Sunday, February 18, 2018

[oebfsidv] Taxicab numbers

There are many ways to generalize the Hardy-Ramanujan number 1729:

The {a}th number which can be written in at least {b} different ways as the sum of {c} numbers all of the form {d}^{e}.

The {d}s could be restricted to positive and/or relatively prime.  The form {d}^{e} could be relaxed to any form, e.g., triangular numbers (Gauss's Eureka theorem).

The most famous generalization is the sequence that is a function of b, restricting a=1 c=2 e=3 and d=non-negative.

I like the sequence that is a function of a, b=2 c=2 e=3 and d=unrestricted.  This is A051347.  Allowing negative numbers seems appropriate for the cubing operation as the range of cubing extends to negative numbers (unlike for squaring).  If cubing can do it, let it.

Waring's problem is about b=1, and its most narrow form restricts to nonnegative d.   But how many signed cubes (what value of c) does it take to express any sufficiently large number?  Probably 4 (same as with positive-only, though the "sufficiently large" threshold might be different).  Coincidentally, this is the same number of squares needed, by Lagrange's Four-Square Theorem.

Incidentally, it is not too difficult to notice that 1729 can be expressed as the sum of positive cubes in 2 different ways.  If one happens to have cubes memorized up to 12^3=1728, then one has probably also noticed that 9^3=729 differs from 12^3 by almost exactly 1000, and 1000 is also a cube.  From this, it is easy to realize 12^3+1^3 = 9^3+10^3.

[pkobcsan] Polyhedron facts

Cube: 6 faces, 8 vertices, 12 edges, 24 face-vertex tuples, 24 face-edge tuples, 24 edge-vertex tuples.  98 items total, maybe good for a deck of cards for a game.

Same for octahedron.

Tetrahedron: 4 4 6, 12 12 12 = 50 items.

Dodecahedron / icosahedron: 12 20 30 60 60 60 = 242 items.

Vaguely an extension of half-edge data structures for computer graphics.

For a general polyhedron, the cards could include additional information in the style of Pokemon cards.  Faces, edges, vertices get names.  Face: fraction of total surface area, number of sides, number of holes, fraction of the interior volume closer to this face than to any other face.  Edge: length (in what units?), dihedral angle, adjacent faces, adjacent vertices, fraction of close interior volume.  Vertex: degree, spherical angle of interior, fraction of close interior volume.  Face-Edge: which vertex is to the left and which is to the right when standing on the edge facing into the face, fraction of the area of the face closer to this edge than any other edge, fraction of the perimeter of the face.  Face-Vertex: angle, which edges are to the left and to the right when standing on the vertex facing into the face, fraction of the area of the face closer to this vertex than any other vertex.  Edge-Vertex: which face is to the left and to the right when traveling along that edge to the vertex.

Edge length could be scaled relative to the longest edge, total length of all edges, maximum distance between two vertices (diameter).

In general, a card contains a fixed amount of information, so we do not for example list all the edges of a face because that is unbounded in number.

We could also define the "angle" of edge on a polygonal face by imagining the face at the center of a very large coplanar circle, and computing what part of that circle is closer to some point on that edge than to any other edge on the face.  For nonconvex polygons, this angle could be zero.  This probably already has a name.  It seems related to Voronoi.  Similarly, spherical angle of a face or vertex.  Maybe also angle of an edge visible from an infinite sphere.

Or, again consider the plane of a face.  Bisect the angles of the vertices adjacent to an edge of a face: give the angle between the two lines, negative if they intersect on the exterior of the polygon due to concavity.  Call this local convexity.

We could also concretely define a center of a face or polyhedron as the centroid and give angles, areas, volumes, distances.  These values might be negative for faces with holes, concave shapes.

Previously, on adding edge cards to a deck representing the vertices of the Hoffman-Singleton graph.

In 4D each face touches 2 cells.  Edges bound an arbitrary number of faces so we would no longer list all of them.  We probably need to consider 3-tuples instead of (in addition to?) 2.  Use ideas from abstract polytopes to organize things.

[rtprjaew] Could we blow up to earth?

If we took all the deuterium and lithium on the earth's surface and crust and did fusion with it, would the energy released sum to more than the gravitational binding energy of the earth?  If not, how thick of a shell could be lifted to infinity? What smaller astronomical bodies could we blow up entirely?  Or, if the energy is more than enough to blow up earth, what larger bodies could we blow up instead?  Blowing up a gas giant avoids the need to bore a hole to the center.

(Why blow up a gas giant?  Because it's there of course.  Though the astroengineers can probably think of a better reason.  Maybe to get a clear shot at a moon on the far side with a rebel base.)

What if we used all the lithium and deuterium on and in the planet, not just the crust?  Though the process of extracting it might leave the planet pretty destroyed.  Which element is the limiting reagent?  If it is deuterium, can we effectively make more deuterium by fusing a neutron to protium?  What other elements can be straightforwardly fused to release energy (i.e., not iron) in a multi-stage thermonuclear bomb?

The original thought was, there is no known upper limit on how large and powerful we can make a thermonuclear bomb, especially one utilizing 3 or more stages.  Making one large one instead of many small ones is more efficient because the former only requires one primary fission bomb.  Of course fission could supplement fusion, but I suspect the total energy available on earth from fission is much less than from fusion.

Depict in science fiction scientifically accurate very large thermonuclear bombs, perhaps planet busters.

[ewzsytrb] Artist caste

The people who make entertainment are often a very different group in society than those who consume entertainment, the latter usually more wealthy.  How do the creators know what to create, what will appeal to people whom they are very culturally different from?

Inspiration was African-Americans who performed jazz and blues, whose recordings were probably mostly purchased by whites.  Presumably the record producers bridged the gap, communicating to the composers and musicians what they believed would sell well.  Exactly how and what did they communicate?

[fbdvgmvu] More computer Jeopardy

There interestingly haven't been follow-ups to Watson playing Jeopardy: computers competing in knowledge competitions.  Lots of room to explore things like tricky questions that might give humans an edge, or different computers playing against each other.

[bpkyrail] Text with timestamped keystrokes

Create an editor which records a time and date for each character, when it was typed.

It could also record the times when characters were deleted, for saving undo state.  Deleted text might be visible grayed out or with strikethrough.

[ypndkvis] Not left-handed chess

When playing strictly by the rules, you are supposed to push your chess clock with the same hand that you move your pieces.

After initially using his or her left hand, a player dramatically declares, "I am not left-handed", and so on, mimicking The Princess Bride.

The duel references chess in naming attacks and defenses.

[irufelsj] Monospace text when mouse UI

Whenever the user might be using a mouse (or finger for touchscreen) to interact with text, e.g., selecting text or positioning a cursor for editing, the text should be in monospace font, because precisely positioning a mouse cursor among long thin characters like lowercase L in proportional font is difficult by Fitts Law.

Ironically, it is old-school terminal applications which use monospace, despite them mostly not using the mouse, perhaps running in environments (e.g. console) which don't take mouse input.  These would be fine in proportional font.

