Not a Book Review 2
Physics wasn’t as captivating to me in high school as it is today.
There are several reasons for this—our tastes and understanding of a subject evolve over time. This also brings to mind one of the posts I wrote two years ago on the topic:
“Follow your passion” is a flawed metric because our passion changes based on our success. Success precedes passion.
You can read it here if you’re interested: https://lnkd.in/dN63P7rD
Reading the first chapter sparked my curiosity and led to several questions, which I’ve outlined below:
Newton vs. Einstein: Gravitational Fields
If we imagine space as a stretchy, invisible fabric across the universe:
- Newton’s view: The fabric was just empty space where objects moved around, and gravity was a mysterious force acting at a distance, like an invisible hand pulling objects together.
- Einstein’s view (General Relativity): Space itself is the gravitational field. A heavy object, like a planet or star, warps the space around it, and this curvature is what we feel as gravity.
When to use each theory:
- Newton: Good approximation for weak gravitational fields (Earth’s surface) and low speeds (cars, rockets).
- Einstein: Needed when gravity is strong (black holes, neutron stars), speeds are close to light, or high precision is required (GPS satellites account for time warping).
Explaining to a Kid
Imagine space as a rubber sheet:
- Place a heavy object (bowling ball) → creates a dip
- Smaller objects (marbles) roll toward the ball because of the curve, not because the ball pulls them directly
In Einstein’s view:
- Rubber sheet = space and time
- Bowling ball = matter (star or planet)
- Dip = curvature of space → what we feel as gravity
Time also bends:
- Imagine time as a river flowing smoothly
- Near something heavy, like Earth → river slows down → time moves slower
- Far from massive objects → time moves faster
That’s why a friend living in the mountains might age slightly faster than one near sea level.
Should we dive into Quantum Theory now?
Well, let’s save that brain-bending journey for another post—after all, even Schrödinger’s cat might need a break!
