pi in base 72

digits are

0123456789

ABCDEFGHIJKLMNOPQRSTUVWXYZ

)!@#$%^&*( en-US keyboard shifted numerals

abcdefghijklmnopqrstuvwxyz

pi=

3.AE1C%zXUc)XaY$FDp@kLpyEbF8$N#Law1MvTjRGY@^RbEY$h3CqSfoQDGTcT)CC2)IQ

image compression of the world

world.200403.3x21600x21600.C1.png (from Blue Marble next generation)

png originally 421780395, bz2 (pbzip2 4 processors, 15 minutes) 444013308, gzip 694902705, gzip -9 694799826, ppm 1399680019.

jpeg2000 (jj2000 5.1) upper and lower halves (runs out of memory otherwise) 153678085 + 171914391 = 325592476

Human Error in Chips

Do microchip designers put things into chips that degrade the performance of the chip, but guard against human error in design?

emacs to stdout

I need a little script that opens with $EDITOR or emacs a tmpfile, quits if the editor exits unhappily, otherwise prints the file to stdout and deletes.

Stadium full of light

How much illumination would a stadium full of people, each with a small flashlight, provide? What would it look like from the field?

Lisp cons cells

Lisp cons cells are quite flexible: more than just lists, they can make backward lists and binary trees. (((nil . c) . b) . a) Can we bring back the days that Lisp is implemented in hardware? Are cons cells too flexible? Can we get by with plain old lists?

English CAPTCHA

Even English cursive calligraphy, Hancock style, should be pretty difficult to machine-read.

about arabic chinese.

shape you can't escape from

Is there a space (2D manifold? that's probably the wrong term) such that if you start at any point (or perhaps a specific point) and go straight in any direction, you eventually end up where you started (like a sphere) but facing the opposite direction?

Power Bricks

AC power adapters for laptops would be better designed with 3 replaceable components: (1) the cord from the outlet to the brick, (2) the brick itself, (3) the cord from the brick to the laptop. The last is quite damage-prone (and Apple's is especially bad), if the cord is yanked accidentally from the laptop in the wrong way. If each part could be replaced separately (and cheaply!) in case of damage, it would be better than having to replace the whole thing all at once.

GPS buses

The buses use GPS to make automated stop announcements. If it gets a stop wrong, does it mean something Very Bad happened?

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AZ_PROJ

AZ_PROJ at WM7D: Azimuthal Equidistant (Great Circle) Projection Map Server (Postscript) by NA3T and NV3Z. It's written in Postscript, i.e., it does the projection calculations in postscript.

Self-referential source and binary

It would be nice if compiled programs by default (but disableable) embedded the source code (and compiler flags) in the compiled binary.

Of questionable usefulness, but theoretically interesting, is to provide a pointer in the source code to itself.

Common Errors in English

Common Errors in English: A clever abuse of Google Alerts and possibly post-to-blog.

Globe shape

What is the shape with Y-axis distance along circumference (equivalently latitude) and X-axis distance around at that latitude? Is it an equal area projection?

Answer: simple sinusoidal with a point at the poles. (It's ellipsoidal with axis ratio 2pi if Y-axis is through the core of the earth.) The point angle is the unusual expression 2*atan(pi) or 144.686 degrees.

square root of two

(sqrt 2)^(sqrt 2) = 1.6325269194381528447734953810247196020791088570531...

Geosynchronous router

Some companies provide internet through a satellite in geosynchronous orbit. It would be very difficult for the RIAA or MPAA to knock a satellite out of such an orbit (20,000 miles away). "Anyone with a clear view of the southern sky can use the internet privately." How would one prevent tragedy of the commons? Denial of Service?

packet-lossy audio

Is it possible to encode audio such that loss in the communication channel results in a smooth degradation of audio quality?

Encoded in a non-adaptive way, UDP or UDP-like, possibly multicast.

Not streaming.

Step 1: FFT the whole thing.

Step 2: ... (Cross Interleaved Reed Solomon?)

billion numbers

numbers 0..999999999 takue 9888888890 bytes (base-10 with newlines) and 2h 20m to generate. Compress to 1068591930 bytes in 34 minutes on a SunFire V440 4-way "Sun UltraSPARC-IIIi" 1062 MHz CPU with pbzip2 0.9.4.