Saturday, February 17, 2018

[jxbgqbof] Boring football

Every possession begins at 1st and goal at the 10.  No field goals.  Alternate possession every 4 downs, earlier if turnover.  Score by total yardage.

Not sure how to score turnovers.  Do they lose up to 90 yards?  Maybe 1st and goal at the 50 to keep things balanced.  Or keep it at the 10 but turnovers lose at most 10 yards (and possession of course): the field is 20 yards.

[zpqnupzy] Slow feedback on durability

People create many things designed to last a long time.  Some actually do.  After the long time and some things have survived and some not, are there surviving records of how the things were made, recorded with enough precision to be able to determine what construction techniques caused which things to survive longer?

Inspired by very old mosaics as a possibility for long-term preservation of data.  How was the cement made?

[wjfejort] A decade of independence referenda

An independence referendum, voting for a portion of a country to secede, should be repeated.  Only after 10 years of consecutive yesses should it count: this is roughly the length of a business cycle of recession and boom, so thwarts a populist from taking advantage of a temporary change in the economy to induce a permanent change in a country border.

Should all decisions be made this way?

[qwpvxadu] PGP hanko

Create a stamp of the QR code of the fingerprint of your PGP public key for ease of communicating it to others in paper settings.  We need to specify a QR code format for key fingerprints.  Key fingerprints are normally expressed in hexadecimal, but hexadecimal is terrible for QR codes.  Decimal or raw binary is better.  Include the key identifier (e.g., email address in all caps) in the QR code.

Some experimentation yielded QR codes typically between 21x21 to 49x49 pixels depending on error correction level and what other information is included in the code.  What is the practical resolution of stamp?  This is probably going to be a fairly large square stamp.  Maybe better would a barcode that has a rectangular shape, which would work better in forms originally designed for text.

This is a good application for 3D printing (or milling) because everyone gets a uniquely different physical object; it cannot be mass produced.

Unlike Japanese hanko, this stamp isn't meant to be used as a signature (these would be very easy for someone else to copy by virtue of the error correcting code in QR codes).  They definitely do not cryptographically sign the document they are stamped on, despite cryptographic signatures being a popular use for public key cryptography.  That would require a different stamp for every document.

Alternatively, carry around a pad or roll of stickers each with your QR code on them.  This is a little bit weaker because a sticker could be removed and replaced with that of a man-in-the-middle.

[lfrgtxqf] Uniquely shaped maze rooms

Create a maze of rooms connected by passageways in which each room has a unique shape.  Useful for remembering whether you've been in a place, at least for people whose memory works that way.

VR or Minecraft.

[cxbuefac] Force Heat

Remake the diner scene between DeNiro and Pacino in Heat with the Emperor and Yoda. (Previously, on why they don't fight.)

[wihcptju] 2D manifold maze embedded in Euclidean 3D

The maze is 2D (every junction is straight, left, right, or backward) but the paths twist, curve, and fly around in 3D.  Assume the character is wearing magnetic boots.  Can the player keep track of where they are in 3D, forming a mental map in 3D?  Perhaps the task is to get to or near a point specified in 3D.  Easier might be if the path direction changes are also only orthogonal, walking up a wall or down a cliff.

Vaguely similar to Perplexus marble dexterity puzzle.

[uoujnmzg] Wanted masse

Adapt the movie Wanted with the characters curving billiard balls instead of bullets.

[omqzhxkn] Lagrange Four-Square Theorem examples

A listing of numbers and how to express them as a sum of 4 squares will probably provoke curiosity: There isn't an obvious pattern of how to express a given number as sum of 4 squares.  Can all natural numbers be expressed this way?  (Yes, by Lagrange.)  Which numbers can be expressed as the sum of just 3 squares (answer: Legendre Three-Square Theorem), or 2?  As numbers get larger, there seems to be a trend of more ways to express it as 4 or fewer squares, kind of reminiscent of Goldbach conjecture.  What is the rate of growth of the number of ways?  What about cubes and higher powers (Waring's problem)?  There's lots of deep mathematics lurking just beneath the surface.  It's just a short skip and a jump to Fermat's Last Theorem.

We generated 4-square decompositions up to 121=11^2 in order to include 112 = 7 * 4^2, the first instance where Legendre's 3-square theorem applies with an exponent (on 4) greater than 1.  The number which had the most number of ways to express it in the range was 90, with 9.

We also provide a more compact list which expresses each number in the fewest number of squares, but still listing all possibilities for that fewest number of squares.  The full version has 436 lines; the compact version has 188.  The compact version makes it more clear (perhaps inspiring more curiosity) which numbers require 4 squares and which ones can be done in less.

Similar lists could be made for Gauss's Eureka Theorem on sum of 3 triangular numbers and the Goldbach conjecture on the sum of 2 primes.

Haskell source code is here.  Here is a pedagogical excerpt of how to choose num decreasing numbers bounded by 0 and amax.  We use the list as a nondeterminism monad.

choose_n_of_max :: Integer -> Int -> [[Integer]];
choose_n_of_max amax num = case compare num 0 of {
LT -> error "negative choose_n_of_max";
EQ -> return [];
GT -> do {
  x <- [0..amax];
  y <- choose_n_of_max x (pred num);
  return (x:y);
}};

Below is a machine-readable listing of the numbers through 121 and all the ways to express each number as the sum of 4 or fewer squares.

