Universe can't be infinite.

[devans99]

Physicists don't care about correspondence. They care about prediction. Utility!

But they should care if something is possible or not. Infinity and eternity are not possible and they cause many problems. Many paradoxes occur because infinity is so illogical. For example Cantor's paradox, Galileo's paradox, Hilbert's hotel.

One thing we can say about nature is that it is logical. One thing we can say about infinity is that it is illogical. It does not belong in nature.

There is a paradox of eternal time in cosmology that is relevant to this discussion:

https://en.wikipedia.org/wiki/Measure_p ... cosmology)

- Assume time is eternal.
- If it can happen it will happen.
- An infinite number of times.
- No matter how unlikely it was in the first place!
- So all things happen an infinite number of times.
- So all things are equally likely.
- Reductio ad absurdum.
- Time is not eternal

[TimeSeeker]

But they should care if something is possible or not. Infinity and eternity are not possible and they cause many problems.

And they solve many problems too. All 500 years of calculus would have been impossible without infinities and asymptotes.

Many paradoxes occur because infinity is so illogical. For example Cantor's paradox, Galileo's paradox, Hilbert's hotel.

There are far worse things to happen to people than paradoxes.

One thing we can say about nature is that it is logical. One thing we can say about infinity is that it is illogical. It does not belong in nature.

Infinity is not "illogical". It's a hack. It works - we use it.

There is a paradox of eternal time in cosmology that is relevant to this discussion:

https://en.wikipedia.org/wiki/Measure_p ... cosmology)

- Assume time is eternal.
- If it can happen it will happen.
- An infinite number of times.
- No matter how unlikely it was in the first place!
- So all things happen an infinite number of times.
- So all things are equally likely.
- Reductio ad absurdum.
- Time is not eternal

There is an even more fundamental problem in physics: https://en.wikipedia.org/wiki/Problem_of_time

But we aren't about to throw the baby out with the bath water

Science is a pragmatic institution. Idealists with preconceived notions of aesthetics, symmetry or simplicity must stay out!

To presuppose that the universe is ANY way whatsoever (symmetrical, aesthetic, infinite or finite) is an error! Even to presuppose that it obeys any universal laws/rules is an error!

The universe is however the universe is. That is what we are trying to figure out. If it is even possible...

[devans99]

And they solve many problems too. All 500 years of calculus would have been impossible without infinities and asymptotes.

Calculus uses "Potential Infinity" whereas I'm discussing "Actual Infinity" from set theory. Aristotle explains the difference something like this:

Potential Infinity - Characterised by a repeating process, such as repeatedly adding to a number. These processes increases towards infinity without ever actually reaching it. Potential Infinity exists and is useful (calculus)

Actual Infinity - The results of carrying out an iterative process forever. Actual Infinity does not exist and is not useful (set theory)

All the paradoxes and problems are associated with actual infinity. Potential infinity, barring the odd Gabriel's horn, is on firmer ground.

There is an even more fundamental problem in physics: https://en.wikipedia.org/wiki/Problem_of_time

I don't buy that article. The speed of light speed limit (speed = distance / TIME) is obeyed by every particle in the universe. To be a normally functioning universe, a speed limit is required. Else it's possible to accelerate objects to infinite velocity and thus straight out of the universe. So both on empirical and theoretical grounds, time can't be emergent; it must be fundamental. As in Einstein's space-time.

[TimeSeeker]

Calculus uses "Potential Infinity" whereas I'm discussing "Actual Infinity" from set theory. Aristotle explains the difference something like this:

Potential Infinity - Characterised by a repeating process, such as repeatedly adding to a number. These processes increases towards infinity without ever actually reaching it. Potential Infinity exist and is useful (calculus)

It's an equation. It's all potential until realized.

Even the infinities in set theory (which is broken by the way and I reject it!) is theoretical.
https://en.wikipedia.org/wiki/Zermelo–F ... set_theory

But, like I said - I much prefer temporal type theory: https://arxiv.org/abs/1710.10258 and Lambda calculus: https://en.wikipedia.org/wiki/Lambda_calculus

Actual Infinity - The results of carrying out an iterative process forever. Actual Infinity does not exist and is not useful (set theory)

All the paradoxes and problems are associated with actual infinity. Potential infinity, barring the odd Gabriel's horn, is on firmer ground.

Special pleading.

