Antininny
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The model Lagrangian is a mathematical expression that summarizes the Standard Model of particle physics, which is the most successful theory of the fundamental interactions between elementary particles. It is composed of four different parts, each describing a different aspect of the Standard Model.
The model Lagrangian is written in a compact notation that uses symbols and operators from quantum field theory, such as covariant derivatives, field strength tensors, Dirac matrices, and gauge group generators. It also uses various constants and parameters that are determined by experiments, such as coupling constants, masses, and mixing angles.
It is one of the longest equations in physics because it contains many terms and factors that account for all the possible interactions and symmetries of the Standard Model.
It was transcribed by Thomas Gutierrez who derived it from Martinus Veltman's Diagrammatica: The Path to Feynman Diagrams.
conklin5
Oh, THAT Lagrangian! Sure, I know that one.
MyBigMouth
Took me a while but I think the answer is 5012394144777
Antininny
are you sure that isn't your phone number and extension?
Antininny
If you want to understand it slightly better, watch this: https://www.youtube.com/watch?v=PHiyQID7SBs
boarbque
Always upvote PBS Spacetime. Gee criminey is that a great channel.
painterofdark
The future of the federal tax form.
Antininny
Laws of physics bring new meaning to the word "law", you should know. You literally cannot violate the law... no no, you don't get it -- it's not allowed. Dammit, still! Let's just call it impossible! It's impossible to break the law. Defund the Physics Police!!
Antininny
Physics, it's not just a suggestion, it's the law.
SwissScars
multiply both sides by the number you first thought of, makes is so much easier.
Antininny
Okay, I'll do the LHS and you do the RHS. We'll meet back here in 20 minutes.
beaubrent
Worst poem ever
landisfloatingrock
I think the -u on line 20 should be a +
Antininny
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Best regards,
The Physics Support Team
landisfloatingrock
Anytime (as the space time continuum collapses into a pile of fruit loops /s) Cool post by the way.
Antininny
Thanks. FWIW, "absolute zero" is likely an emergent property of this equation, so "cool" certainly feels like a compliment to it.
3rdoption
What an idiot. He forgot to carry the 5.
Antininny
The 5 is carried automatically by virtual photons. See line 19.
thatsnotmydog
That'd be a cool tattoo to completely fuck up archeologists of the future.
WhyAreAllGoodNamesTaken
What kind of dimension/value does that give you? Does it all equal out to zero? Does it measure energy in a system? Does it work on macroscopic objects as well as particles?
Antininny
It would be better for you to watch Matt O'Dowd explain it than for me to try to fit it into imgur comments: https://www.youtube.com/watch?v=PHiyQID7SBs
Antininny
and as far as what a Lagrangian is in the first place, you might start here:
https://en.wikipedia.org/wiki/Lagrangian_mechanics
Antininny
Yeah -- Hehh. It's not even straightforward enough to teach to the Freshmen. It's more of a Sophomore-Junior years kind of thing as far as when a physics major would learn it
WhyAreAllGoodNamesTaken
Black magic, literally haunted by ghosts - got it!
Antininny
mhmm
mikecaa
Yeah but most things in nature start complicated and then someone new Einstein comes along and makes a discovery that precipitates a grand simplicication and you end up with something short and sweat.
Antininny
Did you know that E=mc² is actually a simplification of the proper form of that concept?
Antininny
E² = m²c⁴ + p²c²
joe6paques
There’s a term like that at the end of the second line.
Antininny
,where E is total energy of the particle, m is its mass (at rest), p is its momentum, and c is the speed of causality. A direct quote: "Lots of things are squared in quantum mechanics." --my advisor @ physics undergrad
Units of E can be kg*m²/s², units of m can be kg, units of p can be kg*m/s, and units of causality can be m/s.
Antininny
,so the total energy of a particle is only defined _relative_to_an_observer_ who sees the particle moving with momentum p=(absolutevalue(vectormomentum))², or equivalently "the vectormomentum dot-product with itself" relative to them. ...and it is correct to call these quantities -- E, m, and p -- the "relativistic version" of each. You might notice that the units of E and p are different only by a factor of velocity, so I'll add this:
Antininny
E=mc² is the case where p=0, in other words, where the particle is at rest relative to the observer (like th'one you're just lookin' at sittin' in front of ya).