Monthly Archives: December 2005

The Wireworld computer

Wireworld computed primes up to 31I’ve been interested in cellular automata for a very long time, dating back to when I was a kid. One of the first BASIC programs I remember writing was a version of Conway’s Life that would run on my Atari 400 computer (very slowly I might add). But I’ve also been intrigued by a very simple cellular automata called “wireworld”. Unlike Conway’s Life, each cell in wireworld can be in one of four states:

  1. insulator: cells in this state are always insulators
  2. electron head: heads always become tails in the next time step
  3. electron tails: electron tails always become copper in the next state
  4. copper: copper will remain copper unless there are precisely one or two heads adjacent to the cell, then it will become a head.

If you play with this, you might see why it would be called wireworld. I’ve known for sometime that you can create all kinds of logic gates with this automata as a basic technology, but today I found this very cool website which implements The Wireworld computer, a complete computer that computes primes, simulated in a Java applet. Very, very cool.

Addendum: I left the java applet running overnight on my machine at work. It computed primes up until 31, pictured at right (click on the image for a full resolution image of the computer state).

Flash Boil!

A couple of days ago I mentioned the idea of supercooled water existing in liquid form well below the freezing point. Perhaps more dangerous is another delayed phase transition: water can exist in liquid form at temperatures much higher than the boiling point and can flash boil when subject to a disturbance. This usually happens in the microwave oven, which is why sometimes people recommend placing a wooden skewer into a cup of water that you are heating for tea.

Check out the videos here for some examples. Do not try this at home: you can be badly burned by experiments like this. IIf you don’t particularly value your life, you could refer to Bill Beatty’s list of unwise microwave experiments for more dangerous ways to learn about science.

Paris By Night

Stumbleupon sent me to this incredible nighttime panorama of Paris taken somewhere near Notre Dame (you can see the big rosette window in one part), but includes views of the Seine, the Eiffel Tower, St. Eustace, St. Michelle, Sacre Couer in the distance, and the Louvre. Very nice. If you click here, you can see a slightly lower res version of the same panorama in a viewer that will allow you to scroll left and right.

Phil Plait v. Bart Sibrel

Some of you may remember hearing the story about Apollo astronaut Buzz Aldrin punching some lunatic who was trying to badger him into swearing on the Bible that he really did land on the moon. That was Bart Sibrel, and he’s gonna be on the radio today to sell his brand of bullflop on 97.1 FM St. Louis. Luckily for all, Bad Astronomy astronomer and blogger Phil Plait has also agreed to be on the show. It will be at 5:00 PM Central time Monday, Dec 12th, and can be heard via their streaming website. I’ll be tuned in!

Update: Sigh. Their website requires IE, so I guess I won’t be tuned in. Bummer.

Terrible User Interface Design

44 Keys of Confusion

Well, as a stop gap measure to replace my dead Philips DVP-642 DVD player, I went ahead and picked up a TruTech TT 320 DVD player ($34.95 from Target). It’s small, and plays VCD and SVCD (although not DivX like the Philips). I figured I will use it for a while until I figure out what to spend a more serious amount of money on.

It seems to work fine, but it triggers a pet peeve of mine: bad remote control design. I mean really, look at that thing. No less that 44 buttons, all EXACTLY alike, with labels that are printed in gray on gray. Holy crap, how are you expected to actually be able to use this thing? Good remote controls should be able to be used in the dark (yes, kudos to TiVo!). This thing not only needs light, but good lighting, and some glasses.

Bleh.

Chronicles of Narnia: The Lion, The Witch and the Wardrobe

Went to see this last night with my wife Carmen, and all I can say is wow. Really well done. We both enjoyed it, although I thought that the pacing was initially a bit slow. Comparisons with Peter Jackson’s Lord of the Rings are inevitable, and I must say: I found the effects to be of the highest quality, very consistent and I found Narnia’s battles to be even better than those in the Return of the King. The four child actors all did very credible jobs, with (I think) the girls outshining the boys. The movie can be a bit intense (it is rated PG) with some loud scary battle sequences that seemed to upset some of the younger and more sensitive children in the audience, but they calmed down in the more uplifting moments and were clapping.

