Last week a Boulder company unveiled a modified Toyota Prius with extra batteries and a plug-in option so that the car can run on batteries alone, and then switch to the gasoline engine if and when the batteries are depleted. Other companies are exploring similar options. This report in the New York Times points out that there are significant hurdles to making the plug-in hybrid an economically viable alternative for most motorists. The problem is that when a battery is fully charged and then fully discharged its usable lifetime is shortened. Hymotion, a company that plans consumer conversion plug-in kits for the Prius and other hybrids in 2007, offers a warranty of 800 charge-discharge cycles on its battery. With daily use, that’s a little over two years. They anticipate about 30 miles on a charge, which probably means under ideal driving conditions. The conversion kit is $9500 installed, so that works out to about 40 cents/mile. The additional cost of actually charging the battery is negligible by comparison (a couple of pennies per mile). Your run-of-the-mill unconverted Prius, at 44 mpg and $3 for a gallon of gas, costs only 7 cents/mile to drive in fuel. If you pay $25,000 for the car itself and get 150,000 miles out of it, that’s an additional 17 cents/mile for the initial investment. So that plug-in conversion kit dominates the cost of owning and operating the vehicle. If gas cost $10 a gallon and the plug-in battery kit was good good for 4 years instead of two, then it would begin to make economical sense.
Monthly Archives: October 2006
Stay the Course, Even Though It’s Going Backwards
This article has a nice summary of the double-speak from the White House regarding what we should be doing in Iraq. I particularly love this exchange with the White House Press Secretary captured on The Greenbelt blog. Incredibly, Bush actually tried to claim that he’s never been a “Stay the Course” man on Iraq, when that’s been a virtual mantra for the Republicans for the last two years or so.
The Prestige
Like The Illusionist , The Prestige is a turn-of-the-century period piece about magicians whose tricks blow away the stunts performed by modern magicians. Unlike the romantic Illusionist, however, The Prestige is about the destructive nature of obsession. Directed by Christopher Nolan (Memento, Batman Begins, Insomnia), this movie also features characters that are isolated from society and unable to forge any strong or lasting personal bonds. Like Batman, the magicians in The Prestige must keep secrets, and that prevents them from ever letting down their guard. Hugh Jackman plays Rupert Angier, a natural showman with great stage presence and crowd appeal, and Christian Bale plays Alfred Borden, the more clever and dedicated magician who lacks talent as a showman. Both Angier and Borden are crippled by their obsession with magic, just as Leonard is unable to escape his obsessive search for his wife’s killer in Memento.
The title of the movie refers to the third act of a magic trick where the horrible fear of a woman getting sawed in two, or the disappearance of a person into thin air, is relieved by the safe reconstruction of the woman or the reappearance of the disappeared, for example. The audience’s suspense is transformed into relief and admiration. Most of the plot of this movie, co-written by the director’s brother, Jonathan Nolan, is “prestige” and therefore impossible to describe without ruining that thrill of discovery of seeing the trick resolved. Ironically, however, the movie is told in flashback from a grim situation so that we know the grim consequences of the rivals’ actions in advance, and the prestige shows us how they got there. In that sense, the movie is skillfully written and told. But it is generally unpleasant to watch people of immense talent and potential willfully self-destruct.
A fundamental plot point hinges on Angier bypassing an opportunity to have everything he ever wanted in order to pursue a far more dangerous, unpleasant, and violent path. Since Angier is a clever character, I found this decision implausible and a weakness of the movie. If the Nolans were determined to have things come out this way, they could have eliminated the path not taken as a viable option for Angier, or had the character face the choice and justify his decision. I had the same reaction to the end of Terry Gilliam’s “Brazil” in which Sam Lowry is smart enough to (1) realize that the only way to escape the opressive state is to officially become non-existent in the state (that is, die), and (2) figure out how to get to the central computer and officially kill people thus making them immune to the state, and (3) gets to the computer and wipes out the record of his girlfriend, but inconceivably bypasses the chance to wipe out his own record. So the bleak ending of the movie didn’t feel unavoidable to me because Lowry should have (would have) wiped his own name from the state’s computers as well and not been taken into custody. So, what is the corresponding problem in The Prestige? To avoid ruining the surprise, here it is as a key cipher. If you see the movie, check back in and decipher it (okay, you could just ask me, but wouldn’t deciphering be more fun?) and let me know if you agree.
This is a key cipher (like the ones the magicians in the movie use for their diaries). The key word is “RINGS”, and here are the directions on how to decipher it.
Here it is:
ingaeucorlvhadearectndoeeboudldanekhpteiialmvdaneporfertedmhitrecrpekf
lcteyshejaaewmydorbeddinaedbnaeughseccustwishioknlginlx
Dissecting the Saturn High Phase Masterpiece
The picture below, a unique mosaic taken by Cassini last month, is visually stunning (see here for the full resolution images), packed with new information about Saturn’s ring system, and a bit of an optical illusion. At the DPS meeting two weeks ago and the Cassini Project Science Group meeting last week we got a chance to see some of the early analysis being done on these images by the Cassini imaging team (ISS, visible light cameras) and the near-infrared camera team (VIMS). While those teams continue their scientific analysis, we can take a look at why this unusual picture looks so, well, unusual.

