What I learned from reading “A Brief History of Time”:
The doppler effect is that the pitch intensifies the closer an object gets to us, and the lower it gets as it passes.
That Galileo’s observance of Jupiter’s moons, and the fact that they revolved around Jupiter, was the driving force behind the “the universe doesnt revolve around us” theory.
The “string theory” started in 1964.
That I am no physicist!!!