Velocity/Gravitational Time Shift

[Mytical]

If I am understanding this correctly, the greater the gravity the slower time progresses for things and people. The higher the velocity also has this phenomenon. I need a smarter person then me though, to see if I am anywhere near accurate in my understanding of these phenomenon.

Basically here is how I understand it. Somebody in space would age faster then somebody on earth (slightly) if they have zero velocity. Something traveling MUCH slower then something else would also age faster if there is no gravity difference.

So, something traveling much faster and having a higher gravity would age a bit slower. So theoretically if we could figure out how to increase gravity on a space rocket, the people inside would age much slower then us on earth. Which explains the phenomenon of time dilation of a black hole.

The forces are not equal, however. Velocity affects time greater then gravity does (again if I am understanding it correctly). So the faster we can make said rocket go, the less time would affect anybody inside. Also, of course there would be a maximum gravity that the people would be able to withstand.

What I am thinking is this, however. If we could increase the gravity inside one of our 'space ships', we could travel further and further distances before said people would die of old age.

It would take a lot of time and preparation, but we could also increase how much gravity a person could take by finding a way to increase gravity in a specific area, doming it off, and having people start living there. Each generation, increase the gravity slightly, and people would then be able to survive higher gravity.

So.. am I understanding the phenomenon right? Or am I way off?

[Dakhur]

I believe that's the theory, but you know what? I don't think that's how it works. Time passes at a constant rate, but velocity changes. There was a single experiment done that showed something like a millionth of a second lost by an atomic clock. But it's never been repeated and verified.

But then, I'm a weirdo who doesn't believe in the 'galactic speed-limit' either. We know there are particles that cannot travel slower than light, and we know that light goes at different speeds in various guises, so why do we accept this mystical limitation? It's just a speed of a certain particle.

[HYHYBT]

Starting with the small problems first...

Gravity we can survive even for brief periods isn't going to affect time enough to have practical effects anyway, much less gravity weak enough we could actually carry on lives.

If you want to modify people for stronger gravity, evolution isn't going to cut it. First, because it requires a long enough time scale for the relevant mutations to develop, which is especially counterproductive since you're proposing doing it to save time, and second because you have to keep killing off the individuals least suited to the new conditions. Some combination of surgical implants and genetic engineering would be more practical. Except you still won't get to the point where normal life carries on under gravity strong enough to alter time enough to bother. For what you're proposing, you want Lamarckian evolution, which is inconveniently nonexistent.

And now the biggie: gravity is acceleration, not velocity. Making humans better able to handle high gravity would mean being able to get to the maximum speed more quickly, but it wouldn't affect what that speed would be. And when you're talking about interstellar distances, again the time saved by speeding up and slowing down quicker at the very ends of the journey isn't going to be all that much, just as, if you're going to be driving for hours at 70 MPH on the open freeway, flooring the gas pedal as soon as you hit the ramp instead of speeding up normally doesn't get you to your destination noticeably faster.

[Gravekeeper]

There was a single experiment done that showed something like a millionth of a second lost by an atomic clock. But it's never been repeated and verified.

On the contrary, many experiments have been done and the is always observable. The clock on a space shuttle will run slower than the reference time on Earth. Not by any significant amount mind you, but they still do. GPS satellites have to compensate for time dilation. Time will actually dilate just when you're driving at highway speed in a car. Its just by such an incredibly small margin its of no consequence. For the ISS crew, every 6 months they spend on the ISS they are 0.007 seconds younger than they would be if they were on Earth.

Both velocity and gravity will cause time dilation. But they are opposing forces in space. Increasing velocity and gravity will both slow time relative to an observer. But seeing as gravity decreases when you get off planet while velocity increases, they work against each other.

The amount of gravity required to have an appreciable effect on time between you and an observer would absolutely destroy you. You would need a mass several times that of Jupiter sitting on top of you. To say you would be paste is an understatement. Even if we could produce that kind of mass and energy.

And that's before we even get into the mind fuckery that time is effectively an illusion and that the past, present and future co-exist. Your entire life currently exists from birth to death, but you as the observer can only observe it from one point that you call the present.

But then, I'm a weirdo who doesn't believe in the 'galactic speed-limit' either. We know there are particles that cannot travel slower than light, and we know that light goes at different speeds in various guises, so why do we accept this mystical limitation? It's just a speed of a certain particle.

