"Before big bang" is contradictory because including the presupposition of time itself.

We can see that there is the causality due to the evolution of the matter. Without matter we have no time. Hence, any time could not exist without the big bang and the matter created by it...

I think the fundamental building block of the universe that most scientists are  hoping to find is an erroneous concept. The reality is based on the fundamental substance of the universe which is all pervasive infinite, indivisible and perfectly motionless and is generally described as the empty space because it is extremely subtle and cannot be perceived by human senses. In the beginning, everything was perfectly motionless and there cannot be any time without motion. When this fundamental substance made the first motion, it created a wave which had a wavelength and a period. This created the illusion of space time. This is how the time began. 

http://ptep-online.com/index_files/2015/PP-40-11.PDF

Article Periodic relativity: Basic framework of the theory

Actually it's perfectly believable that 'time' existed before the BB, on several grounds.

1- Under certain plausible models, time becomes a pre-condition for a BB to be able to happen (see Martin Bojowald et al.)

2- There is nothing inherently special about our particular BB. Several scenarios can give rise to different types of BB's, which however would all look very alike to post-BB observers. One example would be Roger Penrose's 'bouncing universes' scenario, etc.

There seems to be very little reason why the mediocrity (Copernican) principle should not apply to Big Bangs, and the assumption that there ever only was one seems, in the absence of evidence, to be an unwarranted leap of faith. Furthermore, simple considerations seem to indicate that Time cannot be a fundamental property of the universe (see for instance http://bit.ly/2k3570K etc.)

Hi,

Event A happend before event B. Event B happend before C. Event C happend before A. This is possible in GT of relativityy. Can we piu this events on time scale? The answer is, obviosely, negative. Best jm.

Dear Joseph,

All events A, B, C are not causally bounded and the comparison made by different observers. Those kind of generalizations are futile.

I would ask a related question: is there something beyond the North pole?

Using current theories to answer the question is circular reasoning.  The only plausible answer is: we can't know, no experiment is possible.

The Theory of The Systems may help understanding about 'time existence'. Basically, for sub-atomic particles, time as we feel is something that makes no sense. Time, as defined as an irreversible arrow before>after occur only to systems greater than atoms. So, Universe is eternal because it is basically made of sub-atomic particles to whom time is not a property. But the Universe has a history since there are basic systems (molecules and more complex systems) above which time is a property.

Yes, I do think that there is a certain Kind of Time that exists before Big Bangs. This is similar to the existence of certain Kind of Space that exists beyond our universe as it is expanding. thanks.

Sure. Time is NOT a property for sub-atomic particles. But it DO IS a property of any structure/system more complex than a molecule. That´s how we can understand the paradox of the Universe being at the same eternal and having a history. Moreover, science can prove that Big Bang occurred, however, the Big Bang is not everything, it should be seen as a phenomenum that happened in this region of the Universe we can gather data.

Is this believable that time could not exist before 𝗕𝗶𝗴-𝗕𝗮𝗻𝗴 ?

Absolutely. Of course this assumes that there was a "big bang" (BB) or inflation event in the first place and that you are talking about a finite model. The consensus BB answer was, if it is not still, that the big bang created both time and space. What is the logic? Equate time with change. For any finite cosmological model concerning time, regardless of the type of beginning it proposes, there could have been no change before the first change. If time or space existed before the proposed beginning then the model would be an infinite model concerning time and/or space.

Hawking's "bubble universe" model seems to work. It has two perpendicular time axes.

In it, we imagine a cross-section through an expanding universe as a surface, but instead of visualising it as a cone, we imagine it to be a hemisphere.

Any point on the surface then has two fundamental time coordinates, an "axial time" position that's the distance of the point from the pole measured parallel to the pole-pole axis, and radial time, "a", which is the point's distance from the axis, measured parallel to the equatorial plane.

In Hawking's system, the "proper time" for an object is the distance between two points on the body's worldline measured along the worldline (through the surface), so proper time is measured at an angle to both axial and radial time, and has elements of both. As the universe expands and evolves, proper time arrows start by pointing directly away from each other parallel to the radial time axis (at the pole), and finish pointing parallel to each other at the equator. So the universe age can also be expressed as the angle between zero and 90 degrees that proper time makes with axial and radial time.

