November 23, 2015 by chris on Tidbits

DVe…

Moon Halo chris.cothrun.com/2015/11/23/moo… https://t.co/DVeO6JzN1Q

November 23, 2015 by Chris on General

Moon Halo

Last night’s moon halo.

The 22° moon halo is caused by tiny ice crystals in the upper atmosphere refracting the light on its way to our eyeballs (or my camera). There’s a faint glimpse of Orion in the upper left.

November 23, 2015 by Chris on Web Bookmarks

Bookmarks for November 21st through November 23rd

These are my links for November 21st through November 23rd:

These are my links for July 20th through July 24th:

Ask HN: Best-architected open-source business applications worth studying? | Hacker News -
Monospaced Programming Fonts with Ligatures | Hacker News -
The language of choice - Propositional logic was discovered by Stoics around 300 B.C., only to be abandoned in later antiquity and rebuilt in the 19th century by George Boole’s successors. One of them, Charles Peirce, saw its significance for what we now call logic circuits, yet that discovery too was forgotten until the 1930s. In the ’50s John McCarthy invented conditional expressions, casting the logic into the form we’ll study here; then in 1986 Randal Bryant repeated one of McCarthy’s constructions with a crucial tweak that made his report “for many years the most cited paper in all of computer science, because it revolutionized the data structures used to represent Boolean functions” (Knuth).1 Let’s explore and code up some of this heritage of millennia, and bring it to bear on a suitable challenge: playing tic-tac-toe.
Then we’ll tackle a task that’s a little more practical: verifying a carry-lookahead adder circuit. Supposedly logic gets used all the time for all kinds of serious work, but for such you’ll have to consult the serious authors; what I can say myself, from working out the code to follow, is that the subject offers a fun playground plus the most primitive form of the pun between meaning and mechanism.

You’re encouraged to read with this article’s code cloned and ready

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Chris's Digital Detritus

Videotext for the twenty first century.

Day: November 23, 2015

Moon Halo https://t.co/aJ659qpqSd https://t.co/DVe…

Moon Halo

Bookmarks for November 21st through November 23rd