Trying to measure the size of the universe is no easy task. We know that the universe is expanding, though the exact rate of this expansion is not yet fixed. So one method that astronomers use to tell ...

For the calibration of relatively short distances the team observed Cepheid variables. These are pulsating stars which fade and brighten at rates that are proportional to their true brightness and ...

The cosmic distance ladder is the world’s longest ruler, built to measure the universe. Since the time of the ancient Greeks, scientists have been constructing a cosmic measuring tape to measure the ...