Time Travel and speed

I am by no means a physicist, let alone a astro or quantam physicist, but have for a long time thought about the possibility of time travel of sorts through speed.
My theory goes as follows. Say an object is on a circular track for instance and travels at increasing speed. Would it be possible at a certain point for the object to “catch up” to itself? I believe that if it approaches or exceeds the speed of light it just might, or at least appear to, hence giving at least the impression of time travel.
Einstein theorized that if one was to travel in a straight line away from the earth at the speed of light and return at the same speed the earth would appear to have aged even though the traveler hadn’t. Why would this not work with circular travel? This is all of course assuming we could reach the speeds necessary allowing for the friction on the track etc…
Visualising this in my mind seemed to make more sense than it does having written it, but I will put it out there anyway….just in case there might be others who think the same way and can perhaps express it better than I can.

if you where to speed up in a circular path the centripetal forces would rise with your speed causing the ship to have and infinite mass ripping atoms apart. so with a infinite power source you would have to have a infinitely strong ship.

Originally posted by VIKINGANT
I believe that if it approaches or exceeds the speed of light it just might, or at least appear to, hence giving at least the impression of time travel.
Einstein ...

This sentence alone tells me that you need to research the subject a bit. I'm by no means an expert either, but I do remember from high school and college physics that according to Einstein it would require an infinite amount of force to accelerate an object to the speed of light...hence your statement above is contradictory to his theories.

reply to post by BlueTriangle


Yes and no. I have read that there are some who feel that speed of light travel is not an impossibility. Very difficult granted but not impossible.
That said, even Einstein "theorised" about speed of light travel, but didnt say it was going to happen, as this is also only a theory. Something to ponder if you will.

Is there no one with ideas on this? Im not looking for blueprints or anything but constructive criticims or support? Just so I know I havent totally lost it...

reply to post by VIKINGANT

According to Einstein, the speed of light is not possible to attain, because an object moving at the speed of light would have infinite mass and therefore require infinite energy to accelerate it.

Wait, that is actually not completely true. Accepted as truth, but not actually true.

According to Einstein, an object traveling at the speed of light relative to an observer would appear to the observer to have infinite mass, and therefore would appear to the observer to need infinite energy to accelerate it.

This is where things get dicey... reaching and exceeding the speed of light is relative to an observer... so should your item be able to move in a circular path at the speed of light relative to an observer at the center, would that observer see it meet itself? Actually, the opposite. einstein's equations show that an object's length in the direction of travel appears to the observer to approach zero! So at the speed of light, the object would appear to be two-dimensional! As for time travel, it would appear to the observer to be stopped in time... and I'm gonna stop there unless you have more questions... this could fry a few brain cells if I continue.

TheRedneck

first off,
You would not be able to see an object moving at the speed of light it would have come and gone before your eyes would have time to gather any information.
Also the speed of light is not cumulative, and what I mean by that is, that if you are going a thousand miles an hr and turn on a light, that beam of light isnt going the speed of light plus 1000 mph. Its just going 186,000 miles per second.
So the object arrives and passes you with the photons its giving off. It is in fact a part of a beam of light.
In order to travel in a circular path you would have to be mass-less in order to get by the centripetal accelerations.
the forces exerted on the object and thus on the track are decribed by the equation
F=m*(v^2/r)
where m is the mass, v is velocity, and r is the radius of curvature.
so if you have an object of 1 kilo in mass traveling around a 10,000m radius meter track
the the force on the track would be
1*(2.998* 10^8 meter/sec /10,000) or 8988004000000N or 2049264912000 lbs
thats a pretty big number


and at relatavistic speeds the laws that govern a particle or no different than quantum mechanics, hence you can ony know either its position or its energy level. If you " look" at it you will change one of the two, so you could not see it.

