The Spectre of Math

September 22, 2009

ubuntu karmic

Filed under: Hacking,Linux,Technology — jlebl @ 6:56 pm

So I couldn’t sleep last night so I installed ubuntu karmic. First impressions: boot is not significantly faster, but it gives less feedback that the machine is booting. It takes a long time for some logo to come up. I wonder if having such a graphic intensive logo plus moving mouse throbber doesn’t take up some of the startup time. Anyway since I haven’t done any timing not sure if it is relevant.

Anyway, my first thought was: the new gdm is ugly. There’s definitely some missing functionality and seems to be very rough around the edges. After logging in (into a new account) I noticed that it is still true that to turn off the computer means you have to click your name. Except now there’s not even any sort of button that would indicate so. I’m also still not clear on the whole idea of seeing my user name on the screen all the time. Now it almost looks like I’m part of some chat application and I can set my “status”. Meaning it is one more “status” about me that I’d have to set if I wanted my “status” to be “not wrong” (the other ones are skype, gmail, facebook, linkedin, and some I am forgetting because I don’t really care).

Otherwise, what’s cool is that all the interface bugs due to the buggy intel drivers seem to be gone, gl apps seem to work correctly and at reasonable speed, and fullscreen video seems to sort of work too. flash is still slow as hell fullscreen, but less flickery. I do like the lack of menu icons by default and the tool bars with text next to icons to save some space.

I also used gnome-shell, and I’m not particularly impressed. Yeah it slides around and looks cool, but it doesn’t seem to be a very streamlined interface. It takes more clicks to get anywhere. My mouse has to run around to launch an app. It’s impossible to navigate the thing with a keyboard. Things that before required one or two clicks of the mouse, now require several it seems. Well I’ll see where it goes, but I don’t really see a huge improvement, in some cases it seems like it makes simple things hard, without making anything actually easier. And none of the widgets used in gnome-shell look like widgets, it looks like web designers took over my desktop. It seems that “it looks cool” is prioritized over “being consistent” and “discoverable and logical interface”. These are my problems with Vista (and likely Windows 7). I can’t ever figure out what is a button, what is a label, what am I supposed to click and what can I do with that clutter of things that’s on the screen right now.

September 16, 2009

Over 2000 downloads of my notes

Filed under: Mathematics — jlebl @ 5:19 pm

Actually, 2098 unique IP address downloads of the diffy qs notes. The rate was hovering about 130-140 per week over the summer and jumped to 171 this past week. The semester is starting at most universities. I wonder if I can detect midterms and finals, or if it gets lost in the noise.

September 11, 2009

R is uncountable

Filed under: Mathematics,Teaching — jlebl @ 4:34 pm

Today I did the “\mathbb{R} is uncountable” proof in class. I got a few “understanding nods”, and only one person seemed to be falling asleep (visibly). One person stormed out the moment I finished the proof, but I think it was because I went about 30 seconds over, rather than being angry at Cantor. All in all, I think that was success. Last time I did this a few years ago to a similar audience I got many angry stares. I think they were also not small Kroneckers, but more angry as in “I have to learn this nonsense?” I always find that this theorem has a quality about it that makes people either like it a lot or hate it a lot. I think much more so than anything else they will see in this class. I already had a question in office hours whose answer depended on the axiom of choice. I guess that is more subtle than uncountability of \mathbb{R}, but also I don’t talk about AC in class.

I did something like Cantor’s original proof of 1874. I looked at Wikipedia (which has a simplified version of Cantor’s proof) and I looked at baby Rudin, which has essentially the same proof in completely different language and in greater generality. Though I did it without using contradiction, since proofs by contradiction are evil.

Proof: Given a countable set \{ x_1, x_2, \ldots \} \subset \mathbb{R}, you construct a sequence of closed intervals [a_j,b_j] such that [a_{j+1},b_{j+1}] \subset (a_j,b_j), and such that x_j \notin  (a_{j+1},b_{j+1}). The intersection of all the intervals is nonempty (compactness) and can’t contain any element of the countable set. QED

That’s more analysis-like than the diagonal proof, which is more computer-science-like.

