How does the universe decide what’s going to happen next? Basically it’s running a massively parallel, real-time, infinite-precision numerical simulation.
Time
There is only the present moment. This isn’t philosophical mumbo-jumbo, I mean physically, time is a single point.
Why “Very Universe”?
First, the subdomain ‘veryuniverse’ was available on WordPress.com when I started this, and so were the domain names veryuniverse.org/.com.
The Three-Body Problem
The Three-Body Problem, Classical Version: given three objects/particles interacting according to a 1/r2 law, which means gravity or electricity, can we write and solve the equation of motion in closed form?
The Two-Body Problem
The Two-Body Problem, Classical Version: given two objects/particles interacting according to a 1/r2 law, which means gravity or electricity, can we write and solve the equation of motion in closed form?
The One-Body Problem
The traditional One-Body Problem is solving the equation of motion for a single body in space, often where the space has an energy potential, described by an equation, that affects the body. What’s artificial about this is that space and the potential surface are taken as one unified thing. Or the potential surface is changing slowly vis-a-vis the body motion. These are relatively tractable situations.
In reality the potential surface is determined by the interaction of the test body and all outside objects, with the material of space as the intermediary transmitting those interactions. So separate the potential surface from space itself, then are the solutions absolute in space or only relative to other outside objects (which together with the test particle, create the potential surface)?
The One-Body Problem, Classical Version: given an object/particle in space, can we know and/or does it have an absolute position and momentum (not merely relative to the rest of the objects out there)?
The Ways Multiple Universes Could Be
Why do we care how many universes there are and how they’re arranged?
- We want to know!
- It would be amazing if there were multiple universes.
- The soft anthropic principle is most satisfying if there are many universes with different properties.
My Favorite Concept for How the Universe Fits into Everything
What’s outside the universe? What’s smaller than the smallest thing in the universe? What was before the universe started, and what will come after? Here’s a possibility…
The fundamental particles in our universe could themselves be whole universes, and our universe could be one of the smallest things in another universe one level up. That could go on forever in both directions.
Continue reading My Favorite Concept for How the Universe Fits into Everything
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