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Psychotropic Walls

bushwells — Wed, 19 Sep 2007 07:20:21 +0000

Psychotropic Walls

Via Technovelgy - Where Science Meets Fiction, here's an article on a wild display surface upon which small panels move with precision and "ripple," creating strange, almost biologically protoplasmic motion:

HypoSurface Walls Are Full of Life.

Bill Christensen, the author of the Technovelgy article on HypoSurface notes that this technology is a close approximation of science fiction writer J.G. Ballard's warped domiciles:

HypoSurface is a pretty good implementation of the plastex walls in J.G. Ballard's psychotropic houses from his 1960's Vermillion Sands stories:

It was a beautiful room all right, with opaque plastex walls and white fluo-glass ceiling, but something terrible had happened there. As it responded to me, the ceiling lifting slightly and the walls growing less opaque, reflecting my perspective-seeking eye, I noticed that curious mottled knots were forming, indicating where the room had been strained and healed faultily. Deep hidden rifts began to distort the sphere, ballooning out one of the alcoves like a bubble of overextended gum.

Here's a clip:

More examples may be found on the HypoSurface web site. This company is based in Cambridge MA. Perhaps its location explained why the surface of Spring Street was so pocked and wavy.

bushwells Wed, 09/19/2007 - 03:20

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Doc Bushwell

More Art, Then Science

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The Chimp Refuge Comes OUT.

bushwells — Sat, 01 Sep 2007 14:50:48 +0000

The Chimp Refuge Comes OUT.

A new addition can be found in the sidebar. Yes, the Chimp Refuge has joined the OUT Campaign bandwagon. Click on the Scarlet Letter of Atheism, and you will be taken to the site for the campaign which includes a link to Richard Dawkins' introduction to the initiative.

Since it's a Saturday, and I'm in a frivolous frame of mind, I'll post some atheist-friendly graphics below the fold. They may be already known to many but there's nothing as comforting as friendly familiar faces. Pull up a chair, have a cup of coffee (the Official Beverage of the Devil and Atheists) and have a look.

(Hat tip to to Rhapsody who sent the following flowcharts to me; these were found on a Dutch blog, but the creator of the flowcharts wasn't noted in said blog. Rhapsody & I would appreciate that info if available.. Note added in proof: thanks to mg - see Comments - for directing us to the source, the excellent Wellington Grey site, and specifically here.

And from the OBJECTIVE: Ministries, the place where I get religion, praise the lard!

bushwells Sat, 09/01/2007 - 10:50

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Doc Bushwell

Sounds Cool

... have a cup of coffee (the Official Beverage of the Devil and Atheists) ...

Er, it's almost midnight here in France. I'm finishing off the ast of tonight's vin. Is that Ok? Or am I forever banned for not wanting to make some cafÃ© at the moment?

Check out the one on the Objective Ministries kids' page about the 'Creation Scientist'.

I cringed at the thought that innocent kids are being fed this bullshit.

http://www.wellingtongrey.net/

Flowcharts and other stuff listed under miscellanea. Good stuff.

blf, within minutes, I will be indulging in a glass of red wine so yes, vin will do in a pinch for any red-blooded (and lettered) atheist.

Shalini - Psssssst...OBJECTIVE: Ministries is a parody site, and a rather fine one at that. My teenaged atheist daughter is clamoring for some Ruby lingerie. ;^)

Sorry, navigate to miscellanea then archives located at the bottom.

Screw it, here's the link: http://www.wellingtongrey.net/miscellanea/archive/index.html

Doc, secure your godless spawn's virtue (if it isn't already too late) with Landover Baptist Abstinence Thongs:

http://www.cafepress.com/landoverbaptist/429363

Shalini, don't be too worried about Objective Ministries. It's just a really REALLY well done satire. (And don't feel too bad about having been fooled. It took me a while to figure it out, too!)

I'm glad to see lots of people getting involved in this campaign. It could bring on some big changes!

http://baptistsforbrown2008.wordpress.com/

Parody or sincerity? You decide.

U.S.E. Prison looks a little hinky to me, though.

fuzz - Landovers' panties are cheeky, but how can one beat "Will you be my husband?" The USE Prison with its footnote of SIBS is suspicious and makes my Reverent Antennae of Piety go up.

