Can we truly understand the concept of time?

[zuz]

According to Wikipedia cosmonaut Sergei Krikalev is 22.68 milliseconds younger then he would have been if he had stayed on Earth.

 

[Buzz Bloom]

To the original question, I reply; why do you think that time moves forward?
... You're really asking a question about human perception, not about time.

Hi David:

Unfortunately the OP writer had not participated since the OP, so it is difficult to guess what his intended question meant. For the purpose of post, this is my best guess.

Q: What is physically taking place which corresponds to time advancing from past to future?​

My answer is the following.

A: As time advances from past to future, entropy increases.​

Do you think that this Q and A is about human perception rather than about the physics of time?

Regards,
Buzz

 

[jbriggs444]

My answer is the following.
A: As time advances from past to future, entropy increases.

That accounts for a direction -- an "arrow" of time. It does not account for the rate. Lots of physical processes proceed at rates that correlate well with one another. So we calibrate a scale based on this and call it "time".

 

[Buzz Bloom]

That accounts for a direction -- an "arrow" of time. It does not account for the rate. Lots of physical processes proceed at rates that correlate well with one another. So we calibrate a scale based on this and call it "time".

Hi jbriggs:

As I read the OP, it is not asking anything about the rate of time changing. My interpretation of the OP is that it is asking for a description of a physical process that implies that time is changing, and the change is in the direction of past to future. I am not completely happy with the answer I gave, and I was hoping for a better description than that. The problem I see with my answer is that if the universe were in a state of equilibrium, then entropy would be stable, and as I described the process, time would not change. Intuitively that seems wrong, but I may be mistaken.

Regards,
Buzz

 

[David Byrden]

Do you think that this Q and A is about human perception rather than about the physics of time?

I think that particular question is about human perception, whether it was supposed to be, or not.

Just as this question is about human perception; "Why are the stars so far away?"

We can respond with physics-related reasons why the stars are where they are, but "far away" is the questioner's perception.

David

 

[Levi Woods]

Hi Levi:

Since the verb "move" has been explained to be inappropriate, what other verb would you choose to express the concept of your intended question?

How about:
How does time advance from past to future?
or
What is physically taking place which corresponds to time advancing from past to future?

Hope this helps.

Regards,
Buzz

How time advances from past to future is what I was going for.

 

[David Byrden]

It's hard to explain something that doesn't really exist. The presence of a noun "Time" in the language doesn't imply a corresponding real-world entity.

But, having a general idea of what you're asking, I will try to give you an insight.

Imagine if "time" didn't always move forward, but looped around such that we would eventually repeat the past. You would either
[1] be completely unaware of this, so you'd still come here and ask the same question,
or
[2] you'd be aware of it, which implies that you would remember the previous loop, which implies that you could take different actions and cause a different outcome this time around, and then "time" would no longer be looping. That's a contradiction. It cannot arise.

David

 

[bhobba]

This is a far from trivial topic and requires a whole book to discuss it - with no actual answer at the end of it - but of course along the way your understanding of the issues involved is deepened. I think there are a couple of books on it - the one I recently read is the following:
https://www.amazon.com/dp/0393285235/?tag=pfamazon01-20

My advice is before discussing this topic to become acquainted with the issues involved from a book like the above.

Bottom line is in physics the best definition of time is it is what a clock measures. Go into it deeper - eg the relation of time and entropy - and at the end of it you are aware of a lot new and interesting things - but nothing really is resolved - its still - time is what a clock measures. Time, like space and other foundational things in physics is quite difficult to pin down, beyond simple, almost trite statements.

Thanks
Bill