Bayonet

Today I learned that those little prongs on the sides of the Kitchen-Aid paddles (that slide in and then turn to lock) are officially called "bayonet fittings" or "bayonet mounts."  And that some electrical devices (fuses, light bulbs) are made with them.  They're called that, straightforwardly enough, because that's how you used to attach a bayonet to your rifle.  Not a mount shaped like a bayonet (my first thought), but a mount for a bayonet.

Let me see if I can find a picture.  Oh, never mind, just go to http://en.wikipedia.org/wiki/Bayonet_mount.  They've got some good examples.

Frank's TV redux

In 2009*, the Dallas Cowboys put up in AT&T Stadium some videoscreens that measured 160 feet across and 72 feet high.  Converting that to inches and applying Pythagorean methodology, we find that this yields a diagonal size of... 2,105 inches.  Not yet available for home consumers, but still.  Frank would be pleased.

Also note that there are several stadium screens even larger in scope-- The Safeco Field screen is 2,500 inches, and the brand new (more or less) Reliant Stadium screen is a whopping 3,382 inches diagonally (a bit shorter but a lot longer.  Widescreen, donchaknow.).  There's also a race track in Dubai and a speedway in N. Carolina, but I don't have exact confirmed numbers for those, and I don't think it matters enough to track them down.  I'm sure in a couple of years there'll be another bigger one somewhere else anyway.

*"Frank's 2000 Inch TV" was released by Weird Al et. al. in 1993.  16 years ain't too bad to make something this hyperbolic happen.

Partial source: http://stadiumblog.dallasnews.com/tag/guinness-world-records
Other figures from "Bigger in Texas", Caleb Hannan, Wired, October 2013.

OIH

Another post for the annals of Obvious In Hindsight.

Having recently (last weekend) upgraded from my first ever smartphone to my second ever smartphone, I discovered that the old model (which they let me keep, to my vague surprise-- I guess I assumed they'd claim it as part of the trade-in) is still completely functional in every way except for its ability to make phone calls (arguably one of the least important of its functions as far as I was concerned).  So I can still use it as a music player, or game device, or Facebook check-in-er, or video watcher, or TV remote, or whatever just so long as I'm in range of the WiFi.  Which is good news!

The bad news is that it is also just as good an alarm clock as it ever was.  Which meant an unexpected blaring noise at 5:45 this morning coming from the other room because it never occurred to me to turn off the alarm when I switched the phones.

Don't ask

Turns out, SPITBOL programs actually look a little bit like Perl scripts. Not enough to be really useful, but enough that I can recognize some of the bits.

Don't ask me why we're using SPITBOL.  I won't like the answer.

How to shrink a skyscraper surreptitiously

In Japan, especially in the major metropolitan areas, the laws and regulations regarding construction are EXTREMELY strict.  The amount of noise, disturbance, and physical detritus that can be generated all seem to be much more rigidly controlled than they are here in the States.

And yet-- sometimes, that large building does have to come down!  It might be old, and not up to code anymore, or perhaps the owners can no longer afford the taxes and no one will buy it, or it simply might need to be removed in order to make way for a new bypass.  Over here, it'd be roped off, and depending on how close it was to other buildings, (carefully) knocked down or (carefully) blown up.  More often the former, naturally, since this isn't the movies, but still.

In Tokyo?  They install humongous jacks and a set of screening scaffolding.  The jacks hold up the building while behind the screening (that keeps the noise, dust, and construction unsightliness to a minimum) workers will carefully dismantle the bottom two floors of the building, trucking the bits away for recycling.  The building will be slowly lowered to the ground, the jacks will be reset, and another two floors will be taken away, and so on, until the whole thing quietly disappears.  Sometimes they'll do it from the top down instead, just for a change.


Source, including a time-lapse video of one such demolition:  http://www.nytimes.com/2013/06/18/science/tricky-ways-to-pull-down-a-skyscraper.html?_r=3&

Frank's 2000 inch computer monitor

This is the sort of discovery that will make anyone in the audience under the age of 24 go, "Well, duh."

