i was going with the first thing i could think of. #2 was asking if the jolly green giant is cool in person or if he's a diva.

the mishap is cutting down on prep time, so we're doing a lot of minimal-prep meals. sandwiches, salads and such.

By the end, you'll have forgotten how to cook :)

and she'll have forgotten how to act in public.

She never knew. She follows your lead.

yeah, good point. maybe the silver lining is that there isn't really a more feral state that she can regress to. she's already there.

Is there a limit to ferality?

@TedShifrin Sure.

i guess we're testing this experimentally right now. she crawls around and hisses at the cat. i wish i were joking.

What's been interesting is over the last few weeks, I've had more than one person wonder why I'm leaving education

Did you mention the great respect the US has for educators?

you were tired of all the money. you ran out of places to store it.

For some people, they're willing to tell me what they've had to deal with financially and stress-wise on the job. For others, they can't fathom leaving education in fulfillment of its mission to equalize.

My piano teacher is faculty with a PhD. Usually is part-time. Got credits cut down from 16 pre-COVID, took a year off, and is now at 4 credits this semester.

Well, musicians, academic or not, have always had it pretty rough ... except for the super-famous.

my vault of gold bars and coins in which i swim every day was filled to the top, and the city council wouldn't give me a permit to build a new vault of gold coins. i plan to put my considerable energies and fortune into political activism around this issue and will no longer be able to educate.

It's also interesting to hear what's going on in the community colleges. I'm hearing of a dearth of enrollment aside from college algebra / stats. My former dean told me that they have struggled to fill classes at Calc I and above, attributing some of that to poor retention of prior-year students.

Well, I wonder if there will be a glut of people trying to be plumbers and electricians (who all make good livings).

@TedShifrin I'm hearing that and similar narratives being thrown around, as well as people who question the need for a bachelor's degree whatsoever.

it's a very different world from the world in which many people were first hired. i think the best thing a lot of my wife's colleagues could do to promote equity and access to opportunities would be to tell their students not to go to grad school.

but the script is still, ooh, i have this straight A student, let's see if there's a masters program somewhere that will take them. some people only know one way to advise.

Well, trompism will lead to elementary school dropouts.

I long ago quit encouraging students to go to grad school in mathematics, unless they were very talented and passionate.

@leslietownes Yeah, I was fortunate to have an undergrad advisor who privately expressed her disapproval of people advising their students this way.

the california state constitution has details specific to education in it, but the US constitution notably doesn't. many states don't either.

Big surprise.

you saw a lot of this post-brown. there is almost no obligation in some areas to provide education. the constitutional equal protection minimum is very low. maybe that's where we're headed. laws against "education passports." who's to say i need to graduate from elementary school.

And we are just talking about education as a whole. Data science education is a whopping mess.

i can only imagine.

Career math, CS, and stats faculty should not be teaching DS. That's just my opinion. I've kept in touch with several former students, having to advise them on things that aren't taught in their programs that they'll actually need for their career goals.

The inevitable problem that academia will have to face is what appropriate credentials for DS faculty are. Plenty of people are doing fine DS work with just bachelor's degrees, and more often than not, I have to correct graduate-degree holders on their perceptions of DS

and of course, there's the problem of defining exactly what DS is

Maybe datum science would make it easier.

Hi!

Hi, Wolgwang.

in the first dotcom boom (late 90s-2001 or so) there was a similar thing within CS. the market demanded skills that weren't really traditional CS skills, but were definitely computery. so you had people dropping out and just following the market, on the one hand, and yet also a lot of very watered down trend-chasing y2k stuff being introduced in weaker CS departments.

i knew the bubble was going to burst when one of the least reliable, least computery people from my high school changed to a CS major at his liberal arts school. if i'd owned any stock i would have sold it then.

i imagine all of those people working for facebook now, in a boiler room, cold calling small business owners and asking if they want to buy ads on anti-vaxx feeds.

hope all are well.

Howdy, @copper.

Hi Ted.

Don't mind the morosity.

I am in a pretty foul mood. Dropped son off Thursday, haven't heard from him since.

That's how it should be.

The last thing I wanted when I started college (not too far from home) was to hear from my parents.

i can't imagine going to college now, with the constant engagement. not just with family but peers.

i think i phoned my parents (40 miles away) about once every six weeks.

I suppose. I am a needy dad :-)

You just have to deal with your own empty nest syndrome, copper. Don't be mad at the kids.

i talk to them a lot more now. they're right there on my phone.

> Find the equations of the chords of the parabola $y² = 4ax$ which pass through the point $(- 6a, 0)$ and which subtend an angle of $45°$ at the vertex.

"Subtend 45° at the vertex"? I am unable to draw the diagram :-/

The chords pass through the vertex?

That doesn't make sense, Wolgwang.

I called home weekly when in berkeley. Expensive back then, wonderful AT&T.

You're right to be bothered.

that's overdetermined. you don't have control over the angle if the line has to go through two fixed points.

Reverse working from answer gives desmos.com/calculator/habxvafy1p

My parents lived in the eastern US, copper, and I certainly didn't do that, either. However, my dad's health started to fail (seriously), and then I kept in touch.

i don't know 'subtends' here but it sounds like you just have a line through two points, and it doesn't sound like a is varying or to be solved for.

These Indian problems that are wrong get very tiresome.

The vertex is the origin. The problem is a mess.

yeah, sounds like 'vertex' should instead be something like the point of intersection with the parabola. and if i get a vote, we should retire the word 'subtends,' and just talk about an angle between two curves at a point of intersection.

The chords aren't passing through the vertex.

@TedShifrin I suppose I never really adapted to not having lots of family within reach. My wife & daughter are gone on an RV trip to LA/Santa Barbara for the week.

