# Time travelling

## Recommended Posts

relativity. look into it.

edit:what is wrong with my equations? they are simple equations that answer your question. would you rather have an explaination with no support?

##### Share on other sites

i have looked into relativity. i read a book that is supposed to explain it. it used a garbage example about a mirror and not being able to see your reflection. any moron could tell that it was a closed minded way of viewing the problem and it had logical flaws. a few years ago i was very interested it in relativity(and more importantly time dialation) and asked everyone i could find, including a few physics teachers i knew, and no one found a way of explaining it that didnt have a very large flaw in the logic. id tell them why it didnt make sense and they would be stumped and say things like "when this guy explained it to me it made sense, im forgetting something." it was pretty irritating.

so i saw a thread on time travel and decided to give it another shot. as for your equations, they may be perfectly fine, but you could throw out any equation you wanted and im sure if we assume its correct you could prove that time dialation works. its the process of coming up with said equations that always seems to be flawed.

##### Share on other sites

I dont understand relativity, obviously. However, the logic, and the equations, and the testing are quite clear on the subject.

Now, here is my theory on when I detect a logical flaw in something that

•was written by one of the most intelligent men in history

•has been peer reviewed by some of the most intelligent men over the past 100 years

•has been tested to death, and proven right

I tend to think that its MY logic that is faulty, not theirs, since there is no way I can keep up with the equations involved.

When your v increases, time slows down for you. Equations were already given for this. Why does it work out? It has something to do with c being a constant, which makes absolute time impossible. Get a real textbook on the subject, and read up about it.

##### Share on other sites
ias for your equations, they may be perfectly fine, but you could throw out any equation you wanted and im sure if we assume its correct you could prove that time dialation works. its the process of coming up with said equations that always seems to be flawed.

take it up with Mr. Einstein. it doesn't really matter why time dialation works, it is that it works. it has been proven so many times, it isn't even funny.

##### Share on other sites

i dont care who wrote it. people make mistakes. those who "peer review" it are libel to make even more mistakes precisely because "it was writen by one of the most intelligent men in history." everyone seems to think that Einstein is a synonym for "perfect". its not, he was a guy (albeit a very intellegent one). people are not perfect.

not that any of that really matters since im really just looking for an explanation. im not saying the theory is wrong, im saying it doesnt make much sense from what i have been told and that every explaination i have heard is garbage. im looking for another.

##### Share on other sites

ok how about this. time dialation has been experamentally proven and it was the EXACT amount as in Mr. Einstein's equations.

http://www.walter-fendt.de/ph11e/timedilation.htm

http://aci.mta.ca/Courses/Physics/4701/EText/TimeDilation.html

first one is just an amusing site. the second one is an explaination

##### Share on other sites
i have looked into relativity. i read a book that is supposed to explain it. it used a garbage example about a mirror and not being able to see your reflection. any moron could tell that it was a closed minded way of viewing the problem and it had logical flaws. a few years ago i was very interested it in relativity(and more importantly time dialation) and asked everyone i could find' date=' including a few physics teachers i knew, and no one found a way of explaining it that didnt have a very large flaw in the logic. id tell them why it didnt make sense and they would be stumped and say things like "when this guy explained it to me it made sense, im forgetting something." it was pretty irritating.

so i saw a thread on time travel and decided to give it another shot. as for your equations, they may be perfectly fine, but you could throw out any equation you wanted and im sure if we assume its correct you could prove that time dialation works. its the process of coming up with said equations that always seems to be flawed.[/quote']

First off, thanks to yourdadonapogos and Tycho? for answering my query, I'm still "relatively" new to all this and sometimes I get the travelling fast means slowing time down back to front in different perspectives, so thanks for clearing that one up.

Basically the faster you travel than other people the slower time moves for you than the other people, that's right isn't it??

And I think what Callipygous is looking for is an analogy he can apply to the phenomenon. Like I said, I'm finding it pretty difficult to grasp but I think that's because there are no real analogies you can apply to it. The only thing you can really do is look at the experiments and treat those as an analogy.

