b/c of catalysis ??

Please ponder an electron interacting with a proton. The two particles inter-communicate electromagnetic forces, via 'virtual photons'. Now, by virtue of being 'virtual', those photons are 'off mass shell' -- they do not abide by the Einstein equation E2 = m2 + p2, with m = 0. And, offsetting the particles' gains, in Kinetic Energy, by their losses, in Potential Energy, seemingly implies, that, despite experiences forces, neither particle's overall energy is affected. Does that mean, that the inter-communicating 'virtual' photons, carry momentum (p > 0), but no energy (E = 0), so that they can impart momentum & force, without affecting energy ?? When an electron binds to a proton, a force-carrying virtual photon is "promoted", into an actualized photon, which carries off the appropriate amount of binding energy (Dancing Wu-Li Masters). It seems as if, a virtual photon is 'charged' or 'burdened' with the appropriate amount of energy, like some sort of spring 'compressed' in between the impinging particles, and then 'let loose', in actualized, physical, form.

If, for Gravity (in 'geometric units'), w.h.t. Rkkab = Tab, where R is Riemann, and T is the mass-energy stress tensor... then, is there the suggestion, that the other fundamental forces, could be construed, as contractions of Riemann, over other pairs of indices? Rkkab = TG,ab Rkakb = TEM,ab Rkabk = TEW,ab Rabkk + Rakbk + Rakkb = TC,ab (Color Force is 'odd man out', different from other three (3) fundamental forces, increasing with distance, and having utterly dissimilar shape & form) Such could construct the full-fledged Riemann tensor, using the 'force-generating charge densities', for the four fundamental forces (mass, charge, weak charge, color charge).

When observing distant galaxies, earth astronomers physically observe a Power Flux (W/m2), and an Angular Diameter, and a Velocity Dispersion (<v2>). Now, roughly speaking, if the distance to that distant galaxy is assumed to be D, then its actual physical radial diameter is [math]R = D \theta[/math], and its actual physical luminosity is [math]L = P \times 4 \pi D^2[/math]. So, since the inferred Virial Mass scales as the physical radius, [math]G M_{vir} \equiv \, <v^2> R \propto D[/math], then the inferred Mass-to-Light Ratio is [math]\Upsilon \equiv M/L \propto D/D^2 \propto D^{-1}[/math]. Now, for a given observed redshift, the inferred distance to the redshifted object scales as H-1. So, simply assuming that the older, higher Hubble Constant values, reported in the early 20th century AD, were actually more accurate, would, superficially, seem to allow us to "concentrate" cosmic mass, and thereby "increase" the inferred cosmic matter density. But, since we see only a certain amount of light, simply assuming that "everything's closer to earth than we thought", would actually make dark matter more of a problem -- [math]\Upsilon \propto D^{-1} \propto H[/math]. So, if the Hubble Constant was 3x higher (say), Dark Matter would be 3x more prevalent, since everything would be 3x closer, and so 9x dimmer, on emission... To 'solve' the DM problem, by artificially 'compacting' the cosmos, would require a HC that was 5x higher, so that the 'galactic avg mass density' [math]M_{vir} / D^3 \propto D^{-2}[/math] would be 25x higher, accounting for the difference, between observed baryonic densities, and the critical density. But, increasing the HC, increases the critical density, by the same amount -- you can't 'catch up' mathematically: [math]\rho_{crit} \equiv \frac{3 H^2}{8 \pi G} \propto H^2[/math] [math]\rho_{gal} \equiv \frac{M_{vir}}{D^3} \propto H^2[/math] There seems no easy way, to 'solve' the DM problem, by adjusting the HC.

In the Einstein equation, of GR, Gab comes from Ricciab Ricciab comes from Riemannabcd Thus, in contracting Riemann (rank 4) to Ricci (rank 2), the former is 'dumbed down' significantly, to mate up with the Stress-Energy tensor Tab (also rank 2), in the Einstein equation. But, what about all the information that is 'lost', in 'dumbing down' Riemann to Ricci? Does that mean, that the Einstein equation, even with a 'full' specification, of all the mass-energy distributions, does not fully determine all 256 components of Riemann? To wit, mass manipulates the spacetime fabric in a 'clumsy' way, leaving many 'loose ends' indeterminate?* * What about electric charge, weak charge, and color charge? With four major forces to 'play with', each with their own constituent 'charge' densities and 'stress' tensors, is it possible, to 'augment' the Einstein equation, 'up' from rank two, to rank four, so that, with suitably sophisticated simultaneous specification of mass/charge/weak-charge/color-charge distributions, one could actually 'fully determine' all 256 components, of Riemann ???

If, in EM, the Faraday tensor [math]F^{\mu \nu} \equiv \partial^{\mu} A^{\nu} - \partial^{\nu} A^{\mu}[/math] (Wiki); and if, in GR, the Riemann curvature tensor is [math]R(u,v) \equiv \nabla_u \nabla_v - \nabla_v \nabla_u[/math] (Wiki); then, could one 'visually identify' the EM 4-vector [math]A^{\mu}[/math] as the 'covariant derivative' of 'something else', as [math]A^{\mu} \equiv \partial^{\mu} T[/math], and then view the Faraday tensor, [math]F^{\mu \nu} \equiv \left( \partial^{\mu} \partial^{\nu} - \partial^{\nu} \partial^{\mu} \right) T[/math], as a kind of 'curvature' tensor ?