I wonder, does time really exist, before big bang happens.
which one happens first? time or big bang?

 

If a sphere was a cube, would it have corners?

 

If there is nothing before the big bang, how can there be time?
Time is a sequence of events.
Nothing to sequence, no time.

 

It depends on how you view the big bang. Was the big bang the beginning of everything or was it the result of a previous big bang that contracted and caused another big bang?

 

I mean if there is infinite time and a very large amount of matter and if time travel is possible than it would happen at some point in time. And there had to have been time before the big bang. Just not necessarily anything happening except the POS changing characteristics.

 

The Vulcan Science Directorate concluded that time travel is not possible (http://memory-alpha.wikia.com/wiki/Vulcan_Science_Directorate ).

So, don't worry about it.

 

Were there politicians before the Big Bang? If not, I want to go there...

 

How can time travel be possible? There is , in my opinion, no way to travel into the past or future, regardless of what Dr. Who says.
We(the whole universe) can only exist in this instant. You cannot go back or forward even one heartbeat in time.
All objects in the universe travel relative to each other and I see no way of enabling any object to be in more than one instant of time.
If one imagines a timeline, objects are at some point on this timeline and one point only. If one could look along this timeline there would be nothing in the future and nothing in the past.

 

If one could look along this timeline there would be nothing in the future and nothing in the past.

Not even Langoliers?

 

How can time travel be possible? There is , in my opinion, no way to travel into the past or future, regardless of what Dr. Who says.
We(the whole universe) can only exist in this instant. You cannot go back or forward even one heartbeat in time.
All objects in the universe travel relative to each other and I see no way of enabling any object to be in more than one instant of time.
If one imagines a timeline, objects are at some point on this timeline and one point only. If one could look along this timeline there would be nothing in the future and nothing in the past.

It might be possible with "superdeterminism" where 'time' is just a 3D illusion to us mere mortals but that also means no 'free will' because all future events are already set in stone with fine tuning of initial conditions by a 'God'.

http://www.informationphilosopher.com/freedom/superdeterminism.html

Superdeterminism is a term introduced in the 1980's by John Bell to explain the mysterious correlation of results for spacelike-separated measurements in the Einstein-Podolsky-Rosen experiments.

During an interview by BBC Radio 3, Bell proposed the idea of a "superdeterminism" that could explain the correlation of results in spacelike-separated two-particle experiments without the need for faster-than-light signaling. The two experiments need only have been pre-determined by causes reaching both experiments from an earlier time.

I was going to ask whether it is still possible to maintain, in the light of experimental experience, the idea of a deterministic universe?
You know, one of the ways of understanding this business is to say that the world is super-deterministic. That not only is inanimate nature deterministic, but we, the experimenters who imagine we can choose to do one experiment rather than another, are also determined. If so, the difficulty which this experimental result creates disappears.

Free will is an illusion - that gets us out of the crisis, does it?

That's correct. In the analysis it is assumed that free will is genuine, and as a result of that one finds that the intervention of the experimenter at one point has to have consequences at a remote point, in a way that influences restricted by the finite velocity of light would not permit. If the experimenter is not free to make this intervention, if that also is determined in advance, the difficulty disappears.

http://backreaction.blogspot.co.at/2013/10/testing-conspiracy-theories.html
https://blogs.scientificamerican.co...interview-with-nobelist-gerard-e28099t-hooft/
https://arxiv.org/pdf/quant-ph/0510090.pdf

 

If there is nothing before the big bang, how can there be time?
Time is a sequence of events.
Nothing to sequence, no time.

For practical purposes, time is mathematical construct and it's represented as one of the axis (usually the horizontal axis) when plotting the sequence of events. It's basically an adaptation of the arithmetic number line to physical phenomenon.

For example, the distance traveled by a car is plotted from a certain instant in time usually represented by the zero point on the horizontal axis. The time axis can be extended to the left of the zero point so it could represent "negative" time, that is any given value before the car started moving.

For the Big Bang, the zero point on the time axis is assigned to the exact instant the event started. However, it could be extended into the negative values that represent what was happening before the event. Using this simple concept, even empty space can be modeled to exist for definite amount of time.

 

How long was it before the big bang? An instant or an eternity?

 

How long was it before the big bang? An instant or an eternity?

Since the exact nature of the object that existed prior to the Big Bang has not been determined, the time scale for its existence cannot be determined either. Some theories portray the object as a monstrous and massive object like a black hole that somehow became so unstable that it exploded with relativistic speed.

So the next three questions are:

[1] How the object came to existence in the first place.
[2] Why was it stable (if it was ever stable at all) and for what amount of time.
[3] Then why it suddenly became unstable and exploded.

 

Time travel is absolitely possible. We are all doing it right now...and now...

