Not quite, for an external stationary observer looking into the spacecraft etc time would appeared to have slowed down, but to everyone on the ship time for them would be flowing at exactly the same rate as before.
Speed of light and its affects
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Not quite, for an external stationary observer looking into the spacecraft etc time would appeared to have slowed down, but to everyone on the ship time for them would be flowing at exactly the same rate as before.
I know how it works. I did advanced higher physics
I know how it works. I did advanced higher physics
Yeah, well i did super duper advanced higher physics so nuerghhhhh!
Soldato
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you might have indeed.
It has to do with relativity, an object at the speed of light, will be equal with time, but to the outside observer it would take X amount of time.
If you travel away from earth at the speed of light, to you it would seem instant, however a long time might have actually passed. So when you return to earth, it might be hundreds or thousands of years later.
and to answer your question, yes
Soldato
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I concede. My coworker just made it a little clearer for me, using the ripple example. We have two observable objects a and b that are x metres apart and y metres from the observer. A gravitational wave will affect a before it affects b. Based on x, we can compare to C how long it took for the wave to affect both objects. I understand that all experiments so far show that it is equal to C. Very interesting.
Ok, I kind of understand in my own head now. Tough to explain as you said.
Turning around messes up special relativity (time dilation caused by travelling fgast compared to light) so you'd need more complicated general relativity to explain what the time passed in each frame would be.
If I wasn't clear there, look up the twin paradox.
You don't need to get too complicated to work out the time frames, it's just Lorentz factors. Also the twin paradox is only a paradox if you don't understand the physics. There is no paradox in the twins becoming different ages since one twin is changing inertial frames whilst the other stays in the same one.
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I wasn't talking about mavity, I meant SR.
The twins remain the same age due to the twin that is travelling having to turn around to meet the other twin, this is explained in GR, SR can't explain it.
I'm pretty sure the twins don't remain the same age and Special Relativity explains why just fine. General relativity deals with gravitational time dilation (amongst other things) which isn't needed since acceleration and mavity don't affect the outcome of the so called twin paradox. The reason for one twin ageing differently to the other is because the travelling twin will experience 2 different frames of reference, both of which have to be kept track of when calculating the relative time passed. The twin who stays at home exists in a single constant frame of reference. This is why the journey is different for each respective twin and accounts for the variation in time experienced.
If twin 1 remains, for example, on Earth, and twin 2 travels at a speed close to c for a time, then turns and comes back to Earth (the frame of reference of twin 1) then the twins will be the same age, irrespective of frame of reference. This was told to me, more than once, by my teacher, whose DPhil is in quantum physics. He said it is because the complications, caused by turning around, are not explained by SR.
A question related to the twin paradox.
If each twin had a video camera that broadcasts via radiowaves (i.e. the speed of light) and each twin had a screen to display the other twins broadcast. Would each twin observe the other twin moving/living/ageing more slowly than themselves?
If each twin had a video camera that broadcasts via radiowaves (i.e. the speed of light) and each twin had a screen to display the other twins broadcast. Would each twin observe the other twin moving/living/ageing more slowly than themselves?
I'm sorry but your teacher is wrong.
Twin 2 does not remain in an inertial frame of reference.
The 'paradox' is because you initially think that twin 1 could effectively be moving relative to twin 2, but twin 1 is the only one who remains in a inertial frame.
You can use general relativity to solve things by looking at the acceleration of twin 2 as he moves back towards earth, but there is a perfectly viable solution using only special relativity.
Indeed we covered this fact in a special relativity module during my degree.
Yep i'm sorry but either you teacher is wrong or more likely you've understood him wrongly. Each twin does observe the others clock running slowly but they're not measuring the same thing due to the reference frame changing when the twin comes back. It's not a complication at all. GR isn't used at all for this kind of stuff, it's SR all the way and easily explained.
If what you were saying was true then effectively if you're travelling in one direction time slows down and then if you go the other time speeds up but that's not what happens.
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What if I had a *really* long stick, and poked someone with it who was millions of miles away and at the same time I switched on a super bright laser? In the same way that with electrons down a wire, they move very slowly, but the electromagnetic waves are almost instantaneous. If you had a light enough stick that you could move it reasonably quickly, nothing has to go faster than the speed of light, but you would still have communicated faster than it. Unless there's a reason this wouldn't work
What if I had a *really* long stick, and poked someone with it who was millions of miles away and at the same time I switched on a super bright laser? In the same way that with electrons down a wire, they move very slowly, but the electromagnetic waves are almost instantaneous. If you had a light enough stick that you could move it reasonably quickly, nothing has to go faster than the speed of light, but you would still have communicated faster than it. Unless there's a reason this wouldn't work
Unfortunately sticks aren't perfectly rigid so when you push one end the other doesn't move instantly. In effect relativity places a limit on how rigid a stick can be so that it cannot allow for FTL communication etc. I like the theory though!Also EM waves do not travel almost instantaneously, they travel at the speed of light.
My understanding of that is that the stick movement (message) travels at the speed of light also so there would be a delay at the other end.What if I had a *really* long stick, and poked someone with it who was millions of miles away and at the same time I switched on a super bright laser? In the same way that with electrons down a wire, they move very slowly, but the electromagnetic waves are almost instantaneous. If you had a light enough stick that you could move it reasonably quickly, nothing has to go faster than the speed of light, but you would still have communicated faster than it. Unless there's a reason this wouldn't work
Edit: beaten.
What if I had a *really* long stick, and poked someone with it who was millions of miles away and at the same time I switched on a super bright laser? In the same way that with electrons down a wire, they move very slowly, but the electromagnetic waves are almost instantaneous. If you had a light enough stick that you could move it reasonably quickly, nothing has to go faster than the speed of light, but you would still have communicated faster than it. Unless there's a reason this wouldn't work
If you consider this stick at an atomic level, one atom pushes another and so on. For this to work there must be a repulsion between the outer electron shells of the atoms when they push into each other (otherwise the atoms would simply merge into each other). The repulsion force in this instance is the electromagnetic force, who's force carrier (particle that allows the transfer of the force) is actually the photon which travels at the speed of light.
So sorry, my comment still holds true!
EDIT\ for those cleverer than me, i would be interested to hear an answer to my question in post #73
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