Scanning the list of user reviews on Yahoo! I’m left with two major impressions of negative comments on this movie:

  1. One group claims that anyone who thinks this is better than Harry Potter is crazy. Well, it was better than Harry Potter in virtually every way.
  2. Another small minority thinks that it’s important to bring up the idea that C.S. Lewis’ Narnia books are just thinly veiled metaphors for Christianity. While such accusations are in some sense true, get over it, and enjoy a very nicely done movie.

I suspect we’ll see some Oscar nods for effects, for costume and art design, and maybe even some surprise nods in other categories.

A really boring math trick…

This showed up on digg, but turned out to be one of the most absurdly transparent “math magic trick” I’d ever seen. Imagine that your 7 digit phone number was written as abc-defg. This trick says to:

  1. Enter abc into the calculator.
  2. Multiply by 80. (Accumulator now contains 80*abc)
  3. Add 1. (Accumulator now contains 80*abc+1)
  4. Multiply by 250. (Accumulator now contains 20000*abc+250)
  5. Add in defg. (Accumulator now contains 20000*abc+250+defg)
  6. And add in defg again. (Accumlator contains 20000*abc+250+2*defg)
  7. Subtract out the 250. (Accumulator contains 20000*abc+2*defg)
  8. Divide by 2. (Wow! Accumulator contains 10000*abc+defg, your phone number! What a surprise!)

Weak. Really weak.

read more | digg story

DVD Player Craps Out…

Bummer. My 6 month old Philips DVP-642 crapped out. Seems like the drive just went belly up, it doesn’t spin up at all or eject. I really liked this DVD player because it could play regular DivX avi files, but I must admit, I’m not really all that pleased with the longevity. Harumph.

Cuff him! He might get angry!

In today’s installment of “I Kid You Not”, 42 year old Donald Pirone was cuffed and cited when he handed a fellow passenger who was having difficulty with a subway token one of his, and the person responded by handing him the $1.75 that a token costs.

The most telling part of the story?

As for the handcuffs, [Transit authority spokesperson] Baker said the officer felt they were necessary.

“Our officers do that for their own safety,” Baker said.

Hey officers, here’s an idea: you’ll be a lot safer if you don’t piss people off by citing them for performing a courteous act. I think if he tried to cite me in similar circumstances, he damned well better cuff me for his safety.

I had a cop pull me over for failure to wear a safety belt. Yes, it’s the law, yes, I should have been wearing one. He seemed kind of surprised that I would be angry at his attempt to save my life. I patiently pointed out that he could have done that quite simply without charging me for the warning.

That apparently never occurred to him.

3D Without The Glasses

A Wiggle Stereogram

A couple of weeks ago, I blogged about a screencast I did that showed how you could convert stereographs into red/blue 3D anaglyphs. Jim Gasperini has a nice writeup about “wiggle stereograms”, basically two frame animated gifs which toggle back and forth between two images.

On the right, you can see that I created one of these pretty quickly using the Gimp. Basically you take the left and right images, load them into two different layers, preview them using the Filter>Animation>Playback tool, and then save the result as a gif, and check the box that makes you save them as an animation.

Kind of neat!

read more | digg story

Color Photos taken 96 years ago!

This post does two things. It provides a link to a cool collection of antique color photographs taken by Sergei Mikhailovich Prokudin-Gorskii, and also tests my ability to use digg to directly post interesting articles to my blog.
I wonder how well it will work.

Assuming this works, in the future I’ll try to include more bonus information, such as this link to a class project that utilized these photos.

read more | digg story

P.S. it worked.

Supercooled Water

Courtesy from digg, check out this article with video dramatically demonstrating the freezing of supercooled water.