September 10, 2009

More sketch fun and more textbook fun

Filed under: Hacking,LaTeX,Mathematics,Teaching,Technology — jlebl @ 10:33 pm

I have to brag. Here are some more fun sketch pics. These are probably very close to what we’ll actually put into the paper. Marketa said that the second one looks like bublanina.

more sample sketch pics

On not really related note the rate of downloads for my diffyqs notes is rising in the last week. I think I’m detecting the start of semester for many US colleges. I bet it will increase even more once the fall semester/quarter starts everywhere.

Now on related note, I’m typing up my notes for math 444 here, which is basic real analysis. So I’m writing another textbook: really baby analysis. Take baby Rudin and make it a lot less ambitious. If I were really crazy I could also take my sort of typed notes from last semester’s basic linear algebra and make those into a textbook … some other time I think, I didn’t really like the syllabus for that course, so if I were to make a textbook there it would differ more from the course here at UIUC.

September 9, 2009

Playing around with sketch 3D

Filed under: Hacking,LaTeX,Technology — jlebl @ 10:36 pm

We need figures for our latest paper. And the figures have to be of 3D things. So I’ve been playing around with sketch 3D, and so far it is working pretty well. It’s a 3D modeling language that compiles into latex.

sample figure

Cool huh?

September 4, 2009

Obama must be really sneaky

Filed under: Politics — jlebl @ 4:48 pm

Sorry for the extra bolding here, but I think that’s what seems to not be getting through.

So some school districts will not let the students hear the President of the US (not just some random joe) talk to them about staying in school. I watched the news this morning and there was some guy arguing that this was an unprecedented “unfettered access” to our kids and that shouldn’t be allowed. What is he going to do? Corrupt them? Make them go vote democratic? Come on, he is the President of the US. He is our leader no matter if you like it or not. Just like I didn’t like Bush being president, he did get actually elected (at least once, opinions differ about his first time). So he was the President and I would not mind him telling school kids that they should stay in school and not do drugs, and anything else he might want to say. Think of it as “career day.” I mean there are all kinds of morons that speak to kids in schools. And the schools don’t care.

Anyway, there is a difference between questioning his policies and trying to pretend he is not the President of the US. If Obama was not elected, if he was just some random shmo, then I can understand. I mean if a war starts, he drafts you into the army, are you going to go “I don’t like Obama, so I won’t listen to my commander in chief.”

I remember being yelled at by someone when I went to an anti war rally in ’03. Apparently questioning the president is unpatriotic and a treason. I was supposed to agree with whatever he said simply because he was the president. Same nonsense was on all the cable news networks, FOX most predominantly. I don’t understand. Aren’t you guys now supposed to also agree with the president no matter what he says? Or does that hold only when the president says something that you agree with? Now I can understand that logic, if that’s explicit.

Pretending that Obama is not the president was the same as the people that the first four years of Bush thought that Bush wasn’t president because he didn’t get elected. I mean they just didn’t like the way the system works (I didn’t like the system), but Bush was the president. It wasn’t illegal. It was strange and weird, but it went according to the system. In this electoral system, it is whoever is in power that controls how the elections are run. That might be stupid, but that’s the way it is.

Anyway, it was a good laugh. Though I don’t know why does MSNBC put these morons on TV. I can understand why FOX puts morons on TV. I mean they even give them their own programs. I hate the whole thing with the “republican strategist” or “democratic strategist” or putting loud idiots on TV just because they managed to be really loud somewhere. Just because you find two opposing views doesn’t mean you will get an objective discussion. The distribution of opinions is going to be something like the gaussian curve. To get any meaningful discussion that has anything to do with what the majority is thinking about, you only want to go within one standard deviation from the mean. That way you’ll get 68% of the population. If you take two people, at least one of whom is further than a few standard deviations (a real deviant) then the discussion is going to be 1) funny 2) loud 3) not informative.

