jloughry

17 ms·

121.
by jloughry 11y ago
CPLD = Complex Programmable Logic Device A chip half-way between a PAL (think of a dozen or so gates in a small package, you could choose how they were hooked up; it was fast and it was small) and an FPGA (relatively huge and expensive). Bo
122.
by jloughry 11y ago
I thought exactly the same thing. I can imagine the author smiling at this. <quote>What is true?</quote> he would say.
123.
by jloughry 11y ago
Frank Rowlett, a cryptanalyst breaking Japanese codes at the Navy Annexe in Washington in the 1930s, accidentally invented computers when he haywired some conditional branch circuits into an IBM card sorter [1]. He was only trying to solve
124.
by jloughry 11y ago
The interlocking rings are an Austin Transformer [1]. It's the only way to feed electricity to the aircraft warning beacons on the tower without frying the power supply for the light bulbs. [1] https://en.wikipedia.org/
125.
by jloughry 11y ago
I wish the site had a contact address for feedback or an announcement list. It looks like a good idea; I'm looking for more information. Digging for the Kickstarter to look for more information there...
126.
by jloughry 11y ago
> 1 billion customers...135 lives That's close to the proportional death rate from air travel accidents (3.6 billion passengers/year, around 500 deaths). Facebook takes---in Fermi numbers---about as many lives as plane crashes.
127.
by jloughry 11y ago
What a great way of teaching to draw! I would not have thought of that. Thanks for the idea.
128.
by jloughry 11y ago
You get, on average, one photon back per laser shot. So you need a single-photon detector, a lock-in amplifier, a pulsed laser (50 or 60 Hz will give you a nice tone to listen for) and a reasonable size telescope. It's a really small s
129.
by jloughry 11y ago
The ballast, capacitor, and igniter in the Amazon description refers to using the LED lamp to replace a sodium vapour bulb, usually in a large, outdoor lighting fixture, like a street lamp. The LED doesn't need the same support electro
130.
by jloughry 11y ago
The "International Earth Rotation Service" is a thing that exists [1]. It's where leap seconds come from. [1] iers.org
131.
by jloughry 11y ago
Might present a security risk. Burn-in persistence on CRT screens was a serious concern in olden times. Once they entered a SCIF, monitors were not allowed to leave, at our site. I participated in experiments using flash UV to try to detect
132.
by jloughry 11y ago
It was the Citicorp building in New York City. In 1978, a year after it was built, Diane Hartley (a student at the time) discovered that aerodynamic calculations of wind loads on the skyscraper had been vastly underestimated. She contacted
133.
by jloughry 11y ago
Plague of locusts in 1848; seagulls appeared and ate the insects. It's remembered in the region as a miracle. ETA: https://en.wikipedia.org/wiki/Miracle_of_the_gulls
134.
by jloughry 11y ago
Diane Vaughn wrote about 'normalisation of deviance' in her book The Challenger Launch Decision . The original Space Shuttle SSRB design had redundant O-rings for safety, and while a small amount of O-ring erosion (from the hot g
135.
by jloughry 11y ago
Dilbert: Rocket boosters will move an asteroid into the moon's orbit so we can mine its precious metals. Dilbert's Boss: Why don't we mine for precious metals in Afghanistan? They have lots of them. Dilbert: That only happens
136.
by jloughry 11y ago
French is little-endian. English is big-endian.
137.
by jloughry 11y ago
An interesting feature of switched-mode power supplies like this is that they'll run on DC input, if that's all you have! DC passes right through the bridge rectifier into the chopper---not sure how happy the PFC circuit would be
138.
by jloughry 11y ago
It reminds me of the various usability studies of PGP where new users, tasked to exchange keys with a correspondent, in a large percentage of cases emailed the private key to the recipient. It's awfully easy to do. Exactly how Dell m
139.
by jloughry 11y ago
Argh! You're right; I got the words out of order. It should be: The girl the boy the dog bit hit cried. I tried parenthesising it; I tried Lisp syntax (you're right; it's the mix of direct and indirect objects that c
140.
by jloughry 11y ago
This is the Mel Conway of "Conway's Law" named by Fred Brooks in The Mythical Man Month . Don't skip it just because it seems to be about the F-35; it isn't. It's about complexity, concurrency (the risk thereo
141.
by jloughry 11y ago
And this sentence: The girl the boy the dog hit bit cried. measures the depth of the stack in human brains.
142.
by jloughry 11y ago
I suspect the paper was written by SCIgen.
143.
by jloughry 11y ago
I wonder how many bits each particle of dust represented?
144.
by jloughry 11y ago
"Cyber" (with due respect to Norbert Wiener) is a useful search term right now because it means exactly one thing. Interestingly, "cybersecurity" (one word) and "cyber security" (two words) yield distinct sets
145.
by jloughry 11y ago
Unlike MOOCs, which mainly expect students to use resources online to complete courses themselves, competency-based programs depend on faculty mentors to walk learners through the learning process. It’s almost the opposit
146.
by jloughry 11y ago
Thinking tactically, rather than strategically, has anyone asked the dispatchers? Rail networks are usually not partitioned (in the graph theory sense); moving equipment around for reasons of wear levelling, capacity, maintenance, replaceme
147.
by jloughry 11y ago
The return mechanism is via capillary action; surprisingly, heat pipes work in any orientation, even freefall. Very high g-forces can prevent them working, though.
148.
by jloughry 11y ago
The reason the feature exists is so the equipment can pass EMC (electromagnetic compatibility) tests such as FCC Part 15 for emissions. By spreading the radiated energy further out across the frequency domain, the peak amplitude is reduced
149.
by jloughry 11y ago
Cloud computing users don't care---modulo network latency and, to some extent, national laws regarding data privacy and seizure of servers---where their servers are physically located. When it's summer in the northern hemisphere,
150.
by jloughry 11y ago
It's a side effect of two's complement representation of integers. There ought to be a repository somewhere for neat tricks like this (with a warning never to use them in production). FOR ENTERTAINMENT PURPOSES ONLY

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