I don't buy that article. The speed of light speed limit (speed = distance / TIME) is obeyed by every particle in the universe. To be a normally functioning universe, a speed limit is required. Else it's possible to accelerate objects to infinite velocity and thus straight out of the universe. So both on empirical and theoretical grounds, time can't be emergent; it must be fundamental. As in Einstein's space-time.

And now the denialism starts

The speed of light is ALSO the speed limit of causality! And when you conceptualize it that way you need to explain entanglement and quantum non-locality (Bell's theorem).

To be a normally functioning universe, a speed limit is required.

Says who ?

Presupposition

https://en.wikipedia.org/wiki/Anthropic_principle

[devans99]

I don't buy that article. The speed of light speed limit (speed = distance / TIME) is obeyed by every particle in the universe. To be a normally functioning universe, a speed limit is required. Else it's possible to accelerate objects to infinite velocity and thus straight out of the universe. So both on empirical and theoretical grounds, time can't be emergent; it must be fundamental. As in Einstein's space-time.

And now the denialism starts

Then you need to explain entanglement and quantum non-locality.

Quantum entanglement is an unsolved paradox, but my guess is whatever happens, nothing travels (in this universe) between the two particles so the speed limit is not broken - no physical constant are we more sure of than the speed of light. Maybe reality is virtual and the entangled particles are co-located in base reality but distanced in virtual reality?

The big bang looks a great deal like the start of time. Even the intense gravity of the big bang would have caused time to slow. The big bang theory itself is very successful and it posits a start of time.

So I see time very much as Einstein did.

What do you think time is?

[TimeSeeker]

Quantum entanglement is an unsolved paradox, but my guess is whatever happens, nothing travels (in this universe) between the two particles so the speed limit is not broken - no physical constant are we more sure of than the speed of light. Maybe reality is virtual and the entangled particles are co-located in base reality but distanced in virtual reality?

Which would be consistent with non-locality. And it would also be a causal mechanisms outside of what we are able to measure/detect via the current conception of the scientific method.

Simply because in a simulation time is an illusion ( https://en.wikipedia.org/wiki/System_time ). I can pause the execution of any software on my computer and update any address in memory, then resume execution. As far as the application is concerned - something just changed in 'reality' by divine intervention. To the programmer - it's just good ol' software debugging.

The big bang looks a great deal like the start of time.

OK, but the SI unit for time is defined in terms of Cs133. Which did NOT exist at the time of the big bang.

Even the intense gravity of the big bang would have caused time to slow. The big bang theory itself is very successful and it posits a start of time.

It is indeed very successful at predicting things, except when you start nitpicking its assumptions.

So I see time very much as Einstein did.

Do you reject QM like Einstein did also ?

What do you think time is?

Absolutely no idea. I don't part-take in metaphysical speculation

As best as I care to define it ANY detectable/measurable change is time-progression.

[devans99]

Simply because in a simulation time is an illusion ( https://en.wikipedia.org/wiki/System_time ). I can pause the execution of any software on my computer and update any address in memory, then resume execution. As far as the application is concerned - something just changed in 'reality' by divine intervention. To the programmer - it's just good ol' software debugging.

If we are in a simulation, then there must be an external, base reality time as well as a system time. Its base reality time that we care about - that determines our fate. System time we can disregard.

So we need to be careful to reason about base reality time.

OK, but the SI unit for time is defined in terms of Cs133. Which did NOT exist at the time of the big bang.

But something called time existed at the time of the big bang. Time enables change so it must have existed. Whether our units for measuring it existed is neither here or there.

So I see time very much as Einstein did.

Do you reject QM like Einstein did also ?

I do not reject QM. I feel our understanding of the micro-level universe is in its infancy and QM reflects this. In any case, QM is for micro-level phenomena; we are considering time and the universe; these are largely macro-level phenomena so it is not as relevant as relativity.

What do you think time is?

Absolutely no idea. I don't part-take in metaphysical speculation

As best as I care to define it ANY detectable/measurable change is time-progression.

But time passes without change. Time still happens for a broken clock. The speed of light limit is in effect at all times whether there is change or no.If time has a start the it follows it must be a dimension like Einstein said.

This is my favourite paradox on eternal time:

- Say you meet an Eternal being in an Eternal universe
- You notice he is counting
- You ask and he says ‘I’ve always been counting’
- What number is he on?

