Is change real?

[tim.tdj]

Hi Everyone

I have a poll for you. It is inspired by Albert Einstein's concept of a "Spacetime Block".

Kind regards

Tim

Edited March 4, 2019 by tim.tdj

[koti]

6 minutes ago, tim.tdj said:

Hi Everyone

I have a poll for you.

Kind regards

Tim

Entropy always increases in any system so yes, chsnge is both real and inevitable. 

[tim.tdj]

1 minute ago, koti said:

Entropy always increases in any system so yes, chsnge is both real and inevitable. 

Hi Koti

Thank you very much for your reply.

Some people would argue that even if entropy is greater at greater values of t, this does not mean that the 4D system is itself changing. It would just mean that the 4D system has an entropy gradient.

[koti]

15 minutes ago, tim.tdj said:

Hi Koti

Thank you very much for your reply.

Some people would argue that even if entropy is greater at greater values of t, this does not mean that the 4D system is itself changing. It would just mean that the 4D system has an entropy gradient.

If youre refering to the Universe as the „4D system” then yes, as far as we know entropy always grows on cosmic scales. 

[Eise]

I think the question does not make much sense. Change and time are intimately related. As your 4-D universe contains the dimension 'time' it implies this universe changes. Just have a look at your 4-D universe at time t=0, and look at it at the time t=1: if some aspect of the universe differs between t=0 and t=1 then it means there is change. Per definition. 

[tim.tdj]

5 hours ago, Eise said:

I think the question does not make much sense. Change and time are intimately related. As your 4-D universe contains the dimension 'time' it implies this universe changes. Just have a look at your 4-D universe at time t=0, and look at it at the time t=1: if some aspect of the universe differs between t=0 and t=1 then it means there is change. Per definition. 

Hi Eise

Thank you very much for your reply.

I can very much see why you don't think the question makes much sense. It certainly won't make much sense to anyone who has not heard of the the concept of the "Spacetime Block Universe". A lot of physicists these days believe that the past, the present and the future all simultaneously coexist together prewritten in the Spacetime Block and that the change we perceive is just an illusion as we pass through the Spacetime Block. I personally have my doubts about this concept so I am wondering what other people think. Hence this thread and poll.

Edited March 5, 2019 by tim.tdj

[dimreepr]

42 minutes ago, tim.tdj said:

I can very much see why you don't think the question makes much sense. It certainly won't make much sense to anyone who has not heard of the the concept of the "Spacetime Block Universe". A lot of physicists these days believe that the past, the present and the future all simultaneously coexist together prewritten in the Spacetime Block and that the change we perceive is just an illusion as we pass through the Spacetime Block. I personally have my doubts about this concept so I am wondering what other people think. Hence this thread and poll.

1

That's Depressing...  

[swansont]

1 hour ago, tim.tdj said:

 A lot of physicists these days believe that the past, the present and the future all simultaneously coexist together prewritten in the Spacetime Block and that the change we perceive is just an illusion as we pass through the Spacetime Block.  

How does one "pass through" the spacetime block without change? The very notion of "passing through" implies change.

One problem with the determinism of relativity, from which this emanates, is that it is incompatible with quantum mechanics. The present does not have well-defined states, so one cannot extrapolate to the future.

 

I also think you overestimate when you say "A lot of physicists these days". This is a philosophical notion, and while that may be important to some physicists, especially those looking at foundations of physics, I doubt the majority care. I had not even heard of the notion until a few years ago, when someone brought it up as a topic here. It never came up in any physics class, as far as I can recall. It seems even more esoteric that QM interpretations.

[tim.tdj]

21 minutes ago, swansont said:

How does one "pass through" the spacetime block without change? The very notion of "passing through" implies change.

One problem with the determinism of relativity, from which this emanates, is that it is incompatible with quantum mechanics. The present does not have well-defined states, so one cannot extrapolate to the future.

Hi Swasont

Thank you very much for your reply.

You have made a very good point and to be honest, I have actually already asked myself the same question you have asked.

During this thread, I have actually been doing a certain amount of devil's advocacy. For the sake of the poll, I started this thread from an impartial position. I will now declare that I personally believe that change is actually real at the fundamental level. It seems so far that nobody who has voted in the poll or who has commented in this thread disagrees with this position. I wonder if this will change.