"Mystical limitation"? Uh. >.>

The speed of light through a vacuum is a universal physical constant. It can be slowed down, yes. But the reason we can use it as a measurement ( hence light years ) is because its a universal constant. It's not that we "accept" a mystical limitation, its that its a hard limit we cannot break and have never observed anything in universe so far being able to break.

Yes, its possible for things to give the illusion they are going faster than the speed of light. As is the case with some of the quirkier shit in quantum physics. However, its an illusion. Information can not be transmitted faster than the speed of light. For example, its theoretically possible to use quantum tunneling to have a particle go faster than the speed of light. However, no information or signal can exceed light speed. So the resulting particles are virtual.

This is why we're seriously beginning to bank on stuff like warp drives. We can't break the rules, so we need to find a way to bend them. Which is the entire point of the conception of the warp drive as an excuse to travel faster than light in sci-fi.

Other possibilities are using wormholes. But wormholes are not naturally stable so that kind of bones us there without some major major technological leaps. If we did have a stable one it would be a point A to point B trip. Period.

[Mytical]

And now the biggie: gravity is acceleration, not velocity.

The force that affects time is velocity however. The title was meant as an either or ... not an Gravity = Velocity.

[Gravekeeper]

Whoops, I didn't really directly answer your question did I, Mystical? Sorry. >.>

It would take a lot of time and preparation, but we could also increase how much gravity a person could take by finding a way to increase gravity in a specific area, doming it off, and having people start living there. Each generation, increase the gravity slightly, and people would then be able to survive higher gravity.

The problem is that the amount of gravity required to cause significant time dilation would simply crush any and all matter. Its not something we could survive even with genetic engineering. You're also kind of approaching this ass backwards ( no offense ). It would be much easier and more feasible to simply extend the human lifespan than to try and manipulate time dilation. Seeing as we're getting alarmingly close to simply being able to switch off aging at a genetic level we don't have any real need for time dilation.

To give you an idea, in order to achieve even a 1 year shift in gravitational time dilation ( as in you move ahead 2 years for every 1 year of those outside of the field ), you would essentially need to be beneath a mass equal to something like 72 Jupiters. You would be sub-atomic paste.

The real problem with space isn't time, its that practically everything else in it would be bombarding us with lethal levels of radiation. This is why something like a Bracewell probe is more likely to be what out first contact with another alien species involves.

A Bracewell probe could be sitting anywhere in our solar system just waiting for us to get smart enough to be worth talking to. Our ability to detect small objects within our own solar system is actually horrible both due to too much and too little light. Anything remotely near the sun and the glare basically obscures it. Anything too far away we'd never know it was there because its not reflecting enough light.

Its actually sort of amusing. The closer you get to Earth, the worse the visibility. We can spot a star millions of light years away, but if the USS Enterprise was cruising around our solar system we'd never see it unless it went out of its way to park next to the ISS.

[Mytical]

Ah, so I was understanding correctly then (which was the aim of this, to make sure I understood correctly and was not somehow getting it backwards). Interesting. Yes we will solve the velocity portion a long long time before the gravity portion. Even velocity, however, has a limited amount (though a much higher limit).

Even with being correct about this, however, the experiment I suggested would fail as we would have other methods long before we were able to withstand the increased gravity. Interesting. So we wait until we can download our conscience into robot bodies then

[TheHuckster]

The thing that always blew my mind about relativistic physics is not the idea that space and time are sort of two sides of the same coin, nor that light travels in a vacuum at a constant speed, nor that it has the ability to make you age less than your twin sibling, but that physical information travels at that speed as well.

...meaning, let's suppose the sun flat out disappeared. It didn't turn into a black hole, or went supernova, it just *boink* disappeared. This would obviously have a grave impact on its happily rotating planets that all of a sudden no longer have a maypole to dance around.

The planets, however, would not react to this sudden gravitational difference until that "information" (traveling at the speed of light) has reached them. In other words, from your perspective as an earthling, you'd see the sun disappear and immediately thereafter find yourself suddenly getting thrown about by the sudden difference in velocity the planet will experience.

I would have expected it to be more like, because the sun disappeared, the planet would immediately react to this change (i.e. you feel the effects of the disappearance but looking up, the sun is still there, the lack of light just hasn't reached you yet), but instead the planet doesn't even "know" its own fate yet... if the speed of light were, say, 1,000,000 times slower, the sun could disappear today and we wouldn't ever know it or even feel its effects until 15 years from now.

