0 Members and 1 Guest are viewing this topic.
In the 2D analogy, a moving circle is length contracted so that observer A in the center receives simultaneous reflections from a signal emitted from the center. In the 3D equivalent, the sphere becomes an ellipsoid with the same results.The moving inertial frame behaves like a rest frame.The clock in the radar gun will be affected by time dilation. The device will sense an earlier time and calculate a shorter distance, just as a human would, resulting in the same relative speed for the target.
yes, my reply was for contstant speed scenario, but also for acceleration, however, the shift would vary as speed increased.
Your friend who if could observe the same light as was emmitted by the emmitter travelling at 0.5c compared to him, should see some significant redshiftof the light, in like with the pr experiment d3pending whether the emmitter had pased him or not. No clock no redshift.[\quote]
how do you rectify which time dilation you use depending on whether you are travelling along with the light or at an opposed 180 direction?
Your friend who if could observe the same light as was emmitted by the emmitter travelling at 0.5c compared to him, should see some significant redshiftof the light, in like with the pr experiment d3pending whether the emmitter had pased him or not. No clock.
So the idea of relativity and you observing a different clock is uneeded as you are travelling along with the emmitter .
So if a pulse was fired within the gun sphere it would detect your absolute velocity if we had the technology refined enough , magnetism and gravity allowed for (touch complicated) and the difference between our velocities and c (0.000000001%) due to light pulse arriving at different times in the emmitter.
relativity is only if there are two frames relative to the emmitter ?
You don't. Time dilation has nothing to do with whether you are travelling with or against a light beam. It only has to do with the relative speed of you (with the emitter) and your friend.
I'm not at all sure why you are mentioning PR, in that experiment there is no relative motion only a gravitational potential difference. PR was not a doppler shift.
Also, why do you say “no clock”? If your friend is travelling relative to the emitter then the emitter clock and your friend’s clock will differ./
But your friend isn't, s/he is moving relative to you so you each have differing clocks.
No, it won't tell you anything about absolute velocity, all you can work out is your relative velocities.
But there are 2 frames relative to the emitter, you (even though you might not think you are moving in space) and your friend. All you can ever work out is the speed of yourself relative to your friend and to the emitter. The sphere and emitter are not fixed to any absolute reference.
well this is to do with the way of understanding it of relativity.
If you are travelling toward an ioncoming light beam your "clock " speeds up, showing you no doppler ?
i thought pr was to test wether gravity gave a doppler effect to light, ie travelled faster, and the speaker movement rectifying this ?
It is to do with if you meet light oncoming and being able to tell your position.
Incedentally why did they observe doppler shifts when increaced wavelength was met with slower clocks. Special relativity ?
relative velocity compared to the absolute C that is independant of gravity ?
they are fixed at set distances to each other, and whilst you stay fixed to them you are in there frame ? So one pulse, and measure the strike intervals on the sphere you measure the absolute velocity of the frame ?
Which is it Colin either A pulse in all directions equal to the velcity of the sphere going equally in all directions and hitting the sphere sides all at onceOr a pulse going at its own independant velocity to the velocity of the sphere , striking the sphere at differen TIMES.As i mentioned phyti elongated elliptical sphere is the only way to rectify it?
Which is it Colin either A pulse in all directions equal to the velcity of the sphere going equally in all directions and hitting the sphere sides all at onceOr a pulse going at its own independant velocity to the velocity of the sphere , striking the sphere at differen TIMES. As i mentioned phyti elongated elliptical sphere is the only way to rectify it?
AdWnit it colin it confuses you too
phyti explaination is in the right area. Im gonna mark it best answer ............
The moving inertial frame behaves like a rest frame.
Yes the light gun has to be travelling at the same rate as the sphere, i said so.
If you turn on your headlights at speed c no light is emmitted, if you turn your rear lights on at c light still emmits at c that is basically the paradox. Explained by the ellipsoid.
The light forward of your emmitter within the sphere will be emmitted under increaced velocity, the light behind you under decreaced velocity.
Quote from: Petrochemicals on 19/10/2017 14:15:34The light forward of your emmitter within the sphere will be emmitted under increaced velocity, the light behind you under decreaced velocity. (if I interpret correctly)Light does not aquire the speed of the emitter. That is the subtle difference when adding velocity vectors of material objects. It is the reason for time dilation.
Quote from: phyti on 19/10/2017 16:44:40Quote from: Petrochemicals on 19/10/2017 14:15:34The light forward of your emmitter within the sphere will be emmitted under increaced velocity, the light behind you under decreaced velocity. (if I interpret correctly)Light does not aquire the speed of the emitter. That is the subtle difference when adding velocity vectors of material objects. It is the reason for time dilation.Yep phiti thanks im beginning to get it. Like you say the shape fits the need, i can only think what shape the ellipsiod would take lengthening and narrowing ?, and how light would behave as suggested by Janus , if a reflection was used in the sphere ?How much of the sphere is forward of the emmitter ?How does the light bounce off the inside, given light emmitted sideways will end up along way to the rear of the emmitter, but for reflection purposes it would have to follow its course back ?How long must the sphere become?Would there be lensing as the light passes from the time dilation, to the other time dilation?Pete