Time Travel - Possibility and Speculation

In summary, the conversation revolves around the possibility of time travel and the various theories and methods proposed for achieving it. Some believe that traveling to the future is possible, but not to the past due to the linear nature of time and the laws of thermodynamics. Others discuss methods such as cryogenics, relativistic flights with wormholes, and closed timelike curves. However, it is also suggested that if time travel were possible, we would already know about it. Some also mention conspiracy theories and a website discussing Einstein's theory of relativity in relation to time travel.
  • #71
The model for spacetime is not mine alone; it is the model generally accepted by contemporary physicists. In the model, t does not stand for time--unfortunately, that is what most people get confused about and where they go wrong--it stands for the rate of time (or change) observed in a system at the points x,y,z. Therefore it will not always be zero, and instead must always be greater than 0.

What you are referring to is that "now" equals zero on a time line where negative t is the past and positive t is the future and it is always now--this is correct, but it's not what I was clarifying.
 
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  • #72
it stands for the rate of time (or change) observed in a system at the points x,y,z. Therefore it will not always be zero, and instead must always be greater than 0.
But doesn't that put time on par with velocity, or better acceleration ?

I never did like the 4 dimensional model. I think the idea of a universe that has 3+1 dimensions is far better.
Where there are 3 spatial dimensions and one virtual dimension. The virtual one being time, and in stating that it is virtual means that it doesn't really exist, but is there to cater for our human perceptual needs.
 
  • #73
It need not be only acceleration because gravitational propagation is finite, and so even when an object travels at constant velocity it is running into more of its own propagating gravity towards the direction of motion than in the direction away. It would seem that the rate of time (or change) experienced is a result of gravitational forces alone, but this is rather limited thinking. Perhaps there is another phenomenon that also hinders change in a system and if discovered would make our calculations that much more precise. It is kind of like the precision gained by adding in the effects of gravity to objects of relatively high velocities instead of relying on Newton's equations. A new, mitigating factor of time would make Einstein's equations even more precise. Of course, gravity could just be the first and final factor--time will tell.

The relation is time and gravity, not just time and velocity. This is because an object with velocity is experiencing an increase in gravitational forces (it's running into its own propagating gravity waves.) And, of course, another way for the rate of time in a system to change is for the system to be surrounded by a relatively strong gravitational field. Both methods for accelerating time are based on the force of gravity and its ability to more or less hinder change in a system.

Yes, I agree with you that time is only an abstraction, human or otherwise.
 
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  • #74
Here's a link to my http://gamert.co.uk/Theory/GT-page-1.htm
It contains, amongst other things, a single explanation of why the rate of time changes with respect to gravity and velocity.
 
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  • #75
It's about time someone explained it; keep up the good work.
 
  • #76
I assume from your reply that it makes sense.

The theory does remove the link between time and gravity, replacing it with a far simpler basis, that of the energy of a mass and how that energy interacts.
 
  • #77
As I get older, time "seems" to speed up
A 3 month summer at age 12 after school let out "seemed"
to be a long time, but now 3 months seems like nothing.
HMMM? Any thoughts on this?
 
  • #78
Exponential growth of time ?

Population growth is exponential.
Radioactive decay is inverse exponential.

Exponential growth appears in nature very often.
 

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