How can time "begin"?

[_heretic]

General relativity tells us that there is no universal time. It all depends on your frame of reference and velocity relative to other things.

 

So how can it be that time "began" at the Big Bang? - which is the conventional viewpoint.

 

[IM Egdall]

I think the expansion of the universe gives us a kind of cosmic timeline we can all refer to. From this, we can estimate the age of the universe and when the big bang occurred.

[_heretic]

I think the expansion of the universe gives us a kind of cosmic timeline we can all refer to. From this, we can estimate the age of the universe and when the big bang occurred.

 

But this is only with respect to "our" reference frame. There isn't really a 'cosmic timeline'; so how can we say time had a starting point as if to suggest space-time appeared and started ticking away. Yet GR tells us time does not just 'tick-away' in the background. (Note! I'm not rejecting the fact of the Big Bang here).

[pantheory]

But this is only with respect to "our" reference frame. There isn't really a 'cosmic timeline'; so how can we say time had a starting point as if to suggest space-time appeared and started ticking away. Yet GR tells us time does not just 'tick-away' in the background. (Note! I'm not rejecting the fact of the Big Bang here).

There are several points that could be made here. Time in modern physics is generally considered a complicated concept yet what would be the meaning of time without matter or energy? Essentially time is an interval of change in matter or energy. According to the consensus version of the Big Bang model, all mass and energy in the universe began with the Big Bang. If this is so then what would be the meaning of time, concerning the idea "before the Big Bang."

 

"When forced to summarize the general theory of relativity in one sentence: Time and space and gravitation have no separate existence from matter."

(Albert Einstein)

 

The meaning of this sentence, in the context of this discussion, is that there is no possibility of the existence of time or space before the existence of matter. It would follow that if matter began its existence at the time of the Big Bang, then neither time or space could have had existence before then.

 

The existence of Time and Space, therefore, is a function of matter/energy.

//

Edited September 29, 2012 by pantheory

[_heretic]

There are several points that could be made here. Time in modern physics is generally considered a complicated concept yet what would be the meaning of time without matter or energy? Essentially time is an interval of change in matter or energy. According to the consensus version of the Big Bang model, all mass and energy in the universe began with the Big Bang. If this is so then what would be the meaning of time, concerning the idea "before the Big Bang."

 

"When forced to summarize the general theory of relativity in one sentence: Time and space and gravitation have no separate existence from matter."

(Albert Einstein)

 

The meaning of this sentence, in the context of this discussion, is that there is no possibility of the existence of time or space before the existence of matter. It would follow that if matter began its existence at the time of the Big Bang, then neither time or space could have had existence before then.

 

The existence of Time and Space, therefore, is a function of matter/energy.

//

 

Thanks that has made it a little clearer. What I'm still having trouble grasping is how, with a specific origin of time at the Big Bang, there is not one linear universal progression of time that would come out of it.

[Moontanman]

There are several points that could be made here. Time in modern physics is generally considered a complicated concept yet what would be the meaning of time without matter or energy? Essentially time is an interval of change in matter or energy. According to the consensus version of the Big Bang model, all mass and energy in the universe began with the Big Bang. If this is so then what would be the meaning of time, concerning the idea "before the Big Bang."

 

"When forced to summarize the general theory of relativity in one sentence: Time and space and gravitation have no separate existence from matter."

(Albert Einstein)

 

The meaning of this sentence, in the context of this discussion, is that there is no possibility of the existence of time or space before the existence of matter. It would follow that if matter began its existence at the time of the Big Bang, then neither time or space could have had existence before then.

 

The existence of Time and Space, therefore, is a function of matter/energy.

//

 

 

I can see how it could be asserted that time in the observable universe began with the observable universe but other possiblites are being considerd, one of these called the ekpyrotic universe model that considers that time may pass in a greater bulk space that our universal membrane exists within along with other membranes.

Edited September 29, 2012 by Moontanman

[pantheory]

_heretic,

 

Thanks that has made it a little clearer. What I'm still having trouble grasping is how, with a specific origin of time at the Big Bang, there is not one linear universal progression of time that would come out of it.

Your statement is valid but first consider the progression of time outside the influence of gravity. Light through the largest known void might travel a billion years without the influence of gravity. This would accordingly be 1 billion light years in distance and one billion years of the fastest possible progression of time. If at the end of the void a counter was set that observed such sequential light pulses, one might have a standard time clock to count the age of the universe. But much simpler, we can do the same thing here on Earth. Since time moves only slightly slower here on Earth because of the gravitational influences of the Earth and sun, and because of our relative motion by by the rotation of the Earth, the orbit of the Earth around the sun, the sun's motion around the galaxy, etc. Our time in fact is slower, but only by a very little bit. Big changes of time only occur as velocities represent a substantial portion of the speed of light, by strong gravitational influences close to black holes, etc.

 

Time as measured here on Earth still would be more than 99% accurate concerning its relation to the fastest possible progression of time, and even then we can probably make very good estimations of the remainder. So if the Big Bang model is correct in all regards, the beginning of the universe started about 13.7 billion years ago, concerning a type of "absolute time," which accordingly would be the fastest possible progression of time, as in the "great void" clock example -- but still very close to our measurement of time here on Earth via atomic clocks.