I was moving some papers around the other night, and uncovered the manual that came with the "new" flat-screen TV.  It's a very rudimentary manual-- most of the relevant info is online, things being what they are these days-- but it does have all of the "How to Hook Various Things Up To Your New TV" information.  And one of those "things" was "Your PC."

I am old enough, and our previous TV was old enough, that I have to admit the possibility simply never occurred to me.  The old TV just had a coax and some component video inputs, after all.  Piping a computer into that would clearly have been more trouble than it was worth.  But the new TV has HDMI inputs, and... "Dear?  Can I borrow your laptop for a moment?"

Roughly 10 seconds later, we have a 40+" high-def computer monitor.  I have to admit, I am now sorely tempted to pick up a wireless keyboard/mouse combo, haul the tower downstairs, and see what it's like to play Borderlands 2 on the Big Screen...

To boldly go with our full support

In 1962, the Apollo space program was looking for a manufacturer for spacesuits for their budding astronaut program. These suits would need to be strong, flexible, and supportive, with a combination of fabric and metal. Several companies put in bids, but NASA naturally turned to a company that already had experience manufacturing products with just those characteristics-- the industrial division of Playtex.

Source : Spacesuit: Fashioning Apollo http://books.google.com/books?id=IT-chpAkCZ0C&pg=PA121

To sleep, perchance to zzxxxnnnn...

A week or so ago, I switched out my alarm clock for my phone.  Yes, I'm becoming one of Those people.  For one thing, it lets me easily set different times for my alarm for the days where my morning schedule is different.  For another, instead of having to try tune the clock to an empty band to get static for white noise (something that's getting more and more difficult), I can now use an actual white noise app, that will generate (among other things) wave sounds, rainstorm sounds, fan noise, or my personal favorite, Airplane Cabin.  No, seriously.

And that leads in turn to the Thing I Learned.  You see, I've always felt like I had trouble falling asleep.  I turn off the light, lay down, and proceed to thrash and flop around for a while until I finally go out.  But now I have verifiable evidence!  The white noise app has a timer on it, and I can now say, much to my surprise, that a fair number of nights I have absolutely no recollection of the app shutting itself off after about 15 minutes.  So I'm falling asleep much faster than I thought.

Late att night

We (my significant wife and I) have just discovered that AT&T cellular does a thing of which we were previously unaware.  That's a little redundant, isn't it.  Oh, well, never mind.  Moving on.

You see, late at night, a little after midnight, AT&T will access your phone and download a summary of your phone's data activity.  I had vaguely assumed that they kept a running total, but no, apparently the phone itself keeps the record, and then AT&T just grabs it in one go at a time when most phones are not in use.

Unfortunately, if you've accidentally left a few applications open for a long time, and also coincidentally forgotten to turn on WiFi, this download can end up quite substantial.  Of the, "Hey, where'd all my data go and why am I getting overage charges" variety of substantial.

So let this be a warning-- close out your apps every once in a while.  And don't turn off WiFi and then forget to turn it back on.

Importing files to a PS3

Here's how you import a Theme into your Playstation 3 from a flash drive-- first, you download the files for the theme (archived together as a big file with a .p3t extension).  That file has to be in a folder called "Themes" stored as a subdirectory of a folder called "PS3", and if so, the PS3 will be able to see it and import it correctly.

If you want to import a picture or music file, on the other hand, it just has to be somewhere on the flash drive, and you have to figure out how to tell the PS3 how to open the directories and look around (not at all obvious).  Easy, once you figure it out, but a conceptually completely different process, which has been messing me up all kinds of ways for ages since I was expecting it to be consistent.  Grr.

Turbo Lag

A turbocharger works (traditionally) by using engine exhaust to spin up a turbine, which in turn compresses intake air, resulting in more thorough combustion and more power.  But this means that at low speeds, there isn't enough exhaust speed to power the turbo.  So when you punch the accelerator, there's a delay before the turbo spins up and the extra compression begins to kick in.  Modern turbochargers are looking to minimize this delay by making the turbines lighter and more responsive, and by using electronically controlled timing to make the process more efficient.  In the meantime, there's turbo lag, which makes Jeremy Clarkson grumpy (not that it takes much, really).

