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Time Travel is Science Fiction
- Thread starter Farsight
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The moderator is too good for us.
That's not true. It's rare in time travel movies to see clocks advancing rapidly or going backwards rapidly. More often the time traveller goes from time x to time y without going through the intervening times, so there is a discontinuity. The Time Machine was an exception to this which involved something like a "stasis bubble".
The difference is that you can in principle watch the rocket for the entire 40 years, whilst the TARDIS vanishes from time x and appears at time y without going through the intervening time.
How about you try and point out some flaws in my reasoning? Read the OP and try to point out where it's wrong.
Neither. There is no way you can move such that everything else is back where it was without ever having moved at all. And as you must surely know, there is no motion in spacetime because it models motion through space at all times, and is static as per the block universe. So a wormhole, which is "a shortcut through spacetime" isn't something you can traverse, just as you can't travel along a closed timelike curve.
:Shrug: Maybe I already have, and I have seen you ignore direct questions.
Wormholes, like time travel, are a permissible solution in relativity.
I should have known I needed to be more explicit, you've misunderstood the scenario being posited.
When you have the desired age differential you move the time dilated edge end of the wormhole away from the blackhole, so that all that you have is the wormhole. I would have thought this was obvious. It's the passing through the wormhole that constitutes time travel in this instance, not the gravitational time dilation of hanging around near the blackhole.
I see it as the bloke/sheila that has aged 5 years, moving to another FoR where 10 years has passed, as going 5 years into "his/her" future.
"His/her" future, being the "absolute present" for whoever remains at the end where 10 years has passed..
OK. I prefer when there are two names for the same concept of a thing to stop uing one (keep the one SR also uses). However, I can and do distinguish between time dilation and time travel even though as Trippy informs me, in science fiction stories the time travels don't experience any "Jump" in the time they are conscious of by noting the non-time traveling world/ people do see them a having jumped past of years of their contiguously changing events.
SUMMARY: I don't have two different names for one thing /concept. For me, cosmic ray daughter muons do not time travel - they were in a fast moving frame (wrt our's) so from our POV their clocks were running slow, but they were somewhere in their descent to the earth's surface at ever instant on our clocks - Unlike a jump from 1770 to 2000 on our clocks which I agree is time travel and not time dilation.
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Motor Daddy
Valued Senior Member
What do you mean when you say "a jump in time"? T=1770 years (t=0) is a point in time. T=2000 (t=230 years) is a different point in time that is 230 years later than the point in time that is t=0, which is 230 years earlier than the point in time T=2000 years. That was all the past now that it's t=14 years after T=2000 years which was 14 years ago at t=0! But when it was T=2000 the future was the year 2014, but now that it's 2014 the year 2000 is the past, not now, because 2014 is now, until it's the past. Funny how the future becomes the past and the past always stays the past, or does it?
What for? You have discarded mainstream physics in favour of pseudoscience.
And its useless arguing with speudoscientists.
Let me list a few anyway.....
[1]Time travel is certainly 100% factually allowed for within the present laws of physics and GR, which you deny.
[2] The title of the thread is correct only for the present. [see point [1]
[3] Space, time, henceforth known as spacetime, is real and its effects has been measured in the presence of mass, which you again deny.
I won't at this stage mention your erroneous concepts about the speed of light not being constant, or your claims that we see light and time stopped near the EH of a BH, other then to say they are all grossly in error.
Couple that with your claim of having a TOE, and your credibility is in tatters I would suspect.
I didn't say anything about clocks advancing or rewinding rapidly, I said that time was continuous for the time traveler.
Please stop putting words in my mouth.
Not for the time traveler. Enough straw-men already. Go back and re-read what I actually said. The passage of time measured by the time traveler is continuous.
The description given in the time machine most closely matches time dilation.
No, not quite, and according to cannon, you could contact the occupants of the TARDIS at any time during the trip.
Been there, done that, but then again, strictly speaking, I wasn't talking to you now was I?
Well, that's your opinion based on your understanding anyway...
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I must have missed your answer. Not much trouble for you to tell again whether or not the muons are "time travelers" is it? If I have failed to answer a question from you, ask again. I don't recall "ducking" one of your questions.
I believe that true but can not solve those equations to make sure. Anyway, as I have already observed: a 10 high exactly vertical stack of uniform density, perfect spheres, the size of bowling balls, in a gravity field is also a valid solution of GR (and even of Newton's much less complex) equation.
Not all solutions are achievable, even by a civilization much more technologically advanced than ours - some are unstable, and perhaps some (like time travel into the past) violate causality, etc. for perhaps even conservation of energy and momentum - I don't assert that last pair of violation as can't solve the equations.
I should have known I needed to be more explicit, you've misunderstood the scenario being posited.
When you have the desired age differential you move the time dilated edge end of the wormhole away from the blackhole, so that all that you have is the wormhole. I would have thought this was obvious. It's the passing through the wormhole that constitutes time travel in this instance, not the gravitational time dilation of hanging around near the blackhole.[/QUOTE]
In post 1368 I am mis quoted. I did not say:
The Time Machine was an exception to this which involved something like a "stasis bubble".
Quite sure of that as I have no idea what a "stasis bubble" is or refers to.
