Can the definition of infinity disprove an infinite past?

[Random Person]

You're still faced with an infinite amount of time to transpire before you get to now.

No. Then that amount of time is in the past. that amount of time has already transpired.
Stop this now, it is obvious that you have argument. You just spew up the same unsupported claim again and again.
(Exactly like untermensch... and u has stopped... aha...)

You are spewing the same ridiculous denials.

 

[Random Person]

A discrete unit is not the whole of eternity or infinity, only a finite part. Hence it has reference points in relation to other discrete, finite, units.

If you take a segment out of an infinite amount of time your segment is a finite amount of time.

Nothing is taken out. These are the inseparable parts of the whole of reality. We only happen to experience the finite, discrete objects, units and their relationships....which our brains - being wired as they are - call time and events,

They are inseparable and seamless or continuous.

 

[steve_bank]

Thermodynamics apply to a system with a boundary, like a refrigerator.

What you are descubing sounds like Brownian Motion. It is powered by forces which consume energy. Thermal energy in the environment comes from the Sun, tectonic motion, and the core. Local entropy left to itself is always increasing, running down hill. A refridgerator is an entropy reverser in the refrdgerator, entropy outside must inecrease. The problem occurs when the boundary is increased to the scale of the universe.

As to the problem of entropy reversing itself, gas molcules have a probability in a bottle of returning to exact positions, but not with the same emergy unless there is an energy input.

Wait, what?

Did they repeal the first law of thermodynamics and not tell me? If there is no energy input or output, then the total energy of the system MUST be the same.

If you are treating the 'bottle' as an open system, then a) Why have a bottle at all; and b) Why assume an energy output from the system during the motion of the gas molecules?

What you desribed is perpetual motion, entropy reversing itself. The LOT preclude any form of perpetual motion.

Turn off the power and a refridgerator will go to equilibrium with its surroundings. It can nver cool down without external energy into the system. A tankf gas atoms or molecules stay in motion from anbient heat if there is enough. Otherwise the gas molecules will settle doem due to gravity.You can not use a battery to run a generator to charge the battery. I dealt with those pesky LOT for thirty years.

 

[bilby]

Thermodynamics apply to a system with a boundary, like a refrigerator.

What you are descubing sounds like Brownian Motion. It is powered by forces which consume energy. Thermal energy in the environment comes from the Sun, tectonic motion, and the core. Local entropy left to itself is always increasing, running down hill. A refridgerator is an entropy reverser in the refrdgerator, entropy outside must inecrease. The problem occurs when the boundary is increased to the scale of the universe.

As to the problem of entropy reversing itself, gas molcules have a probability in a bottle of returning to exact positions, but not with the same emergy unless there is an energy input.

Wait, what?

Did they repeal the first law of thermodynamics and not tell me? If there is no energy input or output, then the total energy of the system MUST be the same.

If you are treating the 'bottle' as an open system, then a) Why have a bottle at all; and b) Why assume an energy output from the system during the motion of the gas molecules?

What you desribed is perpetual motion, entropy reversing itself. The LOT preclude any form of perpetual motion.

Turn off the power and a refridgerator will go to equilibrium with its surroundings. It can nver cool down without external energy into the system. A tankf gas atoms or molecules stay in motion from anbient heat if there is enough. Otherwise the gas molecules will settle doem due to gravity.You can not use a battery to run a generator to charge the battery. I dealt with those pesky LOT for thirty years.

I know what the Laws of Thermodynamics say. I am pointing out that the First Law still applies in Bomb#20's thought experiment...

That's merely a reassertion of your conclusion; it's not a counterargument to Juma's rebuttal. He drew the obvious analogy with infinite space. So deal with his objection. Either (1) claim that space has to be finite too because if space were infinite we couldn't possibly be "here", or (2) explain what it is about time that makes the logic of time different from the logic of space, or (3) admit you don't have a justification for your assertion.

Even if you can't wrap your mind around that, we know that the universe would have subject to a heat death by now.

"Heat death" is an 1800s concept, based on an 1800s understanding of thermodynamics. Physicists at that time thought it was a fundamental law of physics that entropy always increases. And yet you can watch entropy decrease all by itself any time you please -- all you need is a drop of water, a bit of dust, and a microscope. It's called "Brownian motion" -- a dust particle that has been brought to rest by friction from a viscous fluid suddenly starts moving, in contravention of every principle of 1800s physics. Welcome to 1902. Thermodynamics is now understood to be an emergent phenomenon resulting from the statistics of large numbers of particles moving mostly independently of one another. Entropy decreases aren't impossible; it's just that a transition from a low-entropy state to a neighboring high-entropy state is more probable than the reverse transition; and big entropy decreases are vastly more improbable than tiny little entropy decreases, such as a dust particle accelerating.

