What does it mean for something to be "logically possible"?

[untermensche]

"Infinite time" is not at all like 300 years of time.

Infinity is not a number you can count up to. It is not a number.

Infinity is a process. A process with no finish. Processes are not numbers.

Here is an algorithm which which would run forever if it could. "Repeatedly subtract zero from three until the result is zero."

The adjective "infinite" means never-ending.

The noun "infinity" is a human contrivance. A mathematician's tool. A complicated one at that. I taught an introduction to the nature of infinity as a professor of computer science. It was a 3-credit course and took a semester to teach.*

Physicists have a problem with their math sometimes. The math may predict a process produces infinite energy in finite time. Hear of the ultraviolet catastrophe?

Be careful with the use of "imaginary" with a physicist or mathematician. There is the imaginary unit i which has the definition that i*i = -1. Infinity is not an imaginary number. This i occurs in the Schrodinger equations which describe the nature of reality.

When I use "imaginary" I mean it in the common everyday manner. Something that only exists as an idea. Something with no objective existence.

This is a concept easily understood. Even by many mathematicians.

I agree with most of what you say.

Which is one reason among several I say it is not possible for time without beginning to have occurred before any given moment.

It is the same amount of time as time without end after all.

 

[George S]

It's really simple. If time has no beginning, then any point in time you pick marks the end of an infinite period of time. If that hypothesis is correct, it not only can happen; it MUST.

There is no such thing as an end to an infinite period of time. It is by definition time that never ends. Even if it has infinite time it will not end. Ever. Under no circumstances can it end.

Even if we resort to imaginary lines there are only two choices for an infinite line.

You could have a line that goes off into infinity in both directions. It has no beginning or end anywhere. There is no logic that says any point on such a line is the "beginning" or the "end". All points are the same distance from the beginning and the end. You can arbitrarily call one point "zero" but that in no way makes that point the beginning or the end of the line. It is no closer to the beginning or the end of the line than any other point.

The other choice is a line with a beginning and no end.

There is no such thing as a line with no beginning and an end. No such thing exists.

There certainly is such a thing. In fact the unqualified noun "line," in mathematics, is always infinite. A line segment is a finite portion of a line.

If time were infinite in the past it means that no matter what instant of time in the past you choose there was an instant before it.

If time were infinite in the future it means that no matter what future instant you choose, there will be an instant after it.

If time were not infinite it would be a line segment. There would be an instant before which there was no time and one after which there will be no more instants.

If time had a beginning there would have been an instant of time in the past with no preceding instant.

There is no way in which "now" can be "counted up to" if the past is infinite. There is no place to start counting.

There is no way in which "now" can be "counted down to" if the future is infinite. There is no "end" to start counting from.

"Now" is the natural zero of the time line. It is the reality we experience.

 

[George S]

Modern physics uses a point in time at which our mathematics fails. That failure is the usual divide-by-zero problem. Physicists call this time t=0 and occurred about 13.799±0.021 billion years ago.

Physics makes no claim about reality before 1 Planck time. (In physics, the Planck time (tP) is the unit of time in the system of natural units known as Planck units. It is the time required for light to travel, in a vacuum, a distance of 1 Planck length, approximately 5.39 × 10−44 s.)

The problem is that there is a distance in space beyond which we cannot peer with our telescopes, only with math. This means that all claims of what happened from Planck time 1 to the last scattering surface (approx 250,000 years) is theory (speculation).

A logical possibility (to make it thread-relevant) is that anything at all could have occurred before our local patch of the universe was 250,000 years of age.

Anything at all. Hence there is a logical possibility of a Boltzmann brain. This is a consciousness with no body.

Anything at all. Any god or gods you'd like to imagine.

Anything at all. Including absolutely nothing.

 

[George S]

It appears that (entanglement notwithstanding) Mother Nature loves causes to precede effects. If time were only positive that beginning would be causeless.

My favorite "anything at all" was devised to give the universe a cause.

Let us call the situation at Planck time 1 "Big Bang Conditions."

Run time backwards to 1, ignore the interval from 1 to -1, and keep going.

What has happened? A universe has contracted to Big Bang conditions. What happens next? A Big Bang.

Let it expand in the negative time direction as we do in the positive.