Weekend Roundup

This long weekend past afforded several opportunities to learn and try new things.  Here are two of them.  Tra la.

First, we broke and had to clean up our third (3rd) compact fluorescent light bulb, commonly abbreviated to "that goddam thing."  Three mercury spills is at least two too many, and we've had enough-- we're jumping ship.  One of the two table lamps received one of our precious stock of incandescents (cunningly stored in plain sight, a la The Purloined Letter, in a different lamp that doesn't get used much), and the other?  Ah, the other.  The other received a shiny new LED light bulb, rated at something like 800 lumens.  It cost 12 bucks, and I'm a little nervous, as reviews of other such bulbs suggest that their reliability... well, isn't.  But even if we end up having to replace it in 6 months (rather than the 20 years some have claimed), I think the piece of mind of not having to clean up mercury is probably worth it.

Secondly, on Sunday we took the dog and joined a (semi)local dog walking group for a roughly 4-5 mile hike.  Ok, not so much "hike" as "meander", but it was still nice-- especially for a couple of learning experiences.  We were on an isolated farm trail, away from roads and traffic, so we (somewhat nervously) let our slightly less than a year-old puppy Jet off of his leash for the first time in public.  Whereupon we learned the first thing-- he may not, in fact, have been named Jet because of his ebon hue.  He was likely named Jet because that's how goddam fast he was.  Holy CRAP fast.  30 mph?  Possibly more at full tilt?  (Greyhounds can go over 40, but I'm not sure he was quite that fast).  I'm pretty sure it'd take an Olympic sprinter to have a hope of keeping up with him in the full stretch.  This, amid our astonishment, also gave us a touch of concern, obviously, whereupon we learned the second thing-- when we called, he came right back.  Immediately.  This was astonishingly reassuring, and he spent most of the next hour or so off leash, running back and forth around the group, making friends and getting valuable experience interacting with other dogs.  Much love to Martha, the 9 year old lab who was willing to smack him around verbally and physically until he behaved.  (Side note-- we're beginning to suspect, based on some of his reactions, that his dam was a lab, and his father the shepherd).  He learned a lot about good behavior, and we learned that we could trust him off leash, at least in some circumstances.

Tuvaluvaleroy

So it turns out that the .tv domain (as seen on such sites as MTV.tv) is actually Tuvalu's country domain.  They're getting paid about 2 million per year for its use by television companies, which amounts to something like 5% of their GDP. (5% of the USA's GDP would be something like 750 billion dollars).  Apparently there was a rumor going around a few years ago that it would be canceled, since "the Island of Tuvalu is sinking!"  This was about as serious as you would expect.  Although, now that I look around, there really aren't a whole lot of .tv websites anymore-- MTV.tv is a mirror of MTV.com, Hollywood.tv redirects to a YouTube page, etc. etc.  It's still a viable domain name, but I guess it's not very popular right now for some reason.

The title of this post is a REALLY damn obscure reference.  I highly doubt that anyone who isn't living in my head will get it, but if you do, please let me know.  Then get out of my head.

Absences

I'll continue to be gone sporadically for the next few days; I'm moving to a new computer and there have been a few stumbling blocks.

But that's provided for several learning experiences!  For example, I learned that my previous monitor is so freaking old that the new computer won't even recognize it without 45 minutes with tech support leading to alterations to the BIOS!

OTOH, in more pleasant discoveries, I learned that the Steam online game store (to which I am relatively new) acts not only as a store, but also as a cloud server-- once I downloaded the games again to the new machine, opening them put me exactly where I had left off in the old one!  A delightful revelation, to be sure.

Someone's calling

The most interesting thing I learned today was how to retrieve a voice mail message from my work phone.

