Perhaps skywave propagation? (See also E-skip.)

CB radio operators sometimes experience the right weather conditions for this to occur; using ionosphere propagation to communicate over long distances is known as "shooting skip"!

[Trump's election shows that] it doesn’t matter if your leader is a liar, a philanderer and a narcissist. It doesn’t matter if he is cruel to the weak and bigoted toward the outsider.

[Clinton self-righteously portrays the election as] us enlightened few against those racist many; us modern citizens against those backward gun-toting troglodytes.

WHICH IS IT, MR. BROOKS? WHICH IS IT?

You can't in one breath say "Trump destroyed the morals of (my favorite) party" and in the next breath say "criticizing the morals of people who voted for Trump is 'triablism'"!

Describing people protesting racism as a "lynch mob" is really something special.

I don't think she's arguing that you should be friends with weev -- you're right, neither of you are in the same tribe and neither of you want to be in a tribe with each other. She's arguing that since she's already in a tribe with weev that she's better off maintaining a relationship with him rather than trying to kick him out of their common tribe or, more likely, removing herself from the tribe, as that seems to be how that sort of thing typically ends up.

Nowhere in this paean to St. Augustine is there argument or evidence that all this lovey-dovey changed anyone's opinions one iota.

https://www.newyorker.com/magazine/2015/11/23/conversion-via-twitter-westboro-baptist-church-megan-phelps-roper

https://www.washingtonpost.com/national/the-white-flight-of-derek-black/2016/10/15/ed5f906a-8f3b-11e6-a6a3-d50061aa9fae_story.html

Outliers? Maybe so. From a personal perspective, though, my views on most political and social things have changed completely over the past 10 years, and I'm disgusted by some of the positions I used to argue pretty strongly for. I can definitely say that I would not have been able to make that change if I wasn't around people who took other viewpoints and, often unintentionally, educated me on a lot of stuff.

I dunno. I don't think I'd be friends with weev, but I do think that long-lasting social change has to include changing peoples' minds.

Absolutely! May tomorrow be better for you.

I am also kind of out of my depth here (Devac, care to chime in if what follows is way off track?), but to my knowledge the interesting bit is here:

Having a “sign problem” thus means that no local transformation that removes the signs and phases is possible. Notably, the definition of a sign problem must involve the notion of locality [see also the study of Hastings (7)]. By performing a nonlocal transformation on the physical degrees of freedom, one can always diagonalize the Hamiltonian and obtain a classical partition function. However, such a transformation requires computational resources that scale exponentially with the system size.

The problem of performing a nonlocal transformation is in NP: if you knew the exact set of steps to take when performing the transformation, you could do it in polynomial time --- but nobody knows whether or not you can compute the steps to take in polynomial time. What we have now is an exponential-time algorithm for finding those steps --- in this case, diagonalizing the Hamiltonian.

Extra-fun fact: You can do C++ style for loops too!

  for ((i = 0; i < 10; i++)); do echo $i; done;

Instead of focusing on big things that could go wrong, focus on small, concrete things you can do to make your presentation better. That way when you're speaking and you wonder, "are they getting it?" or "am I being dull" or whatever, you'll have something you can do to fix that problem.

I also spend a lot of time "rehearsing" various parts of lectures 'n whatnot in my head. It's not really rehearsing--I don't tend to go in order, and most of the stuff I think through I don't actually say. But, I think coming up with a handful of ways to cover a topic makes speaking easier.

Nerves never go away; even after lecturing for a while I still get nervous right before classtime. That's something that you just have to practice getting through, I think. Once I actually start talking I usually relax and things get better.

The thing that catches me the most about this article is the way Kay rejects the popular framing of "entertainment XOR education" and the emphasis that we should be building tools that encourage people to use them in advanced/novel ways.

I don't know really how to do this practically, but it's something I'm going to be thinking about a lot.

I don't mind doing it but I'm worried this is my dad's way of roping me into helping out at the store. I suppose from his point of view I look like I've given up on life.

I've seen something kinda similar happen to students in my research group. When new students come in, they typically get handed a small project that they can contribute to that gets them some experience doing research, their name on a publication, and a bit better idea of what the field is about.

If they don't make much progress on coming up with their own project, their advisor pushes them to take the next step on that initial project, and the next, and so on. Even if it's not what the student really wants to be doing, that kind of project makes sure that they don't end up spending a decade getting a PhD.

I guess my point is that if your dad is leading you into helping out at the store, you should feel happy that your dad cares about you, but if that's not ultimately what you want to do, you should be taking steps to figure out what it is you do want to do.

It can be less messy, but the best approach is most definitely to get an extension cord and do your frying outside.

Summer semester is ending, so I'm even busier than usual.

Also, coop is going up...not my finest work, but it should be fine for a chicken coop.

That's legit! I assume you know of the White Zombie?

Looks like you can use a 3-phase motor and a VFD if you want (and can provide a DC-DC converter or other source of 300ish VDC)....

(damn you, I have other things to do tonight!)

Writing a lab manual for the lab I taught last Spring. Hopefully this way all that knowledge will not leave when I graduate and that other people will be able to teach the lab.

Also writing a paper on my research that's due at the end of June.

Also, chickens, cars, some machining, topology, and discrete math...

Cool. Due to the uncertainty principle, a spike in the momentum space ought to correspond to a wave in the position space, right?

