A question about the present!

[Lord Antares]

The problem here is the notion that there is a "present" that has any meaning outside of a single frame of reference. Time is relative. "Now" does not mean someone's watch agrees with someone else's, if they occupy different frames

 

This is what I'm trying to tell you. There is only a present for one individual. There is no universal present.

 

 

Like I said, the travelling twin drifts into the past. Their relative present being behind in time relative to ground state, then light allows us to see the past.

They have.

 

Yes, each present is simultaneity.

 

This post only says that there is time dilation. No one is disputing that.

We are disputing that this means that someone is going into the past. It doesn't. It only means that one's time is dilated compared to another person's frame of reference. You could use imaginary terminology and say that means travelling into the past, but it would be senseless to say that as it doesn't really mean anything.

[JohnLesser]

 

This is what I'm trying to tell you. There is only a present for one individual. There is no universal present.

 

 

 

This post only says that there is time dilation. No one is disputing that.

We are disputing that this means that someone is going into the past. It doesn't. It only means that one's time is dilated compared to another person's frame of reference. You could use imaginary terminology and say that means travelling into the past, but it would be senseless to say that as it doesn't really mean anything.

Ones time can not be dilated if they remain synchronous in the present. If I wrong then so must be time dilation. Luckily I am correct.

 

This is what I'm trying to tell you. There is only a present for one individual. There is no universal present.

 

 

 

This post only says that there is time dilation. No one is disputing that.

We are disputing that this means that someone is going into the past. It doesn't. It only means that one's time is dilated compared to another person's frame of reference. You could use imaginary terminology and say that means travelling into the past, but it would be senseless to say that as it doesn't really mean anything.

I said pages ago I understood simultaneity.

[Strange]

You mostly are telling me there is no time dilation, huh......

 

 

No one is saying that (apart from madmac and he is a crank opposed to relativity theory).

No, again you are in a way saying there is no time dilation.

 

 

No one is saying that.

 

 

 

The two twins can not both occupy the present unless their time lines are equal length.

 

Clearly wrong. You can end up at the place by taking paths that are different length.

[Lord Antares]

Ones time can not be dilated if they remain synchronous in the present. If I wrong then so must be time dilation. Luckily I am correct.

I wish you understood.

 

 

I said pages ago I understood simultaneity.

 

Who said anything about simultaneity? It certainly has nothing to do with what we are talking about.

[JohnLesser]

 

 

No one is saying that (apart from madmac and he is a crank opposed to relativity theory).

 

 

No one is saying that.

 

 

Clearly wrong. You can end up at the place by taking paths that are different length.

Twin 2 departs , time slows down, twin 2's present falls into the past relative to ground state present?

I wish you understood.

 

 

 

Who said anything about simultaneity? It certainly has nothing to do with what we are talking about.

Then you don't understand the subject if you think that.

[Strange]

Twin 2 departs , time slows down, twin 2's present falls into the past relative to ground state present?

 

 

His clock falls behind. (And note that twin 1's clock falls behind twin 2 as well.)

 

"Falls into the past" has no meaning.

[JohnLesser]

 

 

His clock falls behind. (And note that twin 1's clock falls behind twin 2 as well.)

 

"Falls into the past" has no meaning.

No, twins 1 clock is the ground state constant, twin 2 clock is the only variant.

Edited April 3, 2017 by JohnLesser

[Strange]

No, twins 1 clock is the ground state constant, twin 2 clock is the only invariant.

 

 

Wrong. They are in relative motion. They will each see the other's clock run slow.

 

They can both consider themselves in the "ground state" (it doesn't help that you are inventing terminology - that just adds to the confusion).

Edited April 3, 2017 by Strange

[JohnLesser]

 

 

Wrong. They are in relative motion. They will each see the other's clock run slow.

 

They can both consider themselves in the "ground state" (it doesn't help that you are inventing terminology - that just adds to the confusion).

Wrong, twin 2 knows the length of constant rate. Twin 2 knows relativity and knows the ground state is invariant.

[Strange]

Wrong, twin 2 knows the length of constant rate. Twin 2 knows relativity and knows the ground state is invariant.

 

 

That is pretty meaningless. What is "the length of constant rate"? What is the "ground state"? Why is it invariant?

 

Even Galileo knew that either could consider themselves stationary (when they are not accelerating).

https://en.wikipedia.org/wiki/Galilean_invariance

[JohnLesser]

 

 

That is pretty meaningless. What is "the length of constant rate"? What is the "ground state"? Why is it invariant?

