Time Travel

I suggest that the passage of time is just an artifact of memory. Einstein is quoted as saying that time is what you see when you look at the face of a clock. I think he was exactly right. If we consider the face of the clock as an entire universe, we see the state of that universe and we may remember previous states.

I would go back in time and change things, I suppose.

However, there is a horror genre now, it seems, where someone travels back in time, changes some bad thing that happened, but when they get back to their own time, things are much worse, in some way, so he goes back again, to correct that mistake, but, you guessed it – each time he gets back things are even much worse, so that he is compelled to go back, etc.


I think the miniseries 11.22.63 did this very well. I’m normally not into American history because I like the more ancient stuff, but I was totally into this miniseries.

@spill

Well, I was hoping for a little more than that. I don’t just dismiss time as a dimension, I account for relativity when I do it.

@ibelieveinlogic

Time is way more than just an artifact of memory. It has been proved that time moves more slowly the faster we travel through space. It has also been proved that gravity warps space/time, which are believed to be the same thing just like matter and energy are different forms of the same thing.

I have this crazy idea about the nature of the universe in which time is not a dimension. It’s probably way, way off, but as far as I can tell I can get rid of time as a dimension and gravity as a field without changing any of the math or invalidating any of the observations. It’s essentially just looking at the universe in a different, simpler way than we currently do. But I don’t know enough about physics or the math involved to know if there may possibly be anything to it. However, every test I thought of to test it for which I was able to look up some data has confirmed it so far. I do have one definitive test in mind, but I would need 3 atomic clocks, some precision hardware, a space vehicle and a hell of a lot more mathematical, engineering and programming skills to run that test. And that’s assuming the device I have in mind will even do what I think it can do, determine our nonrelative speed and direction of travel through space.

“It has been proved that time moves more slowly the faster we travel through space.”

I think what was “proved” about time when we go faster was that, from a particular reference point, clocks appear to run more slowly as we accelerate away from that point. Once the clock stops accelerating and it achieves a constant velocity (away from the reference point) the clock appears to run at a consistent slower rate than it did when it was at the reference point. When the clock stops and maintains a consistent distance from the reference point it will appear to run at the same rate it did at the reference point.

This is all consistent with the idea that the speed of light is constant and is independent of the velocity of the light source. The velocity of the light source will not change the speed of the light emitted nor its frequency. The speed of light emitted from any source measured from any reference point will be constant; the frequency of the emitted light may appear to change depending on the velocity of the light source relative to the reference point.

Notice that what we’re talking about is appearance not what “is”. The accepted philosophy of science, since around the middle of the 18th century I believe, has been that science can deal only with the appearance of what we experience not its existential nature.

Bob said,

“It has been proved that time moves more slowly the faster we travel through space.”


One might also posit that time “emerges more slowly the faster the speed of an object”.

IOW, time does not exist until a timeline is created by a chronology of related events.

Timelines can use any suitable scale representing time, suiting the subject and data; many use a linear scale, in which a unit of distance is equal to a set amount of time. This timescale is dependent on the events in the timeline. A timeline of evolution can be over millions of years, whereas a timeline for the day of the September 11 attacks can take place over minutes, and that of an explosion over milliseconds.[2] While many timelines use a linear timescale—especially where very large or small timespans are relevant -- logarithmic timelines entail a logarithmic scale of time; some "hurry up and wait" chronologies are depicted with zoom lens metaphors.
https://en.wikipedia.org/wiki/Timeline

But IMO, time travel is impossible without catastrophic effects on past events. You cannot travel into the past without undoing what has already been done. It is nothing like rewinding a movie where events have a fixed position on the film strip.

It becomes a question of reconstructing all associated dynamic spacetime coordinates, which is physically impossible?

I believe that time does not exist independent of duration of change. Time itself is immeasurable, unless associated with duration of chronological spatial change.

Widdershins: “It has also been proved that gravity warps space/time, which are believed to be the same thing just like matter and energy are different forms of the same thing.”

Last item first: I suggest matter is probably as close to being a thing as we can get, particularly in macro scales. Energy is not a thing; it is a measure of matter’s potential to displace other matter (to do what we call work). Note that the “push” which may cause displacement is the only force we think we really understand well. Not two forms of the same thing.

First item: No way for me to buy into the idea that space (which is probably a thing) being the same as time (which I believe is not a thing at all).

The notion that gravity appears to warp space seems to be correct. If so, how do we determine a “straight” (un-warped) line? Moreover, would’t we need to use gravity-corrected units to describe distance accurately? What a crazy yardstick we would have, stretched out on one or both ends, or even in the middle, and bent this way and that, depending on where we put it and which way we point it.

