• 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!

When is Now?

Nakosis

Non-Binary Physicalist
Premium Member
Since everything is changing all the time (pun not intended) There is nothing called right now, because even if you think "NOW" that moment has already gone into the past.

Not for us, and that is real interesting too, but what about the universe itself?
 

Nakosis

Non-Binary Physicalist
Premium Member
You say you are talking about absolute now, and then you talk about a relative now, an event happening somewhere and light traveling 4 light years, etc.... Universal or absolute now is independent of events happening anywhere within the universe and observations thereof, it is not a relative, it is absolute.

Well, we have to assume, I think there exists absolute time in the universe. Otherwise there'd be no point in relativity. We couldn't talk about events happening at the same time in different parts of the universe.
 

9-10ths_Penguin

1/10 Subway Stalinist
Premium Member
Two things, again you are using observers.
Then replace that with whatever term you want. I'm not trying to suggest quantum effects or whatnot.

Second, you just said these flashes happened at the same time, the same moment in the universe. How could that happen? Your scenario assumes the "now" 8 light years apart is in sync.
Would this work better for you?

- they can be radio beacons each playing songs.
- beacon A plays Bohemian Rhapsody once.
- beacon B is playing Baby Shark over and over.

Observer/detector/whatever 1 receives the first note of Bohemian Rhapsody at precisely the same time as the "Gr" sound of the first "Grandma Shark." Observer/whatever 2 hears the first note of Bohemian Rhapsody at a different point in the song.
 

Nakosis

Non-Binary Physicalist
Premium Member
It happened 4 years ago in our reference frame. But it is 4 light years away in our reference frame. In other reference frames, it will be a different distance and will take a different amount of time.

However, no time passage is involved at the point of origin is it?
Maybe "now" is confusing since now is attached to our conscious awareness. So the question would be, does the universe have an absolute time?
 

Nakosis

Non-Binary Physicalist
Premium Member
Then replace that with whatever term you want. I'm not trying to suggest quantum effects or whatnot.


Would this work better for you?

- they can be radio beacons each playing songs.
- beacon A plays Bohemian Rhapsody once.
- beacon B is playing Baby Shark over and over.

Observer/detector/whatever 1 receives the first note of Bohemian Rhapsody at precisely the same time as the "Gr" sound of the first "Grandma Shark." Observer/whatever 2 hears the first note of Bohemian Rhapsody at a different point in the song.

How can these two events happen at the same time without assuming that absolute time exists in the universe.
Without this first assumption of absolute time, it doesn't matter when either observer head the note because there would be no time reference to measure from.
 

Polymath257

Think & Care
Staff member
Premium Member
However, no time passage is involved at the point of origin is it?
Maybe "now" is confusing since now is attached to our conscious awareness. So the question would be, does the universe have an absolute time?

No, the universe does not have an absolute time. neither does it have an absolute space. What it has is spacetime: a combination of the two into a single geometry. That is the whole point of relativity.

In a sense, again using high school algebra, asking if there is an absolute time is like asking if a plane has an 'absolute y axis'. And the answer is no.

The term 'passage of time' is a subjective one. At least in relativity ALL of time and ALL of space exists as a single geometry. So past, present, and future all are part of this geometry. The subjective feel of the passage of time is linked to the 'arrow of time' and the changes in entropy between different points on a world line (a path through spacetime).
 

Nakosis

Non-Binary Physicalist
Premium Member
No, the universe does not have an absolute time. neither does it have an absolute space. What it has is spacetime: a combination of the two into a single geometry. That is the whole point of relativity.

In a sense, again using high school algebra, asking if there is an absolute time is like asking if a plane has an 'absolute y axis'. And the answer is no.

The term 'passage of time' is a subjective one. At least in relativity ALL of time and ALL of space exists as a single geometry. So past, present, and future all are part of this geometry. The subjective feel of the passage of time is linked to the 'arrow of time' and the changes in entropy between different points on a world line (a path through spacetime).

Then we can never really assume that events which happen 8 light years apart happened at the same moment.
So how could we measure the speed of light without knowing the time it left its destination?
 

