Nope, you don’t need acceleration to get relativistic effects.
What awareness even is is a question beyond science. If you were to jump into another universe, would that be you, or would it be a person like you spontaneously being created in that universe, and the you here mysteriously disappearing? Would there be any difference in the you that was spontaneously created if the you here was not destroyed?
Observing the past is easy. You are doing so right now. If you want to see further back, look further out. If you can find some giant mirror thousands of light years away, you could look back at the earth thousands (times 2) of years ago.
If you could “solve” quantum mechanics and get rid of the uncertainty “problem” and the universe becomes both deterministic (which it might be, or it might not be, we don’t know) and determinable(not likely, IMHO), then you could look not just into the past, but into the future.
…and a real understanding of the mind, since only the mind perceives the flow of time, and is supposedly able to experience timelessness (whatever that means) in deep meditative states. We’re not anywhere close to that.
When I go out and look at the stars, I’m seeing the past. I’m seeing those stars as they existed years or decades ago. Not millions though, unless you’re using a telescope to observe stars outside our galaxy.
Now what I heard is that imagine what you have created the moment you set up that wormhole. The way wormholes are thought to work, mass entering one mouth makes the black hole on that side heavier, while mass exiting the other mouth makes that black hole lighter. (if wormholes can ever be built they probably won’t be transitable by anything but photons or a particle beam - which is just as good as being able to walk through as an intact human if you have sufficiently advanced technology)
Anyways by creating a wormhole you create a potential path for photons to go in one mouth, come out the other, travel through space, and interact with their past self. This “short circuit” happens the very instant you move the wormhole mouths enough to allow the tiniest magnitude trip to the past.
Anyways in theory this would cause so much transit traffic that one mouth of the wormhole would instantly lose infinite mass. Or, in practice, all of it’s mass.
Basically the whole thing would detonate like a mass-energy bomb.
Nah, that part is really, really easy to understand. The explanation is this: It’s meaningless bunk. It’s not even self-consistent bunk: If only the mind were able to perceive time, then everything but minds would be in a state of timelessness.
A bit of a overstatement? I meant to say that while everything is subject to the flow of time, only a self-aware mind is able to *perceive *the flow of time. In deep sleep, with the mind quiescent, time flows but with no conscious awareness to perceive it.
If a self-aware mind can perceive the flow of time, it may be able to peek into the past and future, a not exactly physical but mental time travel. Gross objects, on the other hand, simply move forward with the arrow of time.
Sorry, but I have to agree with Chronos. This is meaningless bunk.
No law of physics prevents ‘effective’ FTL travel; only FTL travel in local regions. Consider the furthest galaxies from us are moving away faster than the speed of light.
Local regions? Does that mean there’s like a minimum range?
Yes, that’s right. You have a personal future light cone; if you open a wormhole to a location within your own light cone, now-you can travel to your own future (and more importantly, future-you can travel back into your present). But if the other wormhole mouth is outside your personal light-cone, you are safe from paradox.
Clocks perceive time a heck of a lot more accurately than human minds do. And of course the human mind can (inaccurately) peek into the past and future: That’s called “memory” and “planning”. Which has nothing to do with time travel, on either count.
The subjective or personal experience of time is also a fascinating subject. For instance, we can see at least two million years into the past with the unaided eye, by looking at the Andromeda Galaxy. I’ve seem M81 through a telescope, more than eleven million years into history.
Conversely a photographer needs to photograph the future, especially if photographing fast-moving objects; if you want to photograph runners, a car race, a horse race or a bike race, you need to aim the camera where the racers will be when the shutter opens. This is slightly ahead of where your eye sees the racers, depending on how quickly the camera responds.
These two posts seem to be contradictory.
I’m confused.
Special Relativity deals with inertial frames of reference. That means no net forces, which means in turn no acceleration. The gamma function is driven by v[sup]2[/sup]/c[sup]2[/sup] not by any a variable.
Acceleration shows up in General Relativity.
It only requires velocity, not acceleration:
Side note, I recall seeing a video on the Fermilab Youtube channel about how the twin paradox had nothing to do with acceleration (which apparently was a common misunderstanding) and demonstrated that it was only the velocity that mattered.
The Twin Paradox is not actually a paradox, not in the same sense as the Grandfather Paradox. This entire discussion is about violations of causality, where you have events where the effect precedes the cause, or the effect has no cause at all. The Twin Paradox merely describes a situation where two observers in two different IRFs have different observations and there is no answer to the question of which one of them is right. So what? This does not violate causality (unless the two IRFs have a relative velocity greater than c).
So, let’s drop the word “paradox”. Sending information of any kind faster than c can create conditions that can violate causality. Sending information of any kind backwards in time can create conditions that can violate causality. Building a wormhole that has the ability to do both of those things can create conditions that can violate causality. Two people passing each other in space ships at different speeds (less than c) does not violate causality.
We are always moving forward through time without violating causality. Moving forward at a “slower” or “faster” rate would not violate causality either. Moving backwards through time is a completely different problem. That’s where you can violate causality.
Yes. According to Matt Visser this is one of the few methods of FTL that does not cause temporal paradoxes, so long as you stick to the rules.
Ah, I see. Thanks!
Is GR the thing that is corrected for in GPS satellites and such?
What are the rules?