Wow! this stuff really does my head in at the best of times. Redneck really did me in with that explaination. I would really like to here more if you could be bothered with the typing. I appreciate the drip feeding though. Gives me time to digest.
One questions though, not meaning to sounf flippant. when you said "relative to an observer at the center", are talking located within the "track"? if so, how would it "appear" from out side the track either on the vertical or horizontal plane? and would the distance from outside the track make a difference?
Punkin, Aside from not being able to visualize the event, and allowing for the extreme mass issues are you saying theoretically at least it is possible?
Please excuse my lack of correct terminologies

reply to post by VIKINGANT

For simplicities sake, I was assuming the observer would be at the exact center of the track, so the speed of the object would be constant relative to him. And I have to point out that the others who are mentioning the mass problem are correct; even if we ignore the relativistic mass increase, the centrifugal force would be so great that such a device would be impossible to construct. My answer is more in line with what Einstein called his 'thought experiments', a visualization of something that was physically impossible (or at least impractical) in order to examine what the result would be and thereby gain insight into how forces work. That said...

If the observer were positioned elsewhere, say at one side of the track, the speed of the object relative to him would vary during its cycle, and therefore the relativistic effects would vary as well. The object may actually exceed the speed of light relative to the observer at some point in the cycle, and be almost stationary in another part. At this point, we get into more conjecture than science. Einstein's equations can not address a velocity greater than the speed of light, since the imaginary number 'i' (square root of -1) appears in the result. What does that mean? We don't really know. Most mathematicians will tell you it means the equation is invalid, and they may well be right. A few, however, have interesting (and brain-frying) ideas which may prove to be right in time. So we just don't know.

If you really want to make your eyes spin around, try this one on for size: if a second observer were riding the object, how would he see the first observer? They are moving at the same speed relative to each other, so the effect would be the same for the second observer watching the first.

Physics: the new drug of choice.

TheRedneck

reply to post by VIKINGANT


theoreticaly, no, it is not possible, for so many reasons.
Both physical and quantum reasons.

Thanks guys,
I love this stuff, even though I have trouble getting my head around it.

Redneck, thanks for more sleepless nights ....

Punkin, Thanks for shooting me down in flames. I will consider myself to be back in my place. I should have known better than to ask.

Vikingant

Most modern theories of Relativity are based on string theory which is to say the conventional thinking extrapolation of Einstein's theories.

String theory also however deters those who question or challenge the conventional wisdom.

String theory also means that if at any stage someone got it wrong then the error becomes compounded by future assumptions.

I have emailed you about a friend who is a Nobel laureate in this field and if you like I will get you his email so you could discuss your theory with him ?

Cheers Simon

Originally posted by VIKINGANT
Thanks guys,
I love this stuff, even though I have trouble getting my head around it.

Redneck, thanks for more sleepless nights

....

My pleasure. And don't concern yourself with those who would tell you 'it's not possible' and leave it at that. All great thinkers throughout history have heard that, and all have ignored it to become great thinkers.

The thought experiments I mentioned above were a favorite tool of Einstein, and similar thinking marks the works of Stephen Hawkins as well. I have always been fascinated by the idea of thinking a situation through when it is not possible to physically manifest it. I recommend starting at the beginning; get a good layman's book on Einstein's theories, and if need be, a good math book to go along with it. There are plenty of choices as to which one; I have several myself that I read from time to time, just to keep my thoughts grounded. sy.gunson said it very well:

String theory also means that if at any stage someone got it wrong then the error becomes compounded by future assumptions.

How true...

TheRedneck

while it is true there are way of bending Einstein's theories it doesn't relate to time at all. the way we measure light is with things traveling just as fast ex optical sensors. so there could be things going faster but we haven't been able to detect them yet.

But time travel should be viewed as a chemical basis its not if you run the reaction faster then the maximum rate it will magically reverse. once you burn a match it is now something else and those exact same molecules will never be a match head ever again exactly as it was.

though there is hope, we look once again to physics and the " multiverse" theory. so in the proposed theory there are a unlimited number stemming from all possibilities. this would be the more likely choice. and then it wouldn't be about speed but rather a means of getting to a destination.

EngenerQ,
With time travel, we don't want the match to be as it was...If for instance I were to go back in time, I would still be me but look at thing as they were not recreate things. a burnt match going back in time would still be a burnt match but it would be possiblt to see the unburnt match at th esame time...theoretically that is

Punkin,
You still confuse me. you throw up all these numbers as to what would happen at light speed but still say it cannot be done. try and get passed the difficult = impossible. If the numbers and theory say what 'might' happen what about 'why not'?