Category Archives: Science

On Crime Dramas…

I watch a fair number of crime drama shows. Early on, I really liked CSI. It had some fairly interesting characters, and tried to present some interesting bits of forensics in a stylized dramatic way. But now that it has branched off into three different shows, it simply makes me wince.

The problem is a basic one of belivability. Yes, it’s just a TV show, I understand. But it has to be even roughly plausible or the sense of drama is destroyed. It is supposed to tease you with its plausibility, not surprise you with its absurdity.

For instance, in CSI they’ve taken to using various kinds of image manipulation to find out key bits of evidence. The simple fact is that the kind of image manipulation they do is impossible. You can’t pull an image of someone’s face reflecting in someone’s eye from a security camera image from a distance of thirty feet, or even five feet. It simply can’t be done. There is not 45% overscan in video images. And don’t get started with what they pretend to be able to do with encrypted files and the like.

It is with this feeling of trepidation that I watched the first episode of NUMB3RS. The basic idea is kind of interesting: a math prodigy teams with an FBI investigator to use mathematics to help solve crimes. Surprisingly, the pilot episode didn’t make me cringe excessively, but I can’t help but think that sooner or later they will be jumping the shark in every episode. It’s just too difficult to come up with real ideas that are remotely plausible. Soon, I suspect they will be resorting to simple magic to “poof”, solve crimes.

We shall see…

Giant squid ‘taking over world’

NEWS.com.au | Giant squid ‘taking over world’

According to scientists, squid have overtaken humans in terms of total bio-mass.

That means they take up more space on the planet than us.

The reason has been put down to overfishing of other species and climate change.

Or, it could be Lord Cthulhu, rumbling in the underwater city of R’lyeh. There are many signs for those who are watchful.

Apollo Guidance Computer Replica

While chatting with Tom over lunch, I was reminded of a guy who built his own Apollo Guidance Computer Replica. Tom was the guy who got me to write an emulator for the PDP-1 (he wrote one as well) so that we could run the original Spacewar! on a PC, so this was right up his alley. He hadn’t heard of it before, so I decided to put up this link.

Enjoy this step back into retro computing.

Iron/Nickel Meteorite Found

Mars MeteoriteIn itself, meteorites are not uncommon, but what’s pretty cool is that the Mars rover Opportunity managed to land close to a basketball sized one lying on the surface of Mars. You can read more in NASA’s press release.

CMU developed a project to find meteorites in Antartica using an autonomous robot that could search the frozen plains for these bits of stellar flotsam. Of course, there are other, more labor intensive ways to find Antarctic meteorites too.

Huygens Down Safe, Pictures To Come Here

The ESA is reporting that the Huygens lander survived it’s descent to Titan, and is transmitting data. According to JPL, the first images should be received around 11:45 PST. Kick ass! As soon as pictures are available, I’ll link ’em up here.

First Huygens Image, snapped from NASA TV in RealPlayerUpdate: In what quite possibly have been the singularly most dull and boring press conference ever convened, a single image taken from 16km was released on NASA TV, followed by ten minutes of people talking about their feelings. Sigh. I’ll post a link to the real image when I find it: this was screen snapped from the RealPlayer stream on NASA TV.

Not much to see here, other than the fairly obvious rivulets which suggest erosion processes. I’ll post more when I’ve got more.

Cassini snaps pictures of Iapetus

IapetusThe Cassini probe has taken some awfully nice pictures, including this one of the moon Iapetus. The equatorial ridge is really very odd.

The most unique, and perhaps most remarkable feature discovered on Iapetus in Cassini images is a topographic ridge that coincides almost exactly with the geographic equator. The ridge is conspicuous in the picture as an approximately 20-kilometer wide (12 miles) band that extends from the western (left) side of the disc almost to the day/night boundary on the right. On the left horizon, the peak of the ridge reaches at least 13 kilometers (8 miles) above the surrounding terrain. Along the roughly 1,300 kilometer (800 mile) length over which it can be traced in this picture, it remains almost exactly parallel to the equator within a couple of degrees. The physical origin of the ridge has yet to be explained. It is not yet clear whether the ridge is a mountain belt that has folded upward, or an extensional crack in the surface through which material from inside Iapetus erupted onto the surface and accumulated locally, forming the ridge. The origin of Cassini Regio is a long-standing debate among scientists. One theory proposes that its dark material may have erupted onto Iapetus’s icy surface from the interior. Another theory holds that the dark material represented accumulated debris ejected by impact events on dark, outer satellites of Saturn. Details of this Cassini image mosaic do not definitively rule out either of the theories. However, they do provide important new insights and constraints.