So this probably needs correcting, especially the things used and the figures but the basic principle should be sound.

I remember reading about an experiment they did. They stuck an atomic clock in either a fast train or a fast plane, when the plane landed the clock on board had lost a really small amount of time, something like a billionth of a second or something like that.

Another thing I remember reading somewhere was that satellites need to compensate for the time dilation effects, since they're orbitting the Earth at 20,000mph or something like that and everything left on Earth is moving at its slower pace.

The best analogy you can make after accepting those facts is..

Two twin brothers, one goes up in orbit for a while and the other stays on Earth. The one who went into space comes back slightly younger than his brother who stayed on Earth.

The thing that's now making my brain melt is if that's true where does that leave other heavenly bodies?? Say Pluto was orbitting the Sun twice as fast as our Earth was, doesn't that mean that Pluto will be physically younger than the Earth??

If it's moving faster it should be aging slower, shouldn't it??

And if that's right it should apply to every body in the universe, shouldn't it??

Another thing I can't help wondering about is Einstein told us and we proved it, that energy and matter are interchangeable. Atoms are made from protons, electrons and neutrons and energy is made from the same things.

Okay, I know it'd be pretty difficult to turn a human being into energy then reassemble the person but if you could do that doesn't that mean that light speed and therefore travelling into the future at a faster rate is possible??

##### Share on other sites
i have looked into relativity. i read a book that is supposed to explain it.

Quote of the week.

##### Share on other sites

why is that the quote of the week? i go on to mention all the people i tried to talk to about it... i read a book, i asked a bunch of smart people, was there something else i was supposed to do?

and no, im not looking for an analogy. i have heard dozens of analogies. i understand the idea(or at least i think i do), i know what the effects supposedly are, i want to understand why.

consider the following:

a------b------c

person "a" is moving left at 1/2c with repect to person "b", person "c" is moving right at 1/2c with respect to person "b". in person "b"s eyes, they are both moving 1/2c faster than himself and will there for experience the effects of time dialation. in person "a"s eyes, "b" is moving 1/2c faster than himself and "c" is moving a full c faster than himself. so "a" thinks "b" is aging at 1/2 speed and "c" isnt aging at all. "b" thinks "a" and "c" are both aging 1/2 speed. who is right? this could work if time dialtion factored in direction. if "a" could be going negative and "c" positive then it would all match up. am i missing something?

##### Share on other sites

and no' date=' im not looking for an analogy. i have heard dozens of analogies. i understand the idea(or at least i think i do), i know what the effects supposedly are, i want to understand why.

consider the following:

a------b------c

person "a" is moving left at 1/2c with repect to person "b", person "c" is moving right at 1/2c with respect to person "b". in person "b"s eyes, they are both moving 1/2c faster than himself and will there for experience the effects of time dialation. in person "a"s eyes, "b" is moving 1/2c faster than himself and "c" is moving a full c faster than himself. so "a" thinks "b" is aging at 1/2 speed and "c" isnt aging at all. "b" thinks "a" and "c" are both aging 1/2 speed. who is right? this could work if time dialtion factored in direction. if "a" could be going negative and "c" positive then it would all match up. am i missing something?[/quote']

Yeah, I think you should forget about direction.

I'm assuming person B is standing still, right??

And that you're saying person A from their perspective will be moving at twice the speed of person C.

What you need to remember is direction has no bearing on this time dilation thing, the law is the closer to the speed of light you move the slower time seems to pass for you in relation to things travelling at different speeds.

Whether 2 objects/people are moving along parallel or in opposite directions doesn't come into it. If they were both travelling at 1/2c then they'd both be moving through time at the same rate no matter which direction.

Hope that helps and more importantly I hope it's right.

I don't know if this is right or of any help but...

Isn't light speed like a universal time keeper??

The rate that time passes at light speed being universal time, the slower you move the faster you feel like you're moving through time.

