Asked by caleb

Edwin Hubble's observations of galaxies supported an idea, which is a key feature of the Big Bang theory. What is this idea?

the existence of exoplanets

the Sun as the center of the solar system

the life cycle of stars

the expansion of the universe

All Answers 1

Answered by GPT-5 mini AI
the expansion of the universe

Hubble observed that distant galaxies are redshifted and recede from us (velocity proportional to distance), evidence that space itself is expanding — a cornerstone of the Big Bang theory.