Part 3/10:
The narrative began to shift in the 1970s when astronomer Vera Rubin and her colleague Kent Ford observed unexpected rotational speeds of stars in the Andromeda galaxy. Their research revealed that stars on the galaxy's outskirts moved at similar speeds to those nearer the center, contradicting Newtonian physics, which predicted a slower orbit as gravitational pull weakens with distance. Rubin’s observations lent significant credibility to the dark matter theory, revealing that an unseen force must be influencing the dynamics of galaxies.