Tuesday, November 30, 2010
Monday, November 29, 2010
After reading this discussion/history of Tron, I actually now want to watch the upcoming Tron: Legacy movie.
Sunday, November 28, 2010
Things to know before you buy a tablet computer.
In particular, Ars Technica says "Run screaming in the other direction" from this particular tablet. Unless you're willing to make use of it like this.
In particular, Ars Technica says "Run screaming in the other direction" from this particular tablet. Unless you're willing to make use of it like this.
Thursday, November 25, 2010
Tuesday, November 23, 2010
"Mail carriers will abuse your package more if it's marked as 'Fragile'".
More details on the testing with hidden accelerometers here.
More details on the testing with hidden accelerometers here.
Monday, November 22, 2010
Sunday, November 21, 2010
Bruce Schneier notes that "TSA Scans Won't Catch Anybody".
He also has a detailed set of links on this issue at his blog.
He also has a detailed set of links on this issue at his blog.
This clever camp stove by Biolite cooks quickly with only twigs and leaves. Includes video. (Via R.B.)
Thursday, November 18, 2010
"Antimatter Trapped For the First Time":
After creating antihydrogen in their antiproton decelerator, scientists at CERN have been able to trap antimatter for the first time in history.I just hope that the containment field doesn't give out, Scotty!
Wednesday, November 17, 2010
Tuesday, November 16, 2010
Monday, November 15, 2010
Sunday, November 14, 2010
Radiation Risks from TSA Scanners?
A friend recently asked my opinion about the possible health risks from the new whole body "backscatter" x-ray scanners now being used by the TSA (Transportation Security Administration) at many airports.
The short answer is that the radiation risk from the TSA scanners is minimal for a member of the general flying public.
(This is separate from privacy concerns -- or the fact that the bad choice offered to passengers between intrusive x-rays vs. an intrusive physical exam is a problem ultimately caused by our government's inept foreign policy.)
Hence, my personal approach when I fly will be to go through the full-body scanners rather than undergo the aggressive new pat-down searches.
The news media has recently given a lot of attention to the following letter sent several months ago by scientists/physicians at UCSF (Univ. California at San Francisco) to the federal government about the radiation risks:
"Letter of Concern", 4/6/2010
This NPR story from last spring that covers the details more fully:
"Scientists Question Safety Of New Airport Scanners", 5/17/2010
The NPR story also includes a sidebar listing the radiation dose generated by a TSA scanner, and comparing it to the dose one receives merely from being on a transcontinental flight, regular environmental exposure, getting a chest x-ray, etc.
Basically, just getting on a transcontinental flight exposes one to roughly 1,000 times more radiation than undergoing a TSA body scan. (This is because there is less atmospheric protection from natural solar/cosmic radiation at high altitude.)
The FDA has posted its own response to the UCSF letter at:
"Response to University of California - San Francisco Regarding Their Letter of Concern", 10/12/2010
First let me note that I am philosophically opposed to the FDA and other such regulatory bodies, on the grounds that they do not serve proper functions of government. But to the best of my knowledge, the FDA's scientific arguments in that specific response are essentially correct. And the FDA letter also addresses some of the technical issues raised by the UCSF scientists, such as the question of the TSA radiation being deposited mostly in the skin (vs. in the whole body).
Female passengers who are (or may be) pregnant while undergoing a TSA scan may also wonder about radiation effects on a developing fetus.
This web page from Duke University covers this topic nicely:
"Fetal Radiation Dose Estimates"
As a point of clarification, the Duke website uses the older units (rems and millirems) for radiation dose rather than the newer units (Sieverts, milliSv, etc.).
The conversion factor is:
If the fetus exposure is between 1,000 and 10,000 millirem (10-100 milliSieverts), then then the fetus is probably still ok. But, this is the range where bad effects to a fetus start to be observable in some studies, using the most conservative (cautious) statistical criteria.
So if a pregnant passenger wishes to take the most cautious approach and keep her fetal exposure below the 1,000 millirem (10 milliSievert) range, she could still undergo thousands of TSA scans per year. Again, the radiation exposure caused merely by flying would far exceed that caused by the scanner. Furthermore, most of the TSA scanner radiation would be stopped at the skin before it could even reach the fetus, as opposed to the various forms of natural gamma and solar radiation received during the flight which would penetrate deeper into the body.
A pregnant woman might naturally wonder how much radiation she'd be exposed to from the air travel itself?
According to this aviation news website, if she logged 1,000 hours in the air, then she'd be at the 5-10 milliSievert range (depending on the exact altitude/route), which is the level where one might begin to be concerned:
"Radiation Exposure Aloft -- Are You Being Nuked?"
So if she took 10 flights during her pregnancy totaling, say, 40 hours of air time, then that should be no problem. But she were an airline pilot or a frequent business traveler logging 1,000 hours of air time per year, then it might become a genuine issue, using the most conservative estimates for fetal exposure.