Checking: 1h 14m

Checksum b0d798fea8e2a52b323cb6ded58890c07660d50c (SHA-1)

XviD

Pirkinning was good for discovering that XviD is what the cool kids are using for MPEG4 generation video encoding/compression. It's open source. I suppose Ogg Theora is back in the pack.

Quicktime Windows

Apple Quicktime player for windows is one of the more evil installers I've seen. You can't get it without also getting iTunes (40 MB download), though it appears you can uninstall iTunes afterwards, but uninstaller requests a reboot. It makes network connections during install (creepy), installs some service/daemon in the system tray (that interferes with drive letter mapping of AFS, of all things), and installs stuff in the quick launch bar without asking. The installer requires IExplore to quit before it can complete install (most people have a window open, because that's where the download came from).

Also, I get the error

RUNDLL: An exception occurred while trying to run ""C:\Program Files\QuickTime\QTSystem\QTJava.dll",QTPostInstallProc"

which stalls the installation. (possibly because the Program Files path is hard coded, and I wasn't installing there.)

And I get a "Send Microsoft Error report" error when trying to view the HD 480p Brothers Grimm trailer

emacs source

C-x K

find-function-on-key

truly open source

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Stone text

What is the longest text that has been carved into stone, or other permanent material?

It's probably those crazy Scientologists with their New Mexico vault of steel tablets of L. Ron Hubbard's Scientology writings (encased in titanium).

hmake 3.10 ghc 6.4 GHCSYM config

The GHCSYM variable in hmake's lib/ix86-Linux/config gets set to something with prefixed with unquoted newlines by the configure script (should probably be GHCSYM=604).

CAPTCHAs arabic chinese

CAPTCHAs (word verification) would be far more difficult for non-humans with all the flexibility in Chinese calligraphy or Arabic calligraphy. We should all learn Chinese and Arabic.

On that note, if would be nice if mailing lists that allow posting only by subscribers allow posting by non-subscribers solving a CAPTCHA (mostly help mailing lists for software). Or else, bring back Usenet.

cpp ghc 6.4 gcc 4.0.2

ghc -cpp doesn't work with backslash whitespace backslash literal strings with newlines in them.

PK coredump

Core dumps should encrypt with public key cryptography.

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Driving off a cliff

Traveling, straight downwards, powered by gravity, an object will go 0 to 60 mph 2.735 seconds. 1g acceleration, or deceleration, takes 120.345 feet. (Digits 0..5, permuted.)

Penrose go

Playing the game of Go 囲碁 on a random Penrose tiling can guarantee that neither player has seen a particular board before playing on it. The dual of a Penrose tiling has each node connected to four neighbors as in regular Go.

What kind of data structure would be good for storing and manipulating Penrose tiles?

Thinkpad R50e disappointments

This is model 1842t4u purchased during late summer 2005 clearance.

Had to pay $28 sales tax. (To where? China?)

No built-in microphone.

No disk drive "Active Protection System".

Battery life is short: 3.5 hrs max.

Windows XP Home does not do EFS (Encrypting File System); only XP Professional does.

Nipple mouse occasionally biased a certain direction

Wireless periodically cuts out for a second

System cannot be made to go automatically to standby after N minutes.

Nipple mouse leaves a greasy spot on display

Encrypted browser cache

Store every web page I've ever seen, in an easily exportable format, encrypted, with public key cryptography. PK prevents the need of having to input a password every time I start up the browser.

Option: do not store (without asking) files larger than a certain cutoff size.

go

from go.

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Encrypt Swap

Virtual memory ought to always be encrypted.

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ICQ 2^31-1

An unusual ICQ number: 2147483647's Unified Messaging Center which is currently hit #2 for that number on google.

factorint nextprime 512

2^512 + 75 - 1 = 48464351211032890093 * n

2^512 - 569 - 1 is harder.

2^384 - 317 -1 = 2633349255961 * 242009720353150597 * n

What is the prime p nearest to 2^1024 such that p-1 is factored?

Leaning Toothpicks alphabet

Balanced Ternary written with slash, pipe, and backslash as digits. Here is 2³¹-1=2147483647:

\/|//|/|||//\\\/\/\|\

Pirkinning BitTorrent tracker

This is exactly the kind of content BT is good for. Azureus : Java BitTorrent Client Tracker: 2.3.0.4/1.5.1