Time travel is not possible right?

[Lorizael]

Moving backward in time, to me at least, implies not just moving backwards but moving in two different dimensions labeled time. There's the one dimension time that all travel implies in the "at time A I'm at point A, at time B I'm at point B" sense, and then there's the actual medium of history you're supposed to be traveling through. So, did the universe just politely generate this extra dimension for our traveling convenience, or what?

I suppose an actual physicist would tell me that the first sense is just some sort of illusion generated by my consciousness or something anyway.

The kind of time travel that seems to be permissible by the laws of physics does not require a second time dimension. You don't step out of time-1, move along time-2, and then step back into time-1 at the appropriate place. Rather, your path through the universe happens to take you from time A in location X to time B in location Y, which is basically what already happens whenever you move through the universe. The only difference is that with "time travel," time B is before time A, which really only means that you can influence events at time A by doing things at time B.

As far as time being an illusion, physicists will say a lot of things but don't yet have good, concrete answers for what time "really" is. Despite that, they can very excellently and accurately manipulate equations involving the variable t.

[Dry]

Interestingly, Dry, the issues you cite are from the direct quote from the archaeologist, Oscar Nilsson. While some science writers get some of the science wrong, it seems that internet critics of science writing are as bad, if not worse.

Ok, my bad.
After second checking, it seems teeth are growing since before birth (https://en.wikipedia.org/wiki/Human_tooth_development).
So contrary to what I thought, the info lies in the growth, not in the erosion of or the deposit on the tooth.

[dannubis]

The kind of time travel that seems to be permissible by the laws of physics does not require a second time dimension. You don't step out of time-1, move along time-2, and then step back into time-1 at the appropriate place. Rather, your path through the universe happens to take you from time A in location X to time Y in location B, which is basically what already happens whenever you move through the universe. The only difference is that with "time travel," time B is before time A, which really only means that you can influence events at time A by doing things at time B.

As far as time being an illusion, physicists will say a lot of things but don't yet have good, concrete answers for what time "really" is. Despite that, they can very excellently and accurately manipulate equations involving the variable t.

I know of no generally accepted theory that allows you to put time B before time A.

[Lorizael]

I know of no generally accepted theory that allows you to put time B before time A.

On phone now, but it involves accelerating one mouth of a wormhole and taking advantage of the resulting time dilation. If the spacial separation between them is smaller than the temporal separation the time dilation creates, then you can go through a wormhole and still have enough time to go back to the entrance mouth before you left.

Again, doing this may be hard or impossible, but it's not currently ruled out by any laws of physics.

[rah]

I always figured if it was possible to go back, we'd would already know it because someone would have come back and spilled the beans. No matter what controls they invented someone would eventually slip.

[dannubis]

OK. If actally flying into a black hole is required for time travel I can see why chances of success are relatively low.

[Lorizael]

I always figured if it was possible to go back, we'd would already know it because someone would have come back and spilled the beans. No matter what controls they invented someone would eventually slip.

With wormhole time machines at least, you can't go back any further than the creation of the time machine.

[pchang]

Before we spend too much time thinking about wormholes whose endpoints are moving at relativistic speeds, maybe we should actually confirm the existence of wormholes.

[My Hubby Loves Civ]

Hmmm...so technically the time machine would need to have physical control over quantum particles vs quantum waves. Perhaps, by creating a wormhole via dark energy waves and photonically creating a particle dispersal of itself through the folding of time and space? I agree, this concept of wormholes does seem like it would only be useful for instaneous space exploration and one would not be able to go backwards within our own space time. Yet such a machine would technically be a time machine right?

[ricketyclik]

Bicycles are time machines. Consider: You go to the gym for a one hour workout, then drive 20 minutes to work. Alternatively, you just ride one hour to work, but you've still gotten your exercise. Voila, you've gone back in time 20 minutes!

[DaShi]

Moving backward in time, to me at least, implies not just moving backwards but moving in two different dimensions labeled time. There's the one dimension time that all travel implies in the "at time A I'm at point A, at time B I'm at point B" sense, and then there's the actual medium of history you're supposed to be traveling through. So, did the universe just politely generate this extra dimension for our traveling convenience, or what?

I suppose an actual physicist would tell me that the first sense is just some sort of illusion generated by my consciousness or something anyway.

If you could move faster than the speed of light, you could go backward in time by moving through four dimensional space.

[Lorizael]

Before we spend too much time thinking about wormholes whose endpoints are moving at relativistic speeds, maybe we should actually confirm the existence of wormholes.

Details!

Hmmm...so technically the time machine would need to have physical control over quantum particles vs quantum waves. Perhaps, by creating a wormhole via dark energy waves and photonically creating a particle dispersal of itself through the folding of time and space? I agree, this concept of wormholes does seem like it would only be useful for instaneous space exploration and one would not be able to go backwards within our own space time. Yet such a machine would technically be a time machine right?

I... uh... monkeys?

[My Wife Hates CIV]

if time travel was possible 911 world be a 1 billoion( think about it time) watch crowd.

whats does thwat meab.... bizzinf here.

[My Hubby Loves Civ]

Details!



I... uh... monkeys?

Not sure what to make of your response, but, oh my, I just had a vision of The Planet of the Apes!

[Lorizael]

My response was meant to convey that I had absolutely no idea what you said. Like, I'm hoping you're trolling me.