brainwagon "There is much pleasure in useless knowledge." — Bertrand Russell


Playing Buzz Lightyear Astro Blasters

Playing Buzz Lightyear Astro Blasters

Oh yeah, while at Disneyland, we gave a shot at the new Buzz Lightyear Astro Blasters ride. At the end, rather than trying to convince you to spend $12.95 to get a photo of yourself, they just have a bunch of terminals where you can mail your picture to yourself. Like the one on the right. I managed to outscore Carmen, but my score was pathetic.

Filed under: My Diary, My Photos 1 Comment


Sorry to both all of my loyal readers, but I've been off with the family enjoying a brief vacation stint at Disneyland. We took the opportunity to see the 50th anniversary celebrations there prior to this week's SIGGRAPH conference. Both the wife and son are now back in the Bay Area, while I go off and enjoy the week's conference.

I got in around noon today, and got checked into my hotel room and then trudged down Figueroa to the Convention Center to pick up my registration. Courtesy of their new barcoded acceptance letters, I merely had to wave a letter under a laser scanner, click OK and within 30 seconds, my badge was printed. My Badge Not bad, and beats the long lines of years past. I also picked up a Boston 2006 pin to clip onto my badge. Boston will be cool. SIGGRAPH was last in Boston in 1989, which was also my first SIGGRAPH conference. I think I'll go. 🙂

It's actually been about five years since I last went to SIGGRAPH. A combination of the dotcom bust, and various internal jugglings and departures made it seem un-fun to go for a number of years, so I just stopped going. It's kind of nice to be back, although it doesn't really seem to have changed much, except for the possibility that people are getting younger (or, more likely, I'm getting older in a field dominated by the young and enthusiastic).

I made a brief jaunt through the art show galleries. The coolest thing I saw was Sustainable: an installation art piece which consisted of a number of tanks of water, each with a gong suspended inside and a pair of hammers controlled by solenoids which bonked them in a periodic fashion. Each tank also contained a series of water level sensors, and they each can pump water from their own tank to the one on the right. Internally, they maintain some notion of how much water they "need", and will vent or not depending on some calculation they internally perform. As the water level rises and falls, the pitch and falloff of each gong is modified. The ensemble of them creates an interesting, continuously varying cadence which I found pleasing. I would have snapped my own pictures of it, but I was immediately accosted by the resident security droid who informed me that photography wasn't permitted, despite the presence of the artist himself, who assured me that he didn't mind.

Anyway, check it out, it was pretty cool.

Tomorrow will be a busy day. I should be there for the first paper session, and have animation theater tickets for tomorrow night, so it should be a long day. Tonight, I trudged over toward the Wilshire Grand, and had a sweet sausage pizza at the California Pizza Kitchen. You can spot the SIGGRAPH attendees: they all look the same to me. More on that some other time.

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List of unusual deaths

Think you are having a bad day? Try the Wikipedia list of unusual deaths. At least no vultures have mistaken my head for a stone.


Doomsday Algorithm

Need to do calendar calculations in your head? Try this page which describes Conway's Doomsday Algorithm, with lots of good links.

Note: I found Lewis Carroll's method of doing the same in a previous post.


It was a dark and stormy night…

Or at least (as Dan noted) it's a dark day for fiction again, as the results for the 2005 Bulwer-Litton Contest are in. For those not familiar with this annual contest, writers submit opening sentences for imaginary novels.

My favorite entry:

When Detective Riggs was called to investigate the theft of a trainload of Native American fish broth concentrate bound for market, he solved the case almost immediately, being that the trail of clues led straight to the trainmaster, who had both the locomotive and the Hopi tuna tea.

Mitsy Rae
Danbury, NE


SIGGRAPH Computer Animation Festival Trailer Available

Next week I'll be leaving for SIGGRAPH, the premiere computer graphics conference. Today I'm trying to work through my agenda, make lists of papers that I want to see, figure out the reception schedule and the list of parties that I'd like to attend. While doing so I noticed that the Computer Animation Festival trailer was available online. This is even cooler than normal because I know the Computer Animation Festival Chair: it's my next door neighbor and former Pixarian Sam Lord Black. Well done Sam, and I'll be mooching party invites off you later. 🙂


Shuttle Discovery Launch Today?!

I'm watching the live feed on NASA TV. They are in a pre-programmed hold at 9:00 till launch, which should go on for another twelve minutes, and then they should launch.

Best wishes to all those aboard.

Addendum: Looks like there are no constraints for launch. Countdown is about to resume. Countdown has resumed. Eight minutes remaining. Launch! Discovery now rolling to a head's up orientation, 70+ miles altitude, 350 downrange. Two minutes to MECO. Performance nominal. MECO completed. Discovery is pitching up away from the main engine, and will roll over so that they can inspect the main engine, footage which apparently won't be downloaded until day three.