Polymath257

Think & Care
Staff member
Premium Member
Then we can never really assume that events which happen 8 light years apart happened at the same moment.

We can determine that they happen at the same time *in our reference frame*. In a different reference frame, they would not happen at the same time.

So how could we measure the speed of light without knowing the time it left its destination?

In *our* reference frame, we measure distance and time. Divide those and get the speed of light. In a different reference frame, the distance and time would be different, but the result of the division will be the same.
 

Nakosis

Non-Binary Physicalist
Premium Member
We can determine that they happen at the same time *in our reference frame*. In a different reference frame, they would not happen at the same time.



In *our* reference frame, we measure distance and time. Divide those and get the speed of light. In a different reference frame, the distance and time would be different, but the result of the division will be the same.

Which requires an observer right?
Does this mean physics cannot escape the need for an observer?
 

Polymath257

Think & Care
Staff member
Premium Member
Which requires an observer right?
Does this mean physics cannot escape the need for an observer?

Physics cannot escape the need for measurement. The measurements and division don't have to be done by a conscious entity. They could be done automatically by a computer, for example. But the detection devices will have a reference frame in which they do their measurements.
 

Nakosis

Non-Binary Physicalist
Premium Member
Physics cannot escape the need for measurement. The measurements and division don't have to be done by a conscious entity. They could be done automatically by a computer, for example. But the detection devices will have a reference frame in which they do their measurements.

So it would seem we cannot know if absolute time exists for the universe or not. Only that the mathematical model of the universe used in physics doesn't require it to exist for accuracy.
 

Nakosis

Non-Binary Physicalist
Premium Member
Yes, now is all there is, was, or ever will be. The concept of time is merely the awareness of the continuation of now, and by measuring some regular movement or oscillation as a proxy for the continued existence of now.

Ok, so in Physics time exists as a measurement of change. In relativity, the measurement changes. So the duration of measurement of a clock on earth differs from the duration of the measurement of a clock that orbits the earth. Therefore "time" changes.

"Now" however has nothing to do with duration. So now exists independent of time. However since the current physical model of the universe is dependent on the existence of spacetime. "Now" is not part of that model.
Not related to the problem of the "now" we consciously experience.

So "when is now" is the wrong question as "now" has no when.

Also, absolute time does not exist. However, absolute now, might.
 

Nakosis

Non-Binary Physicalist
Premium Member
Physics cannot escape the need for measurement. The measurements and division don't have to be done by a conscious entity. They could be done automatically by a computer, for example. But the detection devices will have a reference frame in which they do their measurements.

Nope, sorry. We know absolute time does not exist. It's just not the way it works.
Obvious now:cool: but took me a while to see it.
Thanks for your help.
 

sayak83

Veteran Member
Staff member
Premium Member
Is there an absolute now in the universe?
IOW is there a universal now in which all events occur in throughout the universe.
Our does the universe have different "time zones" such that now in one area of the universe is out of sync with events that happens in other areas of the universe?

So I don't have an answer for this "now";) but I'm looking into it.
Feel free to contribute however.
Different locations have different nows. Einstein showed this.
 

Nakosis

Non-Binary Physicalist
Premium Member
Different locations have different nows. Einstein showed this.

Einstein show that the passage of time is relative. That there is no absolute time in the universe.
However since now is now, it has no time duration.

Because of time, because of space and the fact that neither are absolute, we can experience these events at different times.
However to know/observe this to be true we have to assume our "nows" ought to be in-sync.

Einstein's quandary was described by Rudolf Carnap:
"Einstein said the problem of the Now worried him seriously. He explained that the experience of the Now means something special for man, something essentially different from the past and the future, but that this important difference does not and cannot occur within physics. That this experience cannot be grasped by science seemed to him a matter of painful but inevitable resignation. So he concluded 'that there is something essential about the Now which is just outside the realm of science.'
Now — And The Physics Of Time
 
Last edited:

Ben Dhyan

Veteran Member
No, the universe does not have an absolute time. neither does it have an absolute space. What it has is spacetime: a combination of the two into a single geometry. That is the whole point of relativity.

In a sense, again using high school algebra, asking if there is an absolute time is like asking if a plane has an 'absolute y axis'. And the answer is no.