This discussion makes two important assumptions, including:
1) The TSA scanners are actually functioning properly and operating within the limits claimed by the government. Of course, if a particular machine malfunctions in a way that it produces too much radiation, then all bets are off.
2) The passenger doesn't have any special medical conditions that make him or her more sensitive to radiation than the general public.
Finally, this discussion applies only to the "backscatter" type of TSA scanner, which uses ionizing x-ray radiation. The other type of whole body TSA scanner uses "millimeter wave" technology, which does not involve ionizing x-ray radiation and does not have the same type of carcinogenic effect. Otherwise, I don't have any specialized knowledge about that particular technology and thus can't comment about any other health effects.
Conclusion: From a radiation safety perspective, it's generally safe to go through the TSA "backscatter" x-ray scanner.
The short answer is that the radiation risk from the TSA scanners is minimal for a member of the general flying public.
(This is separate from privacy concerns -- or the fact that the bad choice offered to passengers between intrusive x-rays vs. an intrusive physical exam is a problem ultimately caused by our government's inept foreign policy.)
Hence, my personal approach when I fly will be to go through the full-body scanners rather than undergo the aggressive new pat-down searches.
The news media has recently given a lot of attention to the following letter sent several months ago by scientists/physicians at UCSF (Univ. California at San Francisco) to the federal government about the radiation risks:
"Letter of Concern", 4/6/2010
This NPR story from last spring that covers the details more fully:
"Scientists Question Safety Of New Airport Scanners", 5/17/2010
The NPR story also includes a sidebar listing the radiation dose generated by a TSA scanner, and comparing it to the dose one receives merely from being on a transcontinental flight, regular environmental exposure, getting a chest x-ray, etc.
Basically, just getting on a transcontinental flight exposes one to roughly 1,000 times more radiation than undergoing a TSA body scan. (This is because there is less atmospheric protection from natural solar/cosmic radiation at high altitude.)
The FDA has posted its own response to the UCSF letter at:
"Response to University of California - San Francisco Regarding Their Letter of Concern", 10/12/2010
First let me note that I am philosophically opposed to the FDA and other such regulatory bodies, on the grounds that they do not serve proper functions of government. But to the best of my knowledge, the FDA's scientific arguments in that specific response are essentially correct. And the FDA letter also addresses some of the technical issues raised by the UCSF scientists, such as the question of the TSA radiation being deposited mostly in the skin (vs. in the whole body).
Female passengers who are (or may be) pregnant while undergoing a TSA scan may also wonder about radiation effects on a developing fetus.
This web page from Duke University covers this topic nicely:
"Fetal Radiation Dose Estimates"
As a point of clarification, the Duke website uses the older units (rems and millirems) for radiation dose rather than the newer units (Sieverts, milliSv, etc.).
The conversion factor is:
1 Sievert = 100 rem orAs the Duke website notes, if the fetus exposure to less than 1,000 millirem (10 milliSieverts), then there's no known risk to the fetus.
1 milliSievert = 100 millirem
If the fetus exposure is between 1,000 and 10,000 millirem (10-100 milliSieverts), then then the fetus is probably still ok. But, this is the range where bad effects to a fetus start to be observable in some studies, using the most conservative (cautious) statistical criteria.
So if a pregnant passenger wishes to take the most cautious approach and keep her fetal exposure below the 1,000 millirem (10 milliSievert) range, she could still undergo thousands of TSA scans per year. Again, the radiation exposure caused merely by flying would far exceed that caused by the scanner. Furthermore, most of the TSA scanner radiation would be stopped at the skin before it could even reach the fetus, as opposed to the various forms of natural gamma and solar radiation received during the flight which would penetrate deeper into the body.
A pregnant woman might naturally wonder how much radiation she'd be exposed to from the air travel itself?
According to this aviation news website, if she logged 1,000 hours in the air, then she'd be at the 5-10 milliSievert range (depending on the exact altitude/route), which is the level where one might begin to be concerned:
"Radiation Exposure Aloft -- Are You Being Nuked?"
So if she took 10 flights during her pregnancy totaling, say, 40 hours of air time, then that should be no problem. But she were an airline pilot or a frequent business traveler logging 1,000 hours of air time per year, then it might become a genuine issue, using the most conservative estimates for fetal exposure.
This discussion makes two important assumptions, including:
1) The TSA scanners are actually functioning properly and operating within the limits claimed by the government. Of course, if a particular machine malfunctions in a way that it produces too much radiation, then all bets are off.
2) The passenger doesn't have any special medical conditions that make him or her more sensitive to radiation than the general public.
Finally, this discussion applies only to the "backscatter" type of TSA scanner, which uses ionizing x-ray radiation. The other type of whole body TSA scanner uses "millimeter wave" technology, which does not involve ionizing x-ray radiation and does not have the same type of carcinogenic effect. Otherwise, I don't have any specialized knowledge about that particular technology and thus can't comment about any other health effects.