[TimeSeeker]

If we are in a simulation, then there must be an external, base reality time as well as a system time. Its base reality time that we care about - that determines our fate. System time we can disregard.

So we need to be careful to reason about base reality time.

You have no way of estimating it or measuring it. Except through side-channel attacks.

But something called time existed at the time of the big bang.

Something "called" time? Only humans give things names.

Time enables change so it must have existed. Whether our units for measuring it existed is neither here or there.

Not really. Time is how we measure change. It's a human construct. The units are human construct too.
And the fact that we think clock-ticks occur at regular intervals is an unjustified assumption.

For all we know time dilation is an integer overflow in the computer's floating point engine. Who knows?

But time passes without change. Time still happens for a broken clock. The speed of light limit is in effect at all times whether there is change or no.If time has a start the it follows it must be a dimension like Einstein said.

Time still happens for a time crystal. That's hardly the problem. Lamport clocks are the problem.

What if each and every particle in the universe oscillates to its own frequency/interval? e.g it has its own internal clock? e.g a 'universal' clock doesn't exist and each particle "experiences" time independently of every other particle.

Then physics is fucked

https://en.wikipedia.org/wiki/Lamport_timestamps

[devans99]

If we are in a simulation, then there must be an external, base reality time as well as a system time. Its base reality time that we care about - that determines our fate. System time we can disregard.

So we need to be careful to reason about base reality time.

You have no way of estimating it or measuring it. Except through side-channel attacks.

No, but we can reason about base reality time in the abstract and deduce some of its properties. For example, if base reality time did not have a start then an Actual Infinity of seconds has pasted so far, which is impossible.

For a base reality time moment to be valid, it must have a moment preceding it (imagine taking away Monday, then Tuesday would not exist). Thats the problem with eternity; it has no starting moment, so its 2nd moments is not defined, nor its 3rd and so on - none of it is defined. Eternity is like the universe minus the initial starting positions of all the particles - it’s all UNDEFINED.

The only topology of base reality time that’s possible is a closed loop, IE a circle, that way every moment has a moment preceding it (with the start of time preceded by the end of time).

Time enables change so it must have existed. Whether our units for measuring it existed is neither here or there.

Not really. Time is how we measure change. It's a human construct. The units are human construct too.
And the fact that we think clock-ticks occur at regular intervals is an unjustified assumption.

For all we know time dilation is an integer overflow in the computer's floating point engine. Who knows?

Time is not change. Time regulates change via the speed of light limit. If it regulates change it cannot be change.

I’ve looked at special relativity; its sound; he only uses two axioms (laws of physics constant and speed of light constant) and those axioms both have a huge amount of experimental data behind them. From those two axioms he deduces that time is a dimension and that past present and future are all real.

What is your beef with Special Relativity?

[TimeSeeker]

No, but we can reason about base reality time in the abstract and deduce some of its properties. For example, if base reality time did not have a start then an Actual Infinity of seconds has pasted so far, which is impossible.

You can't reason about anything you've never experienced. You assume that "base reality" shares some or all properties with "virtual reality".

There is no way to test it. So by definition - you are assuming this to be the case.

For a base reality time moment to be valid, it must have a moment preceding it (imagine taking away Monday, then Tuesday would not exist). Thats the problem with eternity; it has no starting moment, so its 2nd moments is not defined, nor its 3rd and so on - none of it is defined. Eternity is like the universe minus the initial starting positions of all the particles - it’s all UNDEFINED.

It's UNIMAGINABLE therefore undefinable.

The universe owes us noting. Not even fitting in our imaginations

The only topology of base reality time that’s possible is a closed loop, IE a circle, that way every moment has a moment preceding it (with the start of time preceded by the end of time).

A circle is impossible - it's 2 dimensional. We know reality has more dimensions than that.
Spheres, mobius strips or a kleinbottles are all possible? Where is the "beginning" and "end" there?

Time is not change. Time regulates change via the speed of light limit. If it regulates change it cannot be change.

Metaphysical claim. Untestable. If time regulates change why do different particles oscillate at different frequencies?

Is time regular or irregular? Nobody knows

I’ve looked at special relativity; its sound; he only uses two axioms (laws of physics constant and speed of light constant) and those axioms both have a huge amount of experimental data behind them. From those two axioms he deduces that time is a dimension and that past present and future are all real.