This annoyed me as well. Correct me if I'm wrong, but it's not even that there's really a dual nature at all here; photons behave like particles when their wavefunction is a single spike, and like waves when it's not, right?

The Avalanches - Because I'm Me

For what it's worth, I definitely come back in the evening and read all the posts that happened during the day, so don't worry about your comments getting lost or ignored.

I'm curious: why would you consider feeling comfortable in front of strangers to be a flaw?

I looked for other cars with similarly shaped pipes, and I didn't seem to find any--there are no pick-n-pulls out this way, and the proprietors of the various junkyards are no-nonsense characters that don't take kindly to requests to "just find something kinda like this".

I thought about a couple ways of doing this but decided that if I was going to bother to re-make the intake pipe I might as well make it good. Otherwise I'd have just scrounged the classifieds on various MR2 forums until I got a used replacement in reasonable shape.

I agree on the toaster...but then again, I don't have a book deal as a result of doing something that seemingly pointless! If I were to go about making something complex from scratch, I'd rather read this instead.

Yep, smart pointers and "modern" (post-2011) C/C++ features are very nice, and fix at least the low hanging fruit of what's wrong with those languages. However, you have to use them religiously and your libraries also have to use them to get their benefits. Rust at least forces you and library developers to write safe code by default.

Not to say C++ is necessarily a bad language...it's probably the language I know best, so I feel justified in complaining about it, but I'll admit that it's very good at what it does (especially considering its age) and Rust isn't quite there yet as a full replacement.

I'm increasingly less sure what I want to do once I finish up my Ph. D. I started it because I wanted to be able to do research. But the more time I spend in academia the more I realize that academia is where innovative research goes to die. I look at how my advisor spends her time, and most of it seems to be administrative stuff rather than anything interesting. Furthermore, professorships are few and far between, and I drew the short straw on several things in grad school, so I doubt I'll stand out from the crowd enough to count on landing one.

Conversely, the stuff I'm doing now is interesting but I doubt there's any immediate industry appeal for it. (Although I'm pretty sure I could angle myself into a position doing semi-related research.)

I was hoping to land a basic research position at some national lab, but it seems that those won't be exactly plentiful in a few years' time either.

Otherwise, research seems to be going better than it did in 2016 (i.e. I am actually able to spend time on it).

I'm not sure that it's libertarianism per se, but Eno's philosophy definitely shares some ideas about decentralization &c. with it. (Namely, I don't think libertarianism does enough to protect against bad actors and long-term power accumulation, but in a band analogy, neither of these† are major problems.)

The fascinating thing I see with Eno is the focus on structures; I've long been interested in these as well, but mostly from a math and programming perspective, rather than music and people.

† with the possible exception of bad bandmates, but you can always kick 'em out...

I'd love to! Probably over the summer, since this semester I'm TAing a different class.

Here, it's a little different:

Calc I:

- Limits

- Derivatives, antiderivatives for single-variable functions

- Riemann sums

- Basic integration, up to u-substitution

Calc II:

- Trigonometric substitutions

- Partial fraction decomposition; applications to integration

- Natural logarithm/Euler's constant

- Logarithmic differentiation

- L'hopital's rule

- Indefinite integrals

- Sequences & series

- Taylor series

- First-order ODEs

The most infuriating part of Calc II is that students are expected to be able to do basic convergence/divergence proofs for the series & sequences part without ever having learned how to write a proper proof in their lives. Grading those exams is painful because the class uses online math homework, so for many, the first time they have to write a proof for another human is on that exam. Each answer you have to read closely to see if they understand the ideas but can't explain them well or if they just wrote random words on the page.

So many students give up on that section since it's not well connected to any other material in the class and some of the concepts (especially the various remainder theorems) cannot easily be rotely applied to a problem.

And, yeah, "I can do this on a computer" does you no favors when you're trying to understand why some technique (even in another field of study) works, rather than just "oh I have this technique, let me apply it to some problems".

Anyway, you and I should be thankful that we've had something of a nonstandard education in math, and do our best to help others see what we see.

Well said. Thanks!

I went looking around and found some pictures & explanation of the actual X-ray pictures Franklin and Wilkins made:

Wilkins' initial X-ray

Franklin's clearer X-ray & explanation

Ooh, we should get some crypto papers up in here. I am wrapping up a graduate level class on cryptography soon, so I could definitely contribute some papers and exposition!

Oh, I reckon most use of ham radio is voice. For local communications, generally people use handheld UHF or VHF radios and a repeater that rebroadcasts transmissions 1 2.

For long distance communications, most people use HF radios, which transmit in frequencies that can be bounced off the sky and ground! 1 2 HF equipment is usually pricier than VHF/UHF stuff, but that's probably partly because it draws the interest of more serious nerds.

A couple CB bands overlap the ham HF range and, given the right atmospheric conditions, can be used for long-distance communication, called shooting skip.

Of course, you can also use the oldest radio mode out there: morse.

I notice this too with my students (introductory programming class). I suppose it feels a lot better to explain doing poorly as "I'm not naturally good at this" instead of "I haven't tried hard enough to wrap my mind around this".

That said, I do think some subjects are more difficult for some people than for others, and the way schooling is set up now doesn't really offer people the option of taking longer to understand something (aside from failing and retaking classes, which isn't fun or good for keeping scholarships).