The term 'passage of time' is a subjective one. At least in relativity ALL of time and ALL of space exists as a single geometry. So past, present, and future all are part of this geometry. The subjective feel of the passage of time is linked to the 'arrow of time' and the changes in entropy between different points on a world line (a path through spacetime).
Spacetime is a mathematical model, a concept, it represents reality but it is not reality, That is where many scientists go wrong, they get so involved in mental models that they forget that the models are only a mental representation of something actually real. It is as though Michael Angelo began to think his sculptures were equal to that which was sculptured.

Now because there is no such thing as absolute now in the mathematical models, you imagine that reality itself, existence itself, has not an absolute now. How can existence itself, change its rate of its continuing to exist. There is no time per say, man observes some regular aspect of reality, planets stars, pendulums, oscillations, etc. as a proxy measurement of the passage of the continuation of existence, whatever the form.

Now I am not saying that our senses don't create the impression of 'time', I say the creation of a measurement of rate of change around us using stars and pendulums were great inventions. But beyond this, there is only the absolute now always being now, that creates the impression of a flow from past to future, only because of an observer..

The pendulum swings 60 times at the rate of one second per swing, it means the universal now was present and continued to be present for 60 swings of the pendulum.
 
Last edited:

Ben Dhyan

Veteran Member
Ok, so in Physics time exists as a measurement of change. In relativity, the measurement changes. So the duration of measurement of a clock on earth differs from the duration of the measurement of a clock that orbits the earth. Therefore "time" changes.

"Now" however has nothing to do with duration. So now exists independent of time. However since the current physical model of the universe is dependent on the existence of spacetime. "Now" is not part of that model.
Not related to the problem of the "now" we consciously experience.

So "when is now" is the wrong question as "now" has no when.

Also, absolute time does not exist. However, absolute now, might.
See my post to Polymath, time per say does not exist as a real entity, it exists in the mind of an observer as an impression of changes taking place in the environment of the absolute now's continuation to exist. Man has even created a proxy measurement method for the observation, but it is the absolute now's continuation to exist that is being measured.
 

Ben Dhyan

Veteran Member
There is no physical tool to measure absolute now. It is a philosophical construct, not a scientific one.
I repeat my example from my post to Polymath.

The pendulum swings 60 times at the rate of one second per swing, you have measured the absolute now's continuation to exist for one minute! There is no time per say, it is a proxy measurement of the continuation of the absolute now's existence.
 

Polymath257

Think & Care
Staff member
Premium Member
Spacetime is a mathematical model, a concept, it represents reality but it is not reality, That is where many scientists go wrong, they get so involved in mental models that they forget that the models are only a mental representation of something actually real. It is as though Michael Angelo began to think his sculptures were equal to that which was sculptured.

But we *know* through actual measurements that this model actually says something about reality. We *know* simultaneity depends on relative motion and on gravity.

Now because there is no such thing as absolute now in the mathematical models, you imagine that reality itself, existence itself, has not an absolute now. How can existence itself, change its rate of its continuing to exist. There is no time per say, man observes some regular aspect of reality, planets stars, pendulums, oscillations, etc. as a proxy measurement of the passage of the continuation of existence, whatever the form.

Now I am not saying that our senses don't create the impression of 'time', I say the creation of a measurement of rate of change around us using stars and pendulums were great inventions. But beyond this, there is only the absolute now always being now, that creates the impression of a flow from past to future, only because of an observer..

And I would ask if you would say the same about space: does it only exist as a proxy? Something that we use rulers and other measuring devices to reveal regularities, but all measuring something that doesn't actually exist?

Is there an 'absolute here'? And why is that seen as such a different question than the existence of an 'absolute now'?

The pendulum swings 60 times at the rate of one second per swing, it means the universal now was present and continued to be present for 60 swings of the pendulum.

And a meter stick shows that the universal absolute here was present and continued for 100 centimeters? or, if you want, a wave on the water gives regularity over a distance in a similar way to the pendulum giving regularity over time.

But, again, that is different than whether simultaneity is absolute. We know it is not.
 
Top