Science, Technology & Health: September 2008 Archives
Here's a neat new system for creating digital 3D models and textures from the real world using a simple flash camera (plus some neat software).
Creating 3D maps and worlds can be extremely labor intensive and time consuming. And ultimately the final result might not survive the close scrutiny of those expecting real-world emulations. A new technique developed by scientists at The University of Manchester's School of Computer Science and Dolby Canada, however, might make capturing depth and textures for 3D surfaces as simple as shooting two pictures with a digital camera--one with flash and one without. ...First an image of a surface is captured without flash. Portions of the surface that are higher appear brighter, and portions that are deeper appear darker. The problem is that the different colors of a surface also reflect light differently, making it difficult to determine if the brightness difference is a function of depth or color. By taking a second photo with flash, however, the accurate colors of all visible portions of the surface can be captured. The two captured images essentially become a reflectance map (albedo) and a depth map (height field).
Pretty neat! Soon we'll have robots that roam the land, image everything, and build a stronger-better-faster-virtualer world for us all to enjoy in complete serenity.
(HT: NC.)
Bill Hibbard grapples with transhumanity and the social contract and raises some provocative challenges. I especially like his attempt to define what greater-than-human intelligence would look like:
The most familiar measure of intelligence is IQ, but it is difficult to understand what a machine IQ of a million or a billion would mean. As is often pointed out, intelligence cannot be measured by a single number. But one measure of a mind’s intelligence, relevant to power in the human world, is the number of humans the mind is capable of knowing well. This will become a A practical measure of intelligence, as we develop machines much more intelligent than humans., is the number of people that a mind can know well. Humans evolved an ability to know about 200 other people well, driven by the selective advantage of working in groups (Bownds 1999). Now Google is working hard to develop intelligence in its their enormous servers, which already keep records of the search histories of hundreds of millions of users. As these servers develop the ability to converse in human languages, these search histories will evolve into detailed simulation models of our minds. Ultimately, large servers will know billions of people well. This will give them enormous power to predict and influence economics and politics; rather than relying on population statistics, such a mind will know the political and economic behavior of almost everyone in detail.
I hadn't considered such a social definition of intelligence before.
(HT: Nick.)
Michelle Malkin quotes a correspondent who explains the technical details behind the "hacking" of Sarah Palin's Yahoo email account. I think it's fascinating that the political crowd is now technically sophisticated enough to be interested in such an explanation.
If you can't clearly see the details, walking men appear to be coming, and walking women appear to be going.
Even when the team added some perspective cues to the models, to suggest a direction of gait, the perceived gender of the model still had a significant effect on the direction judged by the observers.The team speculates that there might be evolutionary explanations for their results.
"If you see a male, but you don't have quite enough information to be sure if they're facing towards you or away from you," says van der Zwan, "it's probably safer to assume they're facing you, so you can get ready to fight, or for flight."
However, it might be more important for young children or infants not to misinterpret a female figure as facing them when in fact she's moving away.
"If you're young and you're not quite sure if your mother or female carer is facing you or not and she's walking, it's probably safer to assume she's leaving, because then you can get ready to follow her if you need to," he says.
(HT: MG.)
There's no real doubt about how fast carbon-13 decays into carbon-12, but if you're going to use radiocarbon dating to estimate the age of dead biological matter than you need to know how much carbon-13 there was in the organism when it died. Apparently the carbon-13 estimates were wrong.
The principal indicator of the amount of organic carbon produced by biological activity traditionally used is the ratio of the less abundant isotope of carbon, 13C, to the more abundant isotope, 12C. As plants preferentially incorporate 12C, during periods of high production of organic material the 13C/12C ratio of carbonate material becomes elevated. Using this principle, the history of organic material has been interpreted by geologists using the 13C/12C ratio of carbonates and organics, wherever these materials can be sampled and dated.While this idea appears to be sound over the last 150 million years or so, prior to this time there are no open oceanic sediment records which record the 13C/12C ratio, and therefore, geologists are forced to use materials associated with carbonate platforms or epicontinental seas. ...
It appears that records related to carbonate platforms which are often used throughout the early history of the Earth are not good recorders of the 13C/12C ratio in the open oceans. Hence, the work presented suggests that assumptions made previously about changes in the 13C/12C ratios of carbonate sediments in the geological record are incorrect.
"This study is a major step in terms of rethinking how geologists interpret variations in the 13C/12C ratio throughout Earth's history. If the approach does not work over the past 10 million years, then why would it work during older time periods?" said Swart. "As a consequence of our findings, changes in 13C/12C records need to be reevaluated, conclusions regarding changes in the reservoirs of carbon will have to be reassessed, and some of the widely-held ideas regarding the elevation of CO2 during specific periods of the Earth's geological history will have to be adjusted."
Unless I'm misreading the results (I'm no expert in this field) it appears that the new understanding of ancient carbon-13 levels means that much of the biological remains being measured are younger than previously thought.
It's hard to write robust software: computer programs are notoriously incapable of handling new, unforeseen situations. One of the primary purposes of artificial intelligence is to develop techniques that allow software to be as flexible as the human brain, to be able to make reasonable decisions in confusing circumstances with incomplete information. There are few more complex and confusing domains than financial markets, so it's not surprising that there are glitches in financial AI programs.
NEW YORK (Reuters) - Computers, unable to see the mold on an outdated UAL Corp (UAUA.O: Quote, Profile, Research, Stock Buzz) article, sparked confusion, a mass sell-off, and an emergency trading halt earlier this week that highlights the pitfalls of increasingly automated financial markets.Shares in the parent of United Airlines plunged about 76 percent after a nearly 6-year-old news story on its 2002 bankruptcy filing appeared online on Monday.
UAL, which is no longer in bankruptcy, scrambled for a retraction and its stock later bounced back -- but for some investors, especially frequent traders, the damage was done.
The use of algorithms -- which allow computers to make decisions in fractions of a second -- appears to be a main culprit in the UAL case.
Experts said the automated programs were applied to both the reading of the outdated news story and the trading of shares based on that information.
Humans can make disastrously bad decisions too, of course, so we shouldn't be too quick to judge our artificial counterparts! The more intelligent our software becomes, the more prone it will be to human-like errors. Even if we do ever achieve human-level intelligence in a machine, there's no reason to believe it will be any more perfect or rational than our own intelligence.
(HT: Nick.)
Looks like I was wrong, because the end of the world is obviously near.
