Why should you learn physics?
December 29, 2016 7 Comments
In a comment, Elliot Temple asked questions about when and why people should learn physics:
what’s the point of learning about physics? who should learn about it and why? should everyone learn about physics? how should someone decide if they should learn some physics, and which physics, and how to learn it?
There are several reasons people might want to learn about physics.
(1) Learning physics involves figuring out stuff, which can be fun. It’s like trying to figure out a very complicated puzzle. One difference from trying to solve a puzzle invented by a person is that for lots of physics problems nobody knows the answer. There are some puzzles invented by people for which nobody knows the answer. You can have computer games in which a program generates a puzzle. But even in cases like that the rules for generating the puzzle are known and written down in the text of the program. The laws of physics are not known or written down in many cases.
(2) You can want to learn physics for technological reasons. The laws of physics rule out some ways of solving problems. For example, you can’t travel faster than light so technology that requires faster than light travel won’t work.
(3) You can want to learn some physics for philosophical reasons. There are philosophical disputes about stuff like whether it is possible to understand the world and physics is relevant to those disputes. A person is a physical object, so a person can’t know X if learning X requires breaking the laws of physics. In The Beginning of Infinity, David Deutsch argues that all problems that are worth solving can be solved. This rules out some bad ideas people have about people being unable to understand how the world works cuz our brains evolved by natural selection only to solve some problems, see BoI Chapter 3 starting at about p. 53.
You can comment on the above or explain reasons I left out in the comments below.
About conjecturesandrefutations
Conjectures and Refutations 
here’s another puzzle i think no one knows the answer to: can a tool-assisted speed run of zelda ocarina of time 100% finish in under 3 hours? it’s typical that people don’t have complete knowledge of the properties of their complex creations. the laws of physics of the OOT game (code governing behavior of objects, responses to inputs, etc) are written down in a difficult to read format and are hard to understand the implications of even if you read it.
so what physics if any do you think I personally should learn in the near future? given your knowledge of my interests and what i already know about physics.
> Deutsch argues that all problems that are worth solving can be solve.
solved
> so what physics if any do you think I personally should learn in the near future? given your knowledge of my interests and what i already know about physics.
I think you’re interested in stuff like what the laws of physics say about information. And maybe some stuff about probability. I’d guess enough quantum mechanics to understand some of DD’s papers. Stuff on information in quantum physics
https://arxiv.org/abs/quant-ph/9906007
https://arxiv.org/abs/quant-ph/0104033
Stuff on probability in QM:
https://arxiv.org/abs/quant-ph/9906015
https://arxiv.org/abs/1508.02048
And you might want to learn some special relativity.
i know some general basics about relativity but not much. wanna do an overview post about special relativity? what it says, what it’s useful for, some implications, some extra stuff you can find out if you study the details of it.
> I’d guess enough quantum mechanics to understand some of DD’s papers.
ok how much is that? how long to learn it? what’s included? can you do a post covering it? or is it like 10 posts worth of stuff or 100 posts? what are good existing sources for learning it? i think i’m not currently interested and motivated enough to learn from shitty materials like e.g. most textbooks (mentioning as FYI and also to expose to criticism if you disagree).
off topic: what do you think of constructor theory? good post topic?
I can cover the stuff you need to read the first two papers in one post. What you need to know is covered also in the first three of DD’s lectures on quantum computation.
i watched his quantum computation lectures a while ago (i forget how many. maybe there’s more now). i don’t remember it very well though. cool that it’ll fit in one post.
> I can cover the stuff you need to read the first two papers in one post.
coming soon?
Constructor theory works at a very high level of abstraction. To understand the problems it is trying to solve you need to have some familiarity with the deepest theories in physics: quantum theory, relativity and thermodynamics. And to understand the solutions, you have to know the theories very well. So constructor theory posts would have to come after posts on all that stuff.