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Pine Forest Vapor Particles Can Limit Climate Change

EdwinFreed Who would have thought? (124 comments)

That all we need to do is to replace existing robots with Robot 1-X?

about 6 months ago
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Doctors Say New Pain Pill Is "Genuinely Frightening"

EdwinFreed The fact is it's not a new drug (294 comments)

This is just a stronger formulation of hydrocodone than what was previously available. The summary makes it sound like a new type of opiate.

A new opiate could, depending on its characteristics, be a most welcome addition. Existing opiates have a lot of drawbacks.

But this? Not nearly as significant as the summary would indicate. On either side of the argument.

about 6 months ago
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Tesla Says Garage Fire Not Charger's Fault; Firemen Less Sure

EdwinFreed Re:Musk's Hubris... (253 comments)

It seems the folks at Tesla had the detection idea too. A software update to the car arrived last night. It contained a single new feature: The car now actively monitors the incoming voltage, and if it starts to fluctuate it lowers the current draw accordingly.

I should also note that the various different adapters have some interlock that informs the car how much current can be drawn. And of course the J1772 standard has a facility for this. Additionally, you can force the car to charge at a lower rate by dialing the current down manually.

There also was a report on one of the Tesla forums that a NEMA 14-50 adapter melted while charging at 40A. From the picture it's not clear if it was a fault in the adapter or because it wasn't plugged in properly.

about 8 months ago
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Tesla Says Garage Fire Not Charger's Fault; Firemen Less Sure

EdwinFreed Re:Musk's Hubris... (253 comments)

Actually, it does rule out the actual charging system, since that's entirely inside the car. What isn't ruled out is the universal mobile connector, although I'd say a problem there is much less likely than the house outlet.

The Model S arrives with two connectors that fit into the connector on the car.. One is an adaptor for a standard SAE J1772 EV charger cable, which makes it possible to charge the Tesla at any Level 1 or Level 2 charging station. You can install one of these in your home if you want, although they aren't cheap. The J1772 plug includes interlocking circuitry that among other things prevents arcing when you disconnect.

The second connector is the so-called universal mobile connector. This is a cable with a plug for the car at one end and a plug that fits various adaptors. A bunch of adaptors are available but the car ships with a NEMA 14-50 (commonly used for RVs) and a standard 3-prong adapter. This thing is quite well made, but there's no way for it to interlock in such a way as to prevent arcing.

There's also a high power wall mount unit available from Tesla. It also has an interlocking scheme.

What a lot of people do - and what Tesla actually recommends - is to install a NEMA 14-50 outlet. They're quite cheap, as in less than $10, and any jackass can install one - or at least thinks they can.

Having spent many years dealing with a wide variety of theatrical lighting equipment that used various NEMA connectors, I'm not a fan of the NEMA 14-50 approach. All it takes is one or two disconnects while the power is flowing to pit both the plug and the socket pretty badly. And that's all it takes to start a fire. This cannot happen with either a J1772 or Tesla charging station.

And even if the outlet is the cause, IMO Tesla does have some responsibility here, because NEMA 14-50 is the approach they recommend.

about 8 months ago
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Ask Slashdot: Geekiest Way To Cook a Turkey?

EdwinFreed Re:Are you cooking the turkey to eat it? (447 comments)

Yeah, my foo is weak on this one too, and it is pissing me off. I even tried paging through Food Network recipes and no joy. As for the paste, I don't recall there being any other ingredients, but it's been a long time and I don't trust my recollection so neither should you. The stuffing had all sorts of stuff in it but nothing really unusual.

I did find a recipe for "Saffron, turmeric Roast Turkey with Glutinous fried rice" that looks interesting. I may have to settle for that.

about 2 years ago
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Ask Slashdot: Geekiest Way To Cook a Turkey?

EdwinFreed Re:Are you cooking the turkey to eat it? (447 comments)

Someone else mentioned sous vide cooking - there are a bunch of sous vide turkey recipes. Another is smoking. I sometimes serve a smoked turkey with a pecan sauce. Very nice combination. If I'm going all out there are pastry-enclosed cinnamon apples with a dab of whipped cream infused with Earl Gray tea for dessert.

But the geekiest turkey I ever made was from a recipe I saw on TV (which I just looked for but cannot find). The stuffing had over 10 ingredients, which of course took a long time to do. Once the bird is stuffed, you make up a paste of turmeric and some other stuff and slather it all over. Put it in the oven at 500 degrees, wait for the paste to dry, then apply more paste. Keep doing this until the bird is completely enclosed in a thick hard layer. Then let it cook until it's completely black. You then crack it open and serve. The result was excellent, but was way too much trouble to do again.

about 2 years ago
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Canadian Researchers Create Wireless Charger For Electric Cars

EdwinFreed J1772 standard provides for this (179 comments)

The J1772 plug has five pins: Two for power, ground, pilot signal, and interlock. The interlock pin is wired to a bit of circuitry in the plug. The car checks for this circuit and won't come out of park if it is present.

