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Comments

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XKCD Author's Unpublished Book Remains a Best-Seller For 5 Months

jeffb (2.718) Re:Ummm.... (162 comments)

I have a different theory. His comic appeal to people who merely believe themselves to be above average.

...but it can't appeal to people who really are above average, because it doesn't appeal to you! Right?

So, can you recommend any webcomics that appeal to people who bolster their own sense of superiority by accusing others of feeling superior, and then mocking them for it? Maybe something with "Projection" in the title...

yesterday
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Iceland Raises Volcano Aviation Alert Again

jeffb (2.718) Re:Bah, character-set ignorance. (35 comments)

Well, cool. It always takes some of the sting out of being wrong when I learn interesting things from the correction. Thanks!

yesterday
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Iceland Raises Volcano Aviation Alert Again

jeffb (2.718) Bah, character-set ignorance. (35 comments)

I feel embarrassed every time I see an English-language site render this as "Bardarbunga", when that "d" should be "th". Yes, the letter "eth" looks like a lowercase d with a crossbar and erectile dysfunction, but it's pronounced like "th".

They should render the a-with-diacritic as "au", too. (Maybe even take the "g" to a "k".) But while there's a long and stupid tradition of dropping diacritics without rewriting the vowel, there's no damn excuse for getting it this badly wrong when you've got to replace a letter that simply doesn't exist in your target alphabet.

yesterday
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Hidden Obstacles For Google's Self-Driving Cars

jeffb (2.718) Re:Baby steps (270 comments)

I did, and I chose that word carefully. If we have a fleet that accumulates experience over time, I expect its performance to improve by a compounding percentage over time. That fits the precise definition of "exponential growth".

You may disagree with my optimistic outlook, but I stand by my choice of words. If anything, perhaps I should have said "exponentially more situations over time", but I think that actually dilutes the point a bit. All the same, I accept that reasonable people may disagree with my wording.

yesterday
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:pulsing (72 comments)

Nope. "High tension" means high voltage, which is done so they can get away with low current, which means low magnetic (b-field) coupling. And the rate-of-change is also low, because it's a 60hz sine wave, not an aggressive fast-rise-time pulse. Finally, it's a line (approximately), not a coil -- the magnetic flux is proportional to the number of turns, and for a transmission line the number of turns is 1.

Now, the electric field effects from high-tension lines are another matter entirely.

yesterday
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Hidden Obstacles For Google's Self-Driving Cars

jeffb (2.718) Re:Baby steps (270 comments)

Exactly.

As TFA illustrates, Google's autonomous cars aren't yet ready to drive on every road in the country. But the same could be said of many, many people who are driving those very roads at this very moment.

We don't need a system that always outperforms the very best human drivers. Even if it only outperforms 95% of human drivers, it will still make the roads safer for everyone -- even that 5%, because they'll be at less risk from the 95%.

And remember, there are an awful lot of people in that lower 95% -- heck, in the lower 50%, or the lower 10% -- who are absolutely convinced that they're in the elite 5%.

2 days ago
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Hidden Obstacles For Google's Self-Driving Cars

jeffb (2.718) Re:Baby steps (270 comments)

I think it's the same as a lot of other AI applications. Because autonomous cars can be so much better than human drivers in so many ways -- more and better senses, faster "reflexes", less susceptibility to distraction/impairment/fatigue, inter-vehicle communication, learning from the experience of an entire fleet (including the vehicles that "died" in serious accidents) -- they may never need to be ANYWHERE CLOSE to "human-level AI".

As a very simplistic analogy, consider anti-lock brakes. It takes humans a huge amount of experience, along with lightning reflexes, to deal with rapidly-changing road conditions. Machines don't have anywhere near the human capacity to attend to weather conditions (and weather forecasts), interpret subtle changes in the appearance of the road surface, remember which local roads are prone to ice or standing water, and so forth. But because machines can observe the actual behavior of each wheel of a car and modulate the brakes independently in response, much more quickly than any human's reflexes, they can reliably outperform even experienced and attentive human drivers. And that's with 1970's mechanical technology.

2 days ago
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Hidden Obstacles For Google's Self-Driving Cars

jeffb (2.718) Re:Baby steps (270 comments)

I'm sorry, but "there will always be situations where a human performs better than AI" sounds an awful lot like "I won't wear a seat belt because it might trap me in a burning car".

I really don't mean to be a jerk about this, but didn't you actually just utter pretty much those exact words?! -- from earlier in your post:

I'm sure that there will always be a few situations where a skilled human driver will make better decisions, and produce better outcomes, than standard automation.

So, given that you said that and that you were "sure" of that statement, does that mean you also don't wear a seat belt because you're afraid of dying in a car fire? Just wonderin'. :)

My point was this:

There are a few situations where you're worse off wearing a seat belt than not wearing one. There are people who have died because they were wearing a seat belt.

Those situations are immensely rarer than the situations in which a seat belt will save your life, and since "accidents" are inherently unpredictable, you can't tell in advance when you should or shouldn't wear a seat belt.

Given these facts, it's really really stupid not to wear a seat belt, even though there are some situations in which it might harm you.

Similarly, self-driving cars will eventually reach a point where they'll sometimes kill you, but far, far more often save your life. At that point, avoiding them because you're afraid of the rarest scenario will be an equally stupid decision. It's one that people will make, though, because people are demonstrably terrible at this kind of risk evaluation.

