Perhaps the greatest and most frustrating mystery in cosmology is the Hubble tension problem. Put simply, all the observational evidence we have points to a universe that began in a hot, dense state, ...

We've known the universe is expanding for a long time. The first solid paper demonstrating cosmic expansion was published by Edwin Hubble in 1929, based on observations made by Vesto Slipher, Milton ...

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 ...

A difference of a few kilometers per second might not sound like much. In cosmology, it has become one of the field's most stubborn problems. An international team of astronomers has now delivered one ...