jloughry

That exists: look for 'trusted path'. It was a feature of compartmented mode workstation (CMW) operating systems like Trusted Solaris and lives on in the requirement to use Ctrl-Alt-Del to call up the Windows login prompt. In Trusted Solaris (TSOL) it was a dedicated area of the screen—along the bottom—where no user mode process was allowed to write; the OS displayed a special symbol there (sort of like the padlock in a web browser) when the user was interacting directly with the OS. Some CMW systems even implemented that functionality in hardware, electronically compositing windows from different physical frame buffers to the video display. Ctrl-Alt-Del is actually in hardware, too (or it used to be); the keyboard interface on the first IBM PC detected that specific key combination and toggled the reset line on the CPU (or maybe it was an interrupt; I forget). Every subsequent PC-compatible machine, to this day, has the same functionality built in to the hardware, on the A20 reset line. It's mostly vestigial today.

Also, you don't want to breathe it; xenon is an anesthetic gas and will put you to sleep.

This is one global-scale geoengineering project I can rally get behind. It has the smallest chance of catastrophic second-order effects of any of the several methods I've heard of.

Mother's maiden name is documented to have been in use for authentication at least as far back as 1882, and even then it was known to be a weakness [1, §3].

[1] Stephen M. Bellovin. 'Frank Miller: Inventor of the One-Time Pad'. Cryptologia 35(3), pp. 203–222, 2011. DOI: 10.1080/01611194.2011.583711

It could be a 12V AC adapter. Not too common, but they do exist. Four of the myriad diodes would be connected in a bridge rectifier to convert the AC to DC. (I don't see any smoothing capacitors though....)

Depending on how creative you wanted to get, a clock might be designed to run directly on a pulsating rectified DC supply. That would give you a sort of baseband embedded clock signal at 120 Hz. Or use two half-wave rectifiers and design the whole clock based on trinary logic, +12V/0/-12V.

Realistically, since the mains connection is hidden behind the frame, it would be easy to tap off internally a connection to the 12V AC signal from the secondary of the transformer, before it gets rectified and filtered to DC.

Build one near the Equator.

Yes:

Interestingly, the audio chipsets in modern motherboards and sound cards include an option to change the function of an audio port at the software level, a type of audio port programming sometimes referred to as ’jack retasking’. This option is available on most audio chipsets (e.g., Realtek’s audio chipsets) integrated into PC motherboards today. Jack retasking, although documented in the technical specifications, is not well-known [34]. For an in-depth technical discussion on malicious retasking of an audio jack, from the hardware to the operating system level, we refer the interested reader to the following previous work [29].

References:

Mordechai Guri and Yosef Solwicz and Andrey Daidakulov and Yuval Elovici. 'MOSQUITO: Covert Ultrasonic Transmissions between Two Air-Gapped Computers using Speaker-to-Speaker Communication'. arXiv preprint 1803.03422v1 [cs.CR], 9th March 2018.

Mordechai Guri and Yosef Solewicz and Andrey Daidakulov and Yuval Elovici. 'Speake(a)r: Turn speakers to microphones for fun and profit'. 11th USENIX Workshop on Offensive Technologies (WOOT 17). USENIX Association, 2017.

Lightsail. You carry a laser and a lightsail. You shoot the laser at the black hole and the laser light gravitationally slingshots around the black hole, returning to you with more energy than you gave the laser. The returning laser light pushes your lightsail. The black hole needs to be moving for this to work, although it doesn't really matter what direction the black hole is moving.

https://en.wikipedia.org/wiki/STS-36

It was an experiment to test radiation effects; the In-flight Radiation Dose Distribution (IDRD) experiment:

This joint NASA/DoD experiment was designed to examine the penetration of radiation into the human cranium during spaceflight. The female skull was seated in a plastic matrix, representative of tissue, and sliced into ten layers. Hundreds of thermo-luminescent dosimeters were mounted in the skull's layers to record radiation levels at multiple depths. This experiment, which also flew on STS-28 and STS-31, was located in the shuttle's mid-deck lockers on all three flights, recording radiation levels at different orbital inclinations.

Here's the most recent article I've seen:

https://www.designworldonline.com/energy-efficient-lighting-...

Near the end of the article is a diagram of the new SDL (Dr. Shuji Nakamura's new company) laser diode, phosphor, and beam dump in an SMD package.

From The Martian by Andy Weir:

"They say once you grow crops somewhere, you have officially 'colonized' it. So technically, I colonized Mars."

The laser doesn't illuminate the road directly; it excites a phosphor puck that lights up white and is then focused and aimed like a regular incandescent filament or gas discharge arc. Just like white LEDs, only much more efficient.

TIL tetrode has a special meaning in biology: a four-conductor microelectrode for probing neurons that gives essentially a direction reading along with amplitudes from each of the four electrode components.

This seems to be relevant:

https://fas.org/man/dod-101/sys/ship/docs/DDG51_04-97.htm

That hardware capability is exploited in the following paper, if you want to know the details:

Mordechai Guri et al. (2016) 'SPEAKE(a)R: Turn Speakers to Microphones for Fun and Profit'.

http://cyber.bgu.ac.il/advanced-cyber/system/files/SPEAKE(a)...

By Mordechai Guri, Yosef Solewicz, Andrey Daidakulov, and Yuval Elovici.