If you ask most people with the freezing point of water is, they will confidently answer that water freezes at 0 degrees Celsius (or 32 degrees Fahrenheit if you are in a backward country that never shifted to the metric system). But what many people don’t know is that water can exist in liquid form at temperatures which are significantly lower than that. I first remember reading about this in Craig Bohren’s excellent book Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics. It’s a great book detailing many of the processes that govern weather. He mentions an experiment where you place a small plate with several individual drops of water on a plate and place it in your fridge. You will find that many remain in liquid form for a considerable period of time, and that mechanical jostling of them can cause them to instantly freeze. The video on the webpage above demonstrates some of the same ideas, but much more dramatically.

Cool stuff with a nice writeup.

SETI@home a security risk?

This rather wacky report talks about the possibility that ETs could infect the earth’s computers with viruses by transmitting certain signals which cause (say) buffer overflows in our computers and infect the internet.

Dr. Carrigan thinks that the SETI scientists should implement some kind of decontamination procedure to clean the signals before they are distributed.

It seems kind of obvious to me that if we knew enough to conclude that a particular signal was trying to act as a virus, we’d have pretty strong proof that extra-terrestrial intelligence was a reality.

I tried to locate the actual article, but could only find this link to the abstract.

Whacky.

What this geek did in Paris…

Microsoft blogger Robert Scoble is apparently over in Paris, and decided to blog about the stuff he did in Paris, of which he only thought the Musee D’Orsay sufficiently interesting to mention, probably because their IT system apparently runs Windows XP.

Get some soul, man.

When Carmen and I went there for our anniversary back in 2003, we spent the entire day in the Musee D’Orsay, and at no time did we even think to ask what operating system their IT system runs. It just never came up.

Here is a by-no-means-comprehensive list of some of the things that this geek did while in Paris:

  1. Day one: Got in fairly late, but decided to go out for a midnight supper. Did a big circle from our hotel near the Place de la Concorde, all the way down to the Louvre and back. Caught some nice views of the Eiffel Tower lit up. Back to bed.
  2. Day two: Cafe au lait and pain au chocolat (forgive my spelling, it’s been a while since I took French, and my ability to type accents in HTML is minimal) for breakfast, er, petit dejuener. Some churches, the double decker buses, visited the Musee de la Marine, and then strolled to the Eiffel Tower via the Champs des Mars. Didn’t bother going up, but had a hot dog at the park underneath. Visited Napoleon’s tomb, and Les Invalides. Then, back to the hotel, where we thought we’d catch a quick nap before going out for dinner. We woke up around 10:00pm. Found out that the restaurant Au Pied de Cochon was still open, so took the Metro down to the station near Ste. Eustace, before wandering over to munch on a dinner of pigs feet (which seemed appropriate, given the restaurant), some real french onion soup, what was probably a laughable wine selection, and a terrific desert. When we got out, it was too late for the Metro, so we walked back to the Place de Concorde.

That was the first day and a half. We were there for a week. We saw the Louvre, including an exhibit on Michaelangelo and Da Vinci. We killed a day at the Musee D’Orsay, skipping their IT department, but did stop to have lunch in their “cafeteria”. We had dinner at Gourmard, the second most expensive restaurant I’ve ever been to, and worth every penny. We took an early morning train to Versaille, where we snapped some fun pics of us in the Hall of Mirrors. We fed birds that flocked to our table in Montmartre as we ate escargot, just because hell, we were in Paris. We went to the Paris airshow, walked around the Fete de la Musique, scaled the Eiffel Tower at sunset, took boatrides on the Seine, took pictures of Notre Dame, Sacre Couer, and other lesser known places. We visited Les Jardins de Luxembourg, and just basked in the late sun. We mastered the Paris Metro, and just all in all had a blast.

Didn’t really think much about blogging.

Sometimes, you just have to unplug, at least, until you get back and post all the pictures to make other people jealous.

That’s what this geek did in Paris. I’d love to go back.