MinutePhysics
How Do We Know The Universe Is ACCELERATING?
2017 • E4 Apr 25, 2017 3m
The universe is expanding – this we know from looking at red shifts of distant galaxies – but the acceleration of the universe's expansion is harder to measure. It requires measuring the change of recession velocity over time, and it's done by comparing Type Ia supernovas as standard candles at different distances, which is how we know the universe is accelerating!