Also in post 1365, I credit Trippy with informing me that in time travel stories the travelers usually don't experience and "time steps" / discontinuities in time. I continue to say if time travel is occurring by my definition (Trippy is not inclined to give one) there is a section of the observer time deleted. As someone mentioned with a jump from 1770 to 2000.
The Time Machine was an exception to this which involved something like a "stasis bubble".
Quite sure of that as I have no idea what a "stasis bubble" is or refers to.
Also in post 1365, I credit Trippy with informing me that in time travel stories the travelers usually don't experience and "time steps" / discontinuities in time. I continue to say if time travel is occurring by my definition (Trippy is not inclined to give one) there is a section of the observer time deleted. As someone mentioned with a jump from 1770 to 2000.
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So the fact that Esintein and Rosen, for example, have said that it's a solution isn't good enough for you? You expect to be able to understand it and solve it for yourself?
The practicality of a solution is a separate issue from whether or not a solution is permissible.
Yes, you're absolutely right, stacking ten perfect spheres, one on top of the other, is a possible solution, it's just not a very probable one.
Do you understand the difference? This thread is about whether or not it's possible, not whether or not it's practical.
That's a matter of opinion, and the practicality of doing something is a different question to the possibility of it. If you now want to say that while time travel may be possible, but may never be practical, then I don't think you'd get a great deal of argument.
I didn't. You please stop disrupting this thread and making a mountain out of a molehill re Billy's point.
Go and read the OP. A clock isn't some kind of gas meter. It doesn't literally measure "the passage of time". It counts some kind of regular cyclical motion and gives a cumulative display that you call the time.
You're talking tosh. Doctor Who isn't real. And the TARDIS goes transparent and vanishes anyway.
No, but I did start this thread.
It isn't just my opinion. I referred to A World Without Time page 142 where Palle Yourgrau said Wheeler conflated a circle with a cycle precisely missing the force of Gödel's conclusion. A world line represents motion through space over time. It's motionless, nothing moves up a worldline.
Geez Billy, don't get your knickers in a tangle. It was a copy-paste error, and one that I thought I had corrected before I posted (I corrected other instances of it, but missed a couple).
The observer time doesn't jump from 1770 to 2000. If James Cook had a chronometer on him that read 12:00:00 1 July 1770, then it would read 12:00:01 1 July 1770 when he arrived in the year 2000.
The difference is that where James Cook experience 1 second of time passing, Joseph Banks and Daniel Solander experienced 230 years. Banks and Solander would conclude that Cooks clock was running slow, Cook would conclude that Banks and Solanders clocks were running fast.
You precisely did put words in my mouth, and sometimes side discussions take place that are part of the broader meta-discussion. If you can't recognize this, you have no hope of ever being a good, reliable, or useful moderator.
I have read the OP.
That's your opinion anyway.
The TARDIS is an example of time travel in science fiction, hence it's relevance. You were perfectly happy addressing it before I pointed out how nonsensical your objection was.
Which entitles you to bupkiss.
And others have pointed out where you have misinterpreted or misrepresented Yourgrau's words.
That is a valid point, however I don't believe it makes time dilation time travel.
I don't keep track anymore Farsight but you have stopped even responding when I point out the contextual knowledge base difference between when Einstein gave his Leyden address and when you read it.
You in my opinion and it seems the opinion of others horribly misquote Einstein's intent there.
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Only I don't. I quote what he said, and he said what he said. You and others try to dismiss what he said because it doesn't tally with some woo you've picked up from some quack on the Discovery Channel pimping his latest popscience book for suckers and kids.
Now, would you like to point out where I misrepresented Palle Yourgrau?
Didn't think so.
Now, would you like to point out where I misrepresented Palle Yourgrau?
Didn't think so.
It is never a bad thing to point out errors in reasoning in a general argument.
However, this is not a reason to deny that there is a time in which these regular cycles occur. Indeed, so that this kind of thing wouldn't be a distraction, Einstein recommended not thinking about such regular clocks at all. Instead, one should think of whatever kinds of physical systems you wish, operating at whatever rate, as long as these systems operate the same way when adjacent.
What is important is not a specific type of clock, but the coordination of any physical system whatsoever over time, which is what relativity theory is about.
It is actually your lie when you misrepresent what Yourgrau wrote. Yourgrau also agrees that there are closed, time-like loops in Godel's solutions and that, thus, there is time travel allowed by GR.
Let's look at the actual passage about Wheeler's mistake.
'Wheeler, unfortunately, has conflated a temporal circle with a cycle, precisely missing the force of Godel's conclusion that the possibility of closed, future-directed,
timelike curves, i.e., time travel, proves that space-time is a space, not a time in the intuitive sense. Whereas a circle is a figure in space, a cycle is a journey undertaken
along a circular path, one that can be repeated, in Wheeler's words, "over and over again." Exactly how many times, one wants to ask Wheeler, is the journey supposed to be
repeated? The question clearly cannot be answered, since the time traveler's journey is not over time, along the closed timelike curve: it is the curve itself. Just as one cannot ask of
a circle how many times the points that constitute that figure have gone around, one cannot sensibly ask how often the time traveler in the Godel universe has made his or her
trip.'
So, yeah, despite Farsight's repeated vague citation of this work as a denial of time travel (supposedly based on the opinions of Einstein and Godel), it is the opinion of the author of the book that Godel proved that there can be time traveling in GR.