Take healhcare: According to polls, for example this one: , americans are overwhelmingly in favour of a public option of some sort (67%). Even half of the republicans are for it (49%). That means that picking a republican voter at random, you have about a 50/50 chance of hitting one who thinks that we need a public option. So in pure number terms it makes no sense that ALL republicans that end up on TV think that a public option will lead to stalinist communism and death panels. It also means that even the moderate republicans in congress are not actually moderate. The distribution of opinion of the elected representatives of the party is to the right of the mean opinion (of republican voters). Moderate republican congressmen are probably ones who are only slightly more right wing than the average republican voter, while the random republican congressman is quite a bit more right wing than the average republican voter.

You could probably pick two republican voters and have a meaningful discussion on the public option. Just pick actual voters and pick sufficiently at random. That is, do not pick loud idiots just because they are loud.

Enough procrastination … off to do work …

September 3, 2009

Suppose I were a greedy bastard

Filed under: Economics,Politics — jlebl @ 6:32 pm

Suppose that were true. Would I want the current healthcare in US, or would I want something different? As a greedy bastard, I want to pay the least amount of money. Given that we all need to see the doctor at some point, I am not going to get out of it. So, we have a choice, pay some sort of tax that goes towards some sort of public health plan. Ideally single-payer or some such. Or we can have what we have right now. Now look at the cost of healthcare (see previous blog post). See how much more it is here, than say Norway or Luxemburg? Why did I pick those two countries? Those are countries with very high cost of living. Things over there are generally more expensive than here in the US. Furthermore they have GDP per capita higher than we do. They should have expensive healthcare. Yet, those damn socialists seem to be doing better. That is: they are paying less period. That is, if you add up the money that they pay in taxes or insurance premiums or to the doctors or whatnot for your healthcare, they end up on top. And given that they end up living longer by a few years and their infant mortality is half of what it is here, I’d venture to say they get better care.

I don’t care if the money goes to the government, or insurance companies, or directly to the doctors, or to tiny green leprechauns. If I am a greedy bastard, my only motivation is to reduce the amount of money I pay. I want to keep my money. Why are republicans OK with paying some insurance company who will charge them apparently a lot more than a working socialized health care plan. Are we supposed to be capitalists even in areas where it is obviously is not working any better (and in fact, much worse) than a government can? Is capitalism a religion? Are you supposed to blindly worship capitalism at all levels?

Why are we fine with police not being done by capitalists principles? Why do we pay firemen out of our taxes? Why are roads paid by taxes? Why do we have public schools? Why isn’t the military a private enterprise? Obviously the vast majority of the population is fine with the government doing a whole bunch of things out of taxes. What’s the deal with health care?

September 2, 2009

The end of good UI

Filed under: Hacking,Linux,Technology — jlebl @ 4:53 pm

I think the UI for most GUI applications is turning into a badly written flash app. Looking over the new mockups of firefox 4.0. I feel the days of consistent UI are over (some could argue before they began). Nowadays every app will have different interface that will look flashy but will behave differently from every other app. Essentially the pioneers in this were mp3 and video players which brought us incomprehensible UI filled with flashy icons for years. They did to look like a stereo or vcr, both of which have really bad UI because they wanted to save on the number of buttons. A UI button is no longer a button, In fact you have to move your mouse around to figure out what things “do something” (where something is not well defined) to figure out which items in the UI may have some sort of function and could conceivably be clickable. The menu bar has disappeared altogether, because obviously giving things names is not the way things are done now. Apps are now supposed to have buttons with only icons, which look cool and don’t at all look like buttons. Imagine a printer or a copier. My print jobs keep getting canceled here since all the students keep canceling them by pressing the single big button with an incomprehensible icon on it if their job isn’t coming out immediately. The button looks like a check mark and does everything, including cancel a job, change priorities of jobs etc… Makes sense right.