Now run time forwards from some negative time to -1, ignoring the interval from -1 to 1, and find that Big Bang conditions have been caused by a universe contracting to Big Bang conditions.

 

[untermensche]

If time were infinite in the past it means that no matter what instant of time in the past you choose there was an instant before it.

It doesn't take much thinking to see this means that prior to any given moment an infinite amount of moments came before it. Moments without end came before it.

It is an irrational situation.

It is the claim that moments without end occurred before some given moment.

In a universe with no beginning nothing could ever happen because before any event could happen infinite moments would have to pass first.

A logical possibility (to make it thread-relevant) is that anything at all could have occurred before our local patch of the universe was 250,000 years of age.

Only what DID happen happened. Nothing else is logically possible.

It is not logically possible that Obama was defeated for president.

 

[George S]

It doesn't take much thinking to see this means that prior to any given moment an infinite amount of moments came before it. Moments without end came before it.

It is an irrational situation.

It is the claim that moments without end occurred before some given moment.

In a universe with no beginning nothing could ever happen because before any event could happen infinite moments would have to pass first.

A logical possibility (to make it thread-relevant) is that anything at all could have occurred before our local patch of the universe was 250,000 years of age.

Only what DID happen happened. Nothing else is logically possible.

It is not logically possible that Obama was defeated for president.

Two lines out of all that you choose to respond to?

Only what DID happen happened. Nothing else is logically possible.

Well, open your mind a bit. Feynman claims that everything that could have happened DID happen. It is not necessarily the case that "Only what DID happen happened." Entanglement, y'know.

And, of course, you make a typo.

Only what DID happen happened. Nothing else is logically [physically] possible.

 

[untermensche]

Feynman claims that everything that could have happened DID happen.

You can't hide behind Feynman.

Only what actually happened is logically possible.

Saying other things are possible actually takes proof.

Two lines out of all that you choose to respond to?

I wrote an argument about how infinite time in the past is an illogical position. You completely ignored it.

Infinite time in the past is not something that can be tossed around lightly.

It is impossible. It is an irrational position. It cannot be used rationally in any argument.

It implies that before any given moment an infinite amount of moments occurred first.

 

[fast]

You can't hide behind Feynman.

Only what actually happened is logically possible.

Saying other things are possible actually takes proof.

Two lines out of all that you choose to respond to?

I wrote an argument about how infinite time in the past is an illogical position. You completely ignored it.

Infinite time in the past is not something that can be tossed around lightly.

It is impossible. It is an irrational position. It cannot be used rationally in any argument.

It implies that before any given moment an infinite amount of moments occurred first.

Your conception of "logical possibility" isn't remotely consistent with how it's ordinarily used, and you know this. It's a technical term with a specified meaning. Just understand it for what it is instead of denying it. If I say that it's possible but it doesn't hold true to your sense of possibility, it's still in line with how the term is used and so I'm right, and if you insist that it is impossible in the sense it's physically possible, all is well.

 

[untermensche]

Your conception of "logical possibility" isn't remotely consistent with how it's ordinarily used, and you know this.

This thread is an examination of the concept.

It's a technical term with a specified meaning.

There are no ultimate authorities on the matter.

 

[fast]

This thread is an examination of the concept.

It's a technical term with a specified meaning.

There are no ultimate authorities on the matter.

Throwing the word, "ultimately" at it alters what my response would be. Sure, there (perhaps) is no ultimate authority, but there are authoritative sources, and your use is not in sync with them.

And why is everything you can't put your finger on a concept anyway?

 

[fromderinside]

So anyone who has defined infinite can establish it's possibility if it is consistent with his logically consistent construction. It matters not whether it is consistent with  Classical propositional logic.

[Classical (or "bivalent") truth-functional propositional logic is that branch of truth-functional propositional logic that assumes that there are are only two possible truth-values a statement (whether simple or complex) can have: (1) truth, and (2) falsity, and that every statement is either true or false but not both ​

So to prove untermenche wrong it is necessary to understand both which logical system he uses and whether his claims are consistent within that construction.

So my first question to untermenche: Is, or, is not your logical system is consistent with classical propositional logic, preferably with an example of how this is so.

 

[untermensche]

So anyone who has defined infinite can establish it's possibility if it is consistent with his logically consistent construction. It matters not whether it is consistent with classical propositional logic. So to prove untermenche wrong it is necessary to understand both which logical system he uses and whether his claims are consistent within that construction.