What is your beef with Special Relativity?

My beef is not with special relativity. My beef is your misunderstanding with the short-comings of logic/mathematical modeling.

"Soundness" is a property of logical systems - which are man-made. The universe doesn't owe you "soundness";)

How do you measure the "speed of light" without a conception of time?

It's measured in meters per second

[devans99]

No, but we can reason about base reality time in the abstract and deduce some of its properties. For example, if base reality time did not have a start then an Actual Infinity of seconds has pasted so far, which is impossible.

You can't reason about anything you've never experienced. You assume that "base reality" shares some or all properties with "virtual reality".

There is no way to test it. So by definition - you are assuming this to be the case.

For a base reality time moment to be valid, it must have a moment preceding it (imagine taking away Monday, then Tuesday would not exist). Thats the problem with eternity; it has no starting moment, so its 2nd moments is not defined, nor its 3rd and so on - none of it is defined. Eternity is like the universe minus the initial starting positions of all the particles - it’s all UNDEFINED.

It's UNIMAGINABLE therefore undefinable.

The universe owes us noting. Not even fitting in our imaginations

The only topology of base reality time that’s possible is a closed loop, IE a circle, that way every moment has a moment preceding it (with the start of time preceded by the end of time).

So a mobius strip or a kleinbottle ? Where is the "beginning" and "end" there?

Time is not change. Time regulates change via the speed of light limit. If it regulates change it cannot be change.

Metaphysical claim. Untestable. If time regulates change why do different particles oscillate at different frequencies?

Is time regular or irregular? Nobody knows

I’ve looked at special relativity; its sound; he only uses two axioms (laws of physics constant and speed of light constant) and those axioms both have a huge amount of experimental data behind them. From those two axioms he deduces that time is a dimension and that past present and future are all real.

What is your beef with Special Relativity?

My beef is not with special relativity. My beef is your misunderstanding with the short-comings of logic/mathematical modeling.

"Soundness" is a property of logical systems - which are man-made. The universe doesn't owe you "soundness";)

How do you measure the "speed of light" without a conception of time?

We can reason about base reality time: we’ve never experienced maths yet we reason about that. We have no option but to reason about it if we want to find the truth. I think it’s natural that a simulation would reflect the properties of base reality but even if that’s not the case, there must be some mechanism in base reality that allows change; IE some sort of time.

Eternity is not unimaginable. I imagined it above and the conclusion is its impossible. Eternity has no start. Everything real has a start. So eternity is impossible. Time has a start.

A mobius strip or a kleinbottle are both closed loops so we can put the start/end of time wherever we like on the closed loop. The start/end points are arbitrary. In the case of our universe, it’s conventional to put the start/end at the Big Bang / Big Crunch.

If you don’t have a problem with Special Relativity then you belief in Eternalism. When you combine that belief with Finitism, then you are heading towards the truth.

[TimeSeeker]

In fact, any property of "time" you claim is "impossible" (reversibility, irregularity, multiple time dimensions) I can demonstrate you to be false with software.

Reversibility: https://en.wikipedia.org/wiki/Reversible_computing
Irregularity: https://en.wikipedia.org/wiki/Time-scale_calculus
Multiple time dimensions: https://en.wikipedia.org/wiki/Multithre ... hitecture)

Being in control means exactly that: omnipotence, omnipresence and omniscience.

[TimeSeeker]

We can reason about base reality time: we’ve never experienced maths yet we reason about that.

Lolwhat? How do you "reason" about maths without experiencing it? My mathematical intuition is unique experience I tell you.

We have no option but to reason about it if we want to find the truth.

Well. It depends. Why are you looking for the truth? What are you going to do with it when you find it?

I think it’s natural that a simulation would reflect the properties of base reality but even if that’s not the case, there must be some mechanism in base reality that allows change; IE some sort of time.

Sure. And it needs not be anything like the way you experience or understand time intuitively.

See my previous post about computational time.

Eternity is not unimaginable. I imagined it above and the conclusion is its impossible.

Then you have a great imagination! Can you tell be anything about eternity? I suspect you will have a hard time since we are all bounded rationalists

Eternity has no start. Everything real has a start. So eternity is impossible. Time has a start.

Your current conception of time - sure. What if we are experiencing it backwards and the Big Bang is "the end" not "the start" ?

