## The Twin Paradox – Once and for All

Check out also – Problems In Advanced Math and Physics and Rare Finds in Special and General Relativity Every science buff has heard of the Twin Paradox. Movies have been made, books have been written, plots and sub-plots all...

## Teaching Relativity

Galilean Transformation – v’ = v +- V –  cannot be applied to light If (x1 , t1) and (x2,t2) are two events in K, and (x1’,t1’) and (x2’,t2’) are their co-ordinates in K’, then (x2 –x1) / (t2 –...

## Time Intervals in Special Relativity

Nothing heckles our common sense notion of ‘time’ more than Special Relativity. Consider a muon particle decaying as it enters the earth’s atmosphere. As per the muon, it should only live a few microseconds. Not...

## What does space-time look like from a photon’s point of view?

A frame of reference cannot ‘travel at light speed’. That frame would (if it DID make it to the c) see space collapse to a point in the direction of travel. So – there is nothing for it to ‘see’...

## Does time stop for a photon? If so, how can it move (travel)?

The photon’s time doesn’t ‘stop’ – as far as we can tell. Relativity doesn’t have frames of reference moving at c, so it’s not possible to define how fast time passes for a...

## Rare finds in Special and General Relativity

Understanding the two theories of relativity is not just a pastime for physicists. There is something existential and comforting about imagining ‘riding on a light wave’ and how the Universe might look to such an observer...

## On the Ether

One of the things I never fully grasped in college was the ‘Michelson Morley’ experiment. I understood what it was for (proving the constancy of the speed of light) – and understood that it proved that very well – but I...