On the other hand, in order for us to realize warped vs not warped wouldn’t we need an absolute frame of reference? And then of course, there’s the question of how a wave could propagate through a variable density medium while maintaining a constant speed.

When you don’t know something, there are two ways to go. Figure out what you don’t know, usually some reading handles this pretty well. Or, make up something to fill in your gaps in knowledge. This idea of a “straight line” across spacetime, is an example of the second one. As for “gravity-corrected”, my understanding is, to do something like land a rover on Mars, you do need to consider relativity, so, you’re on the right track there.

@ibelieveinlogic

I can see a flaw in that. You’re using a very specific definition of “energy” which applies only to specific branches of physics. Scientists don’t use words like we do. In this case you are talking about “physical energy”, which is essentially matter in motion. It’s an electron moving through a circuit, a spring unwinding, etc. There’s also electromagnetic energy, which is a separate thing from matter and does not involve matter. There is also a state in between, such as in the photon, which acts like both. Only physical energy is described as the ability to do work. If that were all there was, you might be onto something.

The photon suggests that matter and energy are two forms of the same thing, with transitional forms in between the two. Even a single electron seems to travel as both a particle and a wave. Of course on a base level both are believed to just be interactions between various fields. In that case there would technically be only one thing, the field, of which all other “things” would be composed. This would likely include matter, energy, space and time, if they were all “things”.

As for gravity warping space, that is an observable, testable phenomena which we absolutely know to be true. However, I believe there may be an alternate explanation for it, and the warping of time, which has not been considered. All of the observations are exactly the same. All of the calculations remain unchanged. Just the explanation for why we see what we see is changed, and that explanation answers a few questions previously unanswered.

It would be too long a post if I laid out what this idea was, and I’m probably wrong anyway. Anyone who believes that they’ve truly found some great truth that all the more educated people with bigger brains have missed is likely delusional. It’s possible, so I still entertain the idea until I find it to be unworkable, but I don’t have much hope that it’s actually correct.

Riddle me this. How did a 16 yr old, now famous, autistic girl get her picture taken as a Klondike gold rush worker 122 years ago?

Gretta is a super hero. She doesn’t have to follow the laws of physics. And, frankly, you’re a dick for questioning it. Do you know the shit I took for questioning how the Hulk put on and lost 1,500 pounds of matter in under a minute? I learned better than to question super hero shit and so should you.

Pardon me if I inferred that Greta might not have powers beyond imagining. I was more just curious as to how and why. But I realize that we can not always know all of her mysterious ways. All hail Saint Greta!

All hail!

TimB said,

Riddle me this. How did a 16 yr old, now famous, autistic girl get her picture taken as a Klondike gold rush worker 122 years ago?


Genetically? Of course it is not the same girl, but she may be distantly genetically related. Why do frogs all look alike?

 

 

Do you mean French ppl? They won’t take kindly to that remark.

But seriously, I wonder whether it is even necessary to be remotely related to “appear” to be identical to one of the other billions of humans who have ever lived at some appearance matching point in the pair individuals’ own development. IOW there may be certain combinations of gene’s and environmental exposures and personal development, that reproduce a particular appearance.

If we set a super supercomputer to analyze all the available photos in history, to do face matching, we would likely come up with a lot of pretty good matches.

 

 

Widdershins: “As for gravity warping space, that is an observable, testable phenomena which we absolutely know to be true.”

I’m a bit disappointed that you seem to have missed the humor I tried to inject into the idea of warped space. Perhaps I’m just not good at humor.

The idea is that if space is warped then everything in that space is also warped. After all everything there is subject to the same forces. If what we observe is warped then our yardstick (our inputs for measuring) will also be warped. We will not be able to distinguish any difference between an inch (or a light-year) on the warped end of the yardstick from an inch (or light-year) on the non-warped end. Because all our inputs for measuring would be warped the same as what we would be trying to observe we couldn’t observe any warp.

The only frame of reference in which we could observe the warp would be one that is absolute (non-warped and external to the warped space). Nice to imagine a warp that could be detected, but only in our imagination. Sort of like imagining a closed universe requires one to imagine being outside.

@ibelieveinlogic

If one could compare the measurements from what you call the warped vs non-warped ends of the yardstick, one would see the difference in duration of time passage, no?

@ibelieveinlogic

Humor can be difficult to impart in text. In this thread I wasn’t absolutely sure that Tim would see the humor in me calling him a dick. I tried to make it obvious, but you never really no because when you’re deciding on the words to use the voice in your head has inflections that don’t come through in the text.

