Faster than the speed of light?

[DTES]

nope. the sat nav still works, and the calculations dont change. its only the theoretical understanding of why it works that changes. one hundred years ago they didnt understand the nature of particle physics as they do today, they still managed to get electricity, radio and all sorts of other technology working fine.

Fair enough - allow me to rephrase. Relativity time adjustments weren't made by trial and error - someone didn't sit there with a Sat Nav trying adjustment after adjustment until they were right. The calculations were generated directly from Einstein's theory and then, when tested, they agreed exactly.

The coincidence involved in the theory being completely wrong but the satellites' path through time being affected by the exact same amount is phenomenal. For me (and the scientists involved - hence them opening up the data and asking for others to analyse it), it's far more likely that there is an error in this experiment than in the theory.

Of course you're right in that it doesn't mean that your sat nav suddenly stops working. It does however mean we got phenomenally lucky by essentially guessing how it would work.

 

[Mr deez]

Shame you didn't pip up with this incredible knowledge anytime in the last 50 years..

It came to me whilst pissed up. I'm know at a loss as to what I was thinking, deciding to start a physics debate at half 2 in the morning.

 

[Doc Lynam]

This means that the faster you go through space, the slower you experience the passage of time.[/I]"

This is why Craig Mackail Smith will live a little bit longer then most

 

[Kalimantan Gull]

Regardless of how robust everyone's experiments have been, we still haven't married Einsteins theories to Newton's theories - so maybe they're both wrong and this is leading us to a third way?

 

[DTES]

Regardless of how robust everyone's experiments have been, we still haven't married Einsteins theories to Newton's theories - so maybe they're both wrong and this is leading us to a third way?

What are you basing this on? As I understand it, general relativity replaced Newton's theory of gravity - however under usual circumstances (i.e. on the surface of the Earth) Newton offers a close enough approximation.

 

[Guy Fawkes]

Time is not an isolated construct, its not a product of our mind and its not linear. If you and I took two watches and sychronised them and you shot off into space for a trip to mars and back, and lets say you hit significant speeds (any decent proportion of light speed), when you return my watch will be ahead of your watch.

Infact if you went fast enough for long enough, you could come back to a world 10 years into the future, while you have hardly aged at all. Hence the sci-fi stories of that kind of stuff.

This fundimental relationship between space and time is what is so amazing about special relativity, but its hard to get your head around at first.

But why is time directly related to speed of light? Does time go faster if you were travelling from A to B in a car or train for instance (even if barely noticable?) compared to walking it? (would you gain or lose millionths of a second?) and so why would light speed make that difference.

Surely it just means that you are travelling at a greater speed than it takes light from an object ahead of you to reach you but the object you are travelling to is in the present and the image you see before you leave is what it looked like beforehand (depending on how far away you are determines how old the image appears) - for example, the image of the sun we see from Earth is that from several seconds before the light left the sun, it doesn't mean the sun is really several seconds in the past or future. If we then travelled at over the speed of light to the sun, the sun is still in the time as it was before and all that has changed is the image we see isn't as old as before but its not time travel.

If you were in Calais and looking at the White cliffs of Dover and the light took 10 second to reach you in france from Dover, by travelling to Dover by ferry you find that the light takes 1 second to reach you from that same cliff as you are nearer, does that mean time travel? Or if you were to travel around the world by plane and arrive at a local time a few hours before you took off from London, would that be time travel, even though the same amount of time has past at both your departure point, arrival point and whilst you were travelling.

Is the speed of light just used as a measure because we don't know of anything (yet ) that travels faster and it is a convenient measure to use as its the faster known thing to man?

 

[DTES]

But why is time directly related to speed of light? Does time go faster if you were travelling from A to B in a car or train for instance (even if barely noticable?) compared to walking it? (would you gain or lose millionths of a second?) and so why would light speed make that difference.