For some reason, that's the part that blew my mind when taking physics classes. As far as Einstein is concerned, that is why faster-than-light speeds are unattainable, because even if you could push your rocket a fraction faster than light (or information) then you would cease to exist in that frame of reference, and the universe would BSOD... or something like that.

Quantum mechanics, of course, change the game a bit in odd ways (and, so far, only across distances measured in planck lengths), but if the above manages to blow my mind, I'm not sure what would happen if I really studied Quantum Theory with any level of seriousness.

[Gravekeeper]

Ah, so I was understanding correctly then (which was the aim of this, to make sure I understood correctly and was not somehow getting it backwards).

You had the basics right, yeah. An increase in velocity or gravity will cause a time dilation and "slow" time for the one experiencing relative to an observer. The problem is it requires such a large increase and so much energy that its outside of our capabilities and in the case of gravity, our suitability.

The ISS for instance is travelling at 7.7 km a second around the Earth and that only nets them a 0.007 second time dilation relative to Earth.

Space time is a weird thing that way. Like I was saying, all time effectively co-exists because of it. A small shift on our side of the universe becomes a massive one by the time it reaches the other side. So someone sufficiently far away from us can co-exist with our past, present or future just based on what direction they're walking in relation to us. The minor dilation brought about by velocity is negligible locally but is equal to decades, centuries, etc once you take the distance into account.

Hence, as I was saying, your past, present and future all effectively exist at the same time. Because to someone, somewhere, they are are the present. The only thing changing is the point at which it is being observed.

Think of your life as a movie you're watching on TV. Everyone on Earth is in the same living room as you so if they turn to watch the movie, they see the same point in the movie as you do. But, the movie already exists as a whole start to finish. If someone on the other side of the universe watches your movie on their TV, they can freely fast forward or rewind it just by making minuscule changes in their velocity such as walking towards or away from the TV.

Their present co-exists with your past or future. Conversely, your present co-exists with their past or future. So the past, present and future are effectively all existing at the same time. Everyone is just perceiving it at different points. Our consciousness can only perceive the immediate part of the movie. So we think time is linear because we can't perceive it otherwise.

In fact, technically speaking, we can't even perceive the present. Biologically speaking, the brain actually has processing lag. There's a hang time between sensory input and the brain being able to translate it into understandable information. What you see, feel, hear, smell, etc right this very moment is actually the past. Its already happened. Your brain actually has a taped delay.

If you need any more reasons to have an extensional crisis, I'll be here all week. >.>

Even with being correct about this, however, the experiment I suggested would fail as we would have other methods long before we were able to withstand the increased gravity.

Well, the problem with the experiment is the gravitational force required to even create a 2:1 dilation ratio is equal to balling around a black hole. So we would need technology capable of withstanding the tidal force of a black hole.

Interesting. So we wait until we can download our conscience into robot bodies then

Trans-humanism is likely our best bet, yes. Especially given that an AI or a trans-human would be able to manipulate their own perception of time and fast forward through all the boring interstellar travel parts.

[TheHuckster]

Think of your life as a movie you're watching on TV. Everyone on Earth is in the same living room as you so if they turn to watch the movie, they see the same point in the movie as you do. But, the movie already exists as a whole start to finish. If someone on the other side of the universe watches your movie on their TV, they can freely fast forward or rewind it just by making minuscule changes in their velocity such as walking towards or away from the TV.

I believe you can't rewind the TV using relative physics (unless you are traveling above the speed of light) but merely slow down its progression asymptotically towards "pausing" it.

[lordlundar]

Somebody in space would age faster then somebody on earth (slightly) if they have zero velocity.

Just have to make a point here. What you are describing is (given current knowledge of astrophysics) impossible due to the necessity of overcoming gravity. Despite it being the weakest of the four universal forces, it also has the largest range of at current no known limit. To establish an orbit around Earth requires a velocity to supply enough centripetal force to overcome the force of Gravity pulling you back down as an example.

Now considering that Gravity is (at current theory) infinite, regardless of where you are in space you are overcoming some form of gravitational pull somewhere in the universe which means you are traveling at some velocity.

[Gravekeeper]

The thing that always blew my mind about relativistic physics is not the idea that space and time are sort of two sides of the same coin, nor that light travels in a vacuum at a constant speed, nor that it has the ability to make you age less than your twin sibling, but that physical information travels at that speed as well.