(0,[[0,0,0,0]]) (1,[[1,0,0,0]]) (2,[[1,1,0,0]]) (3,[[1,1,1,0]]) (4,[[1,1,1,1],[2,0,0,0]]) (5,[[2,1,0,0]]) (6,[[2,1,1,0]]) (7,[[2,1,1,1]]) (8,[[2,2,0,0]]) (9,[[2,2,1,0],[3,0,0,0]]) (10,[[2,2,1,1],[3,1,0,0]]) (11,[[3,1,1,0]]) (12,[[2,2,2,0],[3,1,1,1]]) (13,[[2,2,2,1],[3,2,0,0]]) (14,[[3,2,1,0]]) (15,[[3,2,1,1]]) (16,[[2,2,2,2],[4,0,0,0]]) (17,[[3,2,2,0],[4,1,0,0]]) (18,[[3,2,2,1],[3,3,0,0],[4,1,1,0]]) (19,[[3,3,1,0],[4,1,1,1]]) (20,[[3,3,1,1],[4,2,0,0]]) (21,[[3,2,2,2],[4,2,1,0]]) (22,[[3,3,2,0],[4,2,1,1]]) (23,[[3,3,2,1]]) (24,[[4,2,2,0]]) (25,[[4,2,2,1],[4,3,0,0],[5,0,0,0]]) (26,[[3,3,2,2],[4,3,1,0],[5,1,0,0]]) (27,[[3,3,3,0],[4,3,1,1],[5,1,1,0]]) (28,[[3,3,3,1],[4,2,2,2],[5,1,1,1]]) (29,[[4,3,2,0],[5,2,0,0]]) (30,[[4,3,2,1],[5,2,1,0]]) (31,[[3,3,3,2],[5,2,1,1]]) (32,[[4,4,0,0]]) (33,[[4,3,2,2],[4,4,1,0],[5,2,2,0]]) (34,[[4,3,3,0],[4,4,1,1],[5,2,2,1],[5,3,0,0]]) (35,[[4,3,3,1],[5,3,1,0]]) (36,[[3,3,3,3],[4,4,2,0],[5,3,1,1],[6,0,0,0]]) (37,[[4,4,2,1],[5,2,2,2],[6,1,0,0]]) (38,[[4,3,3,2],[5,3,2,0],[6,1,1,0]]) (39,[[5,3,2,1],[6,1,1,1]]) (40,[[4,4,2,2],[6,2,0,0]]) (41,[[4,4,3,0],[5,4,0,0],[6,2,1,0]]) (42,[[4,4,3,1],[5,3,2,2],[5,4,1,0],[6,2,1,1]]) (43,[[4,3,3,3],[5,3,3,0],[5,4,1,1]]) (44,[[5,3,3,1],[6,2,2,0]]) (45,[[4,4,3,2],[5,4,2,0],[6,2,2,1],[6,3,0,0]]) (46,[[5,4,2,1],[6,3,1,0]]) (47,[[5,3,3,2],[6,3,1,1]]) (48,[[4,4,4,0],[6,2,2,2]]) (49,[[4,4,4,1],[5,4,2,2],[6,3,2,0],[7,0,0,0]]) (50,[[4,4,3,3],[5,4,3,0],[5,5,0,0],[6,3,2,1],[7,1,0,0]]) (51,[[5,4,3,1],[5,5,1,0],[7,1,1,0]]) (52,[[4,4,4,2],[5,3,3,3],[5,5,1,1],[6,4,0,0],[7,1,1,1]]) (53,[[6,3,2,2],[6,4,1,0],[7,2,0,0]]) (54,[[5,4,3,2],[5,5,2,0],[6,3,3,0],[6,4,1,1],[7,2,1,0]]) (55,[[5,5,2,1],[6,3,3,1],[7,2,1,1]]) (56,[[6,4,2,0]]) (57,[[4,4,4,3],[5,4,4,0],[6,4,2,1],[7,2,2,0]]) (58,[[5,4,4,1],[5,5,2,2],[6,3,3,2],[7,2,2,1],[7,3,0,0]]) (59,[[5,4,3,3],[5,5,3,0],[7,3,1,0]]) (60,[[5,5,3,1],[6,4,2,2],[7,3,1,1]]) (61,[[5,4,4,2],[6,4,3,0],[6,5,0,0],[7,2,2,2]]) (62,[[6,4,3,1],[6,5,1,0],[7,3,2,0]]) (63,[[5,5,3,2],[6,3,3,3],[6,5,1,1],[7,3,2,1]]) (64,[[4,4,4,4],[8,0,0,0]]) (65,[[6,4,3,2],[6,5,2,0],[7,4,0,0],[8,1,0,0]]) (66,[[5,4,4,3],[5,5,4,0],[6,5,2,1],[7,3,2,2],[7,4,1,0],[8,1,1,0]]) (67,[[5,5,4,1],[7,3,3,0],[7,4,1,1],[8,1,1,1]]) (68,[[5,5,3,3],[6,4,4,0],[7,3,3,1],[8,2,0,0]]) (69,[[6,4,4,1],[6,5,2,2],[7,4,2,0],[8,2,1,0]]) (70,[[5,5,4,2],[6,4,3,3],[6,5,3,0],[7,4,2,1],[8,2,1,1]]) (71,[[6,5,3,1],[7,3,3,2]]) (72,[[6,4,4,2],[6,6,0,0],[8,2,2,0]]) (73,[[5,4,4,4],[6,6,1,0],[7,4,2,2],[8,2,2,1],[8,3,0,0]]) (74,[[6,5,3,2],[6,6,1,1],[7,4,3,0],[7,5,0,0],[8,3,1,0]]) (75,[[5,5,4,3],[5,5,5,0],[7,4,3,1],[7,5,1,0],[8,3,1,1]]) (76,[[5,5,5,1],[6,6,2,0],[7,3,3,3],[7,5,1,1],[8,2,2,2]]) (77,[[6,4,4,3],[6,5,4,0],[6,6,2,1],[8,3,2,0]]) (78,[[6,5,4,1],[7,4,3,2],[7,5,2,0],[8,3,2,1]]) (79,[[5,5,5,2],[6,5,3,3],[7,5,2,1]]) (80,[[6,6,2,2],[8,4,0,0]]) (81,[[6,5,4,2],[6,6,3,0],[7,4,4,0],[8,3,2,2],[8,4,1,0],[9,0,0,0]]) (82,[[5,5,4,4],[6,6,3,1],[7,4,4,1],[7,5,2,2],[8,3,3,0],[8,4,1,1],[9,1,0,0]]) (83,[[7,4,3,3],[7,5,3,0],[8,3,3,1],[9,1,1,0]]) (84,[[5,5,5,3],[6,4,4,4],[7,5,3,1],[8,4,2,0],[9,1,1,1]]) (85,[[6,6,3,2],[7,4,4,2],[7,6,0,0],[8,4,2,1],[9,2,0,0]]) (86,[[6,5,4,3],[6,5,5,0],[7,6,1,0],[8,3,3,2],[9,2,1,0]]) (87,[[6,5,5,1],[7,5,3,2],[7,6,1,1],[9,2,1,1]]) (88,[[6,6,4,0],[8,4,2,2]]) (89,[[6,6,4,1],[7,6,2,0],[8,4,3,0],[8,5,0,0],[9,2,2,0]]) (90,[[6,5,5,2],[6,6,3,3],[7,4,4,3],[7,5,4,0],[7,6,2,1],[8,4,3,1],[8,5,1,0],[9,2,2,1],[9,3,0,0]]) (91,[[5,5,5,4],[7,5,4,1],[8,3,3,3],[8,5,1,1],[9,3,1,0]]) (92,[[6,6,4,2],[7,5,3,3],[9,3,1,1]]) (93,[[6,5,4,4],[7,6,2,2],[8,4,3,2],[8,5,2,0],[9,2,2,2]]) (94,[[7,5,4,2],[7,6,3,0],[8,5,2,1],[9,3,2,0]]) (95,[[6,5,5,3],[7,6,3,1],[9,3,2,1]]) (96,[[8,4,4,0]]) (97,[[6,6,4,3],[6,6,5,0],[7,4,4,4],[8,4,4,1],[8,5,2,2],[9,4,0,0]]) (98,[[6,6,5,1],[7,6,3,2],[7,7,0,0],[8,4,3,3],[8,5,3,0],[9,3,2,2],[9,4,1,0]]) (99,[[7,5,4,3],[7,5,5,0],[7,7,1,0],[8,5,3,1],[9,3,3,0],[9,4,1,1]]) (100,[[5,5,5,5],[7,5,5,1],[7,7,1,1],[8,4,4,2],[8,6,0,0],[9,3,3,1],[10,0,0,0]]) (101,[[6,6,5,2],[7,6,4,0],[8,6,1,0],[9,4,2,0],[10,1,0,0]]) (102,[[6,5,5,4],[7,6,4,1],[7,7,2,0],[8,5,3,2],[8,6,1,1],[9,4,2,1],[10,1,1,0]]) (103,[[7,5,5,2],[7,6,3,3],[7,7,2,1],[9,3,3,2],[10,1,1,1]]) (104,[[6,6,4,4],[8,6,2,0],[10,2,0,0]]) (105,[[7,6,4,2],[8,4,4,3],[8,5,4,0],[8,6,2,1],[9,4,2,2],[10,2,1,0]]) (106,[[6,6,5,3],[7,5,4,4],[7,7,2,2],[8,5,4,1],[9,4,3,0],[9,5,0,0],[10,2,1,1]]) (107,[[7,7,3,0],[8,5,3,3],[9,4,3,1],[9,5,1,0]]) (108,[[6,6,6,0],[7,5,5,3],[7,7,3,1],[8,6,2,2],[9,3,3,3],[9,5,1,1],[10,2,2,0]]) (109,[[6,6,6,1],[8,5,4,2],[8,6,3,0],[10,2,2,1],[10,3,0,0]]) (110,[[7,6,4,3],[7,6,5,0],[8,6,3,1],[9,4,3,2],[9,5,2,0],[10,3,1,0]]) (111,[[6,5,5,5],[7,6,5,1],[7,7,3,2],[9,5,2,1],[10,3,1,1]]) (112,[[6,6,6,2],[8,4,4,4],[10,2,2,2]]) (113,[[6,6,5,4],[8,6,3,2],[8,7,0,0],[9,4,4,0],[10,3,2,0]]) (114,[[7,6,5,2],[7,7,4,0],[8,5,4,3],[8,5,5,0],[8,7,1,0],[9,4,4,1],[9,5,2,2],[10,3,2,1]]) (115,[[7,5,5,4],[7,7,4,1],[8,5,5,1],[8,7,1,1],[9,4,3,3],[9,5,3,0]]) (116,[[7,7,3,3],[8,6,4,0],[9,5,3,1],[10,4,0,0]]) (117,[[6,6,6,3],[7,6,4,4],[8,6,4,1],[8,7,2,0],[9,4,4,2],[9,6,0,0],[10,3,2,2],[10,4,1,0]]) (118,[[7,7,4,2],[8,5,5,2],[8,6,3,3],[8,7,2,1],[9,6,1,0],[10,3,3,0],[10,4,1,1]]) (119,[[7,6,5,3],[9,5,3,2],[9,6,1,1],[10,3,3,1]]) (120,[[8,6,4,2],[10,4,2,0]]) (121,[[7,6,6,0],[8,5,4,4],[8,7,2,2],[9,6,2,0],[10,4,2,1],[11,0,0,0]])

