Entropy as an arrow of time
The arrow of time is the gravity-induced irreversible decrease in the entropy of the universe's mass, accompanied by irreversible increase in the entropy of the universe's energy.[1]
General concept
Soon after the big bang, the universe's mass-energy became gravitationally separated into the more dense simple vacuum (mass) and the less dense physical vacuum (energy):
No such attempt has succeeded, and we now believe that the quarks and gluons carry a kind of charge dubbed "colour" which is strongly repelled by the physical vacuum in which we now live. It seems that the energy density inside a proton, due to the kinetic energy of the quarks, is large enough to flip the vacuum there into a different kind of state, which we call the "simple vacuum," in which the quarks can move freely. This little hole in the physical vacuum is called a "bag," and a mathematical model based on a simple bag has had a considerable success in explaining the spectrum of masses of the observed elementary particles. In the early Universe, in the first few microseconds after the big bang, the energy density was high enough to keep the whole Universe in a "simple vacuum," and quarks and gluons would have moved freely except for scattering. We call this state a quark-gluon plasma. As the Universe cooled, it flipped into the state of the present physical vacuum, and the quarks would have grouped themselves into the protons and neutrons that we observe. Calculations of the physical vacuum according to the QCD theory, using techniques for which Kenneth Wilson was awarded the 1982 Nobel prize in physics, have shown just such a transition in the vacuum as the energy density is lowered.
- —Willis, Bill ♦ Collisions to melt the vacuum New Scientist, 6 October 1983, p. 10
The density of the newborn matter only slightly exceeded the density of the background physical vacuum. That is exactly why from the gravitational perspective, the entropy of the newborn matter was abnormally high relatively to the abnormally low entropy of the background vacuum. But the actual difference between the entropy of the newborn matter and the entropy of the background physical vacuum was very small. Therefore, the free entropy (a volume-specific entropy surplus above the background), which the newborn matter had from the gravitational perspective, was potential (teleological).
Both the simple vacuum and the physical vacuum are undergoing gravitational blueshifting, during which the more dense simple vacuum is being blueshifted increasingly faster than the less dense physical vacuum, so that from the perspective of particles of matter consisting of simple vacuum, the ambient physical vacuum seems to be redshifting (expanding and cooling). At that, gravitational compression converts matter's bound entropy (which cannot be radiated into the ambient vacuum) into free entropy, which becomes radiated into the ambient vacuum.[1] The growth in the relative volume of the ambient physical vacuum dilutes the entropy emitted by matter and thus makes the loss of entropy by matter irreversible.
An extremely important point here is that due to the quantized nature of radiation, gravitational condensation converts matter's bound entropy into free entropy faster than the latter becomes radiated into the ambient vacuum.[2] This leads to progressive accumulation of free entropy at the centre of the condensing system.[2] Since the universe is a single gravitationally condensing system, the absolute maximum of free entropy—Life—indicates that the planet Earth is the absolute gravitational centre of the universe.
During a gravitational life cycle of the universe, the entropy of matter decreases,[3] while the entropy of the ambient physical vacuum increases.[1] The total entropy of the universe remains quantitatively constant but undergoes a qualitative change from gravitationally free entropy to gravitationally bound entropy.
Life cycle of universe
The constancy of the universe's total entropy implies that the number of the universe's possible configurations is constant, and, to be infinite in space and time, the universe must be spatiotemporally recursive.
- The spatial recursiveness means that our spatial continuum, consisting of rarefied physical vacuum, is embedded in a perfectly identical larger-scale continuum. From the perspective of the much more rarefied larger-scale continuum, our continuum appears to be a "bag" of dense simple vacuum. In plain words, our continuum is the central proton of a perfectly identical larger-scale continuum, and so ad infinitum.
- The temporal recursiveness means that all gravitational life cycles of the universe are perfectly identical, so that during the next cycle of the universe's gravitational evolution, you will again be reading this very webpage.
The apparent metric expansion of space exponentially accelerates because its driver—the autogravitational condensation (blueshift) of the proton—is analogous to the exponentially accelerating autogravitational condensation of a star:
Each successive nuclear burning stage releases less energy than the previous stage, so the lifetime in each stage becomes progressively shorter. For a 20 MSun star:
- Main sequence lifetime ~ 10 million years
- Helium burning (3-α) ~ 1 million years
- Carbon burning ~ 300 years
- Oxygen burning ~ 2/3 year
- Silicon burning ~ 2 days
- Iron core's collapse ~ a few milliseconds[4]
- —Gene Smith's Astronomy Tutorial University of California, San Diego
A gravitational life cycle of the universe progresses in two stages:
- An exponentially accelerating metric expansion of space. The gravitational well, formed by a proton's own mass, is much steeper than the gravitational well of the universe. The outpacing autogravitational blueshift of the proton's matter wave creates the illusion of the external universe's redshift.
- A big bang. Having blueshifted their matter waves to the Planck length of the ambient physical vacuum, protons become delocalized and teleport to the universe's gravitational centre, where they merge into a single ball of quark-gluon plasma.
