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Comment: In theory it's nice. In practice it's ... (Score 1) 165

by jdagius (#47922377) Attached to: Developing the First Law of Robotics
... never going to work.

One could argue that computer viruses are merely robots without a solid body. So the First Law has already been trashed by all the big powers on the planet.

And who's going to decide what is 'harmful'? Governments again are producing semi-automated robots (drones) which harm people. But that's OK because "it's to prevent an even greater harm" they say. But who decides if 'they' got it right?

Comment: Quirk in MATLAB array syntax (Score 1) 729

MATLAB was one of the first languages to allow lists of comma-separated numbers between square brackets e.g. [1,2,3,10] to be interpreted as indexed numeric arrays or vectors. A lot of languages do that now, but MATLAB was perhaps the first to do this in 1984. A little-known quirk is that the commas are optional! [1 2 3 10] etc. This was probably introduced as a 'convenience' feature (though typing a space isn't that much faster than typing a comma). But there is a glitch ("feature") in the syntax that interprets space-separated negative numbers differently than you'd expect. So [ 1 2 -3] is interpreted as [1,2-3] (value = [1,-1]) because the precedence of arithmetic operators is higher than list operations.

MATLAB hasn't fixed this 'feature' yet, because it would undoubtedly break a jillion apps around the world. So you must be careful to type [1 2 (-3)] if you are allergic to commas.

BTW it's been fixed by default in OCTAVE, MATLABS free-software clone, but you turn 'quirks' on, if you want to preserve the quirky behavior.

Comment: Does Learning Mechanical Engineering Outweigh ... (Score 1) 546

by jdagius (#47820803) Attached to: Does Learning To Code Outweigh a Degree In Computer Science?
... learning to operate a rivet gun or steam shovel? A bridge or building could be more cheaply built by skilled operators with little or no knowledge of stress and strain, but how long would these structures stand?

The same could be said for computer programmers, who may be skilled in coding, but have little or no knowledge of the best methodologies for constructing robust and reliable software systems and structures.

Comment: Re:Structure preserving? (Score 1) 60

by jdagius (#47439195) Attached to: Sand-Based Anode Triples Lithium-Ion Battery Performance
@tsa > I don't think it suggests that at all.

Did you read TFA? It says. "In this very simple process, the salt acted as a heat absorber while the magnesium removed oxygen from the quartz, resulting in pure silicon. "

So the article does indeed 'suggest' that Mg is removing O. My question was concerning how is this oxygen removal related to creating porosity. Or not.

In any case, it seems likely that some formerly filled space must be vacated to create porous openings.

Does anyone know how this happens?

Comment: Elephant in the room... (Score 2) 166

by jdagius (#47239933) Attached to: "Eskimo Diet" Lacks Support For Better Cardiovascular Health
... lipid hypothesis
So I get that the "Eskimo Diet" doesn't improve cardiovascular health. But then it doesn't degrade it either. Then why all the "heart smart" low-fat, no-fat, low-cholesterol propaganda we're constantly bombarded with?
It seems Uffe Ravnskov may be right. Dietary cholesterol very likely has little or no bad effects on health. It is probably "good" for you. In fact, statin drugs used to treat CAD are far worse for your health.
Proof: If statins actually were effective against CAD, then the ads on TV could make that claim. If you listen carefully, they don't make any claim that they lower the incidence of CAD. Their sole claim for "effectiveness" is that they lower your blood cholesterol numbers. It would be more compelling if they could claim health benefits of course, but their is no compelling evidence for this.

Comment: Re: In space ... (Score 1) 50

by jdagius (#44111421) Attached to: Satellites Providing Internet To the 'Under-Connected'
Objects "in orbit" around the Earth are actually falling freely to the Earth. But thanks to the very large horizontal component in their motion, orbiting objects always overshoot the horizon and thus stay in orbit.
Such objects have no "weight", because weight is defined as, F=mg, a force F exerted by an object with mass m in a gravity field g, resting on a surface preventing the object from falling freely.
The mass of an object is thus independent of gravity, but it's "weight" is just an artifact imposed by surface constraints, and can vary greatly.

Comment: Re:Probably pretty cold (Score 4, Informative) 43

by jdagius (#43903305) Attached to: Lowest Mass Exoplanet Ever Directly Imaged. Probably.
> ... sad part ...

No need to be sad. Increasing effective aperture size of the telescope increases its resolving power. The imaging element doesn't have to be a single mirror or lens, but can consist of an array of elements scattered over a large area. Tricky part is getting all of the elements in phase agreement. Also doesn't have to be visible light. We are already 'imaging' surfaces of planets with synthetic aperture radar, operating on the same principle.

So imagine a much larger optical array network, many miles in diameter, for imaging the surfaces of these exoplanets.

Comment: Re:wikipedia's got the wrong name (Score 5, Informative) 51

by jdagius (#38372686) Attached to: Atlantic Crossing By Amateur Radio High Altitude Balloon
> Wikipedia has the name wrong.

No, you are wrong. Bob Bruinga, WB4APR, the inventor of APRS has reverted in the naming convention, and now supports the "_packet_ reporting" moniker because he wants to emphasize that APRS is not just for position reporting. For example, it's extensively used for weather reporting from mostly non-mobile CWOP (Citizen Weather Observers Program) volunteers, who include a lot of non-amateur radio enthusiasts who augment NWS mesolevel forecasts with thousands of home-made stations reporting every ten minutes or so over the Internet. (The ham-radio CWOP volunteers can also report weather via amateur RF frequencies).

Also APRS has been used ("firenet") for reporting brush and forest fires.

Comment: No Big Deal (Score 1) 159

by jdagius (#36168868) Attached to: Robots Successfully Invent Their Own Language
The first humanoid "words" were probably grunted utterances representing names of other humanoids, animals, places and (eventually) events.

Even so, automatically generating unique labels is no big deal for a computer. Every automatic "builder" program already do this. Except they're usually enumerated (i.e. box1,box2, box3, ..., box999), instead of randomly generated ciphers ("xyzzy" etc). But computers don't do anything randomly, it all has to be programmed by a human.

Google Caffeine Drops MapReduce, Adds "Colossus" 65

Posted by samzenpus
from the time-to-upgrade dept.
An anonymous reader writes "With its new Caffeine search indexing system, Google has moved away from its MapReduce distributed number crunching platform in favor of a setup that mirrors database programming. The index is stored in Google's BigTable distributed database, and Caffeine allows for incremental changes to the database itself. The system also uses an update to the Google File System codenamed 'Colossus.'"

"Our vision is to speed up time, eventually eliminating it." -- Alex Schure