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/sci/ - Science & Math

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4207959 No.4207959 [Reply] [Original]

>classical mechanics
>hard physics
ISHYGDDT.

>> No.4207963

Little you know, young padawan. Classical mechanics doesn't stop with solving the Kepler problem.

>> No.4207975
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4207975

>electromagnetism
>hard fundamental force
ISHYGDDT

>> No.4207979

>>4207959

>Any college physics
>Hard physics

ISHYGDDT

>> No.4207980

Classical mechanics can get pretty damn hard - what about, for example, rotating deformable bodies? :)

>> No.4207984
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4207984

>newton
>hard physicist

amidoingitrite?

>> No.4207985

>>4207963
Josef I see you on here all the time!

Fill me in. who are you?

>> No.4207987
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4207987

>>4207963
>implying the lagrangian formulation fixes anything
>implying classical mechanics is as accurate as QM
>implying analytical mechanics should be a semester long

>> No.4207994

>>4207979
>going to a bad undergrad college

ISHYGDDT

>> No.4207995

>>4207975
is that a costanzon

>> No.4207999

>>4207959

>implying applied dynamics isn't classical mechanics
>implying applied dynamics isn't the hardest physics possible.

>> No.4208006

>>4207979
so what is /sci/'s interpretation of 'hard physics'? i have yet to find one decent text on geometrodynamics. some things are better left to lecture notes.

>> No.4208007

>>4207994

>Decent university for my country.
>Ranks high for the dept.
>Ranks well in general.

>> No.4208010

Why is physics a science? You don't measure forces or particles directly, only their effects and the disturbances they cause using indirect methods. And when you get down to subatomic physics you're dealing with imprecise potentials, shit that behaves in different ways at the same fucking time, motherfucking entanglement, et cetera. Physicists need to resort to the same shit-tier math like statistics that Sociologists use just to make some special-case correlations.

Physics is just another liberal art. Deal with it

>> No.4208011

Seriously, if you've actually done much physics you almost immediately realize that you can almost trivially come up with problems that are far too difficult to solve analytically (and even numerically, in many cases - especially general relativity, where we can't even simulate two black holes merging properly...). Heck, half of theoretical physics is boldly making approximations that let us get useful answers.

Saying any particular field is harder than another is really just bullshit. Of course, this is assuming you're talking about REAL physics here (i.e. upper-year undergrad / grad level)

>> No.4208014

>>4208010
In WHICH field do you ever actually measure anything directly? :)

Heck, even measuring temperature typically involves measuring either a change in electrical resistance, or exploiting differential thermal expansion rates (such as in a mercury thermometer)

>> No.4208018

>>4207987
>implying the lagrangian formulation fixes anything
Constraints, transition to geometric/algebraic approaches, generally: more rigorous approach
>implying classical mechanics is as accurate as QM
It is, in its domain - like all other standard theories. QM isn't better just because classical mechanics is contained within in the limit <span class="math">\hbar\to0[/spoiler]. (In other words: There's no need to calculate top loops to find out how long a stone takes to fall a meter on Earth)
>implying analytical mechanics should be a semester long
Liouville theorem, what happens when Lorentz invariance is broken in classical physics, transition to statistical physics, complicated phase space geometries, ... There's plenty of stuff you can do.
I'm reading a book about classical mechanics right now and it's highly interesting (and nontrivial). It's going to become even fancier when quantization starts, but I'm not at that point yet. (Super Lie algebras in classical mechanics, woot)

>Josef I see you on here all the time!
Haven't been here 24 hours ago if that's any help

>> No.4208024

>>4208010
Are you an insane? Nobody resorts to probabilities and 'statistics' until you get down to the scale that it is impossible experimentally to produce exact measurement. Everything is probabilities of observables, even a whole fucking planet for chrissake! The funny thing is, it works better than any other method! The precision is so unbelievably phenomenal, people begin to doubt the mathematical aspect of the calculation. The more you look at it, the more you can realize that the mathematical methods are what the reality ACTUALLY is. Virtual particles were only a perturbative method, an abstraction of what 'reality' apparently is. The wave function is probability mapping onto some abstract mathematical concept - a 'graph'. Why does it work so damn well? The answer is really simple if you look at it from a philosophical perspective - it IS the reality.

>> No.4208037

>>4208018
>Constraints, transition to geometric/algebraic approaches, generally: more rigorous approach
sure, but it is still not the real deal. teaching classical mechanics is more analogous to a history lesson in physics as opposed to modern topics.

>It is, in its domain - like all other standard theories. QM isn't better just because classical mechanics is contained within in the limit [...]
>in its domain
but with all of our advancements in technology, why must freshman learn classical bullshit when they could be focusing on mathematical topics as a better preparation for higher level physics? the 'everyday query' argument was surely relevant in the 1987, but it's 2012 - we have computers and matlab

>> No.4208040

>>4208037
FRESHMAN? Dear god, if you're in 1st year, you damn well better learn basic classical mechanics or else you won't have any fucking idea what is going on later. It's the foundation you build everything else on top of.

4th year physics undergrad here...

>> No.4208043

>>4208018
Lie algebras? In CM? õ_Õ
What book? I might have to revisit if this is true...

>> No.4208044
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4208044

>>4208037
>what freshman actually believe

>> No.4208054

>>4208044
HAHAHA yea, I'm pretty disappointed to find out that this thread was started by a 1st year undergrad who thought Newton's 3 laws constituted all of classical mechanics, and thought that "matlab and computers" could solve everything for you XD

>> No.4208057

>>4208037
And I suppose math freshmen should be learning topology and abstract algebra, since we have calculators.

>> No.4208060

>>4208057
To be fair, at my university they start off with analysis and algebra...

>> No.4208062

>>4208037
Freshman classical mechanics (points moving down a slope etc) are an excellent toy model for learning how to apply basic mathematical concepts (analysis, linear algebra) to physics.
Going more theoretical, the approaches taken in more rigorous versions of classical mechanics teach things done later in (Q)FT on a very basic level. Subtracting degrees of freedom in case of a particle constrained to a sphere is conceptually very similar to deriving classical electromagnetism from symmetries. It teaches you the motivation behind the Lagrangian, how you can use symmetries to simplify your problems, that geometry plays a large role in physics.
The next step can be arbitrarily complicated.
>we have computers and matlab
Computers don't do physics, they do what you tell them to. And until somebody writes a "picture of black board to solution converter" function, the thinking has to be done by the human operating it.

>Lie algebras? In CM? õ_Õ
The poisson bracket is linear in both arguments, antisymmetric and satisfies the Jacobi identity. <span class="math">\ddot\smile[/spoiler] (Now you need to make clear in what respect functions are to be seen as vectors, but that's not a problem.)

>> No.4208064 [DELETED] 

Medicine WILL be socialized in the US in our lifetime, whether you like it or not. This means you won't make jack shit. I suggest you just go for your PhD in physics.

>> No.4208069

>>4208064
Socialized doctors in Canada still make tons of money - way more than the average PhD graduate in Physics.

Also, stop derailing the thread lol.

>> No.4208074

>>4208069
i posted in the wrong thread, fuckdouche.
why did you reply to a post that i deleted immediately?

>> No.4208078

>>4208074
HAHAHA well I didn't know you deleted your post, i just refreshed once.