//

Edited September 30, 2012 by pantheory

[dmaiski]

the way I understand it "time" is just a reference point to something's position (it all depends what theory you want to look at time with)

 

sort of like a movie is made up of frames

objects in each frame have a position

time is the frames themselves, giving a sequence to the individual images

 

also the "big bang" is just a minor speed-bump in the greater scheme of things

what you are really looking for is what was before the big bang, ie. the origin (when something spontaneously puked itself into existence from absolute nothingness)

 

 

[pantheory]

I can see how it could be asserted that time in the observable universe began with the observable universe but other possibilities are being considered, one of these called the ekpyrotic universe model that considers that time may pass in a greater bulk space that our universal membrane exists within along with other membranes.

You are right. Outside the consensus Big Bang model, there are many proposals concerning older ages of the universe, an infinite age of the universe, different time progression rates, a different time of beginning, etc. Of the alternative BB models, and all other alternative cosmological models that I have heard of, the present consensus Big Bang model proposes the youngest age of the universe at 13.7 billion years.

//

Edited September 29, 2012 by pantheory

[Airbrush]

also the "big bang" is just a minor speed-bump in the greater scheme of things

what you are really looking for is what was before the big bang, ie. the origin (when something spontaneously puked itself into existence from absolute nothingness)

 

What you call "absolute nothingness" is a fantasy. There is nothing absolute about nothingness. The universe "puked itself into existence from something that seems very nothing-like, but not absolutely nothing.

[Airbrush]

General relativity tells us that there is no universal time. It all depends on your frame of reference and velocity relative to other things.

 

So how can it be that time "began" at the Big Bang? - which is the conventional viewpoint.

 

 

Think of the universe as a car, then time for the car is the odometer reading. We don't know what is outside our car, if anything. I doubt that time for our universe is the only time that exists.

[_heretic]

What you call "absolute nothingness" is a fantasy. There is nothing absolute about nothingness. The universe "puked itself into existence from something that seems very nothing-like, but not absolutely nothing.

 

I, myself, am of the view that the universe has always existed in some form. This abstraction of "absolute nothingness" is useful in as far as being a self-refuting idea.

[granpa]

time does not exist any more than red exists.

 

time is an aspect of "that which exists"

 

"that which exists" began with a single singularity

[_heretic]

time does not exist any more than red exists.

 

time is an aspect of "that which exists"

 

"that which exists" began with a single singularity

 

If that's the case, what's time dilation, length contraction and relativity of simultaneity supposed to be?

[EquisDeXD]

General relativity tells us that there is no universal time. It all depends on your frame of reference and velocity relative to other things.

 

So how can it be that time "began" at the Big Bang? - which is the conventional viewpoint.

 

 

Time can begin because before there was nothing counting how long it wasn't in existence.

[granpa]

If that's the case, what's time dilation, length contraction and relativity of simultaneity supposed to be?

An aspect of "that which exists"

[_heretic]

Time can begin because before there was nothing counting how long it wasn't in existence.

 

I am aware that that is the idea. What I am not clear on is that if time does "begin" how can we have all of these various fields forming? It gives the impression that there is a universal time under which these events are unfolding. Expect relativity tells us that can't be the case. To put it loosely, each thing has its own time.

[granpa]

you completely miss the whole point of relativity.

 

all that changes between different objects is the labels you put on the times for events.

 

the events themselves dont change.

[Astrology]

Time be the now early and later

 

Zone move and recordance also be being of time

 

And so god made the cosmo and the SolarSystem with some assistance from others approximately SixThousandYears in the past

 

 

Thanks

[Moontanman]

And so god made the cosmo and the SolarSystem with some assistance from others approximately SixThousandYears in the past

 

 

Can you support that assertion with any physical evidence?

[Ronald Hyde]

General relativity tells us that there is no universal time. It all depends on your frame of reference and velocity relative to other things.

 

So how can it be that time "began" at the Big Bang? - which is the conventional viewpoint.

 

 

Because time is just an ordering of events that have happened, and in fact will happen. And that ordering starts at t = 1, and continues to

what we call now. Myself, I suspect that there is absolute time, which is discrete, i.e. a number, about 10^42, and relative time which is

finer and what our clocks tell us. Because the 'ordinal numbers' are how one numbers things, and it makes a logical scheme of the world.

But that's just my answer.

[alpha2cen]

This is a diagram about time. Without event, no time exits.

[Astrology]

Can you support that assertion with any physical evidence?

 

 

Well it be recorded in the HebrewScriptures that god did this and god did that and though i do not like the hebrews there recordances be that approximate SixThousandYear span in time

If checking that fact and factualy inquiring about that while of time meaning reading the scriptures and exectra be very carefull because you shall be a part of that specificaly HorrificAspect of theirs

 

Later

[ACG52]

Well it be recorded in the HebrewScriptures that god did this and god did that and though i do not like the hebrews there recordances be that approximate SixThousandYear span in time

If checking that fact and factualy inquiring about that while of time meaning reading the scriptures and exectra be very carefull because you shall be a part of that specificaly HorrificAspect of theirs

 

Later

 

So the answer is no.

[Astrology]

So the answer is no.

 

What do you mean no i do not understand