The point is, vastly improbable is an entirely different beast from impossible. It just means a ridiculously long time can be expected to pass between one occurrence and the next. A ridiculously long time is a finite amount. So if time was infinite, then there has been enough time for arbitrarily large entropy decreases to have already happened, infinitely many times. Thermodynamics is therefore no obstacle to an eternal universe. If something resembling a "heat death" occurs, it will eventually reverse itself. Patience is a virtue.

... even though this thought experiment describes a situation in which the Second Law would not apply. Small systems deviate from the Second Law all the time in small degree and for short durations, because the Second Law is the consequence of a statistical approach - it is VASTLY more likely that any macroscopic system will see an increase in entropy over any non-trivial timescale than that such a system would see a decrease in entropy; And so we can enshrine that likelihood as a physical law, applicable in the finite spacetime that we are able to observe. But over infinite time, even the most implausible events that have a non-zero possibility of occurring will happen. So the Second Law cannot be applicable to infinite systems.

Given infinite time, arbitrarily large deviations from the Second Law must occur. But this does not imply any need for, or likelihood of, a deviation from the First Law. So you are wrong to assert that the Second Law is applicable to the system under consideration; And also wrong to assert that the First Law is not.

Physical Laws apply only to specified systems. The First Law is not applicable to open systems, for example; However it appears to be applicable to all closed systems. The Second Law is not applicable to open systems either; But what Bomb#20 is saying (and I see no reason not to completely agree with his assessment) is that the Second Law also does not apply to infinite systems. This is an inevitable consequence of the application of probabilistic mechanisms to the infinite - all non-zero probabilities will be visited by an infinite system, no matter how small they might be.

As you are unlikely, as an engineer, to be called upon to work on an infinite system, your engineer's approximation of the Second Law as universally applicable is probably good enough for your purposes. But it is unwise to forget that it is an approximation when discussing hypothetical situations that are not constrained by our engineering abilities.

 

[steve_bank]

The LOT only properly apply to a bounded system. A car engine, computer, The Earth, the solar system, or human body. At the scale of cosmology it breaks down and application is speculatory.

For me conservation of matter and energy serves as a rationale for an infinte eternal ubiverse. But that is speculation, it can never be proven. There are many conceptual descriptions of entropy. When applied to a bounded system it is a number in a calculation. Within a bounded system entropy reversing entropy is perpetual motion. A general descrption of entropy I use is that in any bounded system there is enrgy that can not bre used to do work in the system. To me in an ifinite universe entropy does not apply at all. Energfy can never be lost, only the form changes, conservation of energy.

In vasic texts the LOT are not stated as true, only that no exceptions have been found. The LOT grew out of work on steam power in the 19th century. In the times people tried to make perpetual motion engines of various type.

The LOT evolved out of experience and experiment..

 

[DBT]

Nothing is taken out. These are the inseparable parts of the whole of reality. We only happen to experience the finite, discrete objects, units and their relationships....which our brains - being wired as they are - call time and events,

They are inseparable and seamless or continuous.

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

 

[Speakpigeon]

The LOT only properly apply to a bounded system. A car engine, computer, The Earth, the solar system, or human body. At the scale of cosmology it breaks down and application is speculatory.

For me conservation of matter and energy serves as a rationale for an infinte eternal ubiverse. But that is speculation, it can never be proven. There are many conceptual descriptions of entropy. When applied to a bounded system it is a number in a calculation. Within a bounded system entropy reversing entropy is perpetual motion. A general descrption of entropy I use is that in any bounded system there is enrgy that can not bre used to do work in the system. To me in an ifinite universe entropy does not apply at all. Energfy can never be lost, only the form changes, conservation of energy.

In vasic texts the LOT are not stated as true, only that no exceptions have been found. The LOT grew out of work on steam power in the 19th century. In the times people tried to make perpetual motion engines of various type.

The LOT evolved out of experience and experiment..

OK, I think we all understand the two points of view offered and they're both good enough given the assumptions they're based on. And the difference between what's assumed by each side explains the entire difference in perspective. And I don't see how we could decide which assumptions are correct and which are just wrong.
EB

EDIT
Disclosure: I lean on bilby's and Bomb#20's side because at least they explain themselves clearly enough and what they say seems to fit my very limited understanding of this issue. And I don't see anything substantial in what steve_bank says formally contradicting their assumptions.

 

[Random Person]

Nothing is taken out. These are the inseparable parts of the whole of reality. We only happen to experience the finite, discrete objects, units and their relationships....which our brains - being wired as they are - call time and events,

They are inseparable and seamless or continuous.

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

Yet there is no beginning in an infinite past.

 

[Speakpigeon]

The LOT only properly apply to a bounded system.

So it doesn't apply to an infinite universe. End of the discussion, I guess.
EB

- - - Updated - - -

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

Excellent point.
EB

 

[Speakpigeon]

Given infinite time, arbitrarily large deviations from the Second Law must occur.

This is the crucial point. Given enough time, you'll get any very improbable state. And you can't say all of them only if there's an infinite number of them.

