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Ask Slashdot: What Can I Really Do With a Smart Watch?

pz Better solutions exist (230 comments)

How about the extra-ordinary solution of wearing your phone in a pocket that IS accessible within the clean room? Or in one of those exercise arm-band thingies to hold it on your arm outside the gown? There are also bracelets that you can wear that warn you if you get too far from your phone which are inexpensive, so you won't forget your phone in the clean room

The real question becomes what is allowable for you to wear in your clean room. I'm a little surprised that a watch would be OK, or that bringing your phone in would be OK, but I suppose it depends on the situation.

about a week ago
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Reaction To the Sony Hack Is 'Beyond the Realm of Stupid'

pz Re:The Batman, Theater Attack Comparison (580 comments)

Everything in this decision has to do with LIABILITY. Even if the probability is extremely low, the potential liability is astronomical. It doesn't make financial sense for Sony to allow the movie to be shown.

If the expected value of an attack being carried out at all is reasonably high, in other words, there is a credible threat, then that probability is piled all onto the theater that premiers the film. The probability in a credible threat might approach, say 10% (I'm guessing). As an individual, I would not play 1-in-10 odds when the potential outcome is my death. If instead Sony were to open the film in, say, 10,000 theatres simultaneously, the potential liability for each theatre operator drops substantially for any location, and at 1-in-100,000 becomes low enough to perhaps ignore by an individual going to the movies. However, the overall liability remains at 1-in-10 for Sony. The movie is not going to be shown.

about a week ago
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Jaguar and Land Rover Just Created Transparent Pillars For Cars

pz Re:overwhat? (191 comments)

Agreed. My initial reaction to the CGI video is, "wait, why did they TURN IT OFF?!! That's useful information!!"

I can do without the heads-up stuff they were doing (do we really need to be warned about pedestrians like that, or how many parking spaces are available at a garage that we're passing?), but the A and B pillar pseudo-/virtual-transparency are awesome.

about two weeks ago
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Vinyl Record Pressing Plants Struggle To Keep Up With Demand

pz Re:Not really missing vinyl (433 comments)

Perfectly isn't hyperbole here. That is mathematically shown.

And the part of perfect reconstruction that nearly everyone forgets is that it requires an infinitely long sampling of an infinite-time signal. If you use a time-limited sequence, you do not get perfect reconstruction. I've been in the business of signal sampling and reconstruction a long time, but I'm still having trouble finding an instance of a sampling that spans infinite time (for those who are humor impaired, that was a joke).

More practically speaking, because all digitizations that you come across, or design, have finite time span, it means that the reconstruction accuracy starts to get worse and worse the closer you get to the Nyquist threshold, and the effect is worse and worse the shorter the sequence length. Here's an extreme thought experiment: you have two samplings of a signal just a hair below Nyquist. Just a hair below. The sequences are both pretty short, say 4 samples long.

In the first sampling, you got unlucky, and the samples all happened very close to the zero crossings so that all of the quantized values are 0. Reconstructing that yields a DC value of 0V.

In the second sampling, you got lucky to the opposite extreme, and the samples all happened very close to the peaks, so that the quantized values are alternately +PEAKVALUE and -PEAKVALUE. Reconstructing that yields the original sinusoid at the intended amplitude.

Which sampling is correct? If I just give you the sampled values, there is no way to tell. Any reconstruction from amplitude 0 to amplitude PEAKVALUE would be accurate, and there is no way of knowing for sure what the phase was.

Now, if the sequences were infinite length, then, eventually, no matter how fine that hair was below Nyquist, you'd start to see the beating against the sampling clock, and, eventually, be able to observe samples that spanned the entire range of the sinusoid, making accurate reconstruction possible, including phase. But, again, you'd need an infinite sequence, with an infinite sinusoidal signal.

What are the real-world consequences of this problem? (1) you lose phase and amplitude information of the original -- they CANNOT be reconstructed accurately -- as you approach Nyquist, with the effects getting more and more pronounced as the sequence length gets shorter and shorter. (2) If you really want dead-on accurate reconstruction up to a frequency F, you should be sampling at 5F, not 2F. That also gives you more room to design good anti-aliasing filters on the sampling side, and carrier frequency filters on the reconstruction side.

Remember, people, Nyquist is the mathematical limit, not the practical, usable threshold.

about two weeks ago
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Once Again, Baltimore Police Arrest a Person For Recording Them

pz Re:its not as if american cops have anything to fe (515 comments)

I would suggest that when someone is being choked and can barely breathe, their words will not be complex, nor will they carry nuanced meanings such as the level of difficulty they are having with respiration. When faced with life-threatening situations, our minds focus, and become exceedingly direct: "I can't breathe" is entirely within the acceptable range of philosophical inaccuracy under those circumstances. You wanted him to say, instead, "my fellow man, I'm having a rather hard time re-oxegenating my blood -- would you mind releasing the pressure on my trachea for a moment?" Or, "I'm panting because you're crushing my thorax, and am unable to draw a full breath -- would you mind removing your knee from my chest?" Or, "my inability to form full words is because you've pinched off my carotids, and I'm facing imminent loss of consciousness -- would you mind removing your bear-sized hands from my neck?"