Time left
Holographic approach
According to recent measurements, the radius of the proton is 8.768 × 10−16 m:
... since the 1960s physicists have made hundreds of measurements of the proton's size with staggering accuracy. The most recent estimates, made by Sick using previous data, put the radius of the proton at around 0.8768 femtometres (1 femtometre = 10−15 metres).
- —Brumfiel, Geoff ♦ The proton shrinks in size Nature News, 7 July 2010
Craig Hogan has discovered (and the discovery has been preliminarily confirmed by GEO 600 experiments), that the metric expansion of space has magnified the Planck length to about the size of the proton—10−16 m:
According to Hogan, the holographic principle radically changes our picture of space-time. Theoretical physicists have long believed that quantum effects will cause space-time to convulse wildly on the tiniest scales. At this magnification, the fabric of space-time becomes grainy and is ultimately made of tiny units rather like pixels, but a hundred billion billion times smaller than a proton. This distance is known as the Planck length, a mere 10−35 metres. The Planck length is far beyond the reach of any conceivable experiment, so nobody dared dream that the graininess of space-time might be discernable.
That is, not until Hogan realised that the holographic principle changes everything. If space-time is a grainy hologram, then you can think of the universe as a sphere whose outer surface is papered in Planck length-sized squares, each containing one bit of information. The holographic principle says that the amount of information papering the outside must match the number of bits contained inside the volume of the universe.
Since the volume of the spherical universe is much bigger than its outer surface, how could this be true? Hogan realised that in order to have the same number of bits inside the universe as on the boundary, the world inside must be made up of grains bigger than the Planck length. "Or, to put it another way, a holographic universe is blurry," says Hogan.
This is good news for anyone trying to probe the smallest unit of space-time. "Contrary to all expectations, it brings its microscopic quantum structure within reach of current experiments," says Hogan. So while the Planck length is too small for experiments to detect, the holographic "projection" of that graininess could be much, much larger, at around 10−16 metres.
- —Chown, Marcus ♦ Our World May Be a Giant Hologram New Scientist, 15 January 2009
Thus, the metric expansion of space is ending and the universe is about to enter the big-bang stage of its gravitational life cycle.
Thermodynamic approach
In terms of entropy dynamics, the gravitational condensation of the universe's matter is similar to the gravitational condensation of a single giant star.
The key point here is that gravitational condensation converts matter's bound entropy into free entropy faster than the latter becomes radiated into the ambient vacuum. Due to this delay, a collapsing massive star always passes through the stage of a superdense and superhot temporary neutron star characterized by the maximal free entropy (the maximum of free entropy will be observed at the centre of the neutron star):
Even if the compact remnant ultimately degenerates into a black hole, it begins as a hot neutron star. The central temperature immediately after the explosion is roughly 100 billion degrees Kelvin, which generates enough thermal pressure to support the star even if it is larger than 1.8 solar masses.
- —Bethe, Hans A.; Brown, Gerald ♦ How a Supernova Explodes World Scientific, 2003, p. 68
Analogously, the absolute maximum of free entropy (in the form of Life) will be observed at the gravitational centre of the universe. Therefore, the planet Earth is the absolute gravitational centre of the universe, and the terrestrial Life's progress in free entropy (useable information) is an important indicator of the pace of the universe's gravitational condensation:
- In 2005, information was doubling every 36 months. [IBM data—see page 41]
- In June 2008, information was doubling every 11 months. [IBM data—see page 41]
- On 4 August 2010, Google CEO Eric Schmidt said: "Every two days now we create as much information as we did from the dawn of civilization up until 2003." [Source]
- In the end of 2010, information was doubling every 11 hours. [IBM data—see page 2]
See also
References
- ^ a b c Clark, Stuart G. ♦ Life on other worlds and how to find it Springer, 2000, p. 58 ♦ "So the entropy of the cloud decreases as it organises itself into a star but the entropy of the surrounding Universe increases as the star radiates the converted energy into space. Increasing the number of photons in the Universe increases the entropy of the Universe."
- ^ a b Bethe, Hans A.; Brown, Gerald ♦ How a Supernova Explodes World Scientific, 2003, p. 61 ♦ "Even if the compact remnant ultimately degenerates into a black hole, it begins as a hot neutron star. The central temperature immediately after the explosion is roughly 100 billion degrees Kelvin, which generates enough thermal pressure to support the star even if it is larger than 1.8 solar masses."
- ^ Bethe, Hans A.; Brown, Gerald ♦ How a Supernova Explodes World Scientific, 2003, p. 56 ♦ "The entire evolution of the star is toward a condition of greater order, or lower entropy. It is easy to see why. In a hydrogen star, each nucleon can move willy-nilly along its own trajectory, but in an iron core groups of 56 nucleons are bound together and must move in lockstep. Initially the entropy per nucleon, expressed in units of Boltzmann's constant, is about 15; in the presupernova core it is less than 1."
- ^ Bethe, Hans A.; Brown, Gerald ♦ How a Supernova Explodes World Scientific, 2003, p. 56 ♦ "The collapse takes only milliseconds ..."