Some people reading this thread may be aware that the scientist, Lee Smolin, unlike a lot of his colleagues, believes that change is real at the fundamental level.

Edited March 5, 2019 by tim.tdj

[iNow]

1 hour ago, tim.tdj said:

believe that the past, the present and the future all simultaneously coexist together prewritten in the Spacetime Block and that the change we perceive is just an illusion as we pass through the Spacetime Block.

Sounds similar to a proposal put together a while back by Julian Barbour: https://en.wikipedia.org/wiki/The_End_of_Time_(book)

[geordief]

C

30 minutes ago, swansont said:

 

One problem with the determinism of relativity, from which this emanates, is that it is incompatible with quantum mechanics. The present does not have well-defined states, so one cannot extrapolate to the future.

 

Do quantum theories  entertain the notion of  past and future (whatever about extrapolating)?

is it possible to say anything at all about the time ordered nature of any two quantum states (systems?)

 

Are all quantum states(or systems?)  "time virgins"?

[studiot]

21 hours ago, tim.tdj said:

 

Is change real?

 

 

I think the question to be ill defined.

What do you mean by change?

 

Consider the following situation.

A man possesses 7 white shirts, 7 black ties, seven pairs of black trousers, seven pairs of black socks and seven pairs of black shoes.

Every day he washes and changes his set of clothes but he always looks the same.

 

Is there any change of appearance?

[Strange]

11 minutes ago, studiot said:

 

I think the question to be ill defined.

What do you mean by change?

 

Consider the following situation.

A man possesses 7 white shirts, 7 black ties, seven pairs of black trousers, seven pairs of black socks and seven pairs of black shoes.

Every day he washes and changes his set of clothes but he always looks the same.

 

Is there any change of appearance?

This is a version of Theseus's Ship / Trigger's Broom.

https://shaelum.wordpress.com/2013/08/23/sweeping-theseuss-ship-with-triggers-broom/

[Eise]

2 hours ago, tim.tdj said:

A lot of physicists these days believe that the past, the present and the future all simultaneously coexist together prewritten in the Spacetime Block...

I know. The idea is derived from the fact that, because simultaneity is relative to the movement of the observer, so automatically past, present and future must be too. (Of course only when events do not lie in each others light cones.) But this does not follow:

2 hours ago, tim.tdj said:

...and that the change we perceive is just an illusion as we pass through the Spacetime Block.

Changes are differences when we follow the timeline. But timelines do not disappear suddenly when we look at the universe as a 'block universe'.

And as you see, it is notoriously difficult to talk about such things and not using time-like concepts again: in your sentence the word 'pass'.

[tim.tdj]

5 minutes ago, studiot said:

 

I think the question to be ill defined.

What do you mean by change?

 

Consider the following situation.

A man possesses 7 white shirts, 7 black ties, seven pairs of black trousers, seven pairs of black socks and seven pairs of black shoes.

Every day he washes and changes his set of clothes but he always looks the same.

 

Is there any change of appearance?

Hi Studiot

Thank you very much for your reply.

Very interesting question.

I think I define change to be any alteration whatsoever (however small) of the relationship between at least two subatomic particles.

In your example, the man and his clothing are all large macroscopic objects consisting of gazillions of subatomic particles. So each shirt or each tie may look the same but they each consist of a unique pattern of subatomic particles. Also, the processes of washing and changing them entails a huge amount of change.

[geordief]

7 minutes ago, Strange said:

This is a version of Theseus's Ship / Trigger's Broom.

https://shaelum.wordpress.com/2013/08/23/sweeping-theseuss-ship-with-triggers-broom/

Is it  the same as form vs content?

Does the shape "make" the object?

Edited March 5, 2019 by geordief

[tim.tdj]

7 minutes ago, Eise said:

I know. The idea is derived from the fact that, because simultaneity is relative to the movement of the observer, so automatically past, present and future must be too. (Of course only when events do not lie in each others light cones.) But this does not follow:

Changes are differences when we follow the timeline. But timelines do not disappear suddenly when we look at the universe as a 'block universe'.

