Interesting Stuff

Man, would I like to know how that works. Its balancing algorithm is incredible!

I really ought to finish this entry. Better late than never, eh?

Yesterday (being about a week and a half ago), I woke up at 3:30 AM, which was strange, because it was a full half-hour before my alarm was set to go off. I needed to get an early start on the day if I was going to be in Victorville (over 100 miles away) by 7:00. Find out what I was doing →

Some of my readers have said they want me to post more videos I find. So here’s a Lego production line that makes cars. The button-pushing at the beginning selects what colors to use for each of the pieces. I’m very impressed with whoever made this; it’s quite a feat. Side note: how hard do you think it would be to make a von Neumann machine out of Legos? Easier or harder than making it out of custom parts?

…and just for the hell of it, here are some kittens having fun with an empty Coke box:

A coworker and I were having a discussion about general relativity, and wandered down a tangent in which our understandings of the universe differed. We both agree that each others’ explanations are plausible without any hard data against which to test predictions (and we didn’t have real data to back up any of our claims). Does anyone want to weigh in on this debate? Have cosmologists considered this idea and come to a conclusion one way or the other?

Is space itself expanding, or are the things in space just moving away from each other? →

Yesterday, I was asked by an organization I trust for my phone number, home address, and a couple other pieces of information they have no business knowing. When I want their services, I go to them and I don’t need to make an appointment, so I really can’t think of a valid reason they would need my contact information. When I asked the man why he requested it, he replied that he needed to put it into their computer system to make sure my records were up to date. To the best of my knowledge, he doesn’t know why they want this information, either; he elided the question because it’s just something he’s supposed to collect from customers.

I have experienced this on several different occasions. One of the more memorable ones was when I opened my bank account: the bank wanted my social security number, approximate yearly income, and a bunch of other information I really can’t justify their having. Have you experienced a similar problem? What did you do about it? My response has been to hem and haw for a while and then just give them the information to make everything go smoothly, but it’s never sat well with me, and I’d like to find a better way of dealing with this.

Yesterday evening, John, Jacob (though not Jingleheimer-Schmidt) and I had a bull shoot for an hour and a half. We started out with John proposing a memory caching system which was intended to make garbage collection and blocking irrelevant. From there, the conversation natuarally progressed to online algorithms, cache-oblivious algorithms, religion, free will, consciousness, Searle’s Chinese Room argument, Chalmers’ Zombie Planet argument, qualia, logic-based representations of object-oriented programming, the lambda calculus, machine learning, finite discrete universes, quines, the Gödel processor, complexity theory, the No Free Lunch theorems, and probably some other topics that I’m forgetting. It was fantastic.

However, this, along with a couple other conversations this week, have showed me just how much I have forgotten since college. I couldn’t remember the phrase “competitive analysis” when we discussed online algorithms. I couldn’t come up with a representation of linked lists that supported the head and tail functions in the lambda calculus, and worse, I mixed up the S and K combinators and couldn’t even give the definition for what turned out to be the S combinator. Last week I mixed up pipelining and instruction-level parallelism, and couldn’t come up with the phrase, “speculative execution.” Last week at lunch I couldn’t come up with the formal definition of temperature (something about the kinetic energy of the molecules relative to each other and maybe the amplitude of the interatomic vibrations within the molecules, but what do you do if you have a singe atom?). Today I couldn’t explain why (if?) bending a piece of metal makes it harder but more brittle, or why bending a polymer makes it more maleable (though in my defense, I could explain the difference between stress and strain, and what a polymer is as well as a bunch of examples of polymers). I remember why the X combinator is important, but can’t give the definition for it or the Y combinator. Yesterday I realized that something I was working with was a metric space, but couldn’t remember anything useful about metric spaces (I got as far as knowing that the triangle inequality holds, but I didn’t remember anything else). I can no longer use LaGrange multipliers to optimize a quantity subject to a constraint (you need the two to have parallel tangents at the extrema, but I don’t remember how to find the slopes of these tangents). Last week I forgot the name of Topological Sort, let alone how it works (something related to DFS, but that’s all I came up with).

Now that I’m writing this, I’m noticing all sorts of other things that I used to know but can’t quite remember (how Java does garbage collection, queen-asking continuations in Roman Keycard Blackwood, how the telephone lab in Baby Stems worked). It’s scary to realize how much I’ve already forgotten, and know that I’m only going to forget more things from here on out. Does anyone want to have a refresher session? If so, post your questions (or answers) here!

I’ve recently been watching several shows about the wildlife in other parts of the world, and it’s been absolutely fascinating. Last week there was a 3-hour special on the National Geographic channel about the Galapagos Islands which was amazing. I just finished watching Expedition Borneo on the Discovery Channel. There was another program on PBS about Galapagos earlier this week, too. I don’t want to go to Borneo (too many insects, leeches, venomous creatures, and diseases), but it would be really cool to go to Galapagos someday. In the meantime, I’m thrilled to see these things on TV.

Back in November, I watched a bunch of videos from TED, and I’ve been raving to my friends about the first one ever since. It’s by Hans Rosling, who displayed a really neat way to represent statistics and other large sets of data in a simple, intuitive, and basically useful way. Well, it turns out I wasn’t the only one who was impressed: his software, GapMinder, was acquired by Google earlier this week! It would be really cool if we could all use this to look at more pieces of data more easily. You can already play around with a demo. Sweet!

I’ve already learned stuff from it: I had not heard of Comoros or Seychelles before playing with it today. They’re both countries north of Madagascar, apparently. Also, GDP and rate of economic growth don’t appear to be correlated, which surprised me. People in Luxembourg make a lot of money.

Oh, and by the way: it turns out there’s a Firefox plugin to support GPG in GMail. I might start using GMail full-time if this turns out to be easy to use.