Nice article on the Cassini/Huygens mission

On Christmas Eve the Huygens lander successfully disconnected from the Cassini orbiter and is set for a landing on Titan on January 14th. There is a good article published by the IEEE Spectrum on how Swedish engineer Boris Smeds saved the $300 million dollar mission by detecting an undetected problem in the telemetry system which would have hopelessly scrambled the data relayed from Huygens.

Good luck, and soft landings.

Astronaut: ‘Single-Planet Species Don’t Last’

I call bullsh*.

Shuttle astronaut John Young made the following claim:

The statistical risk of humans getting wiped out in the next 100 years due to a super volcano or asteroid or comet impact is 1 in 455. How does that relate? You’re 10 times more likely to get wiped out by a civilization-ending event in the next 100 years than you are getting killed in a commercial airline crash.’

You would think that a shuttle astronaut would know better. Let’s examine this claim in some detail, shall we? First of all, let’s assume that the particular causes mentioned (asteroid collision, super volcanoes etc) have nothing to do with human activity. It’s hard to imagine how they could be. Now, the chances of humanity surviving 100 years is 444/455 454/455. You can multiply these probabilities out, and you find that humanity had only an 8 percent chance of surviving 10000 years, and the chances of surviving one hundred thousand years is about one in 2.35E11. This works out to a 97% chance of surviving ten thousand years, an 11% chance of surviving one hundred thousand years, and only a one in thirty five million chance of surviving one million years.

The Future of Scanners?

Gizmodo had a link to a flexible book scanner, basically a sheet of plastic filled with organic photodiodes and phototransistors that act as a scanner. Chasing down links for a meatier description, I found Semiconductor International – Organic Devices on Flexible Substrates Advance – 11/1/2004 – Semiconductor International – CA476270

In other work to be presented at IEDM, researchers from the University of Tokyo have developed a large-area, flexible and lightweight sheet image scanner integrated with organic field-effect transistors and organic photodiodes (Figure ). The scanner is made of cells that consist of an organic transistor and organic photodetector, with an effective sensing area of 50 x 50 um2. The entire imager has an effective sensing area of 2 in. and resolution of 36 dots per inch (dpi), with the potential to go up to 250 dpi. The photodetectors distinguish between black and white by sensing the difference in reflected light from black and white parts of an image. The thin-film pentacene transistors have 180 um channel lengths and electron mobilities of 0.7 cm2/Vsec.

The current 36dpi resolution isn’t very interesting, but 250dpi sounds pretty good. I wonder if it will be here before electronic paper…

Liquid lenses for camera phones | The Register

This story has been making the circuit, but this Register article is the first that I’ve seen which has any real detail. As part of my interest in telescope design, I’ve developed a passing interest in camera lens design, and I was uncertain just how this would work.

Basically the idea is that two different liquids are held inside a conical chamber, usually an oil in the back and water in the front. A charge is applied differentially between the front and the back with the result that as an increasing charge is applied, the oil layer in the back goes from flat to highly convex. Interesting.

Camera lens design is basically a balancing act to control seven or so primary aberrations that can affect final image quality. This lens assembly would seem to be able to control only one degree of freedom (roughly speaking, power of the element: when the charge is off, the assembly is a simple window, when the charge is on, it acts as a lens with some power and significant chromatic aberration). It seems to me that any successful attempt to use such an element in a camera design will likely require more than one of these elements, particularly in a zoom configuration.

Still, very interesting work. I’ll have to do a patent search to see if I can find some real designs based upon this principle.

Addendum: Apparently Phillips has been persuing similar work, and disputes the patents granted to Varioptic for this design. It will be interesting to see how that plays out, possibly in the court system.