Surely it just means that you are travelling at a greater speed than it takes light from an object ahead of you to reach you but the object you are travelling to is in the present and the image you see before you leave is what it looked like beforehand (depending on how far away you are determines how old the image appears) - for example, the image of the sun we see from Earth is that from several seconds before the light left the sun, it doesn't mean the sun is really several seconds in the past or future. If we then travelled at over the speed of light to the sun, the sun is still in the time as it was before and all that has changed is the image we see isn't as old as before but its not time travel.

If you were in Calais and looking at the White cliffs of Dover and the light took 10 second to reach you in france from Dover, by travelling to Dover by ferry you find that the light takes 1 second to reach you from that same cliff as you are nearer, does that mean time travel? Or if you were to travel around the world by plane and arrive at a local time a few hours before you took off from London, would that be time travel, even though the same amount of time has past at both your departure point, arrival point and whilst you were travelling.

Is the speed of light just used as a measure because we don't know of anything (yet ) that travels faster and it is a convenient measure to use as its the faster known thing to man?

Nope it isn't just a measure, it actually does change. The reason is that you (everything in the universe) is permanently travelling at a constant "speed" - the speed of light - through spacetime. Therefore the faster you are moving through the space dimensions, the slower you are travelling through the time dimension.

If you are stationary, you are going at maximum speed through the time dimension hence time goes fastest. If you are travelling at near light-speed, you don't have much "speed" left to go through the time dimension hence time passes slower.

Sounds crazy, but it's been tested - atomic clocks on planes zooming around the planet tick slower than clocks on the surface, and clocks on satellites tick slower than those at the bases monitoring them.

 

[DTES]

But why is time directly related to speed of light? Does time go faster if you were travelling from A to B in a car or train for instance (even if barely noticable?) compared to walking it? (would you gain or lose millionths of a second?) and so why would light speed make that difference.

Surely it just means that you are travelling at a greater speed than it takes light from an object ahead of you to reach you but the object you are travelling to is in the present and the image you see before you leave is what it looked like beforehand (depending on how far away you are determines how old the image appears) - for example, the image of the sun we see from Earth is that from several seconds before the light left the sun, it doesn't mean the sun is really several seconds in the past or future. If we then travelled at over the speed of light to the sun, the sun is still in the time as it was before and all that has changed is the image we see isn't as old as before but its not time travel.

If you were in Calais and looking at the White cliffs of Dover and the light took 10 second to reach you in france from Dover, by travelling to Dover by ferry you find that the light takes 1 second to reach you from that same cliff as you are nearer, does that mean time travel? Or if you were to travel around the world by plane and arrive at a local time a few hours before you took off from London, would that be time travel, even though the same amount of time has past at both your departure point, arrival point and whilst you were travelling.

Is the speed of light just used as a measure because we don't know of anything (yet ) that travels faster and it is a convenient measure to use as its the faster known thing to man?

Actually, another point to add - the reason all this happens is (despite how counter-intuitive it is), light will travel at the same speed past you whatever speed you are travelling at. If you are sitting still, you will see light coming toward you from the front, left, right or behind at light speed, but if you were flying through the universe at half the speed of light, you wouldn't suddenly see it approaching from the front at 1 1/2 times the speed of light, and only 1/2 speed from behind - you would still see it at exactly 299,792,458 m/s from all directions.

 

[Guy Fawkes]

If you apply the principles of special relativity, and consider that light is a) very fast and b) does not age (pass through time), it makes sense.

The question is, how do we know that light does not pass through time. That is more complicated to answer. My understanding is that no time passes (for the photon) between when it is emitted and when it is absorbed. In fact I think that the implications of the way light works are that there is no time or distance between point A (emission) and point B (absorbtion), despite what we experience. But this starts to go over my head at this point tbh.