So my first question to untermenche: Is your logical system is consistent with classical propositional logic, preferably with an example of how this is so.

This is a thread about logical possibilities.

There are no opinions with any special authority here.

Your appeals to some mystical authority are not something that counts as an argument.

- - - Updated - - -

This thread is an examination of the concept.

There are no ultimate authorities on the matter.

Throwing the word, "ultimately" at it alters what my response would be. Sure, there (perhaps) is no ultimate authority, but there are authoritative sources, and your use is not in sync with them.

And why is everything you can't put your finger on a concept anyway?

I only describe concepts as concepts.

I really see no point in anything you're saying.

 

[untermensche]

My position is there are only possibilities. All of them physical possibilities.

There are things that could possibly happen.

Logic has nothing to do with it. Logic has nothing to do with what is possible. That is determined by the nature of the universe, not any logic.

We can't will possibilities into existence.

A person can address this or try to hide behind some authority.

 

[beero1000]

It's really simple. If time has no beginning, then any point in time you pick marks the end of an infinite period of time. If that hypothesis is correct, it not only can happen; it MUST.

There is no such thing as an end to an infinite period of time. It is by definition time that never ends. Even if it has infinite time it will not end. Ever. Under no circumstances can it end.

Even if we resort to imaginary lines there are only two choices for an infinite line.

You could have a line that goes off into infinity in both directions. It has no beginning or end anywhere. There is no logic that says any point on such a line is the "beginning" or the "end". All points are the same distance from the beginning and the end. You can arbitrarily call one point "zero" but that in no way makes that point the beginning or the end of the line. It is no closer to the beginning or the end of the line than any other point.

The other choice is a line with a beginning and no end.

There is no such thing as a line with no beginning and an end. No such thing exists.

That's the dumbest thing I've heard all day.

Left endpoints of intervals are their 'beginning', right endpoints are their 'end'. There are line segments that go from A to B that have a beginning and an end, rays that go from A to infinity that have a beginning and no end, rays that go from minus infinity to A that have an end and no beginning, and lines that go from minus infinity to infinity that have neither end nor beginning.

How are you so oblivious to this?! Multiple people have tried to explain it to you in multiple different ways, yet you persist in your delusion of defining any boundary point as a 'beginning'. You aren't fooling anyone.

 

[bilby]

There is no such thing as an end to an infinite period of time. It is by definition time that never ends. Even if it has infinite time it will not end. Ever. Under no circumstances can it end.

Even if we resort to imaginary lines there are only two choices for an infinite line.

You could have a line that goes off into infinity in both directions. It has no beginning or end anywhere. There is no logic that says any point on such a line is the "beginning" or the "end". All points are the same distance from the beginning and the end. You can arbitrarily call one point "zero" but that in no way makes that point the beginning or the end of the line. It is no closer to the beginning or the end of the line than any other point.

The other choice is a line with a beginning and no end.

There is no such thing as a line with no beginning and an end. No such thing exists.

That's the dumbest thing I've heard all day.

Left endpoints of intervals are their 'beginning', right endpoints are their 'end'. There are line segments that go from A to B that have a beginning and an end, rays that go from A to infinity that have a beginning and no end, rays that go from minus infinity to A that have an end and no beginning, and lines that go from minus infinity to infinity that have neither end nor beginning.

How are you so oblivious to this?! Multiple people have tried to explain it to you in multiple different ways, yet you persist in your delusion of defining any boundary point as a 'beginning'. You aren't fooling anyone.

Oh, I don't know; I reckon he has untermensche pretty well fooled.

 

[untermensche]

There is no such thing as an end to an infinite period of time. It is by definition time that never ends. Even if it has infinite time it will not end. Ever. Under no circumstances can it end.

Even if we resort to imaginary lines there are only two choices for an infinite line.

You could have a line that goes off into infinity in both directions. It has no beginning or end anywhere. There is no logic that says any point on such a line is the "beginning" or the "end". All points are the same distance from the beginning and the end. You can arbitrarily call one point "zero" but that in no way makes that point the beginning or the end of the line. It is no closer to the beginning or the end of the line than any other point.

The other choice is a line with a beginning and no end.

There is no such thing as a line with no beginning and an end. No such thing exists.

That's the dumbest thing I've heard all day.