##### Share on other sites
why is that the quote of the week? i go on to mention all the people i tried to talk to about it... i read a book' date=' i asked a bunch of smart people, was there something else i was supposed to do?

and no, im not looking for an analogy. i have heard dozens of analogies. i understand the idea(or at least i think i do), i know what the effects supposedly are, i want to understand why.

consider the following:

a------b------c

person "a" is moving left at 1/2c with repect to person "b", person "c" is moving right at 1/2c with respect to person "b". in person "b"s eyes, they are both moving 1/2c faster than himself and will there for experience the effects of time dialation. in person "a"s eyes, "b" is moving 1/2c faster than himself and "c" is moving a full c faster than himself. so "a" thinks "b" is aging at 1/2 speed and "c" isnt aging at all. "b" thinks "a" and "c" are both aging 1/2 speed. who is right? this could work if time dialtion factored in direction. if "a" could be going negative and "c" positive then it would all match up. am i missing something?[/quote']

Well strsaight away you have made one mistake, you have assumed velocity is a vector in relativity - it isn't. What this means is that you can't combine two velocities by vector addition, you must use somehting called the compostion of velcoties law and you find that 'a' will actually view 'c's' velocity as 0.8c .

You've also got a little muddled about time dialtion, the dialiton factor is not beta (the velocity of the object as a fraction of the speed of light), but gamma given by:

$\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}$

i.e.

$t' = \gamma t$

which means from the point of view of b one tick of both a's and c's clocks will both take about 1.15 secs as opposed to one secs in the rest frma eof the clock.

But from the point of view of a, his clock will not appear to be slowed down and he will infact that both b's clock and c's clock will be running slow (one tick on b's clock to him will take 1.15 secs, and c's clock will be even slower taking about 1.67 secs; c will also see the same except it will be a's clock that is running the slowest).

Now this may seem like it's paradox, but it's not, as they all see different things as they are in different frames of reference and all of them can consider their measurements of time to be correct in their own refrence frames. This is a very counterintuitve result of relativity, however the effects of time dialtion have been experimentally observed and the explantion is self consistent.

To summarize: time is frame dependent.

##### Share on other sites

I don't know if this is right or of any help but...

Isn't light speed like a universal time keeper??

The rate that time passes at light speed being universal time' date=' the slower you move the faster you feel like you're moving through time.[/quote']

No it's not quite right, there is no universal time and you must remeber that all speed is relative, except that is for the speed of light. Objects travelling at the speed of light don't have refrence frames tho'.

##### Share on other sites

ok, thanks for the info. but the exact numbers dont really matter much for what i was saying(i think...). because either way, "a" sees "b" as moving away from him, and therefore going through time slower (1.15 seconds per tick) and "b" sees "a" as the one that is moving so from his perspective "a" is ticking slower. it doesnt work out. one of them has to be ticking slower than the other.

with the clocks that were flown around the world, how did they know which one would come out ahead? from the planes perspective the one on the ground was moving away very fast behind it. if speed is reletive then why isnt the one on the ground the one that went slower?

if the guy on the plane looked at the ground clock would it look to him like the ground clock was the slower one? because thats the only way i could see this actually working.

##### Share on other sites
ok, thanks for the info. but the exact numbers dont really matter much for what i was saying(i think...). because either way, "a" sees "b" as moving away from him, and therefore going through time slower (1.15 seconds per tick) and "b" sees "a" as the one that is moving so from his perspective "a" is ticking slower. it doesnt work out. one of them has to be ticking slower than the other.

It does work, because the rate at which they tick is relative.

with the clocks that were flown around the world, how did they know which one would come out ahead? from the planes perspective the one on the ground was moving away very fast behind it. if speed is reletive then why isnt the one on the ground the one that went slower?

if the guy on the plane looked at the ground clock would it look to him like the ground clock was the slower one? because thats the only way i could see this actually working.

if a and b are both travelling with constant velcoity there is symmetry between them,howvere when the clock was flown around the world it was subject to acceleration, so the two obserevrs were not symmetric. It is easy to show that an unaccelarted observer experinces more time between two events than an accelarted observer.