Friday, February 16, 2018

[gmiuenaz] Base 30

Yet another partial attempt (previous attempts yet to be published) at creating something like MIME quoted-printable, a way of encoding any Unicode code point using only printing 7-bit ASCII characters while still keeping English text vaguely readable (so not say Base64 applied to UTF-8).  If there's anything I've learned, there are many ways to do this.

We want the letters a-z to keep plain text readable; let's choose lowercase.  We want space, though maybe we want to use underbar or period as space (similar to URL encoding using plus as space).  We want an escape character, say semicolon (;).  We choose it because it is on the home row on QWERTY keyboards.  Add parentheses because matched delimiters are useful if we want to encode hierarchical structure.  This yields 30 characters.  We could do more, but for simplicity start here.  Previously similar.

Characters that are not the lowercase letters or space are encoded in two possible ways:

  1. Long Parenthesized escape sequences ;(something)
  2. Short escape sequences ;lowercase

Let's choose uppercase to have short escape sequences, specifically the escape character followed by the letter repeated: ;aa ;bb...  Numerals should be similar, though there's a choice between (a=0 ... j=9) or (z=0, a=1 ... i=9).  The former sorts better; the latter follows models like Greek and Hebrew which have used letters as digits though perhaps not in place-value systems.  (Or we could just add 0-9 to the 30 letters.)  Let's choose 0=;z ;a ;b... ;i=9.  Numerals get the second shortest escape sequences.

Short escape sequences in general start with semicolon followed by a sequence of lowercase letters.  How should a short escape sequence end?  Several possibilities we could choose: a space, the escape character again, or the sequence of lowercase letters encodes its endpoint.  The latter is what UTF-8 (very roughly) does: the high bit in each byte indicates we're still in an escape sequence.  More generally, the escape sequence could traverse a Huffman-tree-like structure where in we know we've hit a leaf because we know the structure of the tree.

Let's choose short escape sequences to end with either a space or the escape character again, but the latter signifying the start of another escape sequence.  This keeps compact things like digit sequences.  It does introduce a few awkwardnesses: the encoding of a character requiring an escape sequence followed by a character not requiring one will awkwardly have a space in it: camelCase = camel;cc ase.  A character requiring an escape followed by a space awkwardly needs to be encoded with two spaces after it: the capital letter ;aa  has decimal ;aa;ss;cc;ii;ii  value ;f;e .

Short escape sequences are reminiscent of HTML entity references, though the latter use characters beyond a-z, like uppercase.  They also explicitly mark the end of a reference with a special character, semicolon.

There is no difficulty in finding the end of a Long Parenthesized escape sequence so long as we enforce that parentheses match.

The escape sequence of semicolon immediately followed by a space is uniquely the shortest escape sequence.  Let's keep it unassigned; maybe it gets used by the UI to signify something special like leaving typing mode (similar to vi), or the user can assign it.

At this point, all that remains is to assign escape sequences to the all the rest of the Unicode code points.  Long escape sequences permit many schemata, each preceded by a schema identifier.  One possible schema is a formula to convert back and forth between a Unicode code point number and a digit sequence in base 26.  It's not strictly a number is base 26 because leading "zeroes" (the letter a?) matter.  Use the formula for the sum of a finite number of terms of a geometric series.  Unfortunately, some will spell out vulgar words.

Long parenthesized escape sequences also intriguingly permit a rich Lisp-like language with different combinators for expressing the how a complex Unicode character is put together from components.  This requires the structure of complex Unicode characters be broken down into their component parts.  This probably already exists.  Previously, thoughts on Japanese and investigation into Korean (Hangul).

Thursday, February 15, 2018

[hjyeziee] Energy cost effectiveness of thermonuclear bombs

Suppose we wish to extract useful energy, probably generate electricity, from thermonuclear explosions by blowing up H-bombs.

The motivation is, both magnetic and inertial confinement fusion might be too difficult to ever be commercially successful.  However, if we want fusion, we do have a proven way of doing it now.

How cost efficient is it, counting only the cost of the consumables?  Unfortunately the things that go into an H-bomb, and their costs, are closely guarded military secrets.  Weapons-grade uranium or plutonium for the primary stage.