This was actually more challenging than you might think-- the instructions that I was given are in the form of a scan of a xerox of what I can only hope are the original eight year old instructions that lives on the company intranet.  Oh, and they're actually completely wrong.  Possibly they were written for a different model phone?  It's hard to tell.

Fortunately, the message in question was from myself (last night, testing the system), and it's not likely to happen often, because there's no godly reason anyone would try to contact me outside of business hours, and even during the few times I'm away from my desk during lunch or something most people would just call back a bit later.  This is not a complaint, mind you-- I didn't really want the phone, and I'm just as happy if it never rings.

PS3 DVD

...M-O-U-S-E.

Ahem.

At any rate, I have just learned that our new PS3 has a helpful feature that our old DVD player lacked.  If you stopped the old DVD player in the middle of playback, it would of course remember its position-- as long as you didn't turn the machine completely off (unplug), or more importantly, as long as you didn't remove the DVD.  The PS3, possibly because of the associated hard drive, will not only remember where you stopped while the disc is in the drive, but it will also remember where you left off if you remove the disc and put it back later!  I found this out by accident, as it happens.  I was attempting to watch a library DVD that turned out to be heavily scratched.  I took it back and the librarian was nice enough to find me a different copy from another library.  When it arrived, I stuck it in the machine, and much to my surprise, it started up right where I had left off!

I'll admit that it's occurred to me that perhaps all DVD players of the current generation have this feature.  I wouldn't know-- the one that we replaced is approximately 4000 years old (you learn to interpret the cuneiform eventually).

While I'm on the subject, I am having entirely too much fun downloading free background themes for it.  Because I just can't resist the idea of plastering Wallace and Gromit icons all over it.

Das Blinkenlights

The principle of LEDs is basically the same as that of any other diode-- current, in the form of electrons, flows from one side to the other, but not back.  OK, technically the electrons go the other way around, because they're negative, and it's really confusing but its codified in convention and there's nothing we can do about it*.  Anyway, the particular materials used in LEDs can also be charged by current with a large number of "holes."  These are not physical holes, but rather a sort of "anti-" electron**.  They're empty spaces in atoms that normally would hold electrons, but for whatever reason don't.  When the electrons meet the holes, they "fall in."  This "fall" is a lot like a physical fall, in that it releases some potential energy, in the form of a photon***.  The amount of energy released determines the energy of the photon, and therefore the wavelength, and therefore the color.  Some colors (red) are a lot easier to generate, whereas some (blue) require some fairly complicated chemicals and materials to create.  White LEDs often rely on a two-stage approach, generating blue and ultraviolet photons that also activate a phosphor coating that in turn generates yellow photons, which mix with the blue to get something whitish.


*Damn you Benjamin Franklin!


**The actual antielectron is a positron, which is completely different, being a particle with the same properties as an electron except for opposite charge.  Holes are just absences of electrons.


***I accidentally typed "phorm of a photon" here, but decided to remove it.  You're welcome.

All up and down my left side

Electronics have always been a bit of a weak spot with me.

When I was a wee blogger, I had a "Science Fair 150 in 1 Electronic Project Kit (Cat No. 28-248)."  Ok, technically I still have it, rescued from my parent's basement a few years ago.  Basically, it consists of a board with a number of installed circuit elements-- capacitors, resistors, etc., plus some outputs (a light bulb, a rudimentary LED number display, a speaker, etc).  There's an included booklet that tells you how to hook various things up to other various things in order to get various results-- flashing lights, musical tones, timers, and so on.  I eagerly followed the instructions, and got the effects, but had no real idea of what was going on-- I just followed the directions like a recipe.

So now, today, [mumblety] years later, I'm setting out to rectify the situation.  (Get it?  Rectify?  That's an electrical engineering joke!)  So here, more or less, is how a diode works.

A diode, according to the dictionary, is "an electronic device that has two electrodes or terminals and is used especially as a rectifier."  Not very helpful, actually.  Electrodes/terminals I know, those are the "ends" of a circuit element, that can be attached to other elements.  A rectifier (see, I told you it was an EE joke), as it turns out, is "a device for converting alternating current into direct current."  Ok, that makes more sense to me.  So a diode is an electronic device that has two ends and is usually used to turn AC into DC (generally not the other way around).  But how?


