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Is the end of the world comming


four-wheel-drive
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To give a quick example of importance of this kind of research when it comes to our daily lives....

 

Believe it or not, the satelites in orbit running the GPS system are traveling slower through time 'relatively' than the gps receivers on surface of the planet... Yep... even your (now) humble TomTom is subject to relativity. The clocks on the satelites have to be accurate to the order of nanoseconds to allow earth based systems to measure distances accurately and any error will grow exponentially, soooo... a correction has to be made to account for relativity and the difference between the perceived passage of time in orbit and on the surface....

 

A satellite will lose 7 micro seconds per day (0.000007 seconds), for your information :good:

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Oh goody - after 42 years of driving metal tubes through the sky - I have now discovered that I am 8 micro seconds younger than I thought I was.

Hooray for science - Bring it on.

 

I did say in my previous post that the two atomic clocks which were tested were billionths of a second out..!

 

Sorry to disappoint :P

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Here's a bit of 'light' reading for you

 

http://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment

 

The closer to the speed of light you travel, the slower time goes by. You could in theory do a bit of 'Sound travelling' if you liked:

 

Observe a man shooting a shotgun 100 yards away. You see the gun move and the hear the bang a couple of milliseconds later. If you could physically travel at say 10,000mph and move back from the shooter another 500 yards, you would pass the sound wave and when you stop and reach the 600 yard mark, you'll hear the bang again.

 

The theory is that if you travel faster than the speed of light, you will travel back in time, but up until the moment you reach the speed of light, time for you has been slowing.

 

Are you a reincarnated Douglas Adams? :hmm:

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Here's a bit of 'light' reading for you

 

http://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment

 

The closer to the speed of light you travel, the slower time goes by. You could in theory do a bit of 'Sound travelling' if you liked:

 

 

However... and this is where it gets slightly confusing... the perception of time moving faster or slower is only from the perspective of the oserver, passage through time isn't 'physically' altered only perception is changed but that changed perception manifests itself as a physical change in the eyes of the observer... simples :good:

 

So... in Billy's example, time would only appear to move slower from the stationary observer sat on earth, aboard the spacecraft traveling at near c, all would seem normal and if I am correct, the perception would be changed depending on whether the ship was moving away from or towards the observer

Edited by Vipa
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However... and this is where it gets slightly confusing... the perception of time moving faster or slower is only from the perspective of the oserver, passage through time isn't 'physically' altered only perception is changed but that changed perception manifests itself as a physical change in the eyes of the observer... simples :good:

 

So... in Billy's example, time would only appear to move slower from the stationary observer sat on earth, aboard the spacecraft traveling at near c, all would seem normal and if I am correct, the perception would be changed depending on whether the ship was moving away from or towards the observer

 

Yup, the passage of time is all relative to the 'observer'..if you got on a spaceship and travelled into space at close to light speed for a year, then turned around and came back to earth again, for you 2 years would have passed but on earth you would have been away for decades. It is mind boggling stuff. The very best and easiest explanation I have read is in Brian Cox's book "why e=mc2 and why we should care" Of course, this could now all be rubbish :blink: but this is still worth a read.

 

Another reason why this could be important is that it could get us closer to understanding the nature of mass...imagine if we could remove the mass from an object, transport it thousands of miles at high speed using little or no energy, then replace the mass when it got to it's destination...

 

I just didn't 'get' physics when I was at school, now I keep buying books on the subject, it is fascinating and can't get enough of it. Still difficult to get your head around much of it, especially the quantum stuff (some particles being in two different places at the same time is a bit tough to accept)...but life changing when you eventually get there.

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(some particles being in two different places at the same time is a bit tough to accept)...but life changing when you eventually get there.

 

Please enlighten me on Schrödinger's cat. I still haven't managed to get my head around it.

 

http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_cat

 

Makes me wonder that if I ever wanted to kill someone, putting them in a sealed steel box, I could explain to the police that the laws of quantum physics states that the person in the box is alive, regardless of how long they've been in there.

 

..Would that stand up in court, or would they just arrest me for imprisoning someone against their will, thus meaning the box would be opened and the person would then be dead. I am then arrested for murder :rolleyes:

Edited by Billy.
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Please enlighten me on Schrödinger's cat. I still haven't managed to get my head around it.

 

http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_cat

 

Makes me wonder that if I ever wanted to kill someone, putting them in a sealed steel box, I could explain to the police that the laws of quantum physics states that the person in the box is alive, regardless of how long they've been in there.

 

..Would that stand up in court, or would they just arrest me for imprisoning someone against their will, thus meaning the box would be opened and the person would then be dead. I am then arrested for murder :rolleyes:

 

It's the bit about atoms changing their state when being observed which would suggest they know when you are looking at them that gets me!

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The trouble is, your victim is both alive and dead at the same time. So I suppose they could put you in a box and say you are both free and in prison at the same time...

 

Just finished a book called "How to teach quantum physics to your dog" by Chad Orzel. Understood about a quarter of it, and need to start again to see if I absorb any more, but I did sort of get the Schroedinger's cat bit. The trouble is that the whole concept is just so alien to the way we understand the non-quantum world (ie everyday life) you have to kind of stop your brain and restart it in 'quantum' thinking mode.

 

After about 10 pages I just need to sit somewhere quiet, drink beer and stare into space for a bit. Mind blowing.

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The trouble is, your victim is both alive and dead at the same time. So I suppose they could put you in a box and say you are both free and in prison at the same time...

 

Just finished a book called "How to teach quantum physics to your dog" by Chad Orzel. Understood about a quarter of it, and need to start again to see if I absorb any more, but I did sort of get the Schroedinger's cat bit. The trouble is that the whole concept is just so alien to the way we understand the non-quantum world (ie everyday life) you have to kind of stop your brain and restart it in 'quantum' thinking mode.

 

After about 10 pages I just need to sit somewhere quiet, drink beer and stare into space for a bit. Mind blowing.

Seem to remember reading this book myself - twice. As you I understood about 25% first time. Ditto for the second reading. Trouble was that it was a different 25% on the second attempt. They cancelled each other out and I couldn't tell 'touther from twitch. Next time round I shall read every third page only.

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