But isn't that down to scaling, we cannot calculate this because we can't measure this on a vast enough scale. If we see light detected by Hubble from a far distant galaxy, the galaxy we see is from the time the light was first emitted and we would see it years later after that light has travelled over vast distances to reach us, doesn't that make the light the same age as it has taken to reach us, it can't be instantanious from the galaxy we observe so it must have some measureable age. So in the same respect, we can't necessarily measure the age of light at present, doesn't mean it doesn't pass through time as otherwise we would see what is there currently and not something that might have already died out long ago

If light travels at 299,792,458 metres per second and say a photon moves at 50 times the speed of light or 14,989,622,900 metres per second, its speed over the small distance we might try to use to calculate from could appear to be instantanious, if we were able to scale up our scale and be able to measure we could be talking about having something several hundreds of thousands of miles long in order to see clear definitive result, something we might not be able to measure on Earth but need to use space in order to give enough distance between the emitter and receiver, which is something we can't do at the moment with our technology.

 

[sten_super]

But why is time directly related to speed of light? Does time go faster if you were travelling from A to B in a car or train for instance (even if barely noticable?) compared to walking it? (would you gain or lose millionths of a second?) and so why would light speed make that difference.

It's the reverse - if you are travelling at speed then time goes slower. I read a stat earlier which talked about someone who spend c2 years on the International Space Station - and came back something like 0.000000007 seconds less aged than if he'd spent exactly the same amount of time on Earth.

Surely it just means that you are travelling at a greater speed than it takes light from an object ahead of you to reach you but the object you are travelling to is in the present and the image you see before you leave is what it looked like beforehand (depending on how far away you are determines how old the image appears) - for example, the image of the sun we see from Earth is that from several seconds before the light left the sun, it doesn't mean the sun is really several seconds in the past or future. If we then travelled at over the speed of light to the sun, the sun is still in the time as it was before and all that has changed is the image we see isn't as old as before but its not time travel.

Special relativity states that time and space (that is to say, movement through space) are inextricably linked. The faster you move, the slower time goes (relative to some fixed point). Theory says that, as you approach the speed of light, time slows dramatically; if you got within a few metres per second then trillions of years would pass for everyone else in the blink of an eye for you. This suggests that, if you managed to reach the speed of light (it's thought to be impossible) then time would stop altogether. Therefore if you exceeded it, who knows what would happen.

If you were in Calais and looking at the White cliffs of Dover and the light took 10 second to reach you in france from Dover, by travelling to Dover by ferry you find that the light takes 1 second to reach you from that same cliff as you are nearer, does that mean time travel? Or if you were to travel around the world by plane and arrive at a local time a few hours before you took off from London, would that be time travel, even though the same amount of time has past at both your departure point, arrival point and whilst you were travelling.

They've tested this using atomic clocks, as dingodan stated earlier. They set two atomic clocks to match perfectly and then sent one off on a plane around the world. When it arrived back it was minutely (i.e. 0.0000000000001, probably less, of a second) behind the other other because it had been moving quicker, and therefore time had slowed.

Is the speed of light just used as a measure because we don't know of anything (yet ) that travels faster and it is a convenient measure to use as its the faster known thing to man?

In a word, no. The speed of light is thought to be a fixed constant, and until now (in fact still now, until they can verify these results) it was not thought that anything moved faster than the speed of light - gravity waves move at the speed of light as do many other kinds of waves. It's a fundamental constant in the universe (at least physicists think it is!).

 

[Guy Fawkes]

Nope it isn't just a measure, it actually does change. The reason is that you (everything in the universe) is permanently travelling at a constant "speed" - the speed of light - through spacetime. Therefore the faster you are moving through the space dimensions, the slower you are travelling through the time dimension.

If you are stationary, you are going at maximum speed through the time dimension hence time goes fastest. If you are travelling at near light-speed, you don't have much "speed" left to go through the time dimension hence time passes slower.

Sounds crazy, but it's been tested - atomic clocks on planes zooming around the planet tick slower than clocks on the surface, and clocks on satellites tick slower than those at the bases monitoring them.

