• Welcome to Religious Forums, a friendly forum to discuss all religions in a friendly surrounding.

    Your voice is missing! You will need to register to get access to the following site features:
    • Reply to discussions and create your own threads.
    • Our modern chat room. No add-ons or extensions required, just login and start chatting!
    • Access to private conversations with other members.

    We hope to see you as a part of our community soon!

Is the PAST determined?

Polymath257

Think & Care
Staff member
Premium Member
OK, well at least your answer proves you are somewhat sane. So, if we cant time travel to the past, then please explain, how you even logically or rationally ask the question of "is the *past* determined?" If you can NOT change an event then, yes, it has already been determined.

Whether or not *I* can change it, is it possible for there to be more than one possible past?
 

Polymath257

Think & Care
Staff member
Premium Member
Why do you think this?

For example, do you think there is an actual answer to the question of how much Julius' Ceasar's last drink weighed? Or are there several possible answers to that question that are equally correct?
 

Earthtank

Active Member
Why do you think this?

For example, do you think there is an actual answer to the question of how much Julius' Ceasar's last drink weighed? Or are there several possible answers to that question that are equally correct?

There could be a million possible answers but, there is ONLY one correct answer.
 

shunyadragon

shunyadragon
Premium Member
Why do you think this?

For example, do you think there is an actual answer to the question of how much Julius' Ceasar's last drink weighed? Or are there several possible answers to that question that are equally correct?

There is no evidence that we can reverse the time arrow, . . . yet.

The degree of control of the present and future is marginable, with only limited ability to change things by our own will.
 
Last edited:

Nakosis

Non-Binary Physicalist
Premium Member
Many people like to ask whether the future is determined. This has relevance to issues like free will, for example.

I would like to address the reverse question: Is the *past* determined?

In other words, is the past fixed once we pass it?

Another interpretation of the problem, possible a different spin: Given the state of the universe *now* (and I am flexible about what this means), is the entirety of the past determined? Can every event of the past be *theoretically* deduced from the information of the present?

When framed in this way, I have to say that it seems unlikely. For example, it seems quite unlikely that the weight of Casar's last drink is fixed from anything available in the universe today. It seems unlikely that the question 'was there a T-Rex standing in this spot 68 million years ago exactly' actually has an answer that is determined by the state of the universe now.

So, to what extent is the past determined? If it is NOT determined, how does that affect your views of the past? if it *is* determined, in what sense is it so?

Are you familiar with E8? I'm not but trying to grasp the idea.

An 8 dimensional universe which exists that we perceive 3/4 dimensionally. Like if you take a cube and hold it up to the light and project the image onto a flat surface. All we would observe would be the shadow of the cube, not the entire cube. Depending on the rotation of the cube the shadow could appear as many different 2D dimensional shapes.

Some have the idea that the past, present and future exist simultaneously. Time being one of these dimensions. So what we perceive as the passage of time is like the rotation of the cube. We see the universe changing but what we are perceiving is a "shadow" of the universe. Nothing is actually changing except the rotation of how we perceive the universe.

So the universe is determined, actually unchanging. It is our perception of it that is changing.

If we could exactly reverse our sequence of perceptions of the universe, I suppose we could perceive the exact universe/shadow that we perceive x number of perceptions before. Or perhaps there exists an infinite numbers of pasts that could be perceived.

The exact "shadow" of the universe that we perceive before still exists, exists now, but there is no way to say with any certainty that we would ever be able to perceive that exact same "shadow" of the universe that we did before.
 

Polymath257

Think & Care
Staff member
Premium Member
There is no evidence that we can reverse the time arrow, . . . yet.

The degree of control of the present and future is marginable, with only limited ability to change things by our own will.

I'm not wanting a reversal of the arrow of time. I am asking whether there can be more than one past.
 

Polymath257

Think & Care
Staff member
Premium Member
Are you familiar with E8? I'm not but trying to grasp the idea.

An 8 dimensional universe which exists that we perceive 3/4 dimensionally. Like if you take a cube and hold it up to the light and project the image onto a flat surface. All we would observe would be the shadow of the cube, not the entire cube. Depending on the rotation of the cube the shadow could appear as many different 2D dimensional shapes.

Some have the idea that the past, present and future exist simultaneously. Time being one of these dimensions. So what we perceive as the passage of time is like the rotation of the cube. We see the universe changing but what we are perceiving is a "shadow" of the universe. Nothing is actually changing except the rotation of how we perceive the universe.

So the universe is determined, actually unchanging. It is our perception of it that is changing.

If we could exactly reverse our sequence of perceptions of the universe, I suppose we could perceive the exact universe/shadow that we perceive x number of perceptions before. Or perhaps there exists an infinite numbers of pasts that could be perceived.

The exact "shadow" of the universe that we perceive before still exists, exists now, but there is no way to say with any certainty that we would ever be able to perceive that exact same "shadow" of the universe that we did before.

Yes, modeling spacetime as a single manifold is pretty standard now. But we allow for a probability distribution for events in the future. Why not also the past?
 

shunyadragon

shunyadragon
Premium Member
I'm not wanting a reversal of the arrow of time. I am asking whether there can be more than one past.

The problem is the same with the present and future, and without going out on a limb of the highly hypothetical the evidence indicates only one time arrow.
 

shunyadragon

shunyadragon
Premium Member
Yes, modeling spacetime as a single manifold is pretty standard now. But we allow for a probability distribution for events in the future. Why not also the past?

There is no practical way to test this possibility. At present based on our knowledge there is only one time arrow.
 

Polymath257

Think & Care
Staff member
Premium Member
There is no practical way to test this possibility. At present based on our knowledge there is only one time arrow.

But that is as true of the past as it is of the future. But we allow for the possibility of there being more than one possible future.
 

shunyadragon

shunyadragon
Premium Member
But that is as true of the past as it is of the future. But we allow for the possibility of there being more than one possible future.

No, not true of the future, because of the indetrminancy of the present and future time arrow events including the limited influence humans have on present and future events. We are basically in the flow of time
 

Nakosis

Non-Binary Physicalist
Premium Member
Yes, modeling spacetime as a single manifold is pretty standard now. But we allow for a probability distribution for events in the future. Why not also the past?

I suppose the question would be how do we prove a multidimensional universe?

Otherwise the only thing going for it is that it provides an elegant explanation for many of the phenomenon we do observe.
 

shmogie

Well-Known Member
At relativistic speeds you and I could theoretically travel to the past and change the past of some far away galaxy though the journey would take thousands of years, however we could not travel to the Earth's past. This is not the same as saying our past is missing but the opposite. It evidences that our past is unchangeable by us.

There is another limit to changing the past since we have learned of Entropy. If we assume that the universe is burning out slowly then someday it will no longer be possible for the past to change. That implies an end to change which propagates backwards to our time, a final, settled condition for space-time.
You cannot travel back into the past, past your birth date, you simply cease to exist.
 

Brickjectivity

Turned to Stone. Now I stretch daily.
Staff member
Premium Member
You cannot travel back into the past, past your birth date, you simply cease to exist.
Depends on where you travel back. If you travel fast away from Earth and our galaxy and from every light photon so that you're no longer interacting with the same photons, then you can travel to the past somewhere else, theoretically. It will be so far from Earth that you will never be able to interfere with your past here. Its not convenient in any way except that you could start over somewhere else with younger stars.
 
Top