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Nevada Earthquake Swarm Increases Chance of Larger Quake

dtmos Re:Preferable to Rarer, Larger Quakes (65 comments)

Having been in all three (well, I wasn't exactly inside the tornado, but it was much too close for comfort), I agree that the earthquake is the choice of the lot -- if one has to be in one of the three.

However, if the question is, "Which would you rather live in -- an earthquake-, tornado-, or hurricane-prone area?", my answer would be the hurricane-prone area, because these days they're by far the most predictable and, therefore, escapable. I'm comforted by the fact that should one appear, I will have enough warning to be elsewhere when it hits. It's a lot harder to say that about tornadoes and earthquakes.

about two weeks ago
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SpaceShipTwo's Rocket Engine Did Not Cause Fatal Crash

dtmos Unlocked? (150 comments)

The part I don't get is why one would unlock the feathering system at the start of the burn, well before it is expected to be used -- something that the in-flight videos apparently show. I can see that keeping the feathering system locked would be a safe thing to do before the release, but was the feathering system designed to be used while SpaceShipTwo was in powered flight? I was under the impression that it was not, so it would seem prudent to keep it locked until the burn was complete. Am I missing something?

I confess that I am reminded of Evel Knievel's abortive jump of the Snake River in his Skycycle X-2, which failed when his recovery mechanism (in this case, a drogue parachute) deployed during the first few seconds of powered flight. The design of recovery systems is a difficult problem.

about three weeks ago
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The Greatest Keyboard Ever Made

dtmos Re:Unicomp (304 comments)

There's never a mod point around when you want to use it.

about a month and a half ago
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Scotland Votes No To Independence

dtmos Legal recourse (474 comments)

The US has plenty of attorneys with experience representing plaintiffs in contested national elections, going back at least to 2000.

To those of you in Scotland, feel free to take as many as you want. Return is not necessary. Special volume discounts available.

about 2 months ago
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Scientists Twist Radio Beams To Send Data At 32 Gigabits Per Second

dtmos Re:Microwaves and 2.4 GHz (122 comments)

I think the special part is that 2.4 GHz is a convenient frequency where there is a balance between a larger amount of energy being absorbed by water and a smaller amount of energy being absorbed by glass and plastic.

No, 2.4 GHz was just one of seven convenient open frequency bands when, in 1947, the FCC assigned frequencies for the industrial heating, diathermy, and other RF sources that were causing interference on communication systems. These bands were scattered from 25 MHz to 20 GHz. See p. 8 and p. 50-51 of the Thirteenth Annual Report of the FCC, and the 1947 US Frequency Allocation Proposal to the Atlantic City International Radio Conference (see pdf page 464 of this pdf file). They were collectively called the "ISM bands", because the FCC aggregated Industrial heating, Scientific uses, and Medical heating (diathermy) equipment into bands that would minimize interference to communication systems. The microwave oven (called an "electronic cooker" in the FCC report) was so new that it was explicitly mentioned, and lumped in with other "industrial" heating systems.

about 2 months ago
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Scientists Twist Radio Beams To Send Data At 32 Gigabits Per Second

dtmos Re:Spiral filter, and a Tardis (122 comments)

So let me ask: If the multiplexing is due to "the phase relationship between the oscillations of the field at different positions", may I assume that these systems would be very sensitive to multipath interference -- especially varying multipath interference, as in mobile devices? Is that why the only demonstrations I have seen involve point-to-point links in free space (where multipath would be minimized)?

about 2 months ago
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Scientists Twist Radio Beams To Send Data At 32 Gigabits Per Second

dtmos Microwaves and 2.4 GHz (122 comments)

2.4GHz is perfect for heating anything with a high water content, like tissue. That's why microwave ovens use it.

This is a myth. There is nothing special about 2.4 GHz as far as water is concerned. There is a mild absorption peak at 24 GHz, but nothing at 2.4.

about 2 months ago
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GM To Introduce Hands-Free Driving In Cadillac Model

dtmos I don't get it (185 comments)

Why is this new? I see people driving Cadillacs with no hands on the wheel all the time.

about 3 months ago
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The Grumpy Programmer has Advice for Young Computer Workers (Video)

dtmos Incredibly wise advice (120 comments)

Robin Miller: But age discrimination in employment, have you encountered?

Bob Pendleton: Oh, absolutely. I got laid off on my 49th birthday and haven’t been able to find a full time job since.

One piece of advice I always give younger engineers and programmers is to be increasingly vigilant about your career as you age. In the last decade or so before retirement one is very vulnerable to layoffs, because one's salary is high and one's formal education was a long time ago.

about 2 months ago
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Princeton Nuclear Fusion Reactor Will Run Again

dtmos Re:Spherical Torus (147 comments)

Spherical Torus?