Well, I didn't click anything else apart from the Kids' Page, so there you have it. =)

Doc I a so glad you get yor religion from the one TRUE site Objective ministeries. Their work on the heresy of Triclavianism is particularly illuminating when you finally get the point (or should I say points). And I hope everyone here clicked on the baby jesis page http://objectiveministries.org/babyj/ It is so moving.

There's a good chance I'll never stop laughing about this

Praise be to his Cooing Grace!

Rev. Chimp - The Pterosaur Project forms an unholy hybrid of an image with the truly fine SciFi Original, Pterodactyl. The movie featured plenty of gore, so I can only imagine the bloody hijinks that might ensue as the good folks of OBJECTIVE work to establish a pterodactyl rookery.

It was precisely the rookery that caused me to coat my monitor with an nice film of black coffee this morning.

Audio Obsession

jfiore — Thu, 23 Aug 2007 09:20:49 +0000

Audio Obsession

Regular readers of the refuge know that I've got a "thing" for audio and music, and that I've had some harsh comments regarding the poor quality audio that so many people tolerate these days in the name of convenience. But what of the other extreme? Who are the audiophile extremists? To what lengths will they go in their search for audio nirvana? Is 230,000 Euros enough, and what do they spend it on? Check out this short film of the Audiophile Club of Athens:

Film about Audiophile Club of Athens
Uploaded by skaloumbakas

Up front, I've got no problem with someone spending six figures on their audio gear. Really. There are far worse ways to spend your money. Like being a Bush Pioneer, for example. And I can understand the desire to experience music on a very deep level. (It is interesting to note that many of the club members are filmed listening with their eyes closed. Many years ago I discovered the effectiveness of sensory deprivation and prefer critical listening in a completely darkened room.)

But any thinking observer of this film has to ask the question, "What do you get when you pay in excess of $300,000 for a home music system?" I'll let you ponder this for a bit before I get back to it a little later. In the meantime, check out part one of Loudspeakers: Effects of amplifiers and cables, courtesy of Audio Design Line.

jfiore Thu, 08/23/2007 - 05:20

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Audio Island

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What The Heck Is That Thing?

I've had some harsh comments regarding the poor quality audio that so many people tolerate these days in the name of convenience.

Well, OK. I've had some harsh comments on the people who figure it's any of their bloody business to critique my (or anyone's) preferred audio habits.

I have a system that the high-end freaks ... sorry, audiophiles would spit on. Replacement cost would be something like $2.5K, I'd guess. On the other hand, I neither have nor want an iPod, nor do I listen to music on my computer. And I think "home theatre" is a swindle. Oh, and I still listen to LP's. But I don't feel any need to thrash at those with different preferences.

But on the "high-end" stuff to which you refer, colour me skeptical going on cynical. While not posing as any sort of expert in any sense, I have the feeling that there are a lot of "audio charlatans" out there pushing gear, add-ons, and accessories which are a rip-off. But if someone wants to spend their money on that stuff, they should go for it!

Scott, I don't criticize people's taste in gear, people buy what suits them and can afford. My criticisms have been based on the very poor quality of audio reproduction of the equipment, something that we can quantify with accuracy (whether or not someone actually likes 10% THD or a 5 kHz bandwidth is another question), particularly considering the technology available these days at modest cost.

I very much agree with your second paragraph and I think you'll enjoy my next installment on the subject.

If you've got a six-figure sum to spend on hi-fi, good luck to you. People with lots of money will always look for ways to spend it - that's what it's for, after all. I very much doubt that anybody thinks that, say, a diamond-and-platinum-encrusted Cartier pen (if such a thing exists) writes much better than a biro, but people will buy 'em.

What you get for spending $300,000 on an audio system is the warm glow of the knowledge that you've spent $300,000 on an audio system.

The truly rich are not like us.

The "Inherent Linearity" of Class A Amplifiers?

jfiore — Tue, 02 Jan 2007 09:41:53 +0000

The "Inherent Linearity" of Class A Amplifiers?

I'm what they used to call an audiophile. What with folks listening to music on cell phones, low bit-rate MP3's and the like, it's kind of out of fashion these days. That is, unless you're into music production. In that case, you can buy all manner of interesting goodies, including microphone preamps that will set you back a kilobuck and loudspeaker cables that could pay a semester's tuition. Unfortunately, just as it was true for hi-fi enthusiasts 30 years ago, there's a lot of misinformation floating around in the semi-pro or "prosumer" music field regarding audio circuitry.

