A simple calculation shows that stellar aberration due orbital motion of earth is roughly 20 arcseconds. My questions are: Practically how this small value is measured? Does this value is in the ...
If black holes are phenomena of very high density (gravitational singularities) which don't emit radiation how can we detect them so far away from us where so much other radiation can hide the black ...
If the observable universe keeps expanding would we eventualy see light 24/7… clouds permiting? [duplicate]
If we can see more observable universe could there be a time when day and night looked the same?