 

Even Galileo knew that either could consider themselves stationary (when they are not accelerating).

https://en.wikipedia.org/wiki/Galilean_invariance

huh? What is the ground normally? Obviously invariant because on the ground 0 velocity, what is a constant rate? 9,192,631,770hz/3.24cm

[studiot]

 

John Lesser

 

A Question about the Present

 

The two twins can not both occupy the present unless their time lines are equal length.

 

I am not interested in your squabble with others here, but I am disappointed in your total disinterest in my (only) post#109 before this one.

 

Eddington was the first man to articulate that there is no 'Universal Present', even if he was not the first man to realise this.

(Faraday was the originator in his famous letter deposited with the Royal Society March 12th, 1832

 

 

Faraday

.......When a magnet acts upon a distant magnet or piece of iron the influencing cause proceeds gradually from the magnetic bodies and requires time for its transmission, which will probably be found to be very sensible..........

 

An observer at one point in the universe will record a different 'present' from the 'present' recorded by an observer at any other point.

 

Einstinian relativity is not necessary to understand this.

 

I am trying to dig out the Eddington reference for you, where he develops this idea very clearly.

[Strange]

huh? What is the ground normally? Obviously invariant because on the ground 0 velocity, what is a constant rate? 9,192,631,770hz/3.24cm

 

 

But from the perspective of the moon, for example, the ground is moving at roughly 1000km/h (at the equator). But from the point of view of someone on the ground, the ground is stationary and it is the moon that is moving.

 

You can't treat the ground as an absolute frame of reference.

 

Either twin can consider themselves stationary and the other moving relative to them. They will both see the other's clock run slow.

 

I though you said you understood relativity. It seems not, after all.

[Function]

Are thoughts the only things we perceive instantly?

 

If I move my finger, it moves itself at a certain moment. Proprioceptive information on the movement and location of my finger, arrive in my brain moments after the finger has moved / initiated movement or was at the certain location. Visual information on my finger (me looking at it) is coming in later, sensitive information (my finger feeling something or nothing) is coming in later.

 

Then is there something we experience at the same moment of it happening?

[iNow]

Are thoughts the only things we perceive instantly?

 

If I move my finger, it moves itself at a certain moment. Proprioceptive information on the movement and location of my finger, arrive in my brain moments after the finger has moved / initiated movement or was at the certain location. Visual information on my finger (me looking at it) is coming in later, sensitive information (my finger feeling something or nothing) is coming in later.

 

Then is there something we experience at the same moment of it happening?

Not to derail us, but proprioceptive information is not instantaneous, either.

[Function]

Not to derail us, but proprioceptive information is not instantaneous, either.

 

Ergo, "moments after"

[Janus]

I don't have a problem with the case where acceleration is involved. It's the case where acceleration is removed by the third twin that I struggle with.

With the "Three brothers" scenario there is no way to arrange things so that all three brothers ever are the same age at the same time according to all three "brothers"

 

For example, say we have three "brothers" Blue, Green, and Red. Green leaves Blue, meets Red, transfers his clock reading to Red and then Red travels on to blue.

Below is the space-time diagram for Red's frame. We assume here that according to Red, His, Green's, and Blue's clock all read 0 at the moment Green leaves Blue. Red and Green's velocity with respect to Blue is 0.5c

As he proceeds towards Blue, both Blue's and Green's clock's tick slower than his, with Green's clock ticking the slowest.

When he meets up with Green, Green's clock reads ~3.46, and Blue reads ~5, while Red's own clock reads somewhere around 5.75. After that I show two time readings on his world-line. One is what his clock would have read if not adjusted, and the other what it reads if set to match Green's clock.

Red continues on and meets up with Blue when Blue's clock reads 8, his non-adjusted time is a bit more than 9 and his adjusted time is ~6.92. Green's clock at this moment is between 5 and 6.

 

Now we consider Blue's frame:

Again, Green leaves Blue when both clocks read 0, however, at this moment, Red's clock already reads somewhere between 2 and 3. After this, Both Red's and Green's clock tick slow at the same rate. Once again they meet when Green read 3.46 and Blue ~5.75. However, in this frame Blue reads 4 at this moment.

Things continue on and Red meet up with Blue when Blue reads 8, Red's non-adjusted time is 9+ and his adjusted time is ~6.92. Green's clock at this moment also reads ~6.92.

 

Finally we consider Green's frame:

 

Green and Blue separate when they both read 0, just as in the other two frame. But now Red already reads between 3 and 4.

Both Blue's and Green's clocks tick slow, with Red's clock ticking the slowest.

But as in the other frames Red meets up with Green When Red reads ~3.75 and Green reads 3.46, and meets up with Blue when Blue reads 8 and his non-adjusted time is 9+ and his adjusted time is 6.92. According to Green, his own clock reads between 9 and 10 when this occurs.