You're right. Those people weren't working on a software project; they were in a fight for their lives—literally—with an enemy they just barely won against. It's not the same thing at all. But it is worth watching for the depiction of how hard humans can work, together, for a common objective when the ONLY thing that matters is getting through. I can't think of a single major character not damaged, broken, or killed by the end of the movie. I guess it resonated because that's the only kind of environment I've ever worked in. Yay, Lockheed.

Twelve O'Clock High is a masterclass on running a software project. The higher-ups can see that something is wrong with the team; it's not performing as well as it ought to. The outsider comes in, figures out what the problems are, and fixes them. Not an easy fix, not a quick one, and it takes an awful toll on several people. But the team ends up working well again.

I show this movie to everyone I can. It's full of lessons.

George O. Smith's Venus Equilateral stories from 1942–1945 are wonderful—if you like the idea of vacuum tube technology taken to extreme lengths.

Lots of fun in those stories for engineers and hackers: spaceships that can accelerate at six gees but the passengers can't, capacitors charged up in the gigajoule range, walk-in electron guns (why bother with vacuum pumps when you're in space and can just build devices in the "open air"?), stock market manipulation by means of speed-of-light delay, and SLAs.

This company sells new S-100 boards!

http://www.s100computers.com/Cards%20For%20Sale.htm

They have a Z-80 board. Lots of information about it here:

http://www.s100computers.com/My%20System%20Pages/Z80%20Board...

They also sell S-100 backplanes, serial boards, display boards, memory boards, and so on.

They have a Z80 single board computer too:

http://www.s100computers.com/My%20System%20Pages/Z80%20Board...

I have no connection to the company; I just think it's neat.

From chaper 3 of Marketing That Works: How Entrepreneurial Marketing Can Add Sustainable Value to Any Sized Company by Lodish et al. (Upper Saddle River, New Jersey: Pearson Education, 2007)

Many colleges and some upper socioeconomic high schools also bought the MINIVAC as an educational aid. However, no one in the third segment, the corporate sector, bought the product. The entrepreneur interviewed some target customers to try to find the problem. He found out very quickly. The typical description of the MINIVAC by the corporate types was: "Oh, that—it's just a toy!"

The entrepreneur was creative and he listened carefully. He also understood marketing. His next product was the same basic kit—with the switches upgraded to higher tolerances and the machine color changed from blue and red to gunmetal gray. The name was changed to the MINIVAC 6010 and he increased the price from $79.95 to $479. The MINIVAC 6010 sold very well to the corporate segment at $479.

The paper is open-access at ACM:

https://dl.acm.org/citation.cfm?id=3192369

That's really appreciated; thanks.

Computer science. I worked for Lockheed for fifteen years---long enough to see some programming projects succeed and others fail. I wondered why the difference. I had access to all the project records, and Lockheed was cool with it, so I took copies of all the data and found an advisor willing to let me work on it.

The problem was deep and it ended up taking a lot longer than I expected to solve it, but that's the way of research. I did eventually discover some new things in the data, and got the PhD, and my thesis formed the basis of my new company.

You're right; I didn't get enough sleep. I got into the habit of working 13 to 15 hours a day. But I wasn't making progress on my thesis fast enough for the university's requirements, so I had to choose. I was still working 13--15 hours a day, seven days a week, but exclusively on my thesis. I finished in eight years. Without Lockheed, I would have been done in four.

Ironically, my day job for Lockheed was being the PI (Principal Investigator) for an Air Force research project that was essentially a whole other PhD thesis. [We took the Google Web 1T 5-Gram Corpus and inverted it; essentially we were doing adversarial ML (generators and discriminators) before that term had been invented.] That's why it took me eight years---because I was doing the work of two different full-time PhDs at the same time.

(Only one got me a neat robe to wear at the end, though.)

I was doing a full-time PhD and working. One day my advisor asked, `Are you working for me or Lockheed?'

I chose the PhD.

See https://en.wikipedia.org/wiki/1-Wire

"One distinctive feature of the bus is the possibility of using only two wires: data and ground. To accomplish this, 1-Wire devices include an 800 pF capacitor to store charge and power the device during periods when the data line is active."

You can buy devices that put an entire JVM inside a two-terminal component, of similar physical size.

Look at old battleship rangefinders. Some of them had 8 or 9 metre baselines.

See https://en.wikipedia.org/wiki/Coincidence_rangefinder#Stereo...

Found it: it was called an ectascope and there are diagrams here:

https://www.minnpost.com/stroll/2015/09/seven-stories-down-u...

Not a very good photo of what it looked like:

http://blogimg.goo.ne.jp/user_image/6e/29/0553c64f5a894a9391...

I recall reading something about periscope windows years ago in a book about the University of Minnesota's centre for underground buildings. It was said that looking through the periscope window from underground resembled watching a live diorama in an aquarium. I imagined something like a tilt-shift movie. Ever since reading that description, I have always wanted to see a real periscope window.

* e.g. scaling symbols based on their context and nesting level, just like we do in math equations*

That's a great idea. I can see it working in other languages as well, e.g., what Guy Steele and others were trying to do in Fortress.

Sure. Any incidental effect related to the actual physics used to encode information potentially could leak information. Fluid has mass, and accelerations require forces, so acoustic, acceleration, and thermal side channels are all a possibility.

Casio calculator watch—the black plastic kind—went all the way through a black Lab named Brando. Came out the other end of the dog minus half of its wristband, with teeth marks in the keyboard and a cracked display but it still worked. Cleaned it thoroughly, replaced the band and wore that watch for many more years.