Astronomy
The Significance of the Cosmic Distance Ladder in Astronomy
Quick fact
The cosmic distance ladder uses nearby stars as 'standard rulers' to calibrate brighter 'standard candles' like Cepheid variables, which then let us measure distances to galaxies millions of light-years away.
Why this is interesting
How do astronomers know how far away a galaxy is, when we can't even walk there? The answer lies in a clever chain of methods called the cosmic distance ladder.