Image Credit: NASA/JPL/Space Science Institute
What are we looking at? Cassini was in Saturn’s shadow at a distance of 2.2 million kilometers, and was above the rings. The Sun is shining on the opposite side of Saturn and on the underside of Saturn’s rings. The disk of Saturn is visible because of light scattering off the rings onto the planet. Where the rings pass in front of the planet they block this reflected light. Also there is no reflected ring light along Saturn’s equator (see the dark line above the rings along the planet) because almost no light is reflected by the edge of the rings. The very bright outer edge of the rings is the F ring. This normally faint narrow ring stands out as the brightest feature in this geometry because of the large amount of small particles in the ring. The larger particles in the main rings block light, so only a diffuse glow passes through the gaps between the large particles. In front of the planet, however, the F ring is not visible because the planet blocks the direct sunlight, and the reflected planet glow (light bouncing off the rings, onto the planet, and then back onto the rings) is too faint in this geometry to make the F ring appear. The other rings are visible in front of the planet only because they block our view of the dimly lit planet behind them. The missing F ring in front of Saturn produces the optical illusion in this mosaic of Saturn appearing to be in front of the rings.
The Ballbot
Perhaps coming soon to a house near you is a personal assistant robot based on this cool design of active stability rather than a static platform of wheels or, worse, clumsy robot legs. Check out the videos (here’s one) showing the “Ballbot” moving around on its single spherical foot at the bottom of the page. My colleague Glen remarked that the ballbot’s locomotion is reminiscent of the Jetsons’ assistant Rosie. For the moment it doesn’t appear to do much other than locomote, but it’s much easier to imagine this as a platform for something you could actually have around the house than the clumsy cart-like contraptions that can’t handle obstacles. It reminds me of the Segway personal transport thing-a-ma-jig that is great fun to ride around on (here I am having a ridiculously good time spinning around Prague in July 2005).
The Rain in Goldstone
A particularly valuable stellar occultation of Saturn’s rings was lost over the weekend when rain at the Deep Space Network’s Goldstone DSS-14 antenna prevented reception of any of our data from the Cassini spacecraft. Having spent years planning these occultations and getting them into the Cassini timeline, losing one leaves a hollow feeling. I do have dozens more planned, but this one had the unusual characteristic of providing a particularly high resolution view of part of Saturn’s B ring. Bummer!
A Real Rubble Pile in Space
For years astronomers have speculated that small moons and asteroids are not coherent, solid pieces of rock, but loosely bound piles of rubble, cleverly called “rubble piles”. The reason for this speculation is that while space is fairly empty, time is also fairly long, and given enough time the debris in the solar system has a tendency to crash together. Small objects are more easily broken apart than larger ones, but the fragments of a shattered asteroid will frequently run back into each other as they orbit the Sun on nearly the same path, and their feeble gravity can be enough to reassemble them into a rubble pile. The Japanese spacecraft Hayabusa visited the small asteroid Itokawa and returned the most visually compelling images of a rubble pile I have seen.

This tiny asteroid is a little over 500 meters long, and only 200 meters across its narrow waist. To escape its gravity you only need to move about a half a mile per hour. Check out also this picture where the shadow of Hayabusa can be seen on the asteroid’s strange smooth plain, nicknamed the Muses Sea.
Exotic Destinations
Long days at the DPS meeting, so I’ll just post a couple of cool links. The Virgin Galactic website has been recently revamped with some pretty slick material aimed at getting the very rich pumped up at the idea of dropping 200 grand on a brief foray into space. Sir Richard Branson himself pitches the program in the intro movie. While Virgin Galactic’s Spaceship Two will only spend a few minutes in sub-orbital space, Robert Bigelow (Bigelow Aerospace) is looking further down the road toward an eventual hotel in space. Meanwhile, Poseidon Resorts is planning in the opposite direction with this undersea hotel.
DPS-ing – Rings
The annual meeting of the American Astronomical Society’s Division for Planetary Sciences (DPS) is taking place this week in Pasadena. Today marks the first of several sessions devoted to my favorite topic: planetary rings. A beautiful mosaic of Saturn was released today that was taken in a unique observation by Cassini where the spacecraft spent several hours in the shadow of Saturn and looked back toward the Sun. It’s a fantastic mosaic. Check it out. In this geometry, small particles, cleverly referred to as “dust” by us ring scientists, are particularly bright. It’s like looking back toward the projector in a movie theater 50 years ago when people still smoked in theaters. The particles are too small to block the light completely, instead scattering the light by small angles. Bigger particles block the light, so looking back toward the Sun we just see the light scattered by dust. This geometry allowed Cassini scientists to discover a new dust ring associated with the moons Janus and Epimetheus.
Mars Rover Seen from Orbit
This very cool picture from the HiRISE camera on the Mars Reconnaissance Orbiter shows the Opportunity rover near the rim of the Victoria crater. That little dark thing sticking down to the right at about the 4:30 position from the rover is the shadow cast by the camera mast of the rover. For the full picture and more details, go here.

Image credit: NASA/JPL.