What is conformal cyclic cosmology...(like WTF is this)
"Little bit of background and history and drama"...
Advanced by the English mathematician Roger Penrose and his Armenian colleague Vahe Gurzadyan, conformal cyclic cosmology (CCC) is a theory of the universe, rooted in relativity, which competes in certain respects with cosmological models such as inflation and string theory, and with other cyclical schemes like the ekpyrotic universe.
CCC was the subject of a 2010 paper by Penrose and Gurzadyan and was the major subject of Penrose’s 2010 book Cycles of Time. Both Penrose and Gurzadyan have lectured widely on the subject in the years since.
It is a controversial topic in theoretical physics, considered “fringe” in some quarters. This is in part because CCC contradicts the "inflationary theory", which is widely held to be supported by data — though Penrose would take issue with the idea that the data exclusively support inflation — and in part. After all, proving or falsifying conformal cyclic cosmology through measurement is problematic; it would seem to rely on the as yet only nascent field of gravitational wave astronomy.
First attempts to confirm CCC experimentally quickly led to disagreement over methods.
Since the early days of the inflationary theories of Alan Guth (1979), Linde, and others, Penrose has stood foremost among a sizable minority of theoretical physicists finding the notion of cosmic inflation disagreeable. Although analyses of the cosmic microwave background (CMB) have tended to support inflation on the whole, Penrose holds that inflation as a “best working explanation” is, while extremely elegant, nonetheless speciously artificial and circumstantially unlikely. In particular, he takes issue with the fine-tuned conditions required of the Big Bang; with the questions inflation poses for the universality of the laws of thermodynamics; and with the lack of a confirmed basis for inflation in the realm of particle physics under the Standard Model.
"The main simplified explanation starts from here"
The (grossly simplified) kernel of CCC is this:
the far-future, uniform cold of an infinitely expanding universe is, at least mathematically, no different from the infinitely dense, energetic singularity of a Big Bang event except for a factor of scale.
The Big Bang emerges from a point-like singularity. The infinitely expanded universe, on the other hand, is of course extremely large, empty, and cold.
When conformal scalar adjustments are made to the spacetime metric at the boundary between these two different kinds of infinity, the far-future infinity of a present iteration of the universe can be neatly stitched to the initial singularity of a successive future iteration.
(Conformal geometry involves transformations that preserve shape and angle, but not size. *Penrose good-naturedly refers to this application as a “mathematical trick,” but he is serious about the proposition that it may well represent the ordering of time and entropy in the universe....(yeah I mean, Penrose was definitely sure about this cause "lower entropy will give you a preserved shape and conformality" ))
A cycle results in which the infinitely expansive heat death of one iteration of the universe results in the Big Bang of the next iteration. Well, “results in” is the tricky bit to grasp and is not quite right, as there is a sense in which the two events are not different things, but are simply two sides of the very same boundary, each facing a different direction, as it were. The area between two boundaries Penrose refers to as an "Aeon"...
We are presented with a model that allows for infinities and doesn’t require any reversal of process into a “Big Crunch”; it is more of an oscillating transformation made by the equivocation of one state with another. But why should we conformally rescale the cosmos in this manner at given points in time? Why should such a thing happen?
The apparent age of the universe is about 14 billion years; CCC asks us to imagine a course of future events spanning approximately a googol years to come — that’s a hundred zeroes worth of years, in which context we are not yet so much as fully emerged from the cosmic womb.
Eventually black holes will become the dominant objects in the universe, gradually colliding and merging to gobble up whole clusters of galaxies, taking practically all the mass in existence into their impenetrable interiors.
Crucially, Penrose accepts the phenomenon of Hawking radiation. Although black holes are very cold indeed, if they are infinitesimally warmer than the surrounding medium, they will gradually leak their contents into space as blackbody radiation via quantum effects at the event horizon. In this way, over an extraorbitantly long and boring expanse of time, all of the mass in the cosmos will be converted into energetic, force-carrying particles, like photons. There will be no more mass.
If we accept Einstein’s energy-mass equivalence and Planck’s energy-frequency equivalence, we immediately obtain an equivalence between mass and frequency. In a spacetime in which there is no mass remaining, there are “no clocks,” according to CCC. Measures of distance and time become completely impossible and meaningless in such a state, particularly if massless bosons such as photons and gravitons — pure radiation — travel uniformly at the speed of light.
This condition of equilibrium would mark the end of the phase space of the current aeon, simultaneously representing the initial boundary condition, the Big Bang, of the next aeon.
Interestingly, since the fields governing radiation (that’s Maxwell, for instance) are scale-invariant, there is no reason why the radiation from one aeon cannot pass the conformal boundary into the next. A degree of continuity between eons is provided: to massless, timeless bosons, the timelike infinity of the far future behaves as a spacelike hypersurface boundary, a border that any photon can cross without so much as showing a passport.
One of the predictions of CCC is thus that, in the cosmic microwave background, we should be able to detect the signatures of gravitational waves caused by the collisions of black holes in the aeon before ours — this radiation will have gotten across the boundary in a recognizable form.
The cosmic microwave background permeates the entire sky. It is the observable limit of the universe from our point of view, the oldest radiation visible in our rear-view mirror, greatly red-shifted due to its vast and increasing distance. The CMB is extremely anisotropic, its apparent temperature is absolutely even to about one part in 100,000 in all directions and at all angular scales. Penrose suggests that we should expect to find concentric circular aberrations in surveying this field, ghostly relics of black holes before the Big Bang, a little like circular ripples on the surface of a pond after raindrops have fallen.
Whether such relics actually exist in current data remains a contentious question; if there is evidence, it is not yet clear, to say the least.
CCC is in some sense a fleshing-out of Penrose’s earlier Weyl Curvature Hypothesis (1979), his explanation for a universe in which entropy continuously increases and induces the arrow of time, resulting in a highly anisotropic, uniform expansion of space without recourse to the necessity of a brief period of exponential cosmic inflation in the first instants following the Big Bang.
The idea is that one has to account for gravitation when measuring entropy and that the initial condition of the universe must have been extremely low from a gravitational perspective. A gradual increase in gravitational entropy — a change to the fabric of spacetime expressed by Weyl’s metric tensor — allowed for the clumping of matter and the formation of stars and galaxies. Black holes function, by analogy, as machines for reducing this entropy over time as they gobble up matter and laboriously radiate their contents into the medium in the form of energy over trillions of years. They take their sweet time about it but do at last return the universe to a gravitationally low-entropy blank slate.
Though CCC satisfies Einsteinian relativity and neatly addresses certain cosmological problems, it is not without issues of its own. For example, it is far from clear how absolutely all of the mass would decay out of a far-future expanding universe as CCC seems to require. There are serious unknowns in the matter of the decay of electrons and other fermions.
But Penrose and Gurzadyan believe that the underlying mathematics are too beautiful to ignore and that further investigation is warranted.
"And again, no matter how much your theory is beautiful and elegant to think if it doesn't obey the laws and mathematics(detailed physics), it's "bullshit"...
Well said by the great "Richard Feynman"(the savage man of physics)