2 days ago
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Hidden Obstacles For Google's Self-Driving Cars

jeffb (2.718) Re:Baby steps (270 comments)

It will be decades before these vehicles can handle real life situations. You will need AI that can improvise as well as a human. Good luck with that.

I'm sure that there will always be a few situations where a skilled human driver will make better decisions, and produce better outcomes, than standard automation.

I'm equally sure that there will be exponentially more situations where standard automation will make better decisions, and produce better outcomes, than average (or even well above-average) human drivers.

I'm sorry, but "there will always be situations where a human performs better than AI" sounds an awful lot like "I won't wear a seat belt because it might trap me in a burning car". It's not wrong, but it is foolish, and it's a poor decision.

2 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:You know what else produces magnetic fields? (72 comments)

In related news, since staring at the sun through a large telescope can damage your retina, DON'T DARE LOOK AT YOUR PHONE SCREEN! It emits DEADLY PHOTONS of electromagnetic RADIATION!!11!

Something to keep in mind should you ever decide to timidly stick your head out of your cave.

3 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:Let's get this out of the way... (72 comments)

The peak rate of flow for blood appears to be well under 1 m/s, even in the largest vessels. No, you won't get a noticeable effect.

3 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:pulsing (72 comments)

"How long" isn't the question, but "how fast". You should be accelerating it to a few kilometers/sec, then reversing its velocity when it's a few millimeters from your scalp. You should probably do this in a vacuum, to avoid confounding influences from shockwaves.

3 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:Let's get this out of the way... (72 comments)

No, not spinning, reciprocating -- moving in and out.

You know, like the ones in that Insane Clown Posse song that everyone keeps quoting.

3 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:CHIROPRACTIC (72 comments)

It's a shame Dr.Bob is no longer with us. Your troll is a mere 1/1000th the power of his.

Wow. That's an impressive body of work.

3 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:Let's get this out of the way... (72 comments)

You're on the right track, but I think you'd still be short on power by several orders of magnitude. Even if you strap it directly to your head, your subwoofer's still only good for causing headaches and annoying bystanders.

3 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Re:Let's get this out of the way... (72 comments)

It's the rate of change of magnetic flux that does the trick. You get changing flux from a changing electrical current, or from a moving magnet. So maybe if you loaded the magnets into a shotgun, then fired them through your brain, you'd notice an effect.

3 days ago
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Magnetic Stimulation Boosts Memory In Humans

jeffb (2.718) Let's get this out of the way... (72 comments)

These are magnetic pulses. No, strapping magnets to your wrist/ankle/belly/tinfoil-hat still won't accomplish anything.

3 days ago
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How the Ancient Egyptians (Should Have) Built the Pyramids

jeffb (2.718) So, is there any shred of EVIDENCE? (202 comments)

This is very interesting, and maybe that's good enough. But isn't there some evidence of what method they might have used? Wood fragments? Tracks? Tools?

I'm asking this as a completely naive onlooker. I'm sure there is research on this spanning hundreds of years; anyone want to provide a quick summary?

about a week ago
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Slashdot Asks: Cheap But Reasonable Telescopes for Kids?

jeffb (2.718) Re:4.5" Newtonian on an EQ Mount (187 comments)

If you foresee going far with this as a hobby, you will want to go 8-10" at some point. It's better to decide now as telescopes are utterly worthless on the used market.

This would seem to present a compelling case for buying a telescope on the used market.

about two weeks ago

Submissions

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CES: Laser headlights edge closer to real-world highways

jeffb (2.718) jeffb (2.718) writes  |  about 8 months ago

jeffb (2.718) (1189693) writes "Audi will display laser-headlight technology on a concept car at the 2014 Consumer Electronics Show, joining BMW, whose plug-in hybrid should reach production in 2014. A November article on optics.org describes the technology in more detail. This approach does not scan or project a "laser beam" from the car; instead, it uses blue lasers as highly efficient light emitters, and focuses their light onto a yellow phosphor, producing an extremely intense and compact white light source and then forming that light into a conventional headlamp beam. The beam isn't coherent or point-sourced, so it won't produce the "speckling" interference effects of direct laser illumination, and it won't pose specular-reflection hazards. It's just a very bright and very well-controlled beam of normal white light.

HOWEVER, if multi-watt blue laser emitters go into mass production for the automotive market, it's likely to drive down their prices in other applications — for example, grey-market multi-watt "laser pointers". If you're looking for a tool to burn holes in the tires of drivers who offend you, this technology may indirectly help to fulfill your wish."
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Son of Therac-25: CT overdoses from "reset error"

jeffb (2.718) jeffb (2.718) writes  |  more than 4 years ago

jeffb (2.718) (1189693) writes "As the LA Times reports, 206 patients receiving CT scans at Cedar Sinai hospital received up to eight times the X-ray exposure intended. (The FDA alert gives details about the doses involved.) A misunderstanding over an "embedded default setting" appears to have led to the error. Human-computer interaction classes from the late 1980's onward have pounded home the lesson of the Therac-25, whose usability issues led to multiple deaths. Will we ever learn enough to make these errors truly uncommittable?"
Link to Original Source

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