 

Hello,

As you know, today is yesterdays tomorrow.

Bertus

 

For practical purposes, time is mathematical construct and it's represented as one of the axis (usually the horizontal axis) when plotting the sequence of events. It's basically an adaptation of the arithmetic number line to physical phenomenon.

For example, the distance traveled by a car is plotted from a certain instant in time usually represented by the zero point on the horizontal axis. The time axis can be extended to the left of the zero point so it could represent "negative" time, that is any given value before the car started moving.

For the Big Bang, the zero point on the time axis is assigned to the exact instant the event started. However, it could be extended into the negative values that represent what was happening before the event. Using this simple concept, even empty space can be modeled to exist for definite amount of time.

It doesn't work that way. The Big Bang is a prediction of general relativity (under certain assumptions), and in GR space and time are not distinct, absolute things. When we want to calculate distances and velocities and such, we have to do it on a 4D spacetime with curved geometry.

Once that framework is in place, every event in the universe is associated with a point on a world line, which represents the trajectory of an object through spacetime. The Big Bang is the prediction that all world lines converge at some finite time in the past. This point of convergence is a spacetime singularity -- since there are no more world lines "behind" this point, the past is literally undefined.

In other words, we can't use GR to predict the Big Bang and then try to use the same theory to predict what happened "before" the Big Bang. A similar situation arises with black holes. Certain solutions of the field equations predict such drastic spacetime curvature that, within a certain radius (the event horizon), all future world lines converge. If we want to know what happens inside black holes, or what happened before the Big Bang, we need a stronger theory than GR, almost certainly a quantum gravity theory.

 

I wonder, does time really exist, before big bang happens.
which one happens first? time or big bang?

Yes, you can. I have gone there many times - not much there, tho, just a small, bight dot a long distance away.

 

It doesn't work that way. The Big Bang is a prediction of general relativity (under certain assumptions), and in GR space and time are not distinct, absolute things. When we want to calculate distances and velocities and such, we have to do it on a 4D spacetime with curved geometry.

Once that framework is in place, every event in the universe is associated with a point on a world line, which represents the trajectory of an object through spacetime. The Big Bang is the prediction that all world lines converge at some finite time in the past. This point of convergence is a spacetime singularity -- since there are no more world lines "behind" this point, the past is literally undefined.

In other words, we can't use GR to predict the Big Bang and then try to use the same theory to predict what happened "before" the Big Bang. A similar situation arises with black holes. Certain solutions of the field equations predict such drastic spacetime curvature that, within a certain radius (the event horizon), all future world lines converge. If we want to know what happens inside black holes, or what happened before the Big Bang, we need a stronger theory than GR, almost certainly a quantum gravity theory.

It doesn't work that way. The Big Bang is a prediction of general relativity (under certain assumptions), and in GR space and time are not distinct, absolute things. When we want to calculate distances and velocities and such, we have to do it on a 4D spacetime with curved geometry.

Once that framework is in place, every event in the universe is associated with a point on a world line, which represents the trajectory of an object through spacetime. The Big Bang is the prediction that all world lines converge at some finite time in the past. This point of convergence is a spacetime singularity -- since there are no more world lines "behind" this point, the past is literally undefined.

In other words, we can't use GR to predict the Big Bang and then try to use the same theory to predict what happened "before" the Big Bang. A similar situation arises with black holes. Certain solutions of the field equations predict such drastic spacetime curvature that, within a certain radius (the event horizon), all future world lines converge. If we want to know what happens inside black holes, or what happened before the Big Bang, we need a stronger theory than GR, almost certainly a quantum gravity theory.

That is more a mathematical construct than a practical explanation of what happened when (and after) the Big Bang occurred. If another Big Bang occurred about light year from the earth, we would see a Hell of a lot more happening than equations flying out of it.

 

That is more a mathematical construct than a practical explanation of what happened when (and after) the Big Bang occurred. If another Big Bang occurred about light year from the earth, we would see a Hell of a lot more happening than equations flying out of it.

Without the mathematical construct, there is no Big Bang theory. It's not possible to decouple the two in any meaningful way.

The language of physics is mathematics. While it's easy to lose sight of this fact for phenomena that happen at ordinary human scales, where we've developed an intuition that corresponds pretty well to the math, the situation is entirely different at scales far outside of our daily experience. Here, intuition utterly fails us and the only thing we can rely on is the math. This is true of both the quantum scale and the cosmological scale, and it is certainly true for the birth of the universe!

It is what it is. The universe's complexity is such that, without the equations, practical explanations are -- at best -- meaningless. More often, they're just simply wrong.

 

Time travel has been going on for nearly 60 years , secretly by the US government ...Search "Montauk Project" and "Al Bielek"

As for BB ... an unproven theory.