A diode is, somewhat simplified, a chunk made up of two types of material with a wire sticking out of each bit.  The two sections have specific electrical properties such that the boundary between them allows current to flow only in one direction (at least theoretically). The details on how that works rapidly get very technical, so I'll leave it there, at least for now.  The point is that alternating current builds up on one side of the diode, like waves crashing upon a semiconductor levee (this is getting unexpectedly poetic), and when the waves get large enough, the "water" begins to flow down the other side, away from the barrier.


This has some useful effects, besides the simple rectification property.  The threshold at which the diode allows current to start flowing (the "height of the levee," as it were) is dependent on temperature, so a diode can be used as a simple temperature sensor-- if current is flowing, it must be at least X degrees (where X depends on the type of diode).  They can also temper current surges, like tiny little surge protectors.  And finally, there's the ubiquitous LED, or Light Emitting Diode, poised to be not just Das Blinkenlight on your device, but also a replacement for your household bulbs.  This is starting to get awfully long, so I think I'll stop here, and cover LEDs more specifically tomorrow.

Firearms II

As promised/threatened, I did a little more research into gun mechanisms.  It looks like there's a bit more variation in the way that different types of guns reload themselves, so we'll stick to a basic semiautomatic pistol action.

Bullets for a typical semiautomatic pistol are loaded into a clip or magazine, which is basically just a box, open at the top, with a spring on the bottom.  (Apparently "clip" is not the technical term, and is supposed to refer to something else, but people use them fairly interchangeably, so whatever).  As a bullet is taken off the top, the spring pushes another bullet up into its place.  Basically, it's a really dangerous Pez dispenser.

When the cartridge fires, most of the force of the explosion is channeled into pushing the bullet forwards, but a little bit of it goes backwards instead.  This pushes a slide that rests along the top of the gun backwards, which does a couple of things.  First, it carries the empty cartridge backwards until it hits the back end, which usually has a little flange or something that pops the cartridge out sideways, clearing the chamber.  Second, the motion puts energy back into the spring that drives the firing pin/hammer, readying it for another shot.

Finally, as the slide moves the spent cartridge backwards, the way is cleared for the bullet at the top of the magazine to be pushed up into the chamber and into firing position, a second spring pulls the slide back into place, and the whole cycle is ready to start again.

Firearms

I know in general how a gun works.  You pull the trigger, and a bullet comes out the other end.  Right?

I even know how a cartridge works.  The bullet is at the top, and there's a charge of explosive powder below it.  The powder goes boom, and the rapidly expanding gases push the bullet out the front at very high speeds, eventually transmitting a great deal of kinetic energy to something.

But there's a bit there in the middle that I didn't quite understand.  In an olde-y time-y gun, there'd be a spark or fire or something that would light the powder, starting the explosion.  But I don't think that's how it works these days.  I've heard tell of something called a "firing pin," for instance.  To the Research-mobile!  Nananananana...

The missing piece, historically, is a little separate doohickey called the percussion cap.  This was a small container, open at one end, containing a small amount of a substance that explodes when triggered by a physical impact, rather than a flame or electrical charge (like black powder or C4, respectively).  When the trigger on a gun was pulled, a spring-loaded hammer would strike the percussion cap, causing the contents to burst into flame, which would then travel into the main propellant, causing the bullet in turn to go whoosh.

These days, the percussion cap is integrated into the cartridge, which contains not just the bullet and the propellant (as I thought) but also a separate charge of primer, which is the impact-sensitive stuff.  The hammer or firing pin strikes the primer part of the cartridge, causing an internal chain reaction, making everything go bang.

So that's that sorted.  Heck, if I still feel shooty tomorrow, I may try to figure out how other bits of a gun work.  That whole automatic reload thing is kind of mysterious, too...