With the Hawking hemisphere, plotting a worldline back through the polar region makes it emerge on the opposite side of the same hemisphere, so the hemisphere's contents are duplicated and from a distance, the polar region looks like a particle pair-production site, with the two sides of a single worldline passing through the polar region appearing as a particle-antiparticle pair, half a universe apart, rotated around the hemisphere by 180 degrees. This was Hawking's method of combining quantum mechanics with cosmology. Matter in our universe gets described as Hawking radiation associated with the cosmological horizon. With the right projection, we are all Hawking radiation.

The bubble model has three main problems or issues:

• Number One is the problem of what happens to a worldline as it crosses the surface equator from an expanding universe into a contracting one, which we might expect to be associated with a transition from forward time to reversed time. At first sight this transition seems unavoidably messy, but this can be solved by a further remapping that makes the equator only reachable after infinite proper time, so that by this time all matter in the universe has decayed, and no physical observer can survive the transition.
• Number Two is that while the model appears geometrically consistent, it doesn't obviously make any testable predictions (unless I've missed something), with the exception of problem Number Three.
• Number Three is that reconciling pair production with classical physics makes the cosmological horizon's "acoustic horizon" nature explicit. Unfortunately, we don't get a classical acoustic horizon in relativistic physics unless the Doppler equations are redder than SR by an additional Lorentz redshift, turning SR's equations into the redder E'/E=(c-v)/c.

This turns out to be consistent with current cosmology, which already uses the (c-v)/c relationship for Hubble shift ... but by unifying cosmology with QM, we then need QM to use the same non-SR shift relationships as cosmology. Unification of cosmology with gravitation or unification of QM with gravitation then requires gravitational shifts to also use (c-v)/c , which means that inertial physics has to use the relationship too. at this point, SR becomes "bad" relativistic physics, and GR becomes a wrong relativistic theory of gravity for trying to incorporate SR.

These issues tend to surface anyway as soon as we try to unify things, but the Hawking bubble kinda forced the issue. That's presumably why it wasn't developed any further - as a piece of geometry it required us to consider special relativity as an apparently incorrect physical theory.

I prefer the ideas of Roger Penrose that one universe follows another.

It comes down to an argument about how much energy is contained in the universe and where it came from.

The question is asking about ideas that relate to one popular notion that the universe generated spontaneously from nothing and that there is no net energy in the universe. In this representation time and space did not pre exist.

I'm in the group supporting Paul Dirac opinion about sea of energy, except I require the energy to be partitioned and nearly balanced between concave curving like gravity and convex curving energy like radiation. One way to express this is in the Lagrange function where potential energy like gravity is subtracted from kinetic energy to describe movement in celestial mechanics.

To destroy one universe and create another should have a mechanism. Collapse of a false vacuum is one possibility. If a universe become old and large enough that energy density falls below a critical value, a false vacuum 4D might collapse to a true vacuum 3D at scale zero which is the end of time.

Collapse of a false vacuum is widely expected to destroy everything it contains including the black holes that explode when CMB decreases below the stable equilibrium value. It agrees with Stephen Hawking that black holes are black body radiators in equilibrium with the surroundings.

Explosion of the old black holes creates a new universe and restarts the passage of time. First a 12D of super symmetry is created by enormous energy density. This may be scale 5 in the Scale Relativity representing a squeezed quantum state. Expansion lowers the density until scale 4 is reached in a 6D system of folded space time. Scale 4 represents flat space inside spontaneous wormholes through which rapid inflation occurs in agreement with popular theories. Continued expansion closes the wormholes as scale changes from 4 to 3. Eventually expansion results in 4D at scale 1 and questions on RG about the possibility of scale zero.

I differ from Penrose in that his system "Cycles of Time" requires all the mass to be destroyed into radiation during the end and new beginning. My completed project on RG is predicting that a high speed vehicle will modify the space it passes through creating a small region around it of higher dimensionality and scale that stabilizes the vehicle and its contents. In this representation life, knowledge, and wisdom could come to us from a previous universe, although time stopped and restarted for everything else, outside the vehicle.