If someone in a highly stressful situation tells you "I can't breathe" then you should act accordingly to prevent loss of life. Simple as that.

about two weeks ago
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Bellard Creates New Image Format To Replace JPEG

pz Different Comparison Needed (377 comments)

Although the comparison pages posted in this thread (this is an awesome one https://xooyoozoo.github.io/yo... ) are fun and interesting, they compare the bit efficiency of the two algorithms. That is important yes. But that isn't how these formats are used: when bandwidth is an issue (and it is to web site authors, be they individuals or companies, no matter what anyone on this thread says to the contrary), compression is increased to the threshold of perceptibility, or a little beyond. That is, the provider will increase compression until artifacts are just barely noticeable.

So, the more pertinent question, in terms of image quality, is how the two algorithms compare for equal levels of error, both in number of bits, and also in subjective image quality.

about two weeks ago
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An Algorithm To Prevent Twitter Hashtag Degeneration

pz Not going to bother (162 comments)

It really would be nice to not see these less-than-stellar pieces from Bennett that contain long-winded, half-baked ideas. His ideas are neither particularly good, nor nearly as insightful as he appears to think, especially when it comes to algorithms. Moreover, they always seem to contain some bit of nearsightedness when it comes to human behavior.

Please, someone, come up with a way of blocking his posts.

about two weeks ago
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James Watson's Nobel Prize Goes On Auction This Week

pz Re:Of Course It Was (355 comments)

And the time scale we need to talk about for DNA to change is at the very least tens of thousands of years.

Recent scientific experiments and non-scientific efforts in selective breeding of animals and plants would suggest otherwise. Heck, there's even a story on the Slashdot front page at the moment talking about how HIV is evolving in front of our eyes.

For me, the quintessential directed evolution experiment was started by Dmitri Belyaev in Russia to domesticate the wild fox. It took all of 10 generations. Ten. Not thousands or even hundreds. Ten. Domestication represents a huge shift in DNA. See https://en.wikipedia.org/wiki/...

about three weeks ago
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Clarificiation on the IP Address Security in Dropbox Case

pz Relevance? (152 comments)

Someone, who has no apparent power, wants to correct a judge. Just because they think they're right and the judge had inaccurate reasoning, despite coming to the same conclusion. (There's a good XKCD comic on the subject of correcting people in the Internet.) The critic's opinion will carry no legal weight. The same critic has a history of proposing long-winded, half-baked ideas to correct issues he sees with various societal inefficiencies that have gone no-where. I'm not going to waste my time.

Would someone be so kind as to please remind me how we can block posts from a given author?

about 1 month ago
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Debunking a Viral Internet Post About Breastfeeding Racism

pz Re:Seconded. (350 comments)

You forgot to mention that he has an embarrassingly small sample size and doesn't do any sample correction. He doesn't publish any significance values, so we have no way of knowing if 70% is the same or different than 77%, to the accuracy of the methodology (as well or as poorly thought out as it may be). Then he considers 86% and 67% to be about the same, and subsequently 63% and 79% to be about the same.

I am not a professional statistician -- I hire people to do that sort of work for me when I need definitive answers because I don't know the details. But I know enough to recognize handwaving, and that's all the long-winded original posting is.

about a month and a half ago
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It's Time To Revive Hypercard

pz Balance taxes? (299 comments)

I've never balanced taxes. Is this a new thing?

Oh, you mean balance checkbooks and pay taxes. There's much better software to do that these days.

And there are much better ways to teach programming. For a very long time there has been a movement to bring programming to the masses, as if, somehow, everyone would be able to write beautiful, intricate code to solve their most complex problems. Most people can barely match their clothing (note to the reading-impaired: that was hyperbole); why should we expect them to be able to write code?

Writing programs requires clear, linear thought. It requires thinking in terms of structures and systems. The push in the greater population has been toward valuing non-linear thought (although that baffles me), so there's a big mismatch to overcome. Yes, there are plenty of graphical programming languages that reduce the need for precise syntax, but they only REDUCE it, not eliminate it, and they still require procedural thinking which, ultimately, presents an insurmountable difficulty for many people.

