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Ask HN: How to self-study physics?

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Re: Ask HN: How to self-study physics?

#111

Post by AnthonBerg »

scottlocklin wrote: post #74

For the love of God, don't use Feynman lectures to learn physics. That's something you read after you know physics, for relaxation and conceptual stuff. Resnick & Halliday is a much better freshman/sophomore book. Susskind's "theoretical minimum" is actually pretty good. http://theoreticalminimum.com/courses Fowler gives a pretty conventional undergraduate physics curriculum (adding Feynman in there somehow). If it w…

We all learn differently. Please don't deal in pedagogical certainties that may close doors unventured. Feynman's lectures were crucially eye-opening for me and many others.

Re: Ask HN: How to self-study physics?

#113

Post by ukj »

andrepd wrote: post #100
ukj wrote: post #88

Earlier quoted context omitted.

I am to really glad to hear commentary like this coming from physicists. (read: glad to see others siding with my biases). Ceteris paribus there is one significant distinction between Mathematics and Computer Science: state. The Mathematical Universe is immutable/stateless/timeless. The Computational Universe is mutable/stateful/time-bound. The observer effect in physics can be trivially expressed and evaluated as a…

>The observer effect in physics can be trivially expressed and evaluated as a mutating getter in any programming language. >It cannot be expressed in any Mathematical grammar. What on earth are you trying to say...? There is a whole mathematical treatment of quantum mechanics, measurement effect included (several treatments). More to the point, any algorithm can be formalised in e.g. a Turing machine, or any other eq…

>Any algorithm can be formalised in e.g. a Turing machine, or any other equivalent universal model of computation

Quoting http://math.andrej.com/2006/03/27/sometimes-all-functions-ar...

>>The lesson is for those “experts” who “know” that all reasonable models of computation are equivalent to Turing machines. This is true if one looks just at functions from N toN. However, at higher types, such as the type of our function m, questions of representation become important, and it does matter which model of computation is used.

Mathematics only proves things up to isomorphism. Two things that are theoretically equivalent are not necessarily empirically equivalent.

Or, just the good ol' adage: in theory there is no difference between theory and practice, but in practice there is.

>So there's literally nothing in "computer science" that you cannot express in mathematics.

In addition to the examples in the blog post linked above, you cannot express a mutating getter in Mathematics.

Go ahead. I'll wait.

Re: Ask HN: How to self-study physics?

#114

Post by ska »

AnthonBerg wrote: post #111
scottlocklin wrote: post #74

For the love of God, don't use Feynman lectures to learn physics. That's something you read after you know physics, for relaxation and conceptual stuff. Resnick & Halliday is a much better freshman/sophomore book. Susskind's "theoretical minimum" is actually pretty good. http://theoreticalminimum.com/courses Fowler gives a pretty conventional undergraduate physics curriculum (adding Feynman in there somehow). If it w…

We all learn differently. Please don't deal in pedagogical certainties that may close doors unventured. Feynman's lectures were crucially eye-opening for me and many others.

It's pretty well established now that Feynman is not a good general approach for introductory physics. Plenty of talented teachers have tried it, and moved on to something more effective.

This doesn't contradict your point. A particular individual may find them very helpful in learning and understanding the foundational stuff. By all means try, and if it works for you, great.

However, it shouldn't be at the top of anyone's list of things to try first. And if you have tried, and it didn't work well for you - it's not you.

Re: Ask HN: How to self-study physics?

#115

Post by ukj »

Koshkin wrote: post #104
ukj wrote: post #88

Earlier quoted context omitted.

I am to really glad to hear commentary like this coming from physicists. (read: glad to see others siding with my biases). Ceteris paribus there is one significant distinction between Mathematics and Computer Science: state. The Mathematical Universe is immutable/stateless/timeless. The Computational Universe is mutable/stateful/time-bound. The observer effect in physics can be trivially expressed and evaluated as a…

> Computational Universe is mutable/stateful/time-bound A bunch of functional programmers would like to have a word with you.

A bunch of functional programmers continue to insist that the Turing Machine has no ticker tape which stores state?

Yeah. I know ;)

Re: Ask HN: How to self-study physics?

