Is time physical?

[Sparko]

Right and that contradicts Big bang cosmology, which says that the universe grew from the dot to what we see today. As a matter of fact, of what use is the Big bang in a Block universe.

It did grow from a singularity. From the inside. When we are talking about the block universe it is a mental exercise of looking at the universe from the outside (which is actually impossible) as if you were a 4 dimensional being.

[Stoic]

Err no I'm not. The science is Big bang cosmology, the universe began small then rapidly expanded to the size we see today.

Now you are picking nits. The science is the same whether viewed from the viewpoint of a Presentist or an Eternalist.

[seer]

It did grow from a singularity. From the inside. When we are talking about the block universe it is a mental exercise of looking at the universe from the outside (which is actually impossible) as if you were a 4 dimensional being.

Good grief Sparko, you can't have it both ways! The universe was either created by the Big bang or it wasn't. If Block theory is correct, it wasn't.

[seer]

Now you are picking nits. The science is the same whether viewed from the viewpoint of a Presentist or an Eternalist.

Well, no. If Eternalism is correct, the universe wasn't created by the hot big bang (as science claims). It is either or, and that is not nit picking...

[Sparko]

Good grief Sparko, you can't have it both ways! The universe was either created by the Big bang or it wasn't. If Block theory is correct, it wasn't.

You can have it both ways. Just like you can talk about a film starting and ending, and hold the entire film in your hand at the same time. Like I keep saying you really don't understand the B-theory at all. Your objections are just nonsense most of the time. Basically you are like the flat earther saying "The earth can't be round because people in Australia would fall off!"

[seer]

You can have it both ways. Just like you can talk about a film starting and ending, and hold the entire film in your hand at the same time. Like I keep saying you really don't understand the B-theory at all. Your objections are just nonsense most of the time. Basically you are like the flat earther saying "The earth can't be round because people in Australia would fall off!"

Of course I don't understand! The bottom line Sparko (no matter how you couch it) is either the universe was created via the hot big bang as science presently claims, or the universe was not created by the hot big bang.

About 13.75 billion years ago, all of the contents and energy in the universe was contained in a singularity with infinite density and temperature. It began to expand rapidly and this expansion is known as the Big Bang. The laws of physics as we know them did not apply during the early seconds of the universe and scientists can only speculate about what the early universe was like.

The Big Bang hypothesis states that all of the current and past matter in the Universe came into existence at the same time, roughly 13.8 billion years ago. At this time, all matter was compacted into a very small ball with infinite density and intense heat called a Singularity. Suddenly, the Singularity began expanding, and the universe as we know it began.


https://lco.global/spacebook/cosmology/early-universe/

[Stoic]

Well, no. If Eternalism is correct, the universe wasn't created by the hot big bang (as science claims). It is either or, and that is not nit picking...

Eternalism allows for expansion. What is expansion other than "it takes up more volume at later times than it did at earlier times"?

[seer]

Eternalism allows for expansion. What is expansion other than "it takes up more volume at later times than it did at earlier times"?

Really? So the ENTIRE universe started small then grew? That is what Big bang cosmology claims (see past references and links).

[Sparko]

Really? So the ENTIRE universe started small then grew? That is what Big bang cosmology claims (see past references and links).

If the block universe is real, then God created it whole at once. Inside it was both the big bang and whatever the end will be. Using my gif analogy, he created the whole gif file instantly. The big bang is at the first frame of the gif. At that time the universe was small. At this time it is large. Simple. Just like the gif file. at one frame it is a dot, at a later frame it is a large circle. When the Gif's creator outputted the file from his editor, he created all of the frames at once. File/export. Bam! A new Gif complete with all frames existing at once.

[rogue06]

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Source: Why now doesn’t exist, and other strange facts about time

Einstein’s relativity tells us that time results from gravity warping the fabric of reality – resulting in a picture that is weirdly at odds with our experience

Time is relatively well-described in current physical theories – it’s just that those descriptions are perplexingly at odds both with each other and with our perception of what time should be.

Time is not absolute

Einstein’s general theory of relativity established time as a physical thing: it is part of space-time, the gravitational field produced by massive objects. The presence of mass warps space-time, with the result that time passes more slowly close to a massive body such as Earth.

This effect, although tiny in our own neighbourhood, has been confirmed in experiments. Clocks, for instance, run faster on mountain peaks than they do at sea level, and more slowly at our feet than they do by our heads. While we may think of time as a constant, metronomic beat against which the events of the universe play out, that is an illusion borne out of our own imprecise perception of time. Relativity says there is no single beat to which the cosmos moves.

Time has no direction

The irony of relativity’s abolition of absolute time is that this sort of time keeps our other basic physical theories ticking – from Newton’s laws of dynamics to the equations governing the evolution of the quantum world.

But these equations come with their own wrinkle: they are all fully reversible in time, running backwards just as well as forwards. Relativity gives no direction to time, either: time just “is”. That is at odds with our own perception, in which time determines our direction of travel, propelling us headlong into the future, whether we want it to or not.

The only exceptions to the rule of physical non-reversibility are the equations governing the flow of heat. For this reason, many physicists have sought the source of the sort of flowing time we perceive in thermodynamics – with so far unsatisfactory results.

Time has no “now”

Einstein’s relativity also says that the passage of time is affected by motion, with moving objects seeing less time passing. So not only does how much time elapses vary from place to place, but different observers looking at the same place but moving at different speeds will see different amounts of time passing.