Additionally, the pilot signal is what tells the car the amount of available amperage, since that's something the car cannot sense, like voltage. I won't bother to go through all of the details of the handshake, but this piece of information is provided by the duty cycle of the 1Khz square wave pilot signal, with 50% indicating 30A available. Not only does this let the car know what power is available so it won't try and draw too much, the amount of power can change over time (when there is, say, a power shortage) and the car responds accordingly.

The plug is also designed so that the signal pins disengage before the power pins, so both ends can sense the impending disconnect and stop the flow of power, preventing arcing.

The plug is also designed to be safe to use in wet conditions. There's also a ground fault detector.

With the exception of the ground fault, which I haven't tried to test for obvious reasons, I can attest to the fact that all of this works flawlessly on the Leaf. The situation with the Tesla Model S is more complex since there's an adapter involved and I haven't been willing to play with it to see what happens, but if anything it should be harder to move the Tesla in park since the emergency break engages automatically.

EVs used to be a big hacked up mess but that time is long since past.

about 2 years ago
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How a Google Headhunter's E-Mail Revealed Massive Misuse of DKIM

EdwinFreed Re:Sigh (115 comments)

I fail to see the relevance. Yes, Microsoft has played fast and loose with various standards, including some critical ones in email. And the surrounding the handling of text/plain as text/each-long-line-is-a-paragraph plus the failure to support format=flowed is arguably the email standards violation with far and away the most impact.

But this doesn't mean Google doesn't also have a lot to answer for. Gmail IMAP compliance in particular is pretty bad, and SMTP handling of error conditions pushes things right to the limits if not past them.

about 2 years ago
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How a Google Headhunter's E-Mail Revealed Massive Misuse of DKIM

EdwinFreed Sigh (115 comments)

Shame on Google for using a weak key, but also shame on this article for being more than a little hyperbolic.

If you, you know, actually read the standard, or even the Wikipedia page, you'll see that DKIM is not intended to be used as a signature mechanism in the same way as S/MIME or PGP. Rather, it's a means to assert responsibility for sending the message, it's done at the domain rather than user level, and verification results are intended to be used for message filtering, not for asserting that so-and-so actually signed the message.

Sure, the underlying technology is based on hashes, signatures, signature verification, and so on but that's because there's no other way to do it. The fact that DKIM allows for the application of relaxed interpretation of both message header and body data kinda tells you it's not intended to be used to provide an absolute assurance that what you got is authentic in every way.

DKIM is also not intended to be the ultimate source of information for filtering. Rather, DKIM results are supposed to be combined with other metrics to form an overall assessment of message validity. And that's a very good thing, since I get all sorts of spammy stuff that makes it through Google, including getting a legitimate DKIN signature attached. Other filtering mechanisms are needed to block such crap.

All that said, it's very disappointing to see yet another case where Google has seen fit to play fast and loose with standards. This is happening much too often.

about 2 years ago
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Ask Slashdot: Seamonkey vs. Firefox — Any Takers?

EdwinFreed Interesting (302 comments)

I've been using Seamonkey for many years. I started when I needed a quickie HTML editor for something, tried it, liked the overall browser and stuck with it.

Every so often I try the various other browsers. So far I've seen no reason to change and lots of reasons not to.

But I thought this was very unusual. Seems it isn't.

about 2 years ago
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How Hair Can be Used To Track Where You've Been

EdwinFreed Re:Also skeptical (133 comments)

According to the abstract, their model "explains more than 85% of observed variation". So yes, it may be useful narrowing things down in an investigation, but this is a long way from being a tracking tool, let alone qualifying as an admissible forensic result. And judging from the cites It also looks like a lot of the interest in this has more to do with tracking movements of animals, not people, which is a lot more reasonable.

FWIW, I used to do a lot of laser spectroscopy work, so this is not entirely familiar territory.

about 2 years ago
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How Hair Can be Used To Track Where You've Been

EdwinFreed Also skeptical (133 comments)

I RFTA, and I didn't see the citations to the peer-reviewed studies demonstrating the reliability of this technique. I also didn't see any cites to case law where these results have been found to be admissible in court.

Of course it depends to some extent on how the results are being used. If they are being used for purposes of exclusion of suspects, or as a means of narrowing a search, reliability or admissibility may have yet to be tested. But sooner or later they will be. I just hope it happens before this gets widely accepted and someone gets hurt.