And as you see, it is notoriously difficult to talk about such things and not using time-like concepts again: in your sentence the word 'pass'.

Hi Eise

In my reply to Swasont earlier in this thread, I mentioned that for the sake of impartiality, I have actually been doing a certain amount of devil's advocacy in this thread. My previous reply to you was such an example so I actually agree with what you are saying. On various science documentaries, I have seen some very eminent scientists speaking about the SpaceTime Block as being a static object when viewed from a perspective outside of time. I suppose therefore the question is, does such a perspective really exist?

21 minutes ago, Eise said:

The idea is derived from the fact that, because simultaneity is relative to the movement of the observer, so automatically past, present and future must be too.

Hi Eise

Since my reply to you a few minuets ago, I have looked more closely at this particular part of your reply and have dome some more thinking about it. What you say here assumes that there does not exist a "special" or "preferred" reference frame. I know this is somewhat controversial but I personally believe that a "special" or "preferred" reference frame does actually exist. I might be wrong though.

[dimreepr]

9 minutes ago, tim.tdj said:

I suppose therefore the question is, does such a perspective really exist?

as pointless as the op

Edited March 5, 2019 by dimreepr

[Strange]

1 hour ago, tim.tdj said:

What you say here assumes that there does not exist a "special" or "preferred" reference frame. I know this is somewhat controversial but I personally believe that a "special" or "preferred" reference frame does actually exist.

Beliefs are of no value. How would one test for a preferred frame? And why have all such tests failed?

[Itoero]

Quote

Follow 3

 

Is change real?

 

evolution = change

[tim.tdj]

45 minutes ago, Strange said:

Beliefs are of no value. How would one test for a preferred frame? And why have all such tests failed?

I think that provided that you humbly accept that your beliefs and opinions might be wrong, there is no harm in having them. In various documentaries, I often see eminent scientists expressing their beliefs and disagreements with each other. It is all part of a healthy scientific debate. Science dies if this stops.

I might be wrong but I think that the cosmic dipole might be evidence for a preferred frame.

[swansont]

3 hours ago, geordief said:

C

Do quantum theories  entertain the notion of  past and future (whatever about extrapolating)?

is it possible to say anything at all about the time ordered nature of any two quantum states (systems?)

 

Are all quantum states(or systems?)  "time virgins"?

There are examples of quantum systems where time-ordering is not intuitive.

14 minutes ago, tim.tdj said:

I think that provided that you humbly accept that your beliefs and opinions might be wrong, there is no harm in having them. In various documentaries, I often see eminent scientists expressing their beliefs and disagreements with each other. It is all part of a healthy scientific debate. Science dies if this stops.

Depends on what you mean by beliefs and opinions. If it's not based on some kind of science, it has no value in a scientific discussion.

14 minutes ago, tim.tdj said:

I might be wrong but I think that the cosmic dipole might be evidence for a preferred frame.

Cosmic dipole? Do you mean the CMB dipole, which is caused by our motion WRT the CMB, and vanishes when the motion is removed? And does not, then, represent a preferred frame (in the sense provided by relativity)?

[StringJunky]

2 minutes ago, swansont said:

There are examples of quantum systems where time-ordering is not intuitive.

Does that mean events can apparently occur in some other order?

[swansont]

1 minute ago, StringJunky said:

Does that mean events can apparently occur in some other order?

It means that they can happen in an order that would not be possible classically, but we have plenty of examples of classically impossible things in QM (e.g. tunneling). The example I recall (vaguely; it was >20 years ago) is a multi-photon excitation, where the photon for an excited transition arrives first, and the transition still happens, even though the transitions have different energy.

[tim.tdj]

21 minutes ago, swansont said:

Cosmic dipole? Do you mean the CMB dipole, which is caused by our motion WRT the CMB, and vanishes when the motion is removed? And does not, then, represent a preferred frame (in the sense provided by relativity)?

The fact that we can be either moving or stationary relative to something as fundamental as the CMB seems to suggest to me that a preferred frame does exist. Is there something I am not understanding here? If yes, I would be very grateful if you could explain it to me.