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9:06 PM
@Blue What's wrong with probability per time?
It just means that for a small time $dt$ the probability of the event is $\lambda dt$.
 
There is something about quantities "probability per unit [whatever]" that takes people aback the first time they encounter them.
It is easy to argue that they shouldn't, but it trips most folks at some point.
I can't count how many times I've had to patiently explain to a scorching bright grad student how the vertical extent of a histogram depends on the binning.
 
@dmckee Heh.
Hey, @dmckee, any clue on where I'm confusing myself on that exponential distribution?
We have probability per time of an event (say decay, or whatever) $\lambda$.
The probability of decay in time $dt$ is $\lambda dt$.
What's the probability of going time $T$ without decay, and then decaying at $T$?
Well, divide $T$ into $N$ intervals of length $dt = T/N$.
The probability of not decaying in one of those intervals is $(1 - \lambda dt)$.
The probability of not decaying in any of them is $$(1 - \lambda dt)^N \, .$$
We can write that as $$\left( 1 - \frac{\lambda T}{N} \right)^N$$ which tends to $\exp(-\lambda T)$ as $N \rightarrow \infty$.
I am confused in two ways: 1) That result isn't normalized, 2) I know that formula is almost the usual thing for exponential decay, but that "usual" formula is supposed to be the probability that you survive for time $T$ and then decay at $T$.
Oh maybe I get it...
Έυρηκα!
3
Yay!
 
9:32 PM
::hands @Daniel a towel::
 
@dmckee ::wipes forhead and keyboard::
 
Yayay! Now I understand why Poisson distributions happen in nature
 
::clap, clap,clap,...::
 
>citing wiki
I'm tempted to sabotage
 
9:38 PM
#145. 'Ah. Eureka,' he said.
'That's Ephebian, that is,' Cohen told the Horde. 'It means "Give me a towel." ' ("Interesting Times")
 
@0celo7 k
 
Be nice @0celo7 mentioning "sabotage" is punishable, as I have found out the hard way :(
 
sabotaging wiki is punishable by SE mods?
 
@skullpatrol no, it's not. Not just mentioning "sabotage".
 
that sounds crazy
 
9:44 PM
I seem to have a bad habit of finding out about policies @DavidZ
The hard way
 
SABOTAGE
::waits::
 
::flags::
 
you're hecked
 
Anyone watch the breakthrough prizes?
 
9:46 PM
@0celo7 claiming that you've flagged something is a problem though. At least, it's more punishable than talking about sabotage.
 
::rolls eyes::
ok
 
btw, it's "EV-ree-ka", not "yoo-REE-ka".
 
Ev?
Not Oi?
 
Says who?
 
@skullpatrol Every Greek speaker on the planet.
 
9:48 PM
@0celo7 did u hear the new jake paul album
it's the best album of all time
 
@BalarkaSen No, why would I listen to trash?
I'm not ironic like you
 
it also comes with a christmas remix of Everyday Bro
 
ok I might have to listen to that
link?
 
Welcome back to the USA @DavidZ
 
@0celo7 dont have one
i have a feeling i cant take it
 
9:54 PM
I can't find it
oh well
 
finally so close majorana's in random dimensions...
Hilarious every time
-23
A: Is there an elegant proof of the existence of Majorana spinors?

John Duffield Is there an elegant proof of the existence of Majorana spinors? No. Because they don't exist. The neutrino is not a Majorana spinor. It's a Weyl spinor. See Dirac, Majorana and Weyl fermions by Palash Pal. He said “the neutrinos had to be uncharged because of conservation of electric charge,...

@0celo7 what are your thoughts on these
 
10:25 PM
@bolbteppa bleh
physicists shouldn't teach GR
 
Who should teach it?
 
Clearly not a student of Hawking who actually contributed to the field :p
Malcolm John Perry (born 13 November 1951) is a British theoretical physicist and professor of theoretical physics at the University of Cambridge. His research mainly concerns general relativity, supergravity and string theory. == Biography == Perry attended King Edward's School, Birmingham before reading physics at St John's College, Oxford. He was a graduate student at King's College, Cambridge, under the supervision of Stephen Hawking. He obtained his doctorate in 1978 with a thesis on the quantum mechanics of black holes. In these early years, he worked on several very influential papers on...
 
10:45 PM
The tetrad lecture is pretty good
 
Is the RHS solution just as general as the LHS? $e^{-\beta t}[Ae^{i\omega t} + Be^{-i\omega t}] =?= Ce^{i\omega t + \delta}$ To me it seems not, but it was used by the professor seemingly as if it was. It is the homogeneous solution of a damped oscillator.
I'm thinking, maybe because the general solution covers all three cases of dampening but in reality you always have $A$ or $B$ zero?
 
11:48 PM
@0celo7 My first (of three) GR lecturers was definitely a physicist. He was so good, that a few students bought the textbook, despite him printing everything out for everyone and then got him to sign the textbook
 
How were the other two lectures?
 

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