Left endpoints of intervals are their 'beginning', right endpoints are their 'end'. There are line segments that go from A to B that have a beginning and an end, rays that go from A to infinity that have a beginning and no end, rays that go from minus infinity to A that have an end and no beginning, and lines that go from minus infinity to infinity that have neither end nor beginning.

How are you so oblivious to this?! Multiple people have tried to explain it to you in multiple different ways, yet you persist in your delusion of defining any boundary point as a 'beginning'. You aren't fooling anyone.

Show me this infinite line with an end.

And prove it is the end not the beginning.

 

[fromderinside]

So anyone who has defined infinite can establish it's possibility if it is consistent with his logically consistent construction. It matters not whether it is consistent with  Classical propositional logic.

[Classical (or "bivalent") truth-functional propositional logic is that branch of truth-functional propositional logic that assumes that there are are only two possible truth-values a statement (whether simple or complex) can have: (1) truth, and (2) falsity, and that every statement is either true or false but not both ​

So to prove untermenche wrong it is necessary to understand both which logical system he uses and whether his claims are consistent within that construction.

So my first question to untermenche: Is, or, is not your logical system is consistent with classical propositional logic, preferably with an example of how this is so.

This is a thread about logical possibilities.

There are no opinions with any special authority here.

Your appeals to some mystical authority are not something that counts as an argument.

Like you wrote this thread is about logical possibilities. It is not about opined possibilities. Ergo, since logical you need to have a framework through which you work your logic. If it is not propositional logic you need to either explain what is you logic or provide an example of it in your argument. if not you are just opining.

FDI

 

[Kharakov]

That's the dumbest thing I've heard all day.

Left endpoints of intervals are their 'beginning', right endpoints are their 'end'. There are line segments that go from A to B that have a beginning and an end, rays that go from A to infinity that have a beginning and no end, rays that go from minus infinity to A that have an end and no beginning, and lines that go from minus infinity to infinity that have neither end nor beginning.

How are you so oblivious to this?! Multiple people have tried to explain it to you in multiple different ways, yet you persist in your delusion of defining any boundary point as a 'beginning'. You aren't fooling anyone.

Show me this infinite line with an end.

And prove it is the end not the beginning.

Well, you're observing existence that has existed for eternity, and you're oblivious to its eternal existence, so...... I really doubt showing you something is going to fill in the infinite gap in your knowledge of reality.

 

[untermensche]

Show me this infinite line with an end.

And prove it is the end not the beginning.

Well, you're observing existence that has existed for eternity, and you're oblivious to its eternal existence, so...... I really doubt showing you something is going to fill in the infinite gap in your knowledge of reality.

That is a bad conclusion, an impossible conclusion.

Not something observed.

If infinite time must pass before some moment that moment will never take place. Infinite time never passes. It is impossible for it to be in the past. Impossible for it to have already occurred.

What you describe is a situation where nothing can ever take place, no event can ever occur because before anything can happen infinite time must pass first.

It is irrational and most definitely not true.

 

[untermensche]

So anyone who has defined infinite can establish it's possibility if it is consistent with his logically consistent construction. It matters not whether it is consistent with  Classical propositional logic.

[Classical (or "bivalent") truth-functional propositional logic is that branch of truth-functional propositional logic that assumes that there are are only two possible truth-values a statement (whether simple or complex) can have: (1) truth, and (2) falsity, and that every statement is either true or false but not both ​

So to prove untermenche wrong it is necessary to understand both which logical system he uses and whether his claims are consistent within that construction.

So my first question to untermenche: Is, or, is not your logical system is consistent with classical propositional logic, preferably with an example of how this is so.

This is a thread about logical possibilities.

There are no opinions with any special authority here.

Your appeals to some mystical authority are not something that counts as an argument.

Like you wrote this thread is about logical possibilities. It is not about opined possibilities. Ergo, since logical you need to have a framework through which you work your logic. If it is not propositional logic you need to either explain what is you logic or provide an example of it in your argument. if not you are just opining.

FDI

You are allowed to make any argument in any way you choose. It merely has to be valid. You can't say that infinite time has already passed for example. That is a violation of the definition. Infinite time is time that never finishes. It can't have passed. It can't be in the past.

There is NO authority here.

None exist.

You can't talk your way into becoming one.