I was reading the January issue of EQ Magazine the other day and came across an article entitled "A Touch of Class" by Vincent Miraglia and Rich Tozzoli (full disclosure: many years ago I wrote several articles for EQ's executive editor, Craig Anderton, when he was piloting Electronic Musician Magazine, although I never wrote one regarding the topic following). The article is an explanation of different types of amplifier classes (most notably class A and class B) and how this affects sound quality. I think it's great that the authors are trying to impart some technical knowledge to an audience who generally do not have engineering or technical backgrounds, thus enabling them to get more out of their equipment or make more intelligent purchases. Unfortunately, the authors are guilty of spreading misinformation. Consider this outtake:

What makes a Class A amp great, you may ask?
The sound quality is pure
The design is inherently linear, because the output varies in direct proportion to the input
It introduces no crossover or zero-crossing distortion

Are you getting the idea that class A amps are the cat's posterior? The authors go on to say that the downside includes inefficiency, heat, and relatively low output power. Class B amplifiers, while they are more efficient and offer higher output power, suffer from the afore-mentioned crossover distortion.

So, what's my problem? Well, there's absolutely nothing about class A topology that implies inherent linearity or "pure" sound quality. Class A operation simply means that the amplifying device is active for 360 degrees of the output waveform, whereas class B means that an amplifying device is active for only 180 degrees (and thus, a need for two devices to fill out the entire waveform cycle). Miraglia and Tozzoli state as much, and even go so far as to say that many different amplifying may be used, such as tubes, JFETs and MOSFETs, but don't seem to grasp the concept that these devices are themselves non-linear. (Oddly, they do not mention BJTs, the very common bipolar junction transistor, although they do mention ICs which I find very odd as ICs are themselves normally made of BJTs and FETs.)

Basically, a class A amplifier idles its output devices at one-half of maximum current. As the input voltage swings back and forth, it causes the output current to increase and decrease around this idle point. Precisely how this happens is dictated by the voltage-current characteristic of the device, technically known as its transconductance curve. If the curve is a straight line, then by definition, we have a linear input-output characteristic and supposedly, "pure" sound quality. Note that linearity is a function of the amplifying device, not of the circuit topology being class A. Unfortunately, no amplifying devices in use are perfectly linear. For example, bipolar transistors have a logarithmic characteristic while FETs have a parabolic (square law) characteristic. Obviously, if the voltage-current characteristic is non-linear, then the output signal will not follow the input perfectly, thus indicating distortion (it should also be noted that the output will vary in direct proportion to the input, that is, a larger input will produce a larger output, but it will not do so perfectly, thus their second statement is a non-starter).

OK, so you're thinking "How bad can this distortion be? Is it all just academic and class B's are worse anyway?" Nope. A class A amplifier can produce prodigious distortion. In fact, one of the things I do in my linear electronics lab is to show my students how to take a class A amplifier with heavy distortion and, through minor circuit modifications, reduce the distortion by an order of magnitude. The authors are absolutely correct when they say that class A amps don't suffer from crossover distortion while class B amps do, but this doesn't necessarily mean that class B amps have higher overall distortion inherently. (Crossover distortion, which can be mitigated through proper design, is the result of the two halves of the waveform being "stitched together" by two amplifying devices. Basically, one takes the positive polarity and the other handles the negative. They both idle at zero, thus promoting high efficiency. When conduction is handed off from one device to another, there will be a small glitch, and that's crossover distortion.)

Remember, class B amps use the same sort of devices as do class A, and they'll suffer from the same non-linearities, but there's an interesting twist. As a class A amplifier swings above and below its idle point, the curvature of the transconductance characteristic tends to elongate one half of the waveform while squishing the other half. In contrast, Class B's tend to elongate both halves. This means that practical class A amplifiers produce waveforms without halfwave symmetry while the class B's maintain halfwave symmetry. If a waveform does not have halfwave symmetry, then the distortion products must include even as well as odd harmonics (with symmetry, there will only be odd harmonic distortion).

Ultimately, it all comes down to the details of the individual designs. It is entirely possible for a class A amplifier to produce far more distortion than a class B amplifier. And to keep matters more interesting, if an amplifier is being used by a guitarist to produce a certain sound quality, rather than as part of a "sonically transparent" mixdown system, distortion might be a desired commodity.

jfiore Tue, 01/02/2007 - 04:41

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Audio Island

Sounds Cool

Dude....you have WAY too much time on your hands....