Now this design, which has seem to have caught on in windows (I can never figure out what does the user interface allow me to do when I must set something up in vista), is making its way into free software. Now we have had some bad design decision in the past, but it’s getting worse. I’m afraid GNOME Shell will just be another flash app. We already have this weird behaviour in ubuntu that “to log out, you click on your name, which is next to an incomprihensible icon which afterwards one figures out probably means something like ‘leave’ or ‘exit’ or ‘run to the bathroom’ or ‘it is now safe to cross the street'” That makes total sense, doesn’t it?

Marketa showed me the new Word recently (not new now, but I don’t quite follow the windows world) It looks and feels like a webpage. Essentially, to do something you have to know where to find it. Consistency be damned. Someone says: but you learn how to use this interface and then it works well. Answer: you learn how to use any interface if you must, that doesn’t make it good. A good interface means that I can figure out an application without learning anything. That’s what consistency is for. Oh the other thing about the new Word? It is incredibly unresponsively slow (at least on marketa’s computer which is 1 year old). I remember typing a document in wordperfect on an XT used to be far more responsive. Try doing the following: You want to type a short letter and print it.

Do it with the technology circa 1989 or some such. OK, boot dos (a few seconds at most), start wordperfect (a few seconds) type the letter (as fast as you can type), print (a minute at most with lots of funky noises)

Do it with vista and ms word. OK, boot …. (go grab a coffee in the meantime) … oh darn, now I have to log in, do that (go grab a donut to pass the time) … ok click Word … (now eat your donut) … type your letter and notice that it feels as if you were typing a letter on a BBS back in 1989 over 300 baud modem (feel all nostalgic and wonder where you put that modem) … now you are done, so print (ok this is the only bit that works better and presumably faster now, unless you bought a high res inkjet that can’t print BW text quickly. You also miss the noise of the dot matrix printer that could wake a dead man).

Doing it with Ubuntu or some other Linux is the same experience except as vista except openoffice is more responsive to typing. Though I would probably start vim, type the text in, then run latex on it and get something far better looking than either openoffice or word can produce.

Still this type of job was essentially easier 20 years ago, and the computer felt more responsive then … oh but you didn’t have this flashy UI that you can’t figure out. Oh yeah, I forgot about that. The undergrads have probably canceled my print job thanks to the “one button with icon” type of UI, so I’ll go run back in my office to hit “print” again.

September 1, 2009

Dude … where’s my health care

Filed under: Politics — jlebl @ 4:20 pm

Another interesting (sad) statistic:

US is 33rd (if you ask the UN) or 46th (if you ask CIA) in the world. But the UN skipped 30 countries that the CIA did not, so … Anyway. Even Cuba is doing better in this department. This does say something about how health care is provided. While the US is not completely third world in this department, we are not doing good! Don’t tell me we have the best health care system. And don’t tell me everyone is free to choose to pay for a good health care system. If you are less than one year old, then you have no choice in the matter.

What’s interesting is that it is the same people who are against abortions are also against socialized health care. If we get to scandinavia rates, then you can save 3 children per every 1000 born. So they are OK with those children dying after being born, just as long as they haven’t been aborted … hmmmm … As an aside, do note that western europe also has lower abortion rates than north america. Maybe we could do both at the same time? Reduce rate of abortions and get better health care? I mean, other countries seem to be able to do it. Also note that as discussed earlier, the life expectancy here is lower than developed countries with socialized healthcare. That would preclude those “death panels”. I am sure that having actual death panels going around pulling plugs on people would not make life expectancy go up.

Also to consider: I’m sure the infant mortality rate will be far greater among the poor than among the rich (just a guess). So that means that among the poor the rate in the US is much worse than in say western europe or scandinavia (where there is far less poverty).

And finally, here is the following graph:

healthcare spending as percentage of gdp

Sweden gets their health care for around half the percentage of their GDP than we do. So they pay less and get more. Oh yeah they are socialists, they can’t pick what healthcare they buy. Whereas us capitalists we can pick the best option for the money, thus we are obviously getting more for our … uhhh … wait … where did the logic go in this argument?

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