How far away are the most distant objects in the Universe? How has the Universe expanded over the course of its history? And therefore, how big and how old is the Universe since the Big Bang? Through ...

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 ...

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 ...

It is almost 100 years since scientists discovered the universe is expanding. In the decades that followed, the accuracy of the measurements, and interpretations and implications of this discovery, ...

Artist’s interpretation of the cosmic distance ladder — a succession of overlapping methods used to measure distances across the Universe, where each rung of the ladder provides information that can ...