So even “now” is relative, and you can’t even draw one objectively agreed line between all the points in the universe currently experiencing it. From its own perspective, each event has its own past, formed of those areas from which signals travelling at light speed, the cosmic speed limit, have had time to travel and so influence it. The event also has a future, formed of those areas to which light signals can propagate and feel its influence.

But other observers will see those pasts and futures differently. And outside each of those carefully delimited pasts and futures are vast swathes of the cosmos that are neither past nor future, but also not “now”. Our grammar of time, again born out of local experience, fails to describe what those areas might be.

Time is not (yet) quantum

Most physicists believe Einstein’s relativity is unlikely to be the final word on time. Time emerges out of the gravitational field, and all other fields and forces we know of are described by quantum physics. Gravity should be too. In this view, only by unifying our understanding of gravity and quantum phenomena can we hope to fully understand time. Alternatively, understanding more about the nature of time may point us towards the form of that one true theory.



Source

© Copyright Original Source

Luke-Dunphy-toss-a-grenade-and-run-away-GIF-Modern-Family.gif

[Stoic]

Really? So the ENTIRE universe started small then grew? That is what Big bang cosmology claims (see past references and links).

What big bang cosmology considers "the entire universe" is all of the matter, energy, and space.

When you integrate that over time, you get the Block Universe.

[seer]

What big bang cosmology considers "the entire universe" is all of the matter, energy, and space.

When you integrate that over time, you get the Block Universe.

What did you just say? The fact is, science, presently, says that the universe was created by the hot big bang, expanded from an initial small state to what we see today. Either that is correct or it isn't. I wish you and Sparko just gave up Big Bang Cosmology and just admit that you are science deniers...

[seer]

If the block universe is real, then God created it whole at once. Inside it was both the big bang and whatever the end will be. Using my gif analogy, he created the whole gif file instantly. The big bang is at the first frame of the gif. At that time the universe was small. At this time it is large. Simple. Just like the gif file. at one frame it is a dot, at a later frame it is a large circle. When the Gif's creator outputted the file from his editor, he created all of the frames at once. File/export. Bam! A new Gif complete with all frames existing at once.

Sparko if that is correct then big bang cosmology is incorrect. Because in big bang cosmology the universe as we see it was not all created or formed at once.

[Sparko]

3

2

1

Source: Why now doesn’t exist, and other strange facts about time

Einstein’s relativity tells us that time results from gravity warping the fabric of reality – resulting in a picture that is weirdly at odds with our experience

Time is relatively well-described in current physical theories – it’s just that those descriptions are perplexingly at odds both with each other and with our perception of what time should be.

Time is not absolute

Einstein’s general theory of relativity established time as a physical thing: it is part of space-time, the gravitational field produced by massive objects. The presence of mass warps space-time, with the result that time passes more slowly close to a massive body such as Earth.

This effect, although tiny in our own neighbourhood, has been confirmed in experiments. Clocks, for instance, run faster on mountain peaks than they do at sea level, and more slowly at our feet than they do by our heads. While we may think of time as a constant, metronomic beat against which the events of the universe play out, that is an illusion borne out of our own imprecise perception of time. Relativity says there is no single beat to which the cosmos moves.

Time has no direction

The irony of relativity’s abolition of absolute time is that this sort of time keeps our other basic physical theories ticking – from Newton’s laws of dynamics to the equations governing the evolution of the quantum world.

But these equations come with their own wrinkle: they are all fully reversible in time, running backwards just as well as forwards. Relativity gives no direction to time, either: time just “is”. That is at odds with our own perception, in which time determines our direction of travel, propelling us headlong into the future, whether we want it to or not.

The only exceptions to the rule of physical non-reversibility are the equations governing the flow of heat. For this reason, many physicists have sought the source of the sort of flowing time we perceive in thermodynamics – with so far unsatisfactory results.

Time has no “now”

Einstein’s relativity also says that the passage of time is affected by motion, with moving objects seeing less time passing. So not only does how much time elapses vary from place to place, but different observers looking at the same place but moving at different speeds will see different amounts of time passing.

So even “now” is relative, and you can’t even draw one objectively agreed line between all the points in the universe currently experiencing it. From its own perspective, each event has its own past, formed of those areas from which signals travelling at light speed, the cosmic speed limit, have had time to travel and so influence it. The event also has a future, formed of those areas to which light signals can propagate and feel its influence.

But other observers will see those pasts and futures differently. And outside each of those carefully delimited pasts and futures are vast swathes of the cosmos that are neither past nor future, but also not “now”. Our grammar of time, again born out of local experience, fails to describe what those areas might be.

Time is not (yet) quantum

Most physicists believe Einstein’s relativity is unlikely to be the final word on time. Time emerges out of the gravitational field, and all other fields and forces we know of are described by quantum physics. Gravity should be too. In this view, only by unifying our understanding of gravity and quantum phenomena can we hope to fully understand time. Alternatively, understanding more about the nature of time may point us towards the form of that one true theory.



Source

© Copyright Original Source

Luke-Dunphy-toss-a-grenade-and-run-away-GIF-Modern-Family.gif

You are late, I covered all this already.

Or maybe you are early and time is running backwards.

[Sparko]

Sparko if that is correct then big bang cosmology is incorrect. Because in big bang cosmology the universe as we see it was not all created or formed at once.

No it isn't. You just can't seem to grasp that any specific location in time includes all of space and matter and energy for that instant. At the time of the big bang, all of the matter and energy and space in the universe was one small dot. 14 Billion years later it is the size it is now.