Pipe Logic (2011) | Hacker News Reader

Pipe Logic (2011)

linusakesson.net

178 pointsTomte18 comments

This sort of post is why I love HN. At first while reading it I thought, "is this guy for real?", and then proceeded to be amazed at what he wrought with a very simple but elegant idea. A+

I've fallen in to a hole on his website. Not sure if I'll ever emerge

Numerous other articles by him have appeared on HN, some multiple times (such as the TTY one.) He's amazingly talented.

One of the things I like about his site is he has a section titled "Obfuscated Programming", and another "Sane Programming".

Check out this other mind blowing hack from him.

He sent 256 byte C64 demo to Oldskool 4K Intro compo and he won. https://linusakesson.net/scene/a-mind-is-born/

My first boss, at Spectra-Physics, was a brilliant guy named Joe Hawkins, who had temporarily taken the job as manufacturing engineering manager, having been forced out of a startup he helped found by some other asshole founders. He posed the question, “In heat transfer, what is the equivalent of inductance?,” and claimed to know the answer, Fermat margin-of-the-page style. Maybe you can take a crack at that.

> “In heat transfer, what is the equivalent of inductance?,”

It's the aptly named thermal inductance (change in objects temperature induce a change in convection current surrounding the object). Heat -> kinetic energy transfer. (unit is thermal henry). You can even create thermal mutual inductance by putting two wires next to each other in a fluid.

Electrical-analog method is well known for heat transfer analysis. Heat transfer equations are identical to electric recruits with passive components. Thermal inductance is almost never needed, so it may be little unknown. Back in the old times some even constructed electronic devices to solve transient flow problems using analogous resisistance-capacitance electrical networks. https://nvlpubs.nist.gov/nistpubs/jres/61/jresv61n2p105_A1b....

Here's another creation of this guy - check out this synth based on SID chips: https://www.youtube.com/watch?v=vpa7AQsx7Xw

And if you want to make chiptunes on the go, check out the Pocket Operator synthesizers that he designed [0]. They're a ton of fun, and people on the bus will ask you why you have headphones plugged into your calculator.

[0] http://www.linusakesson.net/music/po-2x/index.php

One of the unusual things about this is that he built a layer of abstraction, but it resembles a lower level of abstraction. It's like he's abstracting in the opposite direction that you normally abstract.

Somewhat related hack by the same author, a "virtual machine" implemented entirely as symlinks: http://www.linusakesson.net/programming/symlinks/index.php

From the title I thought it would be this stuff: http://www.hydraulicspneumatics.com/200/TechZone/PneumaticVa...

> In this model, a UNIX pipe acts like a wire, that is, a conductor with parasitic capacitance.

can someone please explain why / how the 'parasitic capacitance' comes into play here ? thanks !

from my very faint memories of ee courses, iirc, 'parasitic capacitance' happens due to proximity of two parts of circuit e.g. one signal-line and another, signal-line -> earth etc. unwanted coupling causes unwanted effects (duh !) f.e. interference, attenuation, distortion etc.

how does this behavior gets observed here ?

I think the analogy to parasitic capacitance is meant to refer to the fact that the pipe is a buffer: if you connect it to a source of zeros or NULLs its value doesn't immediately change until it is full.

> ... its value doesn't doesn't immediately change until it is full.

ah ! that's vanilla impedance (i.e. Z) in play then, nothing parasitic about it afaik :)

Cool stuff. Are there any cryptocurrencies that take advantage of this property? Seems like a good area for exploration, implementing cryptographically verifiable logic gates over p2p transports.

You might be interested in this: https://en.wikipedia.org/wiki/Verifiable_computing

This is very cool! I like seeing projects like this on here, that don't necessarily have a practical use but are a way to learn more about how a system works.

Oh my god I love this. Magnificent. <3

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