ravikannaujiya, please consider spending a little more effort on your posts. Instead of just asking everything that comes to your mind, narrow it down to one or two key points. Then present those points using paragraphs to organize your thoughts in a logical manner.
ravikannaujiya said:
@ daleSpam, then pls clarify me
If we can not measure absolute time and distance in relativistic case, how two observer can have their clocks synchronised with each other moving in different frames of reference? If I consider they had their clocks synchronised before entering into their frames of refernce, why should they have their clocks remained synchronised? As we can see the twin paradox, where twins had their clocks synchronsed before leaving the Earth but when one of them returnes their clocks are no more synchronised so their age.
None of this is relevant to the topic at hand. For measuring speed, the two synchronized clocks are at rest wrt each other a known distance apart.
ravikannaujiya said:
If they ar not moving but very far away from each other, is there any kind of observation that could show that their clocks are still synchronised?
Yes, the Einstein synchronization method, or any equivalent method.
ravikannaujiya said:
For this you must assume the speed of light is fixed
Yes, of course we assume this. It is the second postulate. A postulate is an assumption. The postulate is well-confirmed experimentally so we can be quite confident making that assumption:
http://www.edu-observatory.org/physics-faq/Relativity/SR/experiments.html
ravikannaujiya said:
If you say anyother particle may exceed the speed of light, then the particle would not be observable until light reaches to our eyes and it shows that the light came before the particle because that was the light which made the particle observable, again destroying the idea that particle moved faster than light.
This is simply not correct. Suppose there is some tachyon that moves at 10 c which we can detect as it passes through some detector block which emits a flash of light as the tachyon passes through.
Now, suppose that we have a tachyon emitter aligned with two detector blocks. The detector blocks are separated by 1000 ft (in the x direction) and 1 ft away (in the y direction) from each detector block is a clock and a high-speed camera which can see both blocks and the time on the other clock. The clocks are synchronized using Einstein's convention (c=1ft/ns).
The following observations are made: at t=1ns the near camera records a tachyon flash in the near block, at t=101ns the far camera records a tachyon flash in the far block, at t=1001ns the far camera records a flash in the near block when the near clock read 1ns, and at t=1101ns the near camera records a flash in the far block when the far clock read 101ns.
From those observations the experimenters can tell that the tachyon hit the near block at t=0ns and the far block at t=100ns. Then they determine its speed as 1000ft/100ns=10c.
ravikannaujiya said:
If there is no limitation to measure the speed and we can measure the speed of an object more than that of light, what would you say about second postulate of special theory of reativity?
I would say it is well-confirmed experimentally. The second postulate is a postulate about the speed of light, not a postulate about a limitation of measuring devices.
ravikannaujiya said:
If the formula for speed is simple distance upon time, why do we need to take relativistic correction when we tackle with the particles with very high speed? Why the Newtonian physics becomes irrelevant while it gives the formula for speed as distance upon time?
I am not aware of a relativistic correction for speed. Can you please provide a mainstream scientific reference for the correction you are thinking about?