Spatial Relativtiy and Time Dilation

[Dan3345]

So I love a good sci-fi book, and I have been reading "The Forever War" which if you are of a mature age I strongly urge you to read, as its very much what I imagine warfare will be like in the next several hundred years. And anyways a major ploy within the story is the main character coping with time dilation. Basically he gets in ship to fight an alien menace thousands of lightyears away and while he is only gone for months or years at a time the Earth advances by several hundred years. Or just by thirty depending on how long he and is company are away.

 

While I didn't create this topic to discuss the book I did create it to discuss the science. I want to know what you guys think about it, because I am not going to lie, I am a huge dork and the implications of this to me are astounding. And its not the book that got me interested in this, I have been studying physics, particularly theoretical physics on my own for years. Sort of a hobby I guess you could say.

 

So any other dorks out there on the nexus that just drool over this kind of stuff?

[AliasTheory]

I've known about Einstein's theories of relativity, antimatter and the many properties that things apparently undergo at near light speeds for while, but only due to books written specifically about physics. The implications are very astounding, and even more so when you do the derivations and calculus.

 

If you haven't already, it might be of interest to you to look at the quantifications of special relativity, too. Special relativity is actually fairly easy to understand and can be grasped with some elementary calculus; general relativity is much more complex, since you can have accelerating systems. The calculations for special relativity aren't very tough at all. They are all very much related by a value which allows the laws of classical physics to remain intact at lower velocities, but creates the crazy exponential curve at high values (.8c, etc.) It's usually designated by the following: gamma = (1-(v/c)^2)^(-.5))

 

In addition to time dilation are length contraction (only in the direction of the applied velocity, which becomes a much simpler problem when you orient your 2D plane correctly,) "relativistic mass" (Einstein didn't like that term) and the many principles of energy that come with conserving momentum. The Law of Conservation of Energy can even be violated on a small enough scale! It's like everything everyone told you before was a lie (at least for me.)

 

Anyway, a good place to start would be Lorentz Transformations for those who are looking into the math. The famous Twins "Paradox" will illustrate the proper use of special relativity.

Edited January 26, 2012 by AliasTheory

[REZ01]

I've been following "quantum entanglement". not so much just the news, but what agencies have put funds into the study.. Pretty interesting stuff

[Dan3345]

Yeah guys, the stuff is very fun to read about. Really makes you think. Once you I understood time dilation I felt really weird because the answer to me seems so outrageous. Makes the whole world feel strange. Like its just so odd.

[Thor.]

Meh over at cern they have already went faster then the speed of light. it brakes the laws of relativity

 

http://www.telegraph.co.uk/science/8782895/CERN-scientists-break-the-speed-of-light.html

 

it needs to be rewritten

Edited January 28, 2012 by Thor.

[AliasTheory]

Meh over at cern they have already went faster then the speed of light. it brakes the laws of relativity

 

http://www.telegraph.co.uk/science/8782895/CERN-scientists-break-the-speed-of-light.html

 

it needs to be rewritten

Oh yes, I heard about that. The implications of that are very interesting, through Special and General Relativity right now seems to model some situations well. Take GPS, for example.

 

The theory needs to be rewritten, but perhaps not entirely.

[nosisab]

To fully understand the issue you need to think not in time and space but they create a net, an interval properly named space-time. This was probably the first interval to be deeper understand by physics for things don't "slide" inside the interval, is more like a "dragging" ... the formant (in the case time and space) reacts complementarily to changes in specific bodies speed (which is related by distance over time) what reflects in turn over other intervals less "known" as matter-force.

 

We are trained by intuition or teaching that matter and forces are independent entities but that is not the case even when locally the relation is imperceptible.

 

The resultant is the (in)famous concepts of time dilation and mass growing and not restricted to these, when the intrinsic body velocity is shifted hard from it's equilibrium point. That intrinsic velocity must not be confused with the relative speed of a body toward a reference point, so when the body is accelerated near relativistic speed (as say near light speed) it experiments those distortions by the formant of the interval reaction. The same happens although the symptoms are seen differently when the intrinsic velocity nears 0 (the reason for the previous warning, it is not the same as the body being at rest) what would be the case of it nearing the absolute 0 temperature.

Edited January 28, 2012 by nosisab

[Jeoshua]

Want something relating to General Relativity (the more generally applicable version of Relativity) and Time Dilation that will REALLY blow your mind?