How do you know conclusively that the atomic clocks weren't affected by other variables like pressure for example which could have affected the outcome and produced the difference? If you take offm fly at a certain altitude and land, the pressure around the clockwill change and this could influence how fast or slow it runs at, whereas the one on the ground would have been in a constant pressure

 

[Shooting Star]

GOSBTS is faster than the speed of light.

 

[DTES]

How do you know conclusively that the atomic clocks weren't affected by other variables like pressure for example which could have affected the outcome and produced the difference? If you take offm fly at a certain altitude and land, the pressure around the clockwill change and this could influence how fast or slow it runs at, whereas the one on the ground would have been in a constant pressure

Atomic clocks will not be affected by such things as pressure.

Also, if it isn't relativity causing it, it's one hell of a coincidence that every single test has agreed within billionths of a second to what the calculations predict!

 

[Garry Nelson's Left Foot]

If you are travelling at near light-speed, you don't have much "speed" left to go through the time dimension hence time passes slower.

.

What are the ramifications for the motto of youthful rebellion-live fast, die young? Does this mean that living life in the fast lane will make you live longer? Should I start running everywhere?

Science is fascinating but I'll be buggered if I can gt my head round much of it.

 

[sten_super]

But isn't that down to scaling, we cannot calculate this because we can't measure this on a vast enough scale. If we see light detected by Hubble from a far distant galaxy, the galaxy we see is from the time the light was first emitted and we would see it years later after that light has travelled over vast distances to reach us, doesn't that make the light the same age as it has taken to reach us, it can't be instantanious from the galaxy we observe so it must have some measureable age. So in the same respect, we can't necessarily measure the age of light at present, doesn't mean it doesn't pass through time as otherwise we would see what is there currently and not something that might have already died out long ago

If light travels at 299,792,458 metres per second and say a photon moves at 50 times the speed of light or 14,989,622,900 metres per second, its speed over the small distance we might try to use to calculate from could appear to be instantanious, if we were able to scale up our scale and be able to measure we could be talking about having something several hundreds of thousands of miles long in order to see clear definitive result, something we might not be able to measure on Earth but need to use space in order to give enough distance between the emitter and receiver, which is something we can't do at the moment with our technology.

My (extremely limited) understanding is that discussions of photons 'ageing' are more to do with the fact that they don't show signs of decay no matter how long they have been travelling for. As you say, we know that the view we have of the galaxy at night is thousands upon thousands of years old in many cases - but the fact that this light still reaches us, even after hundreds of thousands of years travelling through space, indicates that it's not decaying. We are already able to measure very fast speeds over small distances - in fact this whole discovery of particles possibly moving faster than the speed of light was based upon a 730km journey done by these neutrinos which took 2.4 milliseconds.

 

[Guy Fawkes]

It's the reverse - if you are travelling at speed then time goes slower. I read a stat earlier which talked about someone who spend c2 years on the International Space Station - and came back something like 0.000000007 seconds less aged than if he'd spent exactly the same amount of time on Earth.
Special relativity states that time and space (that is to say, movement through space) are inextricably linked. The faster you move, the slower time goes (relative to some fixed point). Theory says that, as you approach the speed of light, time slows dramatically; if you got within a few metres per second then trillions of years would pass for everyone else in the blink of an eye for you. This suggests that, if you managed to reach the speed of light (it's thought to be impossible) then time would stop altogether. Therefore if you exceeded it, who knows what would happen.
They've tested this using atomic clocks, as dingodan stated earlier. They set two atomic clocks to match perfectly and then sent one off on a plane around the world. When it arrived back it was minutely (i.e. 0.0000000000001, probably less, of a second) behind the other other because it had been moving quicker, and therefore time had slowed.
In a word, no. The speed of light is thought to be a fixed constant, and until now (in fact still now, until they can verify these results) it was not thought that anything moved faster than the speed of light - gravity waves move at the speed of light as do many other kinds of waves. It's a fundamental constant in the universe (at least physicists think it is!).

