Cool Lil’ Bits — 1

Seven Brief Lessons on Physics — Carlo Rovelli

I’ve seen a lot of Book Summaries and Key Take Aways and 5 Learnings from Books kinda posts. But I am gonna write about the coolest thing I come across in the books that I am reading. This one’s from a book my friend Atit gifted me.

Something cool from Seven Brief Lessons on Physics by Carlo Rovelli

Imagine a gigantic hollow, curving and flexible water-slide, in the shape of a snail’s shell, and imagine a marble rolling down inside the slide.

This slide is Space. The marble is Matter. And Space is also Gravity.

Planets circle around the Sun, and things fall, because Space curves.

More. Light deviates along this curvature. Even Time curves — just like Space. Time passes faster higher up, near the surface of the marble, than closer to its center. This, incidentally, is what happens in the movie Interstellar when the Astronauts land on a planet with a far greater Gravity than that of Earth. Higher Gravity implies slower Time and they remain young longer.

Even more. When a large Star has burnt up all of its combustible substance, it collapses under its own weight — just like when you turn off the heat on tea boiling in a vessel. This bends Space so much as to collapse into an actual hole. A Black Hole.

Furthermore, Space is expanding — the funnel or the snail shell is flexible. It can expand and contract. Currently, it is expanding because of an explosion of an extremely small, hot and young Universe several billions of years ago — the Big Bang.

This is Einstein’s General Theory of Relativity.

Pretty cool eh?