Bigger bombs are probably more efficient: the fuel of the secondary stage (and later fusion stages) are likely much cheaper than the primary.  Tsar Bomba proved large bombs do work, though we might want to go even larger for cost efficiency.  How large of a nuclear bomb can be built before hitting difficult engineering or science problems?

Of course, harnessing the huge amount of energy released by the bomb in the very short amount of time is a mechanical engineering challenge.  But internal combustion engines harness explosions all the time.  Bullets and Project Orion are other examples of the energy of an explosions harnessed to do useful work.  We imagine an extremely large blast chamber, large enough so that the explosion doesn't destroy it, then heat is collected on the outer surface to generate electricity.  How large does the blast chamber need to be?  Because of the inverse-square rule, there's definitely a size that's large enough. I'm guessing it might be comparable in size to the planet.  What material should the blast chamber be filled with?

If the nuclear explosion could be made anisotropic, a shaped charge, then this could make the blast chamber easier to build, for example, building a hemisphere instead of a giant sphere.

Is the largest hurdle to doing this the mechanical engineering difficulty of containing the blast and extracting energy, or the political / national security traditions of keeping nuclear weapons and information about them off limits to everyone?  What's stopping us from having unlimited energy?

Tuesday, February 13, 2018

[cjauuaxv] Big-game pumpkin hunting

Create a business which offers clients the opportunity to shoot a pumpkin, which gives a satisfying explosion when hit.  Wealthy clients are given the opportunity to shoot very large pumpkins which are rare and difficult to grow, with very powerful guns.  They give a very large and very satisfying explosions.

Of course, this is modeled on trophy hunting of big animals, including how the hunting outfit lures the animal close enough so the wealthy client has an easy shot.  A very large pumpkin could be just as rare as big game -- you might have to wait years for the opportunity to shoot one.  Shooting a stationary pumpkin is approximately a similar amount of challenge as shooting an animal lured in front of you, perhaps more exciting because the pumpkin gun might need to be larger.  Finally, its dramatic explosion makes the pumpkin much more satisfying as a kill.

Inspired by https://www.reddit.com/r/Unexpected/comments/76428m/going_hunting/.

[rkgjmqgg] Partial peer review

A peer reviewer of a scientific paper might have replicated the experiments and analysis and got the same results.  Or, looked over the Methods and deemed them sufficiently clear that the experiment could be replicated, and checked the analysis.  Or something else, perhaps just endorsed that the author is a trustworthy and diligent person.

Accompanying a publication, it would be nice if it were declared how far the peer reviewers went to, well, review.  This would help readers decide how much to trust the paper.

Monday, February 12, 2018

[wyhqwyhd] Spherical pool

Consider playing pool on the surface of a sphere.  Balls travel along great circles, geodesics.

Place some barriers on the sphere for the balls to bounce off of, and some pockets in which to sink.

Ambitiously, build it for real: only one ball is possible, which balances exactly on top of the spherical "table".  When the ball rolls, the table rolls the opposite direction underneath keeping the ball balanced precisely on top.  This continues until friction brings the ball to a stop.  There needs to be some precise tracking.  We need some way of imparting initial rotation to the billiard ball: I think hitting it with a traditional cue will simply knock the ball off.

[vxwwbbud] Learning foreign language songs

Learn -- memorize -- how to sing a large number of songs in one foreign language.  Is this an effective way to learn a foreign language?  The brain will organize the songs into patterns for easier memorization, especially common patterns of form words, idioms, and grammatical constructs, and store them in a way suitable for quick retrieval.  This is exactly language acquisition.

It could be a fun way to learn a foreign language, if you like to sing, if the songs are good.  You'll probably be inspired to learn the meanings.

What songs are good, covering the useful parts of a language?

[rkwktjlk] Time advantage for black

In chess, white seems to have a slight advantage due to first move.  Try to balance it out with a time advantage given to black.  What are the time advantages that are good at various time controls?  Fixed multiplier or something higher order?

Sunday, February 11, 2018

[tnnhqckp] Best poker deck

Poker can easily be modified to decks with a different number of cards per suit and a different number of suits.  Probably want to recalculate probabilities and reorder hand types by probability, including 5-of-kind or greater.  Which deck produces the best game?  How do you define "best"?  Perhaps the ability to segregate humans to many levels of play.

Decks can have more interesting structure than a two-digit number is some base.  The Hoffman-Singleton graph has many structures around the number 5, which happens to be the number of cards in a poker hand.  Previously.

[ievqdaab] Planet-sized Rube Goldberg

Actions in one place emit signals which are received elsewhere, setting off further actions that release signals.  Ambitiously, the sequence circles the earth and repeats.  What kind of cycle time can you achieve?

Internet is of course the obvious global communication network, though others exist: bouncing radio signals off the moon.

[hbrtsvpe] The turn of the wheel

Fairly straightforward framework for a story: People are drinking.  Hookups happen.  Some of those hookups turn into relationships.  Some of those relationships break up.  They take solace in drinking, and then the whole cycle repeats.

Idea from elsewhere.

[uibxcdhp] Speed does not matter in congested traffic

Assuming people are obeying guidelines for safe following distance (a false assumption in reality), then the speed cars are traveling makes no difference in the maximum flux of the highway: a car passes a given point every 4 seconds.

[dahvviwo] Recruiting PreCheck

TSA PreCheck seems like a bad idea because terrorists get to move second.  A person initially completely unaffiliated with terrorism gets approved for PreCheck because they are completely unaffiliated with terrorism.  Terrorists can then target their recruiting to already PreCheck-approved people to get a device through the more lax security measures of the PreCheck lanes, perhaps another shoe bomb because PreCheck does not require X-raying shoes.

Is it even good security theater?  Does the sight of certain people going through more lax security make people feel safer?

[uxttlofp] Plentiful day care and reeducation camps

What would happen if society provided child care, or more broadly child raising support for free as much as the parents wanted until the child reaches adulthood?  Parents can take as little or as much involvement in "parenting" as they wish; government picks up any and all slack.

Perhaps many parents would take very little involvement in their children, essentially putting their kids up for adoption.  Then, the state, given nearly full control over (some) children's lives and development, might deploy procedures that homogenize the next generation of the population, for better or for worse.

What could possibly go wrong?

[emihqled] Acronyms in ideographic languages

Acronyms in languages like Japanese and Chinese can be far richer than those with small alphabets.  Inspired by 全 日本 食品 株式会社 (All Japan Food Corporation), which can be abbreviated 全日食 which could be interpreted to mean "total solar eclipse".  This is similar to an acronym spelling out a real word in English, but the space of real words possible in a small number of characters is much larger with kanji.

[nuyxqahp] Sofa maze

Depict a solution to Moser's Moving Sofa Problem, e.g., the Gerver Sofa, moving around a No Left Turn maze.

Subtleties: is U-turn permitted?  If so, the sofa changes parity in what type of turn it can make.  If the maze has infinitely thin walls, then I think the Gerver Sofa cannot navigate hairpins, two right turns immediately in a row.  This suggests a new problem, the largest sofa which can make that turn.

