What is the difference between present and past?

[ryan]

Increasing entropy is often the constant of what makes the present different from the past. But we also know that entropy is only statistical; it doesn't always have to be that way. So given enough universes, there will eventually be a universe exactly like ours that starts complex, but decreases its entropy as much as our universe increases entropy. This universe would be exactly like ours except it would go backwards.

So, what would this universe be like; would we consciously go from its "early" high entropy state to its lower entropy state? Or would we somehow consciously go from its end to its beginning, in which case there would be no conscious difference between our universe and this "backward" universe? I am really confused.

It's so weird to think about this without assuming or at least considering what the consciousness is and how it relates to entropy/time/present/past/future.

 

[fromderinside]

I go with  Steven Hawking. rather than with  Julian Barbour

 

[ryan]

I go with  Steven Hawking.

What do you mean?

 

[fromderinside]

read above. I hadn't finished my post.

 

[ryan]

I go with  Steven Hawking. rather than with  Julian Barbour

So I typed in "time" into the "find on page" function, and I got in the Hawking link, "Further work by Hawking in the area of arrows of time led to the 1985 publication of a paper theorising that if the no-boundary proposition were correct, then when the universe stopped expanding and eventually collapsed, time would run backwards".

This seems to be the Big Crunch theory. Anyways, he says that if the universe collapses then time reverses. Are you saying that time is more related to gravity than entropy (going against Eddington arrow of time )? I guess that would solve my problem. I wonder what negative consciousness would be like.

 

[Kharakov]

I go with  Steven Hawking. rather than with  Julian Barbour

Are you talking about Hawking's "alternate histories" scenario?

Problems arise when you have multiple witnesses to one history, which always occurs at the non-quantum level.

 

[fromderinside]

See. There you go increasing information with multiple witnesses. I don't think information can be decoupled from entropy. At least so it seems. It would be interesting adding heat over time.

 

[untermensche]

The present is a specific arrangement of energy and matter and whatever else exists.

But the present is only the present for one observer. The arrangement is specific in relation to them.

The past is a different arrangement.

 

[ryan]

See. There you go increasing information with multiple witnesses. I don't think information can be decoupled from entropy. At least so it seems. It would be interesting adding heat over time.

I feel like entropy is just a necessary outcome of matter/energy staying constant while spacetime increases. The larger the chessboard the more possibilities.

I like the gravity connection, not just because it seems to solve my issue but because of time dilation. It just seems more related to time, but I would have to think "they" have thought of this already.

 

[ryan]

The present is a specific arrangement of energy and matter and whatever else exists.

But the present is only the present for one observer. The arrangement is specific in relation to them.

Assuming the past exists, and we kind of have to assume that because of conservation principles, when the present becomes the past, say for event A, nothing changes physically for that event. There is something observing that event, and then there isn't something observing that event. It is hard to avoid the consciousness' part in all of this.

The past is a different arrangement.

What about two identical presents happening at different times?

 

[untermensche]

Assuming the past exists, and we kind of have to assume that because of conservation principles, when the present becomes the past, say for event A, nothing changes physically for that event. There is something observing that event, and then there isn't something observing that event. It is hard to avoid the consciousness' part in all of this.

The past is a different arrangement.

What about two identical presents happening at different times?

What are the odds?

 

[Copernicus]

If you want to understand the difference between present and past in terms of physics, it is natural to bring up the Second Law of Thermodynamics as defining "arrow of time". However, "present" and "past" concepts have a meaning that derives from human experience. From a purely psychological perspective, the present can be defined in terms of the ongoing experience of bodily sensations. The past corresponds to reconstructed memories of such sensations, and the future to projected sensations. From an evolutionary standpoint, brains act as guidance mechanisms. They provide situational awareness and plan future actions on the basis of accumulated experience. All animals have a sense of past, present, and future, but humans probably have the most sophisticated analysis of it for any animal on Earth.

Human language is universally structured to convey thoughts about time. That is, we share experiences of past, present, and projected futures through linguistic communication. So you can learn a lot about the concept of time by examining how language structures communication about it. Every linguistic expression is packaged in phrases that fit together into sentences. All sentences cluster around verbs that are associated with temporal and spatial reference. That is, they have elaborate systems for reference to past, present, and (irrealis) future.

 

[ryan]

Assuming the past exists, and we kind of have to assume that because of conservation principles, when the present becomes the past, say for event A, nothing changes physically for that event. There is something observing that event, and then there isn't something observing that event. It is hard to avoid the consciousness' part in all of this.



What about two identical presents happening at different times?

What are the odds?

I am not saying it's likely. I am just saying that if it happened, your definition wouldn't hold.

 

[ryan]

If you want to understand the difference between present and past in terms of physics, it is natural to bring up the Second Law of Thermodynamics as defining "arrow of time". However, "present" and "past" concepts have a meaning that derives from human experience.

But like I asked in the OP, would our conscious experiences go forwards in a universe with decreasing entropy which may have an effect like watching ourselves get younger. Or is time and consciousness independent of each other where we would still experience a universe in the same order (as we do now) except in the opposite direction of entropy?