Now that should be understood as a logical conclusion from theoretical premises backed up inductively by scientific experiments. Theoretical predictions that inevitably should come true as long as the premises stand good. Maybe they won't but I haven't seen any reason presented here to not take this at face value.
EB

 

[Juma]

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

Yet there is no beginning in an infinite past.

exactly! have you finally got it?

 

[PyramidHead]

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

Yet there is no beginning in an infinite past.

exactly! have you finally got it?

Well, there are beginnings in an infinite past, just not the beginning of time. DBT was referring to "beginnings and endings within the context of the whole, infinite ever changing existence", which itself may be without beginning (or end).

 

[Random Person]

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

Yet there is no beginning in an infinite past.

exactly! have you finally got it?

I've always have had it.

- - - Updated - - -

exactly! have you finally got it?

Well, there are beginnings in an infinite past, just not the beginning of time. DBT was referring to "beginnings and endings within the context of the whole, infinite ever changing existence", which itself may be without beginning (or end).

In context, it is a pointless point.

 

[Speakpigeon]

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

Yet there is no beginning in an infinite past.

exactly! have you finally got it?

Me, I don't see any problem at all with an infinite past having a beginning.

So, could you explain why you think an infinite past should have no beginning?
EB

 

[Juma]

exactly! have you finally got it?

Me, I don't see any problem at all with an infinite past having a beginning.

So, could you explain why you think an infinite past should have no beginning?
EB

Every point in time is finite distance from another point in time.
That is why we can use seconds to mesure it.
If there isnt a point in time that is a finite distance earlier than for example midnight UTC 201804014 there are no first point.

 

[DBT]

Yet quantifiable, distinct features, attributes, beginnings and endings within the context of the whole, infinite ever changing existence .....

Yet there is no beginning in an infinite past.

I didn't suggest that there is a beginning to Eternity My point being that is the composition, the ephemeral parts - for example, the shapes of clouds that come and go in the sky, that enables the brain as an information processor to perceive rares of change as the passing of time, enabling measurement and quantification....

 

[DBT]

exactly! have you finally got it?

Well, there are beginnings in an infinite past, just not the beginning of time. DBT was referring to "beginnings and endings within the context of the whole, infinite ever changing existence", which itself may be without beginning (or end).

Some folks seem to be happy with other definitions of Eternity or Infinity, but I am using the ''without beginning or end'' definition.

 

[Speakpigeon]

exactly! have you finally got it?

Me, I don't see any problem at all with an infinite past having a beginning.

So, could you explain why you think an infinite past should have no beginning?
EB

Every point in time is finite distance from another point in time.

Sorry, doesn't work. How could you possibly know that? You may want to assume that but I don't see how anybody could possibly establish this as a fact.

That is why we can use seconds to mesure it.

???

I think that's totally irrelevant.

If the past was infinite and had a beginning, you could still perform exactly the same measures as with a finite time or an infinite time without a beginning.

If there isnt a point in time that is a finite distance earlier than for example midnight UTC 201804014 there are no first point.

???

Sorry, I can't make sense of that. Could you rephrase?
EB

 

[Speakpigeon]

exactly! have you finally got it?

Well, there are beginnings in an infinite past, just not the beginning of time. DBT was referring to "beginnings and endings within the context of the whole, infinite ever changing existence", which itself may be without beginning (or end).

Some folks seem to be happy with other definitions of Eternity or Infinity, but I am using the ''without beginning or end'' definition.

An infinite past with a beginning is just a past that has an infinite number of moments (e.g. seconds), in the sense that if you had to count them, you wouldn't get to the end of it. So, it's still unbounded in this sense even though it's bounded n the other sense that there's a lower bound.

Those are two very different bounds. The first kind of bound is just a point in the past, the beginning of time. The second kind of bound I'm talking about is just a number, i.e. the number of moments in the past (counting backward from the present or counting forward from the beginning, same result).
EB

 

[DBT]

Some folks seem to be happy with other definitions of Eternity or Infinity, but I am using the ''without beginning or end'' definition.

An infinite past with a beginning is just a past that has an infinite number of moments (e.g. seconds), in the sense that if you had to count them, you wouldn't get to the end of it. So, it's still unbounded in this sense even though it's bounded n the other sense that there's a lower bound.

Those are two very different bounds. The first kind of bound is just a point in the past, the beginning of time. The second kind of bound I'm talking about is just a number, i.e. the number of moments in the past (counting backward from the present or counting forward from the beginning, same result).
EB

Sure, but given the OP issue, is this definition suitable?

''If the universe was eternal, then this moment would never exist. An infinite number of moments would still be unfolding prior to now.
Time happens chronologically. If an infinite number of minutes had to pass before this moment could occur, then this moment would never arrive.''

Some would argue that if time had a beginning, there must be a finite number of minutes from the beginning till now. Of course, there may be a potentially infinite number of minutes in the future, given an open ended system.