I wondered the same thing. However, the National Spherical Torus Experiment web site has this explanation:

The magnetic field in NSTX forms a plasma that is a torus since there is a hole through the center, but where the outer boundary of the plasma is almost spherical in shape, hence the name “spherical torus” or “ST”.

There are also some links to more detailed descriptions.

about 3 months ago
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NASA Announces Mars 2020 Rover Payload

dtmos Coolest of the lot (109 comments)

Can't decide if the UV laser or the ground radar is the coolest of the lot.

That would be the UV laser. Ground-penetrating radar is so Twentieth Century.

about 4 months ago
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Amazon Announces 'Fire Phone'

dtmos Re:Perhaps not the best name (192 comments)

Yeah, "halt and catch fire" has a new meaning when the device has a lithium battery.

about 5 months ago
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Woods Hole Oceanographic Institution Loses Deep Sea Vehicle

dtmos Columbia River. . . . (93 comments)

Well, if it crossed the Pacific and went upstream the Columbia River, it might have made it to Montana -- although there are a surfeit of dams to overcome along the way.

about 6 months ago
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Star Cluster Ejected From Galaxy At 2,000,000 MPH

dtmos Velocity (133 comments)

Two million miles per hour is less than 0.003c, but still quite a clip, even in astronomical terms.

Since they're discussing velocity (vector speed), and not just speed, the headline is correct in saying " -1000 km/s" when the measured value is -1025 km/s, but one can debate whether the abstract is correct in saying "an extraordinary blueshift of -1025 km/s", rather than "an extraordinary blueshift of 1025 km/s", since "blueshift" gives one the sign of the velocity already.

about 7 months ago
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This 1981 BYTE Magazine Cover Explains Why We're So Bad At Tech Predictions

dtmos Most unlikely technology in 1981: Handheld GPS (276 comments)

I always thought the most unlikely technological development in my lifetime was the handheld GPS device. It would be "most unlikely" because it required tremendous, simultaneous, and largely unforeseen advances in several different technologies, each of which was hard to predict in 1981. The list is at least:

1. Low power, low voltage, low noise L-band receivers, sensitive enough to be compatible with the weak signal coming from the internal antenna of a handheld device;
2. Stupendous amounts of digital signal processing, also at low power and low voltage;
3. Digital map databases of (substantially) every road in the world, accurate to a few meters;
4. A substantially world-wide, wideband wireless data link to get the digital map into the handheld device in the first place;
5. Low power, low voltage, high resolution, multicolor flat panel displays;
6. Gigabytes of low power, low voltage data storage memory; and
7. High energy density, high power density batteries capable of supplying the whole thing.

And, perhaps most impressive of all, the manufacturing technology to make all of the above small enough to fit in a handheld device, at a price low enough to sell by the zillions.

Of the list above, probably only #2 could have been predicted, and then only if one were willing to extrapolate the then-relatively-new Moore's Law by a very large amount. (Recall that Mead and Conway had only written their Introduction to VLSI systems the previous year; until then it was not clear that such complex chips could even be designed on human time scales, let alone built for a profit.)

The fact that a handheld GPS device is now an anachronism, since the technology is now small enough and low-power enough to be integrated into other handheld devices, like smart phones, pleases me no end.

about 7 months ago
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Mathematicians Use Mossberg 500 Pump-Action Shotgun To Calculate Pi

dtmos a bunch of dead zombies (311 comments)

AND a bunch of dead zombies.

What's a dead zombie? Is this some kind of recursion?

(Getting old has a lot of advantages, but one of the disadvantages is that it's harder to keep track of popular memes. I mean, I never understood the whole "vampire" thing, and now we're on to zombies. What's next?)

about 7 months ago
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Data Mining the Web Reveals What Makes Puzzles Hard For Humans

dtmos Re:Idiotic summary (44 comments)

The "they" in the quoted line refers to people, not computers. It's the people picking the method (poorly).

The issue with Sudoku is that easy and difficult puzzles can have the same number of boxes to fill.

about 8 months ago
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Data Mining the Web Reveals What Makes Puzzles Hard For Humans

dtmos Value (44 comments)

Somewhere I read an article by a guy who makes and sells Sudoku puzzles to newspapers. He explained that the value of providing the puzzle was near zero, since anyone with a computer could easily generate thousands of them, and anyone without a computer could get them from any number of sources. The value of his service, and the reason newspapers paid him to provide the puzzle, he said, was that he provided an accurate difficulty estimate to the puzzle. People attempting, and failing to solve, a difficult puzzle rated "easy", and people quickly solving an easy puzzle rated "difficult", were dissatisfied, and complained. People that had the experience they expected -- easy puzzles quickly solved, hard puzzles solved only with difficulty -- were much more satisfied.

The result was, newspaper editors got fewer complaints using his puzzles than they did from his competitors, so they bought from him.