 

Check this out:

 

Ideas that must be accepted for mind-blowing

1. Gravity is acceleration, equivalent to actual acceleration, due to the bending of spacetime.

2. Black holes exist and exert gravity.

3. Perception of time is a constant thing, no matter what an outside observer might notice about your speed through it.

 

Falling into another universe

Or, Zeno's Event Horizon

Imagine yourself on a trip in a futuristic space craft. It is a very sturdy craft, able to withstand immense torsion and gravitational forces without breaking up, or leaking out it's precious biological components (ie. YOU). This craft that you are in is heading towards a black hole. Not directly towards it, but an oblique angle co-tangent to the event horizon, such that on your current heading, you will intersect with that event horizon at a 90 degree angle.

 

As you approach the black hole, the gravity starts pulling on the space craft. The closer you get to the black hole, the stronger this pull becomes. As you approach the event horizon, external sensors that have been launched into far orbit around the black hole tell you that you are speeding up, even as the signals you are receiving from them begin to distort and slow down. At your current rate of acceleration you should reach the speed of light at the moment you hit the event horizon.

 

But that moment does not come.

 

As you approach the speed of light, the sensors are telling you that you are traveling the same speed that you have been, plus minuscule fractions every so often. But from your own perceptions from within your space craft, you haven't sped up at all. Longer and longer amounts of time pass between the signals from the orbiting telemetry satellites which are supposed to update you on your progress. They are set to send out telemetry signals at 1 Gigahertz. Soon the signals are coming at 1 Megahertz. After a while, they have reached 1 Hertz. After much time has gone by on your side, the pulses are days apart.

 

Still you are not at the Event horizon. The space in front of you is seemingly expanding as your craft moves "forward". The space behind the craft likewise expands, so you can look behind you and see your satellites, farther away than they logically should be for how far you had to travel until you entered orbit around this black hole. At this point they appear to be almost a light year away.

 

The captain of your vessel panics at this point. All of this is not going according to plan! They attempt to alter course to move farther away from the black hole, in an attempt to get out of it's gravity and go back home to Earth. All of the sensors, observations of the dust particles ejected from your drive, and measurements of other matter which is falling into the black hole along with you show that you are, in fact, moving outward... but the satellites do not appear to be getting any closer. The captain has set his course directly for one of the satellites, but you are not approaching it at all. It's getting farther away! Dimmer. Dimmer....

 

It is at this point that you realize that the satellite's signal has stopped. You can't even see it in the normal wavelengths, and only a faint signal, far up in the radio spectrum, remains. You can't see any of the stars that you once did. Only the matter that fell into the black hole with you is detectable. A bit of quick math shows that if one were to follow the predictions, you have now reached the event horizon.

 

You have fallen into a black hole... and are still alive and well.

 

There is no more sense of where the black hole was. There is only you, your space craft, and the matter which has fallen in alongside you. Measurements by your craft's instruments show plenty of matter all around. Gases, Particles, some bits of rock. And lots of stuff, far off in the distance.

 

Training your sensors farther out you think you see a... is that...

 

A Star.

 

A course is plotted for this star. You should reach it in a few weeks. Entering into your cryo stasis pod, you find yourself drifting off to sleep wondering about what you've discovered.

 

A new universe, within a universe... and you'll never even be able to call home to tell anyone about it...

 

[END]

Edited January 29, 2012 by Jeoshua

[dazzerfong]

TIme's not a constant: even if you remove the perception component of it. We already established that with atomic clocks and flying them 'round the world.

[nosisab]

dazzerfong, think that time you described is the here-now inside the space-time. The concept of here-now sheds some more light on the phenomenon like the sun we see now and receive it's energy now in our proper here-now is the sun that was around 8min in it's own here-now. If 8min is too small time span to jump to the eyes, think the nearest star we see now is the star that was 4years ago from it's own perspective, don't stop, still more distant bodies will bring numbers we hardly can conceive, we may be able to see things from a time earth itself was not yet born.

 

Think our own here-now is what define the physical reality we live on. Edit: (Maybe I must say "... define the physical reality we perceive"). Notice how "physical reality" it is for is not only what we see but that sun that was is what "affect" us and the planet as a whole "now".

Edited January 29, 2012 by nosisab