Romik's ambidextrous sofa can travel through an ordinary maze with no turn restrictions, though it may still have problems with hairpins.

Moser's Moving Sofa Problem can easily be generalized to other angles (e.g., a maze using an underlying equilateral triangular lattice), and probably more dimensions.

[zdcnrpzx] Maze of twisty little passages

The simplest maze-generating algorithms generate mazes with straight passages and only 90-degree turns.  Create an algorithm which permits many more angle possibilities and curved passages (of many and varying curvatures).  There will likely be wasted space because the passages no longer fit nicely next to each other.

3D.

[bnrtnzfv] 3D maze with ramps

Consider constructing a maze based on a grid of square rooms with doors between them.  Adjacent connected rooms can differ in height be a small amount, perhaps an amount small enough to have a ramp that is easy to go up or down, or a short flight of stairs.  It is then possible to have several rooms stacked on top of each other, making it a 3D maze.  Go to the room directly above by traveling though a series of rooms whose small level changes sum to the height of a room.  This is in contrast to a typical 3D maze which requires traveling vertically straight up or down.

Lots of hints possible: 3D coordinates of where you are, windows in which you can see into but not travel to adjacent not-connected rooms.

Minecraft or VR.

Other tessellations possible.  It doesn't even have to have an underlying tessellation.

[ainsclnz] Two types of satire

There are two distinctly different kinds of satire, one which makes the audience feel good about themselves and the other which makes the audience feel uncomfortable about themselves.

Some publications / compilations do a mix of both.

Probably only the former can be commercially successful.

[xzwxflda] Spaces matter in Markdown

Enumerate the situations in Markdown in which whitespace matters.  Inspired by this gotcha with unordered lists.

* one
* two
* three
* four

versus

*one
*two
*three
*four

The latter gets rendered as a paragraph of alternating italicized and non-italicized text: one two three four.

Previously, on other special characters which may trip you up in Markdown.

[xvdfqlev] Dialects with armies

A language is a dialect with an army.  Among countries whose language is named after a different country, list them by size of their army.

  1. American
  2. Brazilian
  3. Mexican
  4. ...
  5. Moldovan
  6. ...

It's not that bad an idea to define a language in terms of an army: it means there's enough mutual intelligibility including shared culture that one can practically organize an army with it.  Curiously, the word Urdu means "army".  Urdu is Hindi with its own nuclear arsenal so is of course a separate language.

Go further and define the normal or standard dialect as the one belonging to the country with the largest army.  Hugh Laurie speaks American with an Englandish accent, but can lose the accent and speak normally when playing an American character.

[bducdsxa] Gravity on non-spherical planets

Given a hypothetical non-spherical planet, especially one wildly different from a sphere, compute its gravity at its surface.  One way to depict it is drawing arrows on the surface saying which way and how fast a drop of water would flow.  Compute basins and watershed boundaries.  It is also possible that gravity is such that water might be pulled off the surface in certain locations.

[yczsdnxs] Neural net backdoors

A vendor provides you with a neural network system that identifies bad entities, for some definition of "bad".  Does it contain a backdoor?  It is currently very difficult to look at a neural network and determine what is does.  How would one design a difficult-to-detect backdoor into a deep neural net system?  How would one prove a system doesn't have a backdoor?

Of course, the ultimate example of such a "system" is a double-agent human whose brain is the neural network.

Saturday, February 10, 2018

[wwhkkicd] Emoji as heraldry

A cumbersome but arbitrarily easily extensible framework for encoding emoji is to index them (at least, new ones) by arbitrary text strings instead of numeric code points.  The font rendering agent has access to the text string and can render it appropriately, perhaps using NLP AI to generate an emoji image for text it has never seen before.  Such emoji (probably) cannot have interesting properties like specifying alphabetization, but usually that's not needed for emoji.  It is a little strange that a large number of characters as data go into producing a single displayed character, but this is similar to characters composed of multiple combining characters or joined by zero-width joiners.

This is similar to heraldry, in which the text describing an image is canonical; different artists may render the text in different ways.

The Unicode consortium can establish standard characters for the beginning and end markers of the descriptive text strings and standards for what goes in them (what language?  What encoding?  All caps?  Are emoji recursively permitted within the descriptive strings?).  Then, a decentralized process happens with people inventing text strings describing emoji and font designers inventing how to render them.  Standardization can then do things like the following: Identify popular emoji supported by many fonts and used commonly.  Popular emoji can be assigned code points to conserve data usage.  Multiple different text strings describing the same thing could be combined into one code point.  Identical text strings describing different things (homonyms?) could be separated out to different code points.

[fcgqncyr] Typing Latin

What portion of the world (among the subset that uses computers) use computers with keyboards with which it is difficult to type the Latin letters A-Z?  I suspect very few: a keyboard with local orthography will also have additionally marked the Latin alphabet for ease of typing web and email addresses.

What portion of the computer-literate world does not know the Latin alphabet?  By "know", probably something like: given a web or email address in print, they can type it on their computers.  How much of a barrier to access to computing is learning the Latin alphabet?

If the barrier is low, then maybe we don't have to push so hard to do internationalization, at least in some areas.  Inspired by IDN, Punycode, and attacks against it, though domain names are not necessarily a domain we should decrease efforts at internationalization.  If a user remembers only how a website is spelled in the local orthography, he or she will need a search engine to find the ASCII address.  This puts search engines in the position to be gatekeepers.  In contrast, if the user can directly type the address in the easier-to-remember local orthography, DNS is a decentralized system for which it is far more difficult to be a gatekeeper.

[ztqmslvh] Psycho XXX

Consider creating a porn parody of Hitchcock's Psycho.  Easy: just expand the peephole scene and cut out the rest of the extraneous filler.  The motel should get a sexually suggestive name -- oh wait it already has one...

Was Hitchcock creating straight-up porn?  In order to do so, he would have had to comply with the Hays Code of the time.  Of course, don't show too much skin, which Hitchcock complied with: definitely far less skin than today's standards of porn, though he was pushing the boundary at the time.  More subtly, the Code roughly required that only bad people do anything sexual.  Being the subject of a peep show is sexual: Marion Crane had been established as a dishonest office worker who steals a tremendous amount of money from her firm.  This plot point had always seemed irrelevant: the suspense and horror would have worked just fine without it.  However, it does make sense if Hitchcock was needing to comply with the Hays Code.  What else about the movie is there just to avoid the whole thing being censored?  Maybe all the suspense, mystery, and horror -- the things that make it one of the greatest films of all time -- was just extraneous filler to distract the censors from the real point of the film.

Tangentially, it would have been cute if Tom Cassidy reappeared later in the film.  Upon learning his money had been stolen, he subverts expectations and does not get angry.  He simply pays out another 40K (this time with a check), staying true to his earlier statement that the earlier cash 40K was "money he could afford to lose".  He even assumes the best of Marion Crane, that she is putting stolen money to good use to "buy off unhappiness", and even takes some pleasure in helping someone he fancied accomplish that.  He sends a private investigator after her not to recover the money but out of genuine concern for her well-being after her mysterious disappearance.  (Of course, such a plot would not be Hays Code compliant.)