 

Each frame measures the other two clocks as ticking slower, but everyone still agrees as to the respective times on clocks when they meet.(and it is only when two clocks meet that everyone will agree as to their respective readings.)

 

The thing with Relativity is that you can not treat space and time as completely separate entities, But instead two aspects of a larger whole called space-time.

To draw an analogy, space-time is like a box with space and time being the width and length of the box. The point being that If I look at a box I might see its width as being 3 in and its width as 4 in. However, some looking at this same box from a different direction would say that it is 4 in wide and 3 in long.

In the same way two observers measuring the same region of space-time, and which have a relative motion relative to each other will measure a different temporal and spatial separation between two events. They are measuring the same space-time, but from different perspective.

 

So for example, if you have a clock on the Earth and one 1 light hr away as measured from the Earth, and according to the Earth, both its own and that removed clock both read 12:00 at the same time, then in the Earth frame the two events of the Earth clock reading 12:00 and the remote clock reading 12:00 are separated by 0 in time and 1 light hr in space.

If you are flying past the Earth towards the remote clock, then according to your measurements, the remote clock will be less than 1 light hour from the Earth and the remote clock will read some time after 12:00 when the Earth clock reads 12:00. You will measure the spatial separation between the events of the two clocks reading 12:00 as being smaller and the temporal separation as being larger.

 

Relativity required a re-think about the very nature of time and space, and it is not always easy for people to re-adapt to this new way of thinking about them. This is likely why you are struggling. You are trying to make Relativity conform to a model of time that is not compatible with the theory.

[Strange]

Not to derail us, but proprioceptive information is not instantaneous, either.

And can arrive hundreds of milliseconds after the visual signal. The brain does a great job of tricking you into thinking it all happens "now".

[Function]

And can arrive hundreds of milliseconds after the visual signal. The brain does a great job of tricking you into thinking it all happens "now".

 

Tricking itself.

[JohnLesser]

 

 

His clock falls behind. (And note that twin 1's clock falls behind twin 2 as well.)

 

"Falls into the past" has no meaning.

Contradictory, if his clock falls behind he will measure 2016 while the faster measurement measures 2017. How is that not in the past?

Are thoughts the only things we perceive instantly?

 

If I move my finger, it moves itself at a certain moment. Proprioceptive information on the movement and location of my finger, arrive in my brain moments after the finger has moved / initiated movement or was at the certain location. Visual information on my finger (me looking at it) is coming in later, sensitive information (my finger feeling something or nothing) is coming in later.

 

Then is there something we experience at the same moment of it happening?

Are you trying to say that from the present to the immediate future is an increment so small it is fractionally 0t?

Edited April 3, 2017 by JohnLesser

[Function]

Contradictory, if his clock falls behind he will measure 2016 while the faster measurement measures 2017. How is that not in the past?

Are you trying to say that from the present to the immediate future is an increment so small it is fractionally 0t?

 

I'd say that I'm not scientifically gifted enough in physics to state something like that and dare to take the risk of being eaten alive by the physicists here.

 

However, if that seemed as what I'd wanted to say - sounds good; yup, exactly what I'm trying to say.

Edited April 3, 2017 by Function

[JohnLesser]

 

I'd say that I'm not scientifically gifted enough in physics to state something like that and dare to take the risk of being eaten alive by the physicists here.

 

However, if that seemed as what I'd wanted to say - sounds good; yup, exactly what I'm trying to say.

What an interesting notion you have. The smallest increment we have is a Planck length and Planck time, do you mean something like that?

An interesting notion by our friend and adding some ''workings'' to what he said by what I deem he was saying.

 

The immediate future is 5.39 × 10⁻⁴⁴ s away.

 

Hmmmm, I wonder if that would be absolute time like Newton believed?

Edited April 3, 2017 by JohnLesser

[studiot]

@John Lesser

 

I see you are quite unable to address my comments.

[JohnLesser]

 

I am not interested in your squabble with others here, but I am disappointed in your total disinterest in my (only) post#109 before this one.

 

Eddington was the first man to articulate that there is no 'Universal Present', even if he was not the first man to realise this.

(Faraday was the originator in his famous letter deposited with the Royal Society March 12th, 1832

 

 

An observer at one point in the universe will record a different 'present' from the 'present' recorded by an observer at any other point.

 

Einstinian relativity is not necessary to understand this.

 

I am trying to dig out the Eddington reference for you, where he develops this idea very clearly.

Was awaiting reference.

[studiot]

Was awaiting reference.

 

Do you not read your own thread? This one is not quite 2 days old.

 

There were references in both my posts, which were quite recent.

 

I could feel quite insulted.