##### Share on other sites
It does work, because the rate at which they tick is relative[/i'].

ok, relative to himself, b sees a as ticking slower. relative to himself, a sees b as ticking slower. they cant both be right. or are you talking "relative" on some other level.

##### Share on other sites
ok, relative to himself, b sees a as ticking slower. relative[/i'] to himself, a sees b as ticking slower. they cant both be right. or are you talking "relative" on some other level.

I am tlaking about the fact that the relative rate at which clocks 'tick' is itself relative.

a is correct for a's frame and b is correct for b's frame there is infact no contradiction.

##### Share on other sites
ok, relative to himself, b sees a as ticking slower. relative[/i'] to himself, a sees b as ticking slower. they cant both be right. or are you talking "relative" on some other level.

length also changes with speed. You get thinner as you speed up.

##### Share on other sites
The thing that's now making my brain melt is if that's true where does that leave other heavenly bodies?? Say Pluto was orbitting the Sun twice as fast as our Earth was' date=' doesn't that mean that Pluto will be physically younger than the Earth??

If it's moving faster it should be aging slower, shouldn't it??

And if that's right it should apply to every body in the universe, shouldn't it??

[/quote']

The sun is not the center of the universe. Nor is it stationary. The speed that pluto is moving, in relation to the earth, is not much different, considering the speed that our sun is moving in the galaxy. And the speed our galaxy is moving. Etc. Etc. I have no idea how *absolutely* fast we are moving, relative to the center of the universe, but might it be theoretically possible that something at the center of the universe, at a perfectly relativistic standstill, would be accelerated through time at a rate directly proportional to the rate at which we age, divided by the ratio of our absolute speed through the universe to the speed of light?

##### Share on other sites

I had thought about movement in space and the time distortion. What I ended up with was the thought about a single body like a pulsar for example. I it is rotating very fast and has a larger diameter then its center would be older than its surface. What does this mean for the reactions that occur within it.

##### Share on other sites

The sun is not the center of the universe. Nor is it stationary. The speed that pluto is moving' date=' in relation to the earth, is not much different, considering the speed that our sun is moving in the galaxy. And the speed our galaxy is moving. Etc. Etc. I have no idea how *absolutely* fast we are moving, relative to the center of the universe, but might it be theoretically possible that something at the center of the universe, at a perfectly relativistic standstill, would be accelerated through time at a rate directly proportional to the rate at which we age, divided by the ratio of our absolute speed through the universe to the speed of light?[/quote']

All motion is rrelative; there is no sauch thing as a 'relativstic standstill', 'absolute speed' or the centre of the universe.

##### Share on other sites

The sun is not the center of the universe. Nor is it stationary. The speed that pluto is moving' date=' in relation to the earth, is not much different, considering the speed that our sun is moving in the galaxy. And the speed our galaxy is moving. Etc. Etc. I have no idea how *absolutely* fast we are moving, relative to the center of the universe, but might it be theoretically possible that something at the center of the universe, at a perfectly relativistic standstill, would be accelerated through time at a rate directly proportional to the rate at which we age, divided by the ratio of our absolute speed through the universe to the speed of light?[/quote']

This is an interesting thread. But, the fact that the universe is expanding faster than the speed of light is different than the relative discussion here.

##### Share on other sites

This is an interesting thread. But' date=' the fact that the universe is expanding faster than the speed of light is different than the relative discussion here.[/quote']

what makes you think the universe expands at the speed of light? afik, it only contracts at c. it expands @ sub c.

##### Share on other sites
what makes you think the universe expands at the speed of light? afik, it only contracts at c. it expands @ sub c.

Think carefully what you mean by the universe expands at such and such a speed. Really the rate at which the universe expands is not a speed, it's measrued in units of s^-1. You can certainly talk about recssion velcoties, which may certainly be greater than c (infact the recession velcoties of the furtherest galaxies are greater than c) but these are dependent on distance, so they're not a measure of how fast the universe expands as a whole.

##### Share on other sites

how does a galaxy travel faster than c? link plz

## Create an account

Register a new account