Wednesday, January 28, 2015

cosmology in SI-units

can you formulate the speed and acceleration of a FLRW-universe in human-understandable units? what would be your favourite choice?

Wednesday, January 21, 2015

Einstein's grandfather clock

the Einstein clock is a set of parallel mirrors with a flash of light bouncing between the mirrors serving as a pendulum. it is a particularly nice way of illustrating time-dilation in special relativity. how would the path of the flash of light look like if the Einstein clock was inside a gravitational field (or was accelerated)?

Wednesday, January 14, 2015

fine structure for Keplerium

we wish all CQW-readers a happy New Year 2015:

Keplerium is a gravitationally bound atom with angular momentum quantisation identical to the Bohr-model for atoms. can you draw analogies between atomic fine structure and gravitomagnetic effects arising in weak-field relativity?