#116

Post by Koshkin »

JabavuAdams wrote: post #109

1) Richard Wolfson's _Essential University Physics_ is excellent! It doesn't get lost in math, but also doesn't oversimplify. It's thinner than Halliday & Resnick, e.g. I've read a lot of Classical Mechanics books, and this is my favourite for a solid foundation for university-level physics. The first half (volume) is Mechanics, and the second volume is on electricity and magnetism. So, that's a typical first-year (t…

> Purcell for Electricity & Magnetism

This once came out as part of Berkeley Physics Course [1] which I think would be a great complement to Feynman's Lectures.

[1] https://en.wikipedia.org/wiki/Berkeley_Physics_Course

Re: Ask HN: How to self-study physics?

#117

Post by [deleted] »

ukj wrote: post #107
davidivadavid wrote: post #91

Earlier quoted context omitted.

It seems likely that anything that can be expressed in "any programming language" is isomorphic to something that exists in math and can be expressed in that language (automata theory, type theory, category theory, pick your poison).

That is probably because you think expression end evaluation are isomorphic. They aren't. Not all functions are referentially transparent. All Mathematical functions are assumed to be.

[deleted]

Re: Ask HN: How to self-study physics?

#118

Post by petermcneeley »

andrepd wrote: post #97
petermcneeley wrote: post #84

Earlier quoted context omitted.

"I'd suggest not actually trying to simulate physical systems on a computer" I cannot disagree enough with this statement. I am double major in Physics and CS. There are two kinds of physics, Math and Physics. Most of what you learn in uni physics is Math. But the Math is only one (outdated) description of the nature of physical law. Leonard Susskind himself has said on multiple occasions that the equations of physic…

And I cannot disagree enough with your comment. > There are two kinds of physics, Math and Physics. Most of what you learn in uni physics is Math. But the Math is only one (outdated) description of the nature of physical law. Lord knows what you mean by this. By "math physics" do you mean theoretical, and by "physics physics" the experimental part? Even then, this doesn't make any sense. Every physics course teaches…

Let me see if I can do a defense that doesnt merely look like an obvious backpedal.

If you want to do a standard study in physics you are probably going to go through a significant amount of mathematics. This is because the laws "universe at the most fundamental level/low level" are expressed as math equations. If OP wants to go that route then there are tons of resources available to them.

But since OP already has a CS degree I think a possible entry point is exploring these laws through computers and in some way deriving them from simulation (here is one such simulation https://www.falstad.com/gas/)

lets leave the more outlandish claims alone for now. Perhaps I went to far.

Re: Ask HN: How to self-study physics?

#119

Post by jshevek »

ukj wrote: post #113
andrepd wrote: post #100

Earlier quoted context omitted.

>The observer effect in physics can be trivially expressed and evaluated as a mutating getter in any programming language. >It cannot be expressed in any Mathematical grammar. What on earth are you trying to say...? There is a whole mathematical treatment of quantum mechanics, measurement effect included (several treatments). More to the point, any algorithm can be formalised in e.g. a Turing machine, or any other eq…

>Any algorithm can be formalised in e.g. a Turing machine, or any other equivalent universal model of computation Quoting http://math.andrej.com/2006/03/27/sometimes-all-functions-ar... >>The lesson is for those “experts” who “know” that all reasonable models of computation are equivalent to Turing machines. This is true if one looks just at functions from N toN. However, at higher types, such as the type of our func…

Please don't use that style of quotation for non-code. It is awful on mobile.

Re: Ask HN: How to self-study physics?

#120

Post by nearmuse »

scottlocklin wrote: post #74

For the love of God, don't use Feynman lectures to learn physics. That's something you read after you know physics, for relaxation and conceptual stuff. Resnick & Halliday is a much better freshman/sophomore book. Susskind's "theoretical minimum" is actually pretty good. http://theoreticalminimum.com/courses Fowler gives a pretty conventional undergraduate physics curriculum (adding Feynman in there somehow). If it w…

So far, they seem like a good way of reconnecting odd pieces of university program scattered around in my head. Maybe from scratch, they do not have enough math and overexplain some stuff. What are the usual arguments against this though?
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