Space has no affect on matter, so our measurements are still reliable. And it is fluid, warped by gravity, but then spreads out to the nice, even space we know and think we perceive no matter where we are (we are actually living in warped space, warped by the gravity of our planet). It doesn’t matter if our yard stick is warped or not because it measures space using to relative points within that space to measure from. If you lay your yard stick down to measure 2 points 3 inches apart and then step away and use a telescope, moving outside of the warped space, it may not look like 3 inches to you from that perspective, but whether you go back there or bring it to you, it is 3 inches. By measuring the difference you can measure the amount of spatial warp.

But changing the shape of space does not change the shape of the objects within it. They stay exactly the same (the distances between points may change minutely with gravitational waves, but that’s a different conversation). If you take a straight ruler which is exactly 12 inches long into warped space and out the other side then at any point you observe that ruler right there you are going to see a perfectly straight ruler exactly 12 inches long. If you watch the ruler travel from a fixed point then it will appear to warp as it travels through the warped space. However, it will remain completely unchanged. It is the space which is warping, not the object.

And there are no “absolute” points in space. All points in space are relative. You must have a point of reference to tell when you are in empty space. Although, that may not always be true (in the future). Currently we only know our relative speed and direction through space, but I believe it should be possible to measure our nonrelative speed and direction through space with a simple device. You simply need 3 signals, each at 90 degree angles to a central signal detector. While the signal generators will all be traveling through space in the exact same speed and direction, the signals they produce will be traveling to the detectors at different angles, meaning the signals are not traveling in the same direction, though they are traveling at the same speed, the speed of light. Simply measuring the Doppler shift of these three signals should produce a nonrelative speed and direction through space. The same could be done with lasers or atomic clocks with communication lines to the detectors at exact right angles.

TimB: If one could compare the measurements from what you call the warped vs non-warped ends of the yardstick, one would see the difference in duration of time passage, no?

Since I believe the passage of time is nothing but different states of the universe (different configurations of objects) which we remember I can’t see how it could be warped. I see no evidence that time acts upon anything or is acted upon by anything nor that time causes anything or is caused by anything. If time is not a cause, not an effect, not a force and not an object then what is it? My answer: an artifact of memory.

Consider the classic flat universe presented as a ribbon twisted into a continuous figure eight. Anyone in that universe can’t know what it looks like from outside; they will not know it is twisted. In the same way, if our universe is warped we can’t know it because we have no way of observing it from outside, except in our imagination.

In the case of our yardstick, we won’t observe that it is warped. Everything we might measure with our yardstick will be warped the same as our yardstick, and anything we use to measure the inch marks will be warped too. Thus our yardstick and everything we measure will not appear to be warped.

I agree with most of your argument, but you are not accounting for gravity, which I believe is the cause for warped spacetime.

Evidence of Warped Spacetime

If Einstein's theory of General Relativity is an accurate description of gravity, then there are some bizarre consequences. In this section the implications of General Relativity's claim that gravity is the warping of spacetime will be explored in a prediction-observation format. A scientific theory must make testable predictions which are tested through observations and experiments.

Prediction: light passing close to a massive object should be noticeably bent. The amount of bending increases as the mass increases.

Observation: During a solar eclipse you see that the stars along the same line of sight as the Sun are shifted outward’’. This is because the light from the star behind the Sun is bent toward the Sun and toward the Earth. The light comes from a direction that is different from where the star really is. But wouldn’t Newton’s law of gravity and the result from Einstein’s Special Relativity theory that E = mc2 predict light deflection too? Yes, but only half as much.

General Relativity says that time is also stretched so the deflection is twice as great.


 

 

http://www.astronomynotes.com/relativity/s4.htm

TimB said,

But seriously, I wonder whether it is even necessary to be remotely related to “appear” to be identical to one of the other billions of humans who have ever lived at some appearance matching point in the pair individuals’ own development. IOW there may be certain combinations of gene’s and environmental exposures and personal development, that reproduce a particular appearance.


I agree.

If, as Tegmark proposes that all objects are mathematical patterns, then it would be possible, that many people mathematically resemble each other and any differences would be so small that for all purposes they are the same basic pattern.

Bob said “…I see no evidence that time acts upon anything or is acted upon by anything nor that time causes anything or is caused by anything…”

 

TimB asks: How do you explain that an atomic clock in orbit keeps a consistently different (although the difference is slight) time than an atomic clock on the Earth?