Michel's Q.s about time co-ords - Split from "what is time?"

[Strange]

What is contradicting Relativity?

 

You. That is how we know you are wrong.

[michel123456]

 

You. That is how we know you are wrong.

Where am i contradicting Relativity?

[Strange]

Where am i contradicting Relativity?

 

Almost everywhere, from your misrepresentation of light comes to your model of time.

[michel123456]

 

Almost everywhere, from your misrepresentation of light comes to your model of time.

That is strange.

 

Light cones are diagrams that come from Relativity.

 

I may be misinterpretating something.

 

 

I begin with 4D spacetime continuum. that is relativistic stuff.

I begin with SOL as a constant. that is also relativistic stuff.

 

Then i say that we cannot observe directly the inside part of the light-cone.

if you don't like that, I can drop it. Anyway you will agree that the outside part of the light cone is not directly observable. that is not contradicting relativity as far as i know.

 

Then i say that particles change coordinates in 4D continuum.

You and many other disagree. Anyway i do not see where my position contradicts Relativity.

 

 

 

 

Where am I so wrong?

[MigL]

You also say they vacate previous coordinates.

GR says they do not.

 

As a matter of fact, GR being classical, says future co-ordinates are populated also.

[michel123456]

You also say they vacate previous coordinates.

GR says they do not.

 

As a matter of fact, GR being classical, says future co-ordinates are populated also.

I don't think GR says that. Otherwise Einstein couldn't question the existence of time itself.

it is an interpretation.

Of philosophical nature according to Swansont

[MigL]

You don't think it does, or, you know ?

[david345]

You can receive signals from anything in your past light cone. The moon 1 hr ago the moon 10 hrs ago. You can send signals to anything in your future light cone. You can not send signals to your past cone. You can not receive signals from your future cone. I asked you how is Krikalev standing on our planet. He is .02 sec behind us and according to you particles travel through time at the same speed. A second per second. Why hasn't earth vacated that position?

[michel123456]

You can receive signals from anything in your past light cone. The moon 1 hr ago the moon 10 hrs ago. You can send signals to anything in your future light cone. You can not send signals to your past cone. You can not receive signals from your future cone. I asked you how is Krikalev standing on our planet. He is .02 sec behind us and according to you particles travel through time at the same speed. A second per second. Why hasn't earth vacated that position?

 

I don't disagree with the bold part.

 

I haven't said that "particles travel through time at the same speed. A second per second.". I said particles change coordinates.

It baffles me that we disagree on what motion is. Motion, classically, is a change of spatial coordinates. Velocity is a change of spatial coordinates in relation to time coordinates. The concept that says that particles extend through the time dimension like spaghettis is outside the concept of motion. IMHO.

 

The Krikalev argument is unaccurate, he hasn't travel in time the way you say he has. He has been time dilated.

[david345]

The Krikalev argument is unaccurate, he hasn't travel in time the way you say he has. He has been time dilated.

It is you who is misinterpreting a quote you found on a Wikipedia page. Are you trying to say time has not slowed for Krikalev? Are you saying 6pm in our time is also 6pm in Krikalev's time? Did you actually go to the Wikipedia page on time travel? The page uses this type of dilation as an example of of time travel into the future.

 

The Wikipedia page on time travel:

 

"This form of "travel into the future" is theoretically allowed (and has been demonstrated at very small time scales) using the following methods:[30]

 

Using velocity-based time dilation under the theory of special relativity, for instance:

Traveling at almost the speed of light to a distant star, then slowing down, turning around, and traveling at almost the speed of light back to Earth[59] (see the Twin paradox)

Using gravitational time dilation under the theory of general relativity, for instance:

Residing inside of a hollow, high-mass object;

Residing just outside of the event horizon of a black hole, or sufficiently near an object whose mass or density causes the gravitational time dilation near it to be larger than the time dilation factor on Earth."

[michel123456]

It is you who is misinterpreting a quote you found on a Wikipedia page. Are you trying to say time has not slowed for Krikalev? Are you saying 6pm in our time is also 6pm in Krikalev's time? Did you actually go to the Wikipedia page on time travel? The page uses this type of dilation as an example of of time travel into the future.

