Drinking and Deriving | Maxwells Wave Equations

Today I crack open a cold one with the smart people and and derive the wave equations for an electric and magnetic field in terms of the D'Alembertian.

[peternolan]

Hello Andrew,

Excellent video. Just exactly what I was looking for. Well done. I'm 68yo and I care for a semi wild cat whom I feed and give warm shelter to while having three other cats also in my life all of whom have warm loving homes.
I however cannot no way no how cope with alcohol.

All the best and many thanks,

Peter Nolan. Ph.D.(physics). Dublin. Ireland.

[AndrewDotsonvideos]

Last equation should be minus mu times the curl of J. Doesn’t change anything if you assume no current, but still missing a sign.

[AlbinoJedi]

I laugh every time you say "right meow". And I really thought you were going to use your cat as an eraser.

[christopherhall]

This is amazing.
When you're on the study grind but the pregame starts in 15 minutes...
Finally a teacher who can hold my attention...

[johnchristian]

More importantly, is there a limit for alcohol consumption while deriving?

[andrewstallard]

Great lecture!


I often watch you in order to help plan lessons for my AP physics students.


I have to dumb down some of the vector calculus and include some scaffolding explanations but in the end they get it.

[kaga]

Andrew must be drunk as shit, his vectors don't even have arrows on them.

[acatisfinetoo]

I love the cat cameo appearance it's so random i love it. The math is very cool too.

[francargeric]

Me: Fails Physics III(Electromagnetics and optics).
Andrew: can solve it drunk.

[lloydangelo]

Oh my God. Even drinking beer, you can still make it understandable. Great lecturer!

[lad]

Holy hell. I'm here during corona and i DIED seeing the beer he's got.
Best homework ever!!!

[michalbotor]

this ∇⨯∇⨯V = ∇(∇⋅V) - (∇⋅∇)V identity is not hard to derive if one knows the BAC-CAB rule for triple cross products, namely A⨯B⨯C = B(A⋅C) - C(A⋅B), and knows that an operator L acting on some vector is written as LV and not as VL.
so if we substitute A := ∇, B := ∇, and C := V into the above equation, we will get ∇⨯∇⨯V = ∇(∇⋅V) - V(∇⋅∇).
but this last part V(∇⋅∇) is exactly VL, where L := (∇⋅∇), and so it needs to be written as LV to make sense.
and so we get ∇⨯∇⨯V = ∇(∇⋅V) - (∇⋅∇)V, like we wanted.
and this ∇⋅∇ is always written as either ∇² or Δ, and it's called a laplacian of a vector field.
poor ∇(∇⋅_) however doesn't have a name.. :( it's just a gradient of divergence (btw, what does it measure anyways?).
so finally we get ∇⨯∇⨯V = ∇(∇⋅V) - ∇²V,
or equivallently ∇⨯∇⨯V = ∇(∇⋅V) - ΔV.

Your videos are getting me through my undergrad! Keep it up

[santiagofernandezasensio]

1:12 bold of you to assume that the identity is trivial to my high school physics ass.

[RealSlavGod]

My professor said you have to be drunk to understand this so thats what we doin

[mastershooter]

ooohh someone's turning into a hamilton

[ivankaticos]

You can't drink and d(e)rive. It's illegal.

[avinsharma]

You are favourite. I'm in my final year of school gonna go to college from next year super hyped up watching your videos and imagining the life of a physics undergrad.

[jessemonroe]

You have great handwriting for a physicist, wish my professor had the same

[michalbotor]

but if ∇² is Δ, then doesn't it mean that ◻² is ◻? :p