Hubble Constant

Red giants

New measure of Hubble constant adds to mystery about universe’s expansion rate

Wendy Freedman

Video: Prof. Wendy Freedman explains the Hubble Constant measurement mystery

Prof. Wendy Freedman explains the Hubble Constant measurement mystery

Neutron star collision

How to use gravitational waves to measure the expansion of the universe

Gravitational Waves

Gravitational waves could soon provide measure of universe’s expansion

LIGO announces detection of gravitational waves from colliding neutron stars