The Biggest Ideas in the Universe: Space, Time, and Motion

by Sean Carroll

physics is a field by and for specialists. Practitioners talk to one another in a highly specialized jargon, one that is dominated by mathematical concepts most people have never heard of,

The Biggest Ideas in the Universe is dedicated to the idea that it is possible to learn about modern physics for real, equations and all, even if you are more amateur

we’ve divided the material into a three-part series: Space, Time, and Motion; Quanta and Fields; and Complexity and Emergence.

The key is that things don’t just happen—all of the happenings fit into certain patterns. It’s those patterns that we call the laws of physics, and our job is to uncover them.

The most basic kind of predictability is conservation, the fact that some things don’t change at all.

The energy that a wineglass has just from being located on a table can, if the glass is knocked off the edge, rapidly be converted into energy of motion as it falls, and then into heat and noise and other forms of dissipated energy as it breaks on the floor.

Conservation of energy is simply the idea that the total energy, given by adding up all the individual forms, remains constant throughout the whole process.

you’re sitting with a coffee cup on the table in front of you, by itself the cup will just sit there. You can make it move by pushing it, but when you stop pushing, it will come to rest again.

Aristotle imagines, to a basic feature of the universe. Objects are naturally at rest, and motion only occurs when something pushes them away from this natural state.

there is a universal relationship between momentum, mass, and velocity, which always takes precisely this form for every object.

Isaac Newton in 1687, the theory known as classical mechanics.