[nxqmwkox] Death Star morality, or lack thereof

It is cute that Rogue One established (via kyber crystals) that the Death Star is just an oversized lightsaber (or maybe a lightsaber is a miniaturized Death Star?), explaining away with the same "magic" two of the more scientifically implausible technologies in Star Wars (though the Death Star is not that implausible).

Curiously, before firing the Death Star, there is depicted no philosophical hand-wringing about whether mortals should wield such a power akin to a god.  Depict such conversations, or explain why not.  Such conversations did occur before detonating the first atomic bombs.

Some possibilities why not: The Emperor is a god, so firing his weapon to do godlike tasks is perfectly normal.  The Empire had been regularly destroying planets already, perhaps with Base Delta Zero or telekinesis by the Emperor or Darth Vader, so this is nothing new, just a slightly new way to go about it.  The history of ancient superweapons is still very much present in people's minds, so firing a Death Star feels like firing an old firearm, nothing godlike.  The Emperor is doing vast Battle Meditation to prevent subordinates from thinking such thoughts.  The Empire is deeply atheistic (perhaps due to its high level of technology) so does not believe that there are powers that only gods should have.

Friday, February 09, 2018

[fksvzxxv] 60 redundant connectors

A dodecahedral device interfaces with the outside world by plugging into a pentagonal socket.  All faces work with any of the 5 rotations of a face.  There are therefore a total of 60 interfaces (icosahedral symmetry), one for each fifth of a face.  Make them all redundant, because the interface is often the most fragile part of a device, so having many copies is good.

Motivation is the transfer interface of a highly reliable data storage device.

Less elegantly, it could simply have many ports (even more than 60), perhaps arranged on a grid on a face, each to which a cable may be connected, e.g., KVM.

[bapjmsrb] Better numerals

Design some numerals for 0 through 9 so that the symbols depict the cardinality or ordinality of the number.  Best is if the value can be decoded from the visual appearance of the numeral, but next best would be if the ordering of two numerals can be easily seen visually, perhaps in complexity of the symbol.

A few possibilities:

This first one is inspired by runes.  Let 0 and 1 be special characters, represented by their current symbols, a circle and a vertical bar.  Be careful about serifs on 1.  The remaining 8 numbers, 2 through 9, are represented by a vertical bar with short horizontal lines or loops (like the letter P) hanging off of it. A horizontal line represents +1 and a loop represents +2.  The vertical bar implicitly represents a start value of 1.  There can be up to 4 loops (2 on each side of the vertical bar), signifying the digit 1+4*2=9.  This number looks like a butterfly.  The lesser digits are butterflies with fewer wings or one wing replaced by a stick.  There only needs to be at most one horizontal bar.  We should standardize the positions of the loops and the bar for each digit.

For 10 distinct digits we could do something combinatorial with 2*5.  We could also go larger and (generally) not use digits greater than 9, though they could be used for larger bases.  12=4*3, 16=2^4 look attractive.

If we special case 0, then we only need to design 9 digits, doing something combinatorial with 3*3: a stack of 2 items, each with 3 possibilities.  If we special case 0 and 1, we only need to design 8 digits, 2^3: a stack of 3 items, each with 2 possibilities.  We need to be careful that none of the combinatorial digits look like the special case digits.

We did a survey through Wikipedia of writing systems whose numerals depict the number or at least made some sense in ordering based on visual appearance:

  • Counting rods
  • Japanese and Chinese for 1 2 3 only
  • Roman
  • Aegean
  • Babylonian
  • Chuvash
  • Kaktovik Inupiaq
  • Mayan

[odxhzxko] Source diffs and commit messages teach

Looking at a source code diff and its corresponding commit log message or ChangeLog seems like a good way to slowly learn computer programming in a low-pressure environment.

Adding this feature to a software package manager should be a high priority given the importance of having a more coding-literate populace.

[ebpjoocq] The Death Star is realistically buildable

Use a Nicoll-Dyson beam powered by a Dyson swarm around a star much brighter than the sun, e.g., Deneb.  Either focus the beam and precisely aim it from afar, or just drive the star, swarm, and beam generator to the target with a Shkadov thruster, the latter also requiring no technology we don't currently have.

Star Wars's Death Star's hyperdrive is unknown technology requiring unrealistic science; its superlaser is not. This proposed Nicoll-Dyson beam is certainly not the size of a small moon; it has the mass of a large star and size of a planetary system.

Moving a star with a Shkadov thruster unfortunately takes millions years which has both the problems of keeping the generations of crew focused on the task for that long and bright stars with their short lifetimes might go supernova before reaching the target.  In fact, it might even be a challenge to build the Dyson swarm within the lifetime of any star with energy output high enough to vaporize a planet in a few seconds.

So this superlaser is probably not practical as a weapon, but it might be useful as a toy: blow up nearby planets for fun just like the did in the movies (recreate the effect, as the Mythbusters do).

Inspired by Isaac Arthur.

Tuesday, February 06, 2018

[ikjtaeuy] A few popular foreign-language songs

  • Despacito - Spanish
  • 강남스타일 (Gangnam Style) - Korean
  • Dragostea Din Tei (Numa Numa) - Romanian
  • Neunundneunzig Luftballons (99) - German
  • Garota de Ipanema (Girl from Ipanema) - Portuguese
  • 上を向いて歩こう (Sukiyaki) - Japanese
  • Tu Vuò Fà L'Americano (sampled in We No Speak Americano)- Neapolitan
  • Очи чёрные (Dark Eyes) - Russian

[zfevsaab] Circular wipe

Consider the iris wipe between two slideshow frames with the next image becoming visible from the edges first.  The center, presumably the most important part of the current image, persists the longest.

Inspired by: we can't see detail in moving images.  Slides sliding is wasted time.

[syetklhk] Weight change due to stress

Some people gain weight when under stress; other people lose weight.  Which people do which and why?

[hipkucuc] Emacs pinky

People complain of Emacs pinky in having to press the Control key often but generally do not complain about having to press the Shift key often.  Why not?  I suspect Shift is pressed just as often as Control if not more so.

[izvsgyut] A whole circle in a piece

Circles are neat because seeing any portion of the arc is enough to uniquely determine the radius and center.  This is not true for other shapes. For regular polygons with small numbers of sides, we need to see the regions around at least 2 vertices, which are only a small parts of the whole perimeter.  Most of the perimeter of a polygon is a line, completely useless for telling anything about the polygon.

[dqelykfe] Accidentally a word

In languages not so dependent on the positions of words in a sentence, can you more easily recover from accidentally omitting a word earlier in the sentence?

[qzjsuabg] Yale vs Chicago speech

The differing policies and philosophies between the University of Chicago versus Yale University conveniently allows naming them.

Yale-style policies: safe spaces, triggering speech forbidden or required to be labeled.

Chicago-style policies: free speech.