If you can travel faster than the speed of light and you could travel out far enough you could then observe the light from the time when dinosaurs roamed the Earth and see them if you had a powerful enough telescope. If you were to then travel back to Earth at greater than the speed of light again you wouldn't find that there were still dinosaurs there or still to appear, so is it time travel? The Earth would have carried on aging while you were gone and if you were gone 20 years, and when you returned the Earth would be 20 years older as expected, you would have been observing an echo and not the present.

 

[Guy Fawkes]

Atomic clocks will not be affected by such things as pressure.

Also, if it isn't relativity causing it, it's one hell of a coincidence that every single test has agreed within billionths of a second to what the calculations predict!

Not necesasarily pressure then, but there could be other factors, like Gravity, effects resulting in the atomic clocks density changing (possibly minutely and not really detectable but enough to influence the result) or maybe some unknown influence / forces at work.

Scientific fact is always something that is deemed correct until proven wrong and is not and possibly never will be a 100% certainty.

 

[sten_super]

If you can travel faster than the speed of light and you could travel out far enough you could then observe the light from the time when dinosaurs roamed the Earth and see them if you had a powerful enough telescope. If you were to then travel back to Earth at greater than the speed of light again you wouldn't find that there were still dinosaurs there or still to appear, so is it time travel? The Earth would have carried on aging while you were gone and if you were gone 20 years, and when you returned the Earth would be 20 years older as expected, you would have been observing an echo and not the present.

It's more fundamental that simply seeing light from an earlier time (in fact it's nothing to do with light at all). It's that the rate at which time passes (relatively) is inverse to the speed that you are travelling at (relatively).

Let me give you an example. If I sat here, and you set off in a super-fast spaceship (a lot faster than anything in existence today), and you came back to Earth after 20 years of flying around, you'd find that I would be 21 years older, even though you are only 20 years older. Because you were moving faster than me, you experienced time more slowly.

It's a bit of a headfuck but that's our current understanding (and, as DTES says, there is plenty of evidence that it's true, even if our understanding is not spot on) of how it works.

 

[Guy Fawkes]

My (extremely limited) understanding is that discussions of photons 'ageing' are more to do with the fact that they don't show signs of decay no matter how long they have been travelling for. As you say, we know that the view we have of the galaxy at night is thousands upon thousands of years old in many cases - but the fact that this light still reaches us, even after hundreds of thousands of years travelling through space, indicates that it's not decaying. We are already able to measure very fast speeds over small distances - in fact this whole discovery of particles possibly moving faster than the speed of light was based upon a 730km journey done by these neutrinos which took 2.4 milliseconds.

Is that because of scale again? We are not able to measure them at 2 points far enough apart to be able to spot any differences?

Going back to light, if we observe the oldest galaxy found so far at 13.2 billion years old and measure the light there and if it was possible to measure the same piece of light again but another 13.2 billion years later we could see if there was any difference or decay in ther light however we are only able to measure it over a very small piece of time and space - we don't know if that image was a lot brighter originally than light from later galaxies found but time and decay have dulled it or vice versa.

 

[Guy Fawkes]

It's more fundamental that simply seeing light from an earlier time (in fact it's nothing to do with light at all). It's that the rate at which time passes (relatively) is inverse to the speed that you are travelling at (relatively).

Let me give you an example. If I sat here, and you set off in a super-fast spaceship (a lot faster than anything in existence today), and you came back to Earth after 20 years of flying around, you'd find that I would be 21 years older, even though you are only 20 years older. Because you were moving faster than me, you experienced time more slowly.

It's a bit of a headfuck but that's our current understanding (and, as DTES says, there is plenty of evidence that it's true, even if our understanding is not spot on) of how it works.

However as DTES said, it was done on a small scale in a plane around the planet. If both clocks were in space to start with and all conditions were the same (they weren't in the planes test) and one travelled a very long distance and returned you may get a diefferent result.