The h Bar

2:04 AM

$$\begin{align}
\vert\Psi\rangle & = z_1\vert a_1\rangle + z_2\vert a_2\rangle \\
\mathbf{\hat A}\vert\Psi\rangle & = z_1\mathbf{\hat A}\vert a_1\rangle + z_2\mathbf{\hat A}\vert a_2\rangle \\
& = z_1a_1\vert a_1\rangle + z_2a_2\vert a_2\rangle \\
& = w_1\vert a_1\rangle + w_2\vert a_2\rangle \\
& = \vert\Phi\rangle \\
\end{align}$$

$$\vert\Psi\rangle\ne\vert\Phi\rangle$$

is chatjax broken?

$no$

hmmm it works for me on the test page but not in chat

anyway if the Operator A is Observable does the above manipulation have any meaning? (mathb.in/35021)

$\vert\Psi\rangle=z_1|a_1\rangle$

is an*

Maybe the $$\align thing doesn't work?

2:11 AM

$$\begin{align}
\vert\Psi\rangle & = z_1\vert a_1\rangle + z_2\vert a_2\rangle \\
\mathbf{\hat A}\vert\Psi\rangle & = z_1\mathbf{\hat A}\vert a_1\rangle + z_2\mathbf{\hat A}\vert a_2\rangle \\
& = z_1a_1\vert a_1\rangle + z_2a_2\vert a_2\rangle \\
& = w_1\vert a_1\rangle + w_2\vert a_2\rangle \\
& = \vert\Phi\rangle \\
\end{align}$$

there we go :)

If we take the Operator A to be an Observable does the above manipulation have any meaning? Or does the Collapse Postulate render it meaningless?

If we take it to be the Position Observable acting on a Superposition of Position Eigenstates for example. Then acting on the Superposition with the Observable doesn't collapse it into a single Eigenstate but instead seems to "push" it's probabilities around (separately, in a way that you can't normalize away).

I've heard a prof say that the Collapse Postulate is "unnecessary", which I can understand from philosophical perspective incorporating decoherence and a universal wavefunction etc. But mathematically without the Collapse Postulate then it seems to me that Observables can act on Superpositions of their Eigenstates without Collapsing them?

Icosahedron

2:53 AM

@ᴇʏᴇs Everyone was talking about eyes.

DemCodeLines

Not sure if this has anything to do with physics but the lower portion of my room is cool while mid-to-upper portion is hot

Don't know why

0celo7

3:20 AM

@NeuroFuzzy I have 75 minutes to introduce matrices to people who have never seen matrices before.

I'll be extremely surprised if I get through a simple inverse calculation.

"As a general rule, 'we do not discourage homework' questions, as long as they are related to physics. But do keep in mind that Physics Stack Exchange is not primarily a homework help site; it's a place to get specific conceptual physics questions answered." Well, hello Wikianswers. — Saxasianguy 3 mins ago

ᴇʏᴇs

@Icosahedron I'm used to people talking about me

NeuroFuzzy

4:22 AM

@0celo7 Hm. Well it IS eye-catching! (to cool people, at least).

David Z

5:20 AM

@DanielSank done, thanks for the reminder

7:11 AM

Anyone want to help me take over the world?

sure

Excellent.

Do you have mathjax running?

Does this look like math:
$\int f(x)\,dx$
?

nah, no mathjax

Do you know how to start it?

nope, but are on omeone else's computer

7:15 AM

Go here:
http://www.math.ucla.edu/~robjohn/math/mathjax.html
and then drag the "start chatjax" link onto the browser tab for this chat room.

done!

holy crud!

Do you see math?

I can see!

Great

Now the fun part where we take over the world.

Do you know TeX?

lol

vaguely

7:16 AM

Try typing an integral.

an integral

lol