@FenderLesPaul SRGF could have been better if: there was a discussion of the galilean group and multiple derivations of $\eta=\diag(-+++)$. other than that, fantastic book

oh and not setting $c=1$ is a pain

I finally get why Fermi-Walker transport --> nonrotating, nonaccelerating observer

@FenderLesPaul what on earth does your username mean

Google says it's a guitar

The fender comes from fender guitar

Les Paul comes from Gibson Les Paul

which is also a guitar brand

never heard of him

I just combined the two

never heard of the band

I typically use Les Pauls since I'm more into electric blues

but Fenders are pretty sweet

I'm in the library...why are people talking here

I came here to get away from the dorm noises

also just a note

Fermi-Walker transport only means non-rotating observer

not necessarily non-accelerating

if the observer is non-accelerating then it's just parallel transport

hmm

HMMM

we have a problem

get out HE

I need some GR shit ::throws Lin Alg HW out of the way::

heavy breathing

page 81

it says fermi transporting the triad leaves them (the basis vectors) unrotated

yes

but does not constrain acceleration

Fermi-Walker transport is the analogue of parallel transport for non-accelerating observers

oh

OK I misread what you wrote

so it is possible for the Fermi derivative to be zero, but not for the covariant derivative of the velocity?

yes

ok then

time to resume Dr. Dydak

inner product...yay

intuitively what FW transport means is I take an arbitrary spatial triad and keep reorienting them until they are non-rotating relative to a comoving set of torque-free gyroscopes

which can always be done even if I'm accelerating

but of course the process will depend on my acceleration

looks like Dydak decided to do this lecture in his study...I spy with my little eye some GTM books on his shelf

damn yellow/orange things

@FenderLesPaul are we doing a Skyrim stream + GR tonight?

yeah sometime after 9pm EST?

ill be done with my work by then

OK hopefully I still won't have a roommate

but he Skypes with people too

so it's whatever. 9 works

@ACuriousMind oh god Dydak is trying to justify using infinite dimensional vector spaces...with quantum mechanics...he's not good at physics

"the quantum wave"

what is he doing o.O

is his last name tik?

Dydak Tik

badumtiss

cries

yes feel really bad about that

@FenderLesPaul ::groan::

@FenderLesPaul he's Polish, so it's Dee-dak

not Dai-dak

aww

@ACuriousMind "algebraic definition of dot product has no meaning"

he is a geometer through and through

@0celo7 Well, he's not wrong

@ACuriousMind is the cosine definition really a definition? I've always thought of it as something to be derived from the algebraic definition.

@0celo7 I've always thought of it as defining the angle, not the dot product

@ACuriousMind interesting...yes I've seen that

But if you define the angle some other way, you might take it as a definition for the dot product

especially for higher dimensions

I like the algebraic $g(u,v)$

then show the conventional angle formula follows from this

hah should I leave a suggestion on the lecture that he actually show the Born rule instead of just waving his hands and saying "the quantum wave gives a probability density for the molecule"

I'm curious...what was it?

...you probably made a dumb joke :P

But I can't remember

I was trying to find that one thing where you said you used to write really condensed

no luck

Dydak just went on a rant saying it's not like you have to fit everything in a small journal article

@ACuriousMind is the multiplication of a state vector by a number w/o modulus 1 measurable?

@0celo7 Nope

@ACuriousMind ok so "states are rays in Hilbert space" means that $\Psi$ and $7\mathrm{i}\Psi$ are the same state?

@0celo7 Yes, exactly

@ACuriousMind I thought I knew that...

I swear Weinberg says it's only up to a phase

Well, most people require the vector representing a state to be normalized.

whoops, he does this

nvm then, dumb me

@FenderLesPaul holy crap it took him 97 pages to write down the Lorentz factor

@0celo7 yeah

@ACuriousMind after 500 hours I guarantee they all make sense