When Augmenting Photons and Longitudinal Pressure Waves Meet with Impeachment Demands

jfiore — Thu, 24 Aug 2006 15:18:51 +0000

When Augmenting Photons and Longitudinal Pressure Waves Meet with Impeachment Demands

My wife and I went to a Crosby, Stills, Nash & Young concert the other evening at the Saratoga Performing Arts Center. It was a great show in spite of a little rain. You can read a local review of it here. What does this have to do with photons and pressure waves? I'll get to that in a minute.

First, a little about the show. This concert was part of their 2006 "Freedom of Speech" tour. They did two sets, each around 90 minutes long. We had lawn seats (if you're not familiar with SPAC, the facility is on a hillside with a portion of the seating on a grassy slope). The first half was dominated by material from Neil Young's new "Living with War" CD while the second set featured some of their quieter material, but eventually got quite raucous with tunes like "Ohio" and Young's new "Let's Impeach the President", complete with sing-along lyrics presented on the big view screens. It was one of our favorites. The concert had a clear protest/anti-administration vibe to it, but that shouldn't come as any surprise to long time CSNY fans (although it did, apparently, if you check out the comment posted at 11:08 am on August 20 which follows the review link above- the responses to it are even better). It wasn't 1969, but the crowd certainly had its share of grey hairs, and I'd guess that a fair number of them even remember (parts of) 1969 (I was eleven at that time). Some songs, like Deja vu, had a sense of, well, deja vu about them. Unfortunately, "We have all been here before" wasn't referring to a concert, but more a time of war and anger over it.

From our (lack of) vantage point, it was sometimes difficult to see the stage. This was not helped by those in front of us using large umbrellas or tallish chairs (we came prepared with our usual inches-off-the-ground beach chairs along with ponchos to shed the rain). Fortunately, we had clear sight of one of the large view screens, and while you're not looking directly at the stage, the result is certainly more appealing than peering through wet binoculars.

My wife made an interesting comment after the show, namely that it seemed that the musicians (Neil Young in particular) seemed to be "out of sync" with the music. That is, the body movements seemed ill-timed. While in younger days I might attribute this to an ingestion of "trendy chemical amusement aid", as Frank Zappa might say, on the part of audience members, musicians, or both, I knew there was more to it than this. What my wife had noticed was a multiple propagation delay effect.

As a drummer, I have developed a tendency to note whether or not things are out of sync, sonically speaking, by relatively small amounts. As an engineer, I have studied the subjects of audio and acoustics, and I remember being fascinated when first introduced to the subject of psycho-acoustics and items such as the Haas Effect. Yes, I was one of those kids who used to count the seconds between lightening flashes and thunder crashes. Anyway, back to the concert. For all practical purposes on a human scale, the speed of light is fast enough to be considered instantaneous. At approximately 3x10 to the 8th meters per second, the images of the band on the view screen (the photons that augmented those directly from the stage) were reaching us in under a microsecond. There's no way normal human vision would notice any timing discrepancy between the stage and screen. Unfortunately, sound pressure waves in air propagate much more slowly, at about 340 meters per second. Consequently, the sound was arriving at our location perhaps 100 to 150 milliseconds after the corresponding visuals. That's enough to notice if you know what to look and listen for, and of course, if you're not inebriated. I have a tendency to watch a drummers' hands as they play, and given the rapid wrist flicking and stick movement, along with my own sense of playing the instrument, a strange sense of disconnect comes over me when the audio and video are not in sync. Sometimes it can be so bad that I simply cannot watch further. I don't seem to have as much difficulty with guitar players, particularly while they flail through a solo, perhaps because most rock players tend to toss in a wholesale crate of tortuous body bending and associated facial contortions while they tweedle the top frets. Rather distracting actually. Consequently, I found it interesting that my wife noticed the variance with the guitar playing, but then, she's not a drummer, and well, Neil was on camera a whole lot.

In any case, propagation delays or not, like Mr. Young, I think the president should be impeached.

jfiore Thu, 08/24/2006 - 11:18

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Sounds Cool

Interesting - there is an encoding plus de-encoding plus transmission to the screens. I have sometimes seen the video out of sync with reality when I could see both. 150 ms seems like a long time though, enough for that stuff.

Ni Hao! Kannichi Wa!Sounds more like combined symptoms of pre-senility at the signal and receiver.Particularly buttressed by your closing statement.MOTYR

Yes, I agree that support of a Bush impeachment is a sign of PRE-senility, because support for Bush himself is a sign of senility (or just plain stupidity).