A mobius strip or a kleinbottle are both closed loops so we can put the start/end of time wherever we like on the closed loop. The start/end points are arbitrary. In the case of our universe, it’s conventional to put the start/end at the Big Bang / Big Crunch.

Ok. Then I arbitrarily decide to put the "end" there.

If you don’t have a problem with Special Relativity then you belief in Eternalism. When you combine that belief with Finitism, then you are heading towards the truth.

I am not very fond of truth-seeking. In fact - I despise the very notion of truth-seeking and I regard all truth-seekers as theists.

Truth-seeking is not an activity that bodes well with the Halting problem

In order for the "search for truth" to ever terminate - first we must know what the "exit condition" of the search algorithm is. So - what does "truth" look like and how will you know when you have found it?

Will the search ever halt?

If you answer "yes" then you need evidence to justify your answer...

[devans99]

My point is maths is purely in the mind. Numbers don’t have physical existence; they are a logical creation. Yet we’ve built a huge amount of useful work from this abstract starting position. So you don’t have to have real world experience of numbers to reason with them. Likewise we can reason about base reality purely in the mind and make some progress.

For example, it’s impossible to get something from nothing if we define nothing as no time, space, matter/energy, so we can conclude something has always existed. So we know base reality must be eternal from this. If you believe in finitism then it can’t be eternal in time, it must be eternal outside of time. So we’ve established that base reality (and therefore our contained reality) must comply with Eternalism. What is wrong with this type of reasoning? Base reality must have some sort of time analogue to support change and even if we are not in a simulation the argument still holds for our version of time.

What can I say about eternity apart from give you another proof that it does not exist:

Imagine an eternal being; he would have no start in time so could never exist. Being is possible we therefore conclude Eternal is not (imagine if your moment of birth was removed somehow, would you still exist?)

I don’t think the quest for truth ever ends. But a good intermediate goal is a purely deductive theory of the universe with no axioms (if thats possible). Obviously the theory should be testable as well.

[TimeSeeker]

My point is maths is purely in the mind. Numbers don’t have physical existence;

My mind is a physical entity. The brain operates on electrical impulses. There is no reason to resort to special pleading when talking about the mind or experience.

they are a logical creation. Yet we’ve built a huge amount of useful work from this abstract starting position. So you don’t have to have real world experience of numbers to reason with them. Likewise we can reason about base reality purely in the mind and make some progress.

Naturally. But in the end - it either agrees with experiment or it doesn't. And there are mathematics which don't agree with experiment. Euclidean geometry in 2D space. Because the world is not 2D

For example, it’s impossible to get something from nothing if we define nothing as no time, space, matter/energy, so we can conclude something has always existed.

The universe doesn't give two hoots about our definitions though. And many of our definitions have been proven to be wrong over the centuries.

So we know base reality must be eternal from this. If you believe in finitism then it can’t be eternal in time, it must be eternal outside of time.

And if I don't care about metaphysical notions such as "believing in things" ?

I care about prediction and control in service of subjective utility.
https://en.wikipedia.org/wiki/Construct ... istemology

So we’ve established that base reality (and therefore our contained reality) must comply with Eternalism. What is wrong with this type of reasoning?

Well it seems untestable/unfalsifiable, so you are necessarily taking it on pragmatic adequacy and definitely not on evidence! As long as you are happy to throw it all in the trash can the moment you find a Black Swan I have no problem with it.

Base reality must have some sort of time analogue to support change and even if we are not in a simulation the argument still holds for our version of time.

I can barely speculate about this reality - I certainly can't speculate about base reality. Best you'll get out of me is "I don't know".

What can I say about eternity apart from give you another proof that it does not exist:

Metaphysics. Science doesn't care. What science cares about is how it BEHAVES and how it INTERACTS and what consequences can be observed.

No consequences - no science.

Imagine an eternal being; he would have no start in time so could never exist. Being is possible we therefore conclude Eternal is not (imagine if your moment of birth was removed somehow, would you still exist?)

I can't imagine it. But observe you have still assumed the arrow of time.

You are yet to tackle the "What if" we are experiencing time in reverse.

I don’t think the quest for truth ever ends. But a good intermediate goal is a purely deductive theory of the universe with no axioms (if thats possible). Obviously the theory should be testable as well.

Deduction without axioms is impossible. It's a function without input - only output.

Which is as good as a First Cause e.g God.