Conclusion: From a radiation safety perspective, it's generally safe to go through the TSA "backscatter" x-ray scanner.
Thursday, November 11, 2010
Wednesday, November 10, 2010
Ian McKellen discusses filming the Balrog scene from Lord of the Rings:
More information here. Unfortunately, he can't comment on negotiations for the upcoming Hobbit movie. (Via BBspot.)
More information here. Unfortunately, he can't comment on negotiations for the upcoming Hobbit movie. (Via BBspot.)
Hack of the day: Turn your elevator into an express elevator.
In the comments, one person says it works 30-40% of the time. (Via @garrytan.)
In the comments, one person says it works 30-40% of the time. (Via @garrytan.)
Tuesday, November 09, 2010
"NASA's Fermi Gamma-ray Space Telescope has unveiled a previously unseen structure centered in the Milky Way -- a finding likened in terms of scale to the discovery of a new continent on Earth."
"A 'whiffletree' is a mechanical digital-to-analog converter. Brilliant..."
Includes links to two cool videos. (Via @Qwertz0.)
Includes links to two cool videos. (Via @Qwertz0.)
Monday, November 08, 2010
"Is radiation from the new airport security scanners endangering my health?"
In the answer, they note that the radiation risk is minimal, but there are genuine privacy concerns:
In the answer, they note that the radiation risk is minimal, but there are genuine privacy concerns:
Let's be blunt: a full-body scan means whenever you pass through airport security, you're going to have a total stranger look at you naked. Millimeter-wave scans in particular are luridly detailed. True, faces are purposely blurred, the scan inspector is in a remote locked room, never sees you in person, and isn't allowed to carry a cell phone with a camera, and the images are discarded immediately after inspection.
But remember we're dealing here with the TSA, the outfit whose agents made a nursing mother drink her own breast milk, mistook a Congressional Medal of Honor for a ninja throwing star, and forced a woman to remove her nipple rings with pliers. In March of this year a British Aviation Authority employee got a harassment warning from police after he captured an image of a female colleague passing through a full-body scanner at Heathrow airport. In May a TSA employee in Miami took a baton to a coworker who'd made fun of his genitalia after he passed through a scanner.
You may think that's a small price to pay if it means bad guys can never sneak weapons onto planes. But scans don't guarantee that. They can't detect items concealed in body cavities or by folds of flesh. "These technologies can be evaded relatively easily," a radiation safety expert tells me. "It's a money-making invasion of privacy."
Sunday, November 07, 2010
Conjoined twins with partially fused brains:
Adding to the conundrum, of course, are their linked brains, and the mysterious hints of what passes between them. The family regularly sees evidence of it. The way their heads are joined, they have markedly different fields of view.(Via Kottke.)
One child will look at a toy or a cup. The other can reach across and grab it, even though her own eyes couldn't possibly see its location. "They share thoughts, too," says Louise. "Nobody will be saying anything," adds Simms, "and Tati will just pipe up and say, 'Stop that!' And she'll smack her sister."
While their verbal development is delayed, it continues to get better. Their sentences are two or three words at most so far, and their enunciation is at first difficult to understand. Both the family, and researchers, anxiously await the children's explanation for what they are experiencing.
If you own an iPhone, beware this DST glitch with recurrent alarms:
Apple says devices using the mobile operating system iOS 4.1 are likely to see have their preset alarms go off an hour late.
The company recommends turning off repeating alarms and setting them manually until Monday, when it's safe to set them to repeat again.
Apple is releasing an update of the software later this month to address the glitch.
Thursday, November 04, 2010
Invisibility update:
Using tiny atoms that can interact with light, the St Andrews' researchers have developed a flexible new 'smart' material that could theoretically appear invisible to the naked eye.
It is the first practical breakthrough in a much-theorised area of physics that has inspired characters such as the Invisible Woman and Harry Potter...
Magazine editor steals another writer's entire article on the grounds that "the web is considered 'public domain'". (Via Cynical-C.)
Wednesday, November 03, 2010
"Life aboard the International Space Station".
One tidbit:
One tidbit:
Unsurprisingly, falling asleep can take some getting used to. Just as you are nodding off, you can feel as though you've fallen off a 10-storey building. People who look half asleep will suddenly throw their heads back with a start and fling out their arms. It gets easier with time. One Russian crew member is renowned for doing without a sleeping bag and falling asleep wherever he ends the day. Anyone still awake after bedtime would see his snoozing form drift by, slowly bouncing off the walls, his course set by the air currents that gently pushed and pulled him.(Via Kottke.)
Tuesday, November 02, 2010
Monday, November 01, 2010
"Israel has forbidden soldiers from using social networking sites (like Facebook) while on active duty."
Apparently too many soldiers have been posting details of ongoing (or future) military operations on their pages.
Apparently too many soldiers have been posting details of ongoing (or future) military operations on their pages.
The "John Galt" options trading strategy for coping with capital gains tax rate uncertainty. (Via @rndx.)
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