From a purely psychological perspective, the present can be defined in terms of the ongoing experience of bodily sensations. The past corresponds to reconstructed memories of such sensations, and the future to projected sensations. From an evolutionary standpoint, brains act as guidance mechanisms. They provide situational awareness and plan future actions on the basis of accumulated experience. All animals have a sense of past, present, and future, but humans probably have the most sophisticated analysis of it for any animal on Earth.

Human language is universally structured to convey thoughts about time. That is, we share experiences of past, present, and projected futures through linguistic communication. So you can learn a lot about the concept of time by examining how language structures communication about it. Every linguistic expression is packaged in phrases that fit together into sentences. All sentences cluster around verbs that are associated with temporal and spatial reference. That is, they have elaborate systems for reference to past, present, and (irrealis) future.

 

[Copernicus]

But like I asked in the OP, would our conscious experiences go forwards in a universe with decreasing entropy which may have an effect like watching ourselves get younger. Or is time and consciousness independent of each other where we would still experience a universe in the same order (as we do now) except in the opposite direction of entropy?

From a purely psychological perspective, the present can be defined in terms of the ongoing experience of bodily sensations. The past corresponds to reconstructed memories of such sensations, and the future to projected sensations. From an evolutionary standpoint, brains act as guidance mechanisms. They provide situational awareness and plan future actions on the basis of accumulated experience. All animals have a sense of past, present, and future, but humans probably have the most sophisticated analysis of it for any animal on Earth.

Human language is universally structured to convey thoughts about time. That is, we share experiences of past, present, and projected futures through linguistic communication. So you can learn a lot about the concept of time by examining how language structures communication about it. Every linguistic expression is packaged in phrases that fit together into sentences. All sentences cluster around verbs that are associated with temporal and spatial reference. That is, they have elaborate systems for reference to past, present, and (irrealis) future.

The problem with "going backwards" is that causation is asymmetric. Multiple events all contribute to bring about a single resulting event, but different caused events have very different causal trees that precede them. The whole point of a brain is to model reality and predict future outcomes. So I don't see how consciousness can even begin to work in a backwards direction.

 

[untermensche]

What are the odds?

I am not saying it's likely. I am just saying that if it happened, your definition wouldn't hold.

My definition only concerns one observer. The past and the present only have meaning to an observer.

Not possible one observer could ever see the same two arrangements.

The paper burnt will not unburn.

 

[PyramidHead]

I think you're both onto something with the relationship between consciousness and time. My personal feeling is that consciousness itself simply is the flow of time, and the flow of time is simply consciousness. I guess that puts me in the Barbour camp.

A great tweet was posted by Sean Carroll some years ago, in which he was trying to be intentionally obtuse to show the consequences of believing time's flow is an illusion:

My consciousness freely travels up and down my world line, but sadly it only carries the memories appropriate to the moment it inhabits.

I think he is describing a reality. Furthermore, I think he could have said that consciousness travels up and down all the world lines of all conscious beings, carrying only the memories appropriate to the moment and the being it inhabits. None of this would contradict our experience, and it solves many conceptual problems to interpret things this way.

 

[ryan]

But like I asked in the OP, would our conscious experiences go forwards in a universe with decreasing entropy which may have an effect like watching ourselves get younger. Or is time and consciousness independent of each other where we would still experience a universe in the same order (as we do now) except in the opposite direction of entropy?

The problem with "going backwards" is that causation is asymmetric. Multiple events all contribute to bring about a single resulting event, but different caused events have very different causal trees that precede them. The whole point of a brain is to model reality and predict future outcomes. So I don't see how consciousness can even begin to work in a backwards direction.

So then the other option is what interests me. If a universe essentially did the opposite of what our universe does, we all would be doing everything backwards. So if the consciousness does go with this universe in a backwards fashion, would it go backwards in the backwards universe giving every consciousness the same kind of progressive experiences that we have in this universe?

 

[ryan]

I am not saying it's likely. I am just saying that if it happened, your definition wouldn't hold.

The paper burnt will not unburn.

It can, but it's unlikely.

 

[Copernicus]

The problem with "going backwards" is that causation is asymmetric. Multiple events all contribute to bring about a single resulting event, but different caused events have very different causal trees that precede them. The whole point of a brain is to model reality and predict future outcomes. So I don't see how consciousness can even begin to work in a backwards direction.

So then the other option is what interests me. If a universe essentially did the opposite of what our universe does, we all would be doing everything backwards. So if the consciousness does go with this universe in a backwards fashion, would it go backwards in the backwards universe giving every consciousness the same kind of progressive experiences that we have in this universe?

I don't see how. Causation is a temporal relationship between two events, where the occurrence of the result depends on the occurrence of the antecedent. That dependency is usually conceived of in terms of a physical force--a loss of energy during the transition between events--which depends entirely on the progression of entropy. Consciousness depends on memory, but the memory of a reverse-entropy entity would be constantly disappearing. There would be no basis for consciousness to function as a guidance mechanism. No way for memory to develop or a mind to mature.