 

The Wikipedia page on time travel:

 

"This form of "travel into the future" is theoretically allowed (and has been demonstrated at very small time scales) using the following methods:[30]

 

Using velocity-based time dilation under the theory of special relativity, for instance:

Traveling at almost the speed of light to a distant star, then slowing down, turning around, and traveling at almost the speed of light back to Earth[59] (see the Twin paradox)

Using gravitational time dilation under the theory of general relativity, for instance:

Residing inside of a hollow, high-mass object;

Residing just outside of the event horizon of a black hole, or sufficiently near an object whose mass or density causes the gravitational time dilation near it to be larger than the time dilation factor on Earth."

So you say that in the twin paradox, when the twins meet, they are not meeting simultaneitly? The one is in the future of the other?

I don't think so. Simply they have aged differently. When they meet, they meet. That's what a meeting is.

[imatfaal]

So you say that in the twin paradox, when the twins meet, they are not meeting simultaneitly? The one is in the future of the other?

I don't think so. Simply they have aged differently. When they meet, they meet. That's what a meeting is.

 

Agree with Michel - a meeting is an event with a coincidence of spatial and time coordinates (in whichever coord system you choose). David's post seems to posit some form of absolute time such that the stay at home twin is inherently on 18:00:00 and the adventurer is on 17:59:58; whereas it is just that their watches vary by two seconds because the time of the adventurer has been dilated. If we are talking time-travelling - both twins have travelled in time; the stay at home has travelled solely in time and the adventurer has travelled in some space so he has travelled through less time

[david345]

Agree with Michel - a meeting is an event with a coincidence of spatial and time coordinates (in whichever coord system you choose). David's post seems to posit some form of absolute time such that the stay at home twin is inherently on 18:00:00 and the adventurer is on 17:59:58; whereas it is just that their watches vary by two seconds because the time of the adventurer has been dilated. If we are talking time-travelling - both twins have travelled in time; the stay at home has travelled solely in time and the adventurer has travelled in some space so he has travelled through less time

Can you demonstrate that if they both traveled along their world lines at the same speed they would meet up. This would be according to Michaels claims. They would vacate previous positions and not occupy future positions. Is their world lines the same length from the beginning of the journey until the end? Edited December 16, 2014 by david345

[phyti]

Can you demonstrate that if they both traveled along their world lines at the same speed they would meet up. This would be according to Michaels claims. They would vacate previous positions and not occupy future positions. Is their world lines the same length from the beginning of the journey until the end?

If they separate and later rejoin, both could not have maintained the same speed for the trip.If you use a Minkowski drawing, which shows the speed profile or history of each, it demonstrates why the shape of each profile determines the elapsed time.

Edited December 16, 2014 by phyti

[david345]

If they separate and later rejoin, both could not have maintained the same speed for the trip.If you use a Minkowski drawing, which shows the speed profile or history of each, it demonstrates why the shape of each profile determines the elapsed time.

The Minkowski drawings can be misleading. The space time interval is s^2=x^2-(c^2t^2) For c the interval would be 0. The traveling twin had a shorter interval. In the Minkowski diagram the twin on earth would appear to have the shorter world line. The straight world line is actually the longer line. The traveling twin would have a shorter world line between the start of the journey and the end. Michael describes the world line as a train track and the particle as a train. The end of the journey is where the tracks intersect. If both trains are traveling at the same speed then they should not meet at the intersection at the same meta time. The traveling twins path is shorter. Edited December 17, 2014 by david345

[phyti]

The Minkowski drawings can be misleading. The space time interval is s^2=x^2-(c^2t^2) For c the interval would be 0. The traveling twin had a shorter interval. In the Minkowski diagram the twin on earth would appear to have the shorter world line. The straight world line is actually the longer line. The traveling twin would have a shorter world line between the start of the journey and the end. Michael describes the world line as a train track and the particle as a train. The end of the journey is where the tracks intersect. If both trains are traveling at the same speed then they should not meet at the intersection at the same meta time. The traveling twins path is shorter.

It’s misleading when misinterpreted as a 2D roadmap, and viewing the longer world line as the x=vt relation, when it should be the t=x/v (inverse) relation. Even without relativistic effects, and all other factors equal, the faster clock will reach the target showing LESS time.