On a personal note, I drink bottled water almost exclusively for health reasons (immune suppressed and bottled water has, on average, lower bacterial counts than tap). But I buy what's cheapest and available, which means I switch brands all the time. Assuming water does account for the majority of the isotopes these tests check, the stuff I'm drinking right now comes from two different sources, one 600+ miles north, the other 200+ miles northeast of here. Since this is in California, that's not exactly narrowing things down.

about 2 years ago
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Shut Up and Play Nice: How the Western World Is Limiting Free Speech

EdwinFreed Re:And Another Bit from Franklin (1160 comments)

"“In the name of Annah the Almaziful the Everliving, the Bringer of Plurabilities, haloed be her eve, her singtime sung, her till be run, unhemmed as it is uneven. " - Finnegan's Wake

I liked Finnegan's Wake enough to read it a couple of times. Then again, "de gustibus non est disputandum" is kind of the point here.

about 2 years ago
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Shut Up and Play Nice: How the Western World Is Limiting Free Speech

EdwinFreed Re:the maiming and killing must be ok with them (1160 comments)

"I'm sure we all agree that we ought to love one another and I know there are people in the world that do not love their fellow human beings and I hate people like that." - Tom Lehrer

about 2 years ago
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The Sweet Mystery of Science

EdwinFreed That's actually pretty funny (259 comments)

Because what I did in college was write software which among other things was used to model digestive processes. As I recall, the medium sized model was a fairly non-sparse system of more than 200 differential equations, mostly linear but with a few key highly nonlinear terms. And in case it isn't obvious, 200+ equations translates into a hell of a lot more chemicals involved than you could reasonably memorize.

Difficulties of solving the thing aside (the system turns out to stiffer than you'd expect), the fun part for the chemists was getting all the coupling coefficients right, because they come from lots of different sources and are expressed in lots of different units. I built dimensional analysis into the software, but they decided not to use it because it would take to long. That was a bad call, because after publication a mistake turned up (an add that should have been a multiply) that dimensional analysis would have caught. The good news is they reran the model and the mistake didn't change the results significantly, so they were able to issue a simple correction.

I couldn't name even one enzyme involved then or now, but back then I knew quite a bit about how digestion actually worked.

about 2 years ago
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Apple and Samsung Both Get South Korea Bans

EdwinFreed Re:Not I (216 comments)

Darn! Forgot to log out and go AC. Sigh.

about 2 years ago
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Apple and Samsung Both Get South Korea Bans

EdwinFreed Not I (216 comments)

Writing a post without that symbol in it is difficult, but if you work at it... Voila!


- Gadsby

about 2 years ago
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Khan Academy: the Teachers Strike Back

EdwinFreed Re:Pfah (575 comments)

First of all, your initial assertion that university professors don't get training in teaching is incorrect in many cases. In many places the overlap between the "college of eduction" sorts and the other departments is considerable, with the education professors teaching lots of courses, usually the entry level ones.

And guess what? It's entirely possible for them to be the ones who suck at teaching. That was certainly the case in the department where I taught: Consistently lower student ratings and student performance for that subgroup.

Oh, and as for the non-English speaking graduate students, in a lot of places they are handling entire classes with little or no supervision. Maybe that's still a TA, but when they are the only person teaching the class and doing all the grading, it's pretty much a moot point. And it's a HUGE problem: My calculus classroom used to be SRO because poor guy teaching another section one room over spoke great Russian but almost no English at all. (I say "poor guy" because it is not his fault he was given a job he couldn't possibly do well.)

about 2 years ago
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Khan Academy: the Teachers Strike Back

EdwinFreed Re:Slope as rise over run. (575 comments)

I'd actually go a bit further, and say that defining slope in the obvious geometric fashion is the better way to do it. It's not like we have a shortage of terms for the change in a car's position or whatever, e.g., "speed" or "velocity". And the more general concept is better referred to as "rate of change".

I used to teach calculus, and even at the college level the grasp students have over the relationship between what that car is doing on the road and those lines on the chalkboard is often fairly tenuous. So a good teacher spends time explaining how the things connect. When you're doing that it helps to have different words for what's on the board and whatever it is in the physical world you're talking about. And it helps if the terms you use connect naturally to the domain where they are being applied.

And as long as I'm nattering on about this, another thing I picked up on pretty quickly is what sort of explanation works best varies from one student to another. For some students geometric arguments work best. For others that's completely opaque, and they get more out of an abstract symbolic approach. There are even some that just naturally get trigonometric arguments. So when I'd do a problem talking about, say a ladder sliding down a wall, I'd typically work at least two ways and sometimes three.

Anyway, it strikes me as more than a little ironic that someone who is supposedly trying to rework curriculum to better suit student needs is so pedantic about terminology. In my experience excessive pedantry is completely at odds with effective teaching.

about 2 years ago

Submissions

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Bob Pease, analog designer, dies in car crash

EdwinFreed EdwinFreed writes  |  more than 3 years ago

EdwinFreed (1084059) writes "Hardly a scop; it's being widely reported that Bob Pease, well known analog circuit designer and author of Pease Porridge has died in a car accident. He reportedly was driving alone in his 1969 Beetle and failed to negotiate a turn."
Link to Original Source

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