'vertex' should definitely be banished from the problem

We're looking from the vertex to intersections of the chord(s?) with the parabola.

Ah, so they abandoned you at just the wrong time, @copper.

oh, is that it.

:-)

And, of course, for fun they made the parabola have the $x$-axis as its axis of symmetry.

so with P = (-6a, 0) and V = (0,0) the vertex, we're drawing lines through P that intersect the parabola at points C, and want to find the equations of those lines for which the angle PCV is 45?

points $C$ and $D$.

No. $\angle COD$ is $45^\circ$.

You shouldn't do anything with a picture in it.

oh.

Oh, $O=V$.

this problem should be administered in the style of jeopardy! here's the answer, what's the question.

Some solution ⚠️

REF img

There's a typo near the beginning, but you basically have to do what they did, yes. Find intersection points and use the tan of a difference formula.

What is your complaint?

Should I ignore the vertex...?

You're finding the angle between two lines at the vertex (the origin). How do you say they're ignoring it?

I can't imagine I would replicate that solution if I did the problem myself, but the ingredients have to be the $\tan(\theta_1-\theta_2)$ formula and the point-slope formula for a line.

Ah, yeah, I explained that one up a bunch of lines.

what's name of this symbol?

theta

\vartheta comes pretty close in tex

Oh, now leslie will go around editing \vartheta in for \theta everywhere, since he so admired the person who replaced \epsilon with \varepsilon.

i'm actually against vartheta. i will purge math.SE of its malign influence.

It's used almost exclusively for theta functions.

not for long, it isn't.

. o O ( suspension watch )

weierstrass P also has to go.

LOL

I have no idea why vartheta is.

I love $\wp$.

who made it in the first place....is it like theta.

It is a script theta. What's your hangup here?

technically it's the same letter, just written different.

As I said, it is used primarily in writing theta functions (abelian varieties, modular forms, etc.).

thanks you guys :)

i agree that there seems to be no rhyme or reason to which letters get \var versions and which don't. except as ted suggests perhaps some historical reasons, and in the case of epsilon, people maybe aesthetically preferring one to the other.

The theta function is always written with the script letter. Varepsilon is a matter of taste. I tended to use varepsilon when teaching because regular epsilon looks too much like $\in$ on the blackboard.

some old books use an actual epsilon for that. it's very 'cringe' as the kids would say.

And then there's the theta divisor, which is $\Theta$, although its cohomology class is often written $\theta$. Ha ha ha.

$\frac{\overline{\Xi}}{\Xi}$

Are you writing on parchment? I cannot decipher.

Xi-bar divided by Xi. just computing with complex numbers.

Ah. Illegible on my screen.

Answer this to stay out of trouble.

on the blackboard it would look like eight stacked lines. at least if you do it right.

he seems to be assuming u is in the domain of the laplacian? that seems like a gap.

He said he wanted to prove that (assuming that $u_n$ were in the domain).

in the first sequence of displayed equations he appears to apply the laplacian to u before concluding that u is in the domain of the laplacian.

i'll think harder about this

@leslietownes that is a BIG sandwich you have there.

it's on the hidden menu at in n out.

it doesn't look like an easter egg...

@leslietownes what was Morpheus' middle name?

Was that when Perseus morphed to Orpheus?

that's a good question.

Got double vaxxed yesterday

if it's all the same to you, i'll send my congratulations over the next gen 5G vax network instead of this chat

lol

thought i had the fever spell over with yesterday night but after 24 hours i feel a little feverish again

much better than the first one though

i had a very sore arm for days, but my second was much better than the first one too

I didn't feel anything

either dose

well, a bruise

Although the second dose I got a 4 inch stab wound so I was more worried about that

But it all worked out

pain wasnt an issue for me either time. its my immune system going nuts at the thing thats a little tiring

I usually change sides like 5 times when I sleep

so I wasn't able to do that

Congrats, a @Balarka. I had fever a day after the second one.

thanks, @Ted. i think i have an extremely mild temperature but enough for some discomfort.

had to take paracetamol (tylenol for americans) yesterday night tho

No big deal. ... Although who knows what inventive mathematics you'd do with a fever :D

i think i have a theorem statement which looks awfully lot like a conjecture in someone else's paper

Better to skip the tylenol :D

haha.

You have a proof of said theorem, or just an enunciation?

Apparently this is conjecture to some.

Nothing fancy, pretty modest

With global coordinates it helps to be on non-compact domains :)

I know nothing about such things.

I was being quite blithe with that choice of words. I don't mean an independent system of coordinates; eg a manifold in R^n has "global coordinates", x1, ..., xn.

A constrained Hamiltonian phase space is known to a mathematician as a symplectic reduction.

Alternatively, GIT quotient

My coauthor Malcolm did lots of stuff with symplectic reduction.

So what does "global coordinates" mean?

Malcolm Adams, right? I know your other coauthor, Clint McCrory, did stratified spaces.

Right.

There's still another coauthor. Varley ... the complete algebraic geometer.

Global coordinates is just a Whitney embedding in R^2n, but it has to be symplectic; so a better choice of codomain is CP^n.

@TedShifrin The scary kind

I think I have only a handful of solo papers. But the collaboration was the most fun.

It's good to have someone to talk to.

Why do they call an excess of coordinate functions coordinates?

They certainly don't, I made it up on the fly for a one-line explanation of what I'm up to :)

Ohhh, you.

The enjoyable part in it for me is that I'm learning quite some math I did not know before.

Can't wait for the writing part to be over and reading all my citations diligently, just for fun.

Luckily for you, there is still a bit of math left that you didn't know before :)

On the contrary, there's too much. I sometimes wish I started even earlier!

You'll be fine.