Not everyone can or should be a programmer: Not everyone is a writer, Not everyone is a photographer, Not everyone is a painter. Sure, everyone should be given basic skills in writing, and perhaps in drawing or painting as a child, and so perhaps everyone should be given basic skills in programming, but beyond that, why? Not everyone is able to understand calculus; why should we automatically expect that everyone should be able to write Java, Python, or whathaveyou?

about 2 months ago
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How Apple Watch Is Really a Regression In Watchmaking

pz Re:cell phones and notepads (415 comments)

I always have my appointment book with me in my briefcase, right next to my laptop and phone. When I'm in my office, it's open in front of me. The only time that it isn't nearby is when I've intentionally left it aside.

My scheduling isn't as interdependent as yours. Meeting times are negotiated via email. My schedule has only 2-3 meetings per week, and most of the entries in my book are for allocation of time to work on one project or another. Perhaps it also helps that I'm the boss.

Use the right tool for the job -- for your application, the best tool appears to be electronic. Not so for mine.

about 2 months ago
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How Apple Watch Is Really a Regression In Watchmaking

pz Re:cell phones and notepads (415 comments)

Pen and paper have some very serious advantages that should not be overlooked when distracted by the new and shiny. Use the right tool for the job.

Personally, I keep my appointment book with paper and pencil. I can access it anywhere, at any time, whether or not I remembered to bring a charger, whether I'm on a plane or in a meeting (and in a meeting, no one can accuse me of playing with my phone instead of paying attention). I also keep a personal journal in acid-free paper and fade-resistant ink so that my grandchildren can enjoy learning about me when I'm long dead and hold a cherished physical object that I held, just as I have enjoyed learning about my grandmother decades after she passed away, and cherish being able to touch something she touched.

But, the right tool for the job also means that I do most of my writing electronically, often switching between multiple virtual desktops. I keep my phone book electronically (although I do periodically dump to printed paper for disaster recovery). My most recent publication will only be made available in an electronic version.

New does not automatically mean better. Use the right tool for the job.

about 2 months ago
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We Are All Confident Idiots

pz He knows just enough to be dangerous. (306 comments)

Seems to explain the effect where a little knowledge in a field appears to make one reckless and dangerous, whereas deeper knowledge makes one cautious.

about 2 months ago
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Detritus From Cancer Cells May Infect Healthy Cells

pz Re:How is this different from a virus? (46 comments)

And that should have been part of my posting above that asked the question -- these fragments dock with other cells, inject the RNA, and that RNA causes the cells to become cancerous, which, in turn creates more of these little RNA capsulettes.

I'm sure there are some differences between these and classical virus structure, in some way, but given my ignorance of the subject, they walk and talk like viruses.

about 2 months ago
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Detritus From Cancer Cells May Infect Healthy Cells

pz How is this different from a virus? (46 comments)

A small encapsulatory structure containing a fragment of RNA. I'm not a microbiologist, so can someone tell me how these things are different from a virus?

about 2 months ago
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Incapacitating Chemical Agents: Coming Soon To Local Law Enforcement?

pz Re:A tragedy, but stretching the bounds of relevan (152 comments)

It wasn't the chemicals, as you point out, but the penetrating object that killed her. She bled out. If she hadn't bled out, she would have likely suffered severe brain damage as skull and projectile fragments entered her cranium.

The relevance being, also as you point out, that shooting anything into the face is a bad idea when non-lethality is the intent. But any chemical that is going to be delivered in such a way has exactly that potential, as do rubber bullets (have you seen what those do? non-lethal does not mean non-damaging).

Any chemical means to convince a highly agitated crowd to cease and disperse is going to have extraordinarily strong effects, even when used correctly, with some suffering the effects more than others. Some fraction of the population is always going to be sufficiently vulnerable for lethality.

Ultimately, I think we're agreed: The very idea of a non-lethal chemical weapon is absurd.

about 2 months ago
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Incapacitating Chemical Agents: Coming Soon To Local Law Enforcement?

pz VICTORIA SNELGROVE (152 comments)

In 2004, VIctoria Snelgrove was hit in the eye with a pepper spray bullet by the Boston Police as part of crowd control (for a non-riotous crowd that was not responding to their commands). She subsequently died of her injury.

Non-lethal ICA? No such thing.

about 2 months ago
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No More Lee-Enfield: Canada's Rangers To Get a Tech Upgrade

pz Re:May I suggest RTFA? (334 comments)

Thank you for that very clear and succinct assessment of my intellectual capacity after reading a full paragraph of my writing. Touche. You perfectly hit the nail on the head. I am totally and utterly lacking in intellectual capacity, despite any evidence to the contrary.

Now, if you'd care to engage in a rational debate without ad hominem attacks, I'd be happy to respond. If not, please go away.

about 2 months ago

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pz pz writes  |  more than 11 years ago

The Blackjacks were a small (okay, perhaps not-so-small) band in Boston from the heyday of local music in Boston. Their biggest hit Saturday, which made a splash on the college airwaves, starts with the lyrics in my signature.

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