Welcome back to space, Shuttle Discovery, and congratulations to all those at NASA and elsewhere who worked to return the fleet to flight status.

Filed under: News, Science No Comments

New “business” card…

I've been thinking for quite some time that I need to make some cards that I can hand out to people when I meet them so that they can remember my blog. These aren't really business cards, but rather just reminders.

Here is my first (well, second actually) attempt:

To illustrate what a geek I am, this image is generated by a CGI script written in perl which calls a program written in raw PostScript to do all the graphics.

Any criticisms on the graphic design can be made via comments.

Filed under: General, My Projects 1 Comment

Microsoft Virtual Earth is out…

This is getting a lot of play everywhere, but Microsoft's new mapping application, Virtual Earth is now live. In most respects, I find it very similar to Google's offering, but the API seems a bit more refined, and it doesn't have the problems associated with generating usage keys. You can find information about programming the api here, or the simplest example here. You can pan around, or double click somewhere to zoom in. I'll try to work up some bigger examples later.


Humble Pie

If there is ever a time that I seem like I sound too smug and self assured, just whisper "39th out of 40, and only by three seconds."

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Need more help with color blending?

I'm hopeless when it comes to color. But has a really nice interface that allows you to match and generate color palettes. Fun.


Pixar Motorama 2005

Motorama 5 Commerative KeychainEvery year Pixar has a small auto show. People who work here bring in some of their classic cars, and a couple of local dealers usually bring out some top of the line dream cars. We have a picnic and lots of people show up. It's kind of fun. I snapped a bunch of pictures, and put them in my Brainwagon Photo Gallery for you to enjoy.

Apologies for the corner vignetting that most pictures have: I was shooting with a polarizing filter, and at very wide angles you can see the corners of this filter. Stupid Nikon 4500.

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Extra Stuff: Gambling Ramblings

I picked up a new book on my trip to Reno: Extra Stuff: Gambling Ramblings by Peter Griffin. Griffin is the author of one of my favorite books in my collection of books on gambling topics: The Theory of Blackjack. This book includes all sorts of interesting tidbits of gambling theory.

The book had a particularly interesting and surprising discussion on the Kelly Criterion: a method of wagering that ensures the quickest maximization of bankroll when you have positive expectation in a game. Basically, if you have a probability p > 0.5, you maximize your bankroll when you wager a fraction of your bankroll equal to 2 * p - 1.

Griffin asked an interesting question: what is the probability at any step that you actually have reached the highest bankroll that you've ever seen in that step. When the bets are unit sized, you can derive rather simply (and prove via simulation) that the odds are 2 * p - 1 (interestingly, the same fraction used by the Kelly Criterion) that you have reached your peak earnings. But if you try to graph the resulting curve when you use proportional Kelly style bets, you get a function which is not only fairly complicated, but is in fact discontinuous. This seemed very unintuitive to me, so I wrote a simple program to duplicate the result and plotted it with gnuplot. For each probability p, I simulated one million wagers, and counted the number of times that I reached a new maximum.

Check out the graph:

Odds that you reach your maximum payroll given 2 * p - 1

The discontinuities are real, and the discussion is quite illuminating.

Addendum: The discontinuities occur because of the following. Imagine that you are at an all time high, and then suffer a loss, then a win. When you lose, your bankroll is multiplied by 1-f, and when you win it is multiplied by 1+f. Taken together, you get 1 - f2, which is always less than one, so you know that after all possible sequences of length two that ends in a win (you need to minimally end with a win to reach a peak) you can't reach a peak.

How about length three? Well, let's try a loss followed by two wins. You have (1-f) (1+f)2, which you want to be one (or higher). Solving this, we get 1 + f - f2 - f3 = 1, which means f - f2-f3 = 0, or 1 - f - f2 = 0. Solving using the quadratic formula, we find that f yields a value of one precisely at (sqrt (5) - 1)/2, a number commonly referred to as the golden mean or phi. Sure enough, our graph displays a discontinuity there. At just below this value, a loss followed by two wins is insufficient to generate a new high, but at just over this value, it is. Since the probability of these particular sequences varies only infinitesmally, we see a strong discontunity in the chances of reaching a new high when f varies in this neighborhood.

Other possible sequences (two losses followed by three wins, for example) also generate similar but smaller discontinuities.

Very interesting.

At least to me.

But I'm a geek.

Addendum2: For fun, try reading Kelly's Original Paper and figure out what it says about gambling.

Filed under: Books I Read 6 Comments

The Rise and Fall of Popularity

I feel strangely sad by the following graph:

Popularity by Month


The Wall

The Internet Archive has a version of the 1962 documentary The Wall about the first year of the Berlin Wall, including the murder of Peter Fechter on August 17, 1962. A sobering glimpse into the Cold War.

For those young-uns without historical perspective, check out the Wikipedia entry for the Berlin Wall.