Recent content by John_M

OK...thanks guys. I think the statement from Chroot at the start clears it up... 'Velocities in special relativity do not add in the normal Galilean way.'

Where do you get the number 0.999949498c from?

"An observer might see one object leaving at almost the speed of light in one direction, and another object leaving at almost the speed of light in another direction, but that doesn't violate that bottom line." Why not? It seems very clearly to violate the bottom line to me, seeing as...

"Both particles maintain a velocity of .05c relative to the Earth as measured by the Earth. Each particle also measures its relative velocity to the Earth as 0.5c." It's this statement I don't understand. Do you accept that it's possible for a particle to travel at greater than 0.5c relative...

actually, I could have read over your post a bit more closely...you've posted an equation for working out relativistic velocities...

How do they add then? It's news to me :smile: I read something about 'neutral pions' going at 185,000 miles per second - presumably relative to the Earth - in experiments to test the speed of light. How does your statement that 'From your Earthly perspective, one particle will be moving at...

According to Einstein nothing can move faster than c. But whereas c is constant in all frames of reference, the speed of massive objects is defined relative to other massive objects. So when we say nothing can go faster than c, we surely mean nothing can go faster than c relative to another...

I'm a law student in the UK...my institution certainly doesn't have access. :smile: I suppose you couldn't send me a copy? (hope I don't get banned from the forum for asking that...)

Is there a book you can buy on the twin paradox which outlines all the main arguments - and who's made them? One that includes how to deal with SR in accelerating frames of reference...

The point I was trying to make with my post was as followed: SR means that different truths hold within different frames of reference. The examples people quote are only small, eg a couple of seconds, or a couple of centimetres, either way. But is it possible for those differences, by a sequence...

How would this work??

OK...slight error over the electrons then. :smile: I dropped physics at GCSE level (But I still find it interesting...) But would the speed of the electrons really make any difference here? It would only determine the speed at which the message is conveyed to the brake once the circuit has...

The current won't flow through the circuit instantaneously but surely an electrical current, like light, is a form of electromagnetic interaction and will therefore move at the same speed in both frames of reference?

About that train experiment. Everyone probably knows the story. For the person on the train, the flash of light hits both ends of the train at the same time. For the person watching on the embankment, the flash of light hits the back end of the train first. Now, I'm reading a book on SR...

there are a few misleading websites suggesting it is...oh well.