Yep. That's why even though we can theoretically use quantum tunneling to have a particle exceed the speed of light it does us no good. Because information itself is literally speed capped. So the resulting particle that comes out the other side is virtual.

The only way to bypass this would be to use quantum entanglement to simply ignore distance all together.

The planets, however, would not react to this sudden gravitational difference until that "information" (traveling at the speed of light) has reached them. In other words, from your perspective as an earthling, you'd see the sun disappear and immediately thereafter find yourself suddenly getting thrown about by the sudden difference in velocity the planet will experience.

Well, technically there wouldn't be a sudden difference in velocity like that. The planet's velocity doesn't actually effect us like that. We're within its gravitational field. But space is missing that friction thing. The Earth is hurdling and spinning through space right now at hilariously absurd speeds.

Granted, we will have WISHED it was a sudden horrible death. Because what follows would be a slow, horrible death. Even if we somehow managed to survive without a parent star, without the sun's gravity well the planet's gravity wells would be freely pulling on each other. So after the Moon fell on us we would get to enjoy a slow, terrible ride towards Jupiter while Jupiter sling shotted asteroids in every direction. If we got really lucky, Jupiter would throw Mars at us for lawls. If we were really lucky, rather than crashing into Jupiter it would just fling us out of the solar system all together and we would hurdle through space as a frozen, lifeless rogue planet for eternity. ;p

Jupiter is an asshole you know. Neptune for instance use to be an inner planet until Jupiter and Saturn flung it out with their gravity wells.

because even if you could push your rocket a fraction faster than light (or information) then you would cease to exist in that frame of reference, and the universe would BSOD... or something like that.

Frankly, I think quantum physics IS the universe's BSOD screen judging from what I know of it. >.>

[TheHuckster]

Well, technically there wouldn't be a sudden difference in velocity like that. The planet's velocity doesn't actually effect us like that. We're within its gravitational field. But space is missing that friction thing. The Earth is hurdling and spinning through space right now at hilariously absurd speeds.

I'm referring to the difference in angular momentum. Earth is currently following an elliptical path. No more object to orbit, and it suddenly becomes a straight line, not to mention whatever solar tidal forces would suddenly cease. I think the effects of such a sudden change would be catastrophic to life on Earth.

Frankly, I think quantum physics IS the universe's BSOD screen judging from what I know of it. >.>

True enough. I think it's more like just a giant cosmic "Fuck you, we're going to change the rules now" to the scientists who started building microscopes powerful enough to look that deep into the tiny nooks and crannies of the universe.

[Gravekeeper]

I believe you can't rewind the TV using relative physics (unless you are traveling above the speed of light) but merely slow down its progression asymptotically towards "pausing" it.

You're not actually rewinding it as in rolling time back, just changing your viewpoint as an observer. Think of it as an angle of view. Up close the angle is very narrow, you only see the present. But the further you get, the wider the possible angle. So the angle of view of someone on the other side of the universe encompasses our past, present and future. The further away they are, the wider the scope of time they could feasible "view".

I'm referring to the difference in angular momentum. Earth is currently following an elliptical path. No more object to orbit, and it suddenly becomes a straight line, not to mention whatever solar tidal forces would suddenly cease. I think the effects of such a sudden change would be catastrophic to life on Earth.

Well yes, but it the sudden change wouldn't do much in the short term. The gravity well would dissipate at the same rate as the speed of light as gravity propagates at the same speed so it would take around 8 minutes or so to completely lose its gripe on us. Each planet would lose its grip on the merry-go round in order and fly off in a straight line unless drawn by another gravity well. Solar tidal forces aren't significant enough to cause us massive damage in the short term though me thinks. Losing the moon or having it crash into us would suck immensely however.

The problem would be where each planet was at the time it got off the ride. Jupiter has the next largest gravity well in the solar system after the sun and its moving slower than we are and we'd get an hour or so head start before it lost the sun's gripe. Plus there's the abject chaos that would be the asteroid belt. Also the inner planets will be flying out faster than we are. Everything would be cancer and madness.

Best case scenario we get out of the solar system and then slowly die a cold and horrible death. Worst case scenario we hit or get hit by something significantly large and all die screaming.

[HYHYBT]

I'd think we'd die directly from lack of the sun before we'd make it out of the solar system, even if we got "lucky" and didn't hit anything on the way. At least we'd know there was no point in going to great lengths to keep on.