He said he spent far more time tweaking his difficulty-rating algorithm than he did his software that generated the puzzles themselves -- since that was what kept him in business.

about 8 months ago

Submissions

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Amateur Radio Gets Secondary MF Allocation at WRC-12

dtmos dtmos writes  |  more than 2 years ago

dtmos (447842) writes "The ARRL is reporting that "delegates attending the 2012 World Radiocommunication Conference (WRC-12) in Geneva have approved a new 7-kilohertz-wide secondary allocation between 472-479 kHz for the Amateur Radio Service." This band, below the AM broadcast band, will retain its primary ship-to-shore and radionavigation beacon allocation. Due to the unique propagation characteristics of this part of the spectrum, an allocation has long been desired by the amateur radio community. Much as moonbounce and meteor scatter have produced their own amateur digital communication protocols (OSS under the Gnu GPL, of course), I expect the unique channel impairments of this band will lead to the development of dedicated digital communication schemes (beyond QRSS)."
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Coronal Mass Ejection hits Earth

dtmos dtmos writes  |  more than 3 years ago

dtmos (447842) writes "Spaceweather reports "A coronal mass ejection (CME) hit Earth on Oct. 24th at approximately 1800 UT (2:00 pm EDT). The impact strongly compressed Earth's magnetic field, directly exposing geosynchronous satellites to solar wind plasma, and sparked an intense geomagnetic storm. As night fell over North America, auroras spilled across the Canadian border into the contiguous United States." Aurora were seen as far south as Baileyton, Alabama."
Link to Original Source
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Sports Bars Changing Channels to Video Gamers

dtmos dtmos writes  |  more than 3 years ago

dtmos (447842) writes "This summer, 'Starcraft II' has become the newest barroom spectator sport. Fans organize so-called Barcraft events, taking over pubs and bistros from Honolulu to Florida and switching big-screen TV sets to Internet broadcasts of professional game matches.

As they root for their on-screen superstars, "Starcraft" enthusiasts can sow confusion among regular patrons ... But for sports-bar owners, "Starcraft" viewers represent a key new source of revenue from a demographic—self-described geeks—they hadn't attracted before."

Link to Original Source
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DARPA Hypersonic Vehicle Splash Down Confirmed

dtmos dtmos writes  |  more than 3 years ago

dtmos (447842) writes "The U.S. Defense Advanced Research Projects Agency (DARPA) has announced that its Falcon Hypersonic Technology Vehicle 2 (HTV-2) flight on Thursday, 11 August, "experienced a flight anomaly post perigee and into the vehicle’s climb. The anomaly prompted the vehicle’s autonomous flight safety system to use the craft’s aerodynamic systems to make a controlled descent and splash down into the ocean."

“According to a preliminary review of the data collected prior to the anomaly encountered by the HTV-2 during its second test flight,” said DARPA Director Regina Dugan, “HTV-2 demonstrated stable aerodynamically controlled Mach 20 hypersonic flight for approximately three minutes. It appears that the engineering changes put into place following the vehicle’s first flight test in April 2010 were effective. We do not yet know the cause of the anomaly for Flight 2.”"

Link to Original Source
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IEEEXtreme 24 Hour Programming Challenge Announced

dtmos dtmos writes  |  more than 4 years ago

dtmos (447842) writes "IEEEXtreme is a global challenge in which teams of student members, supported by an IEEE Student Branch, advised and proctored by an IEEE Member, compete in a 24-hour time span against each other to solve a set of programming problems. IEEEXtreme 4.0 will take place on Saturday 23 October, 2010. Not a student? The IEEE is looking for proctors."
Link to Original Source
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Factorization of a 768-bit RSA modulus

dtmos dtmos writes  |  more than 4 years ago

dtmos (447842) writes "The 768-bit, 232-digit number RSA-768 has been factored. From the introduction:

The number RSA-768 was taken from the now obsolete RSA Challenge list as a representative 768-bit RSA modulus. This result is a record for factoring general integers. Factoring a 1024-bit RSA modulus would be about a thousand times harder, and a 768-bit RSA modulus is several thousands times harder to factor than a 512-bit one. Because the first factorization of a 512-bit RSA modulus was reported only a decade ago it is not unreasonable to expect that 1024-bit RSA moduli can be factored well within the next decade by an academic effort such as ours . . . . Thus, it would be prudent to phase out usage of 1024-bit RSA within the next three to four years.

"

Link to Original Source
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USPTO Asking For Ideas to Enhance Patent Quality

dtmos dtmos writes  |  more than 4 years ago

dtmos (447842) writes "Tired of seeing poor-quality patents issue? Have a great way to solve the problem? Well, here's your chance to be part of the solution. The USPTO has issued a Request for Comments on Enhancement in the Quality of Patents [pdf], seeking public comment on ways to improve "the process for obtaining the best prior art, preparation of the initial application, and examination and prosecution of the application." Comments should be sent to patent_quality_comments@uspto.gov by February 8, 2010."
Link to Original Source

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