Both spawn weapons for devious political purpose.  In Chicago-style, the content of the speech could matter less than the political position it represents: use triggering speech to exclude certain groups.  In Yale-style, use the punishment mechanism (or threat thereof) against certain objectionable speech to exclude certain groups for whom that kind of speech forms their identity.

Which policy is good when and for what purposes?  Probably depends on the self-qi levels of the listeners.

[cnpvmelm] Kinesis key remappings

Some key remappings I've used on the Kinesis Classic Ergonomic keyboard:

Logical ESC to where the physical Tab key is, which is where it was on the keyboard that the vi editor was designed for.

Tab to where the Delete key is (left thumb cluster) because I type it often for command completion and indentation.

Delete to Escape key, completing the 3-cycle.

Super key (Windows key) to where Caps Lock is for use as the modifier key for XMonad.

Sometimes I get around to moving Capslock to where the Super Key was in the Keypad layer.

[msquaaah] Precedence of equality and boolean operators

Some expressions to measure the relative precedence of equality versus boolean operators, in a language like C where 0 and 1 are false and true.  The first of the easiest to remember.

  • 0 == 0 && 0
  • 0 == 0 || 1
  • 0 == 1 || 1
  • 0 == 1 && 0

[kpkkdeyc] A dinghy is not an aircraft carrier

Depict a series of predictably disastrous unsuccessful attempts to land a plane on various sized boats, each time concluding, "We're going to need a bigger boat."  Not sure what the punchline should be.

Previously.

[rxwvezsq] Francis

Deadpool catches up with Ajax after a year of hunting, attempts to rudely address him as Francis, but Ajax is not offended, in fact he goes by that name nowadays. "It's a fine name: Francis Bacon, Francis Crick, Sir Francis Drake the greatest pirate who ever lived, oh and that awesome and dashing villain in that superhero movie that just came out who has a change of heart about his name..."

(Were all those Frances knighted?)

Maybe poke fun at identity politics.

[xfbvnjxv] Astroturfing further from the center

Organize a political movement that deceptively suggests to right-wing politicians that they should move even further to the right.  This would put right-wing politicians in a quandary with both outcomes beneficial to the left:

They can heed the mostly fictitious ultra-right, moving their platform further right.  This will erode their support from real people in the center right, which they will pay for in the next election (assuming they don't destroy the country before the next election).

Or, they can regard with suspicion any seemingly far-right grassroots support, which will also cause them to ignore some actual far-right grassroots support.  This will cause the politician to move toward the center.

Are the politicians fooling the people or are the people fooling the politicians?  Tricky is if the movement to create a fictitious ultra-right involves manipulating actual suggestible people join and support the ultra-right.

Of course, this could also be done in the opposite political direction, though the right wing currently seems more vulnerable to such tactics.

[awrabqaz] Muses and dwarves

One class of supernatural beings, muses, inspire people.  But inspiration is not enough: another class of supernatural beings deal with the seemingly more mundane and thankless tasks of creating a environment around the inspired one wherein which the inspiration can be taken to the fruition of an actual work of art, science, etc...

[mylfjyle] Avoiding government by the low self-qi

Design a government robust to some of its members having low self-qi.  Dictatorship is of course terrible for this: a dictator having a bad day will cause a lot of harm.  Even if the method by which government members are selected -- the way people acquire power -- tends to filter out those with low self-qi, people will occasionally have bad days.

In parallel, design an environment around those with power that maintains a high level of self-qi for them, so they don't commit harm with their power.  Such social environmental engineering is applicable beyond just government, anywhere where power of exercised.

We can also look at this descriptively: successful governments are those which have found a way to accomplish the above tasks.

[ambrpygb] Park your car near Harvard Yard

Modify the famous sentence from "in" to "near".  "Near" gets pronounced distinctively in the Boston accent and makes the sentence semantically possible to do.

[dyvqyimt] What men want

Both as a literary trope and probably also in the real world, a mentor, perhaps a bitter feminist, advises a naive girl that men are pigs and are interested in only one thing: to have sex with her.

Rarely (at least when following the trope) does the girl then respond with the critical question, "Why?"

That is, "Why does the act of having sex with me dwarf in pleasure and satisfaction all the other ways I can improve, entertain, or be useful in the life of a boy or man?  What is going on inside the his mind that having sex with me has so much value to him compared to everything else?  How did he come to have and to keep maintaining such a system of values?"

In the real world (as opposed to literature) do girls ask those questions?  If not, why not?  (That was a meta question.)  Do you assume you already know the answers?  (If so, what are the assumed answers?  Are your answers accurate?)  Do you not care what the answers are?  In the context of a social class boundary between the girl and the pig-like lower class men, no, she does not care to know more about those below her.

They might be uncomfortable questions to answer.

Monday, February 05, 2018

[aamkajwr] Worst packing convex shape

What convex shape has the worst (least) packing density?  https://golem.ph.utexas.edu/category/2014/09/a_packing_pessimization_proble.html

In two dimensions, the answer is conjectured to be the regular heptagon.  Currently the best known packing of regular heptagons achieves a density of 0.89269.  However, if a denser packing of regular heptagons is discovered, in particular, one with density greater than 0.902414, then the heptagon will no longer be the worst shape: there exists a "smoothed octagon" whose highest density packing is proven to be that number.

One way to look for better packing of a regular heptagon is simulated annealing.  Or actual annealing followed by determination of crystal structure if you can create a regular heptagonal molecule.

In going from the regular hexagon to the regular heptagon, we go from the best to conjectured worst packing shape.  After the regular hexagon, do the regular polygons steadily increase in packing density approaching the packing density of a circle?

The question could easily be generalized to a sphere or other manifolds.  What convex shape of unit area requires the largest sphere to fit N copies on the sphere?

Friday, February 02, 2018

[dtethwpm] Unicode hexadecimal

Create a block of Unicode characters denoting hexadecimal digits.  This would be helpful in marking a string intended to be hexadecimal data which happens not to have any digits 0-9, avoiding it from being interpreted as a regular word: DEAD BEEF, etc.  It would also be helpful in avoiding a hexadecimal string which happens not to have any digits A-F from being interpreted as a decimal number.  Previously.

Of course, with some programs using these characters but some not, it will be a mess, kind of reminiscent of curly quotes versus 7-bit clean quotes.

We could similarly have a block of 256 Unicode characters representing bytes.  The visual appearance of a byte character could be its value in hexadecimal, similar to placeholder characters seen when a font does not have a character.  The ability to encode binary data inline with text seems intriguingly potentially useful, though I'm exactly sure for what.  It accomplishes a similar purpose as MIME and base64.

Octal.

There are clock characters for representing base 12 starting around U+1F550, and even sort of base 24 using the half-hour clocks.  Base 6 has dice at U+2680.  I Ching symbols: U+2630 (base 8), U+268a (base 2 and base 4), U+4DC0 (base 64), U+1D300 (bases 3, 9, 16, and 81, but not 27).  6-dot Braille U+2800 (base 64), 8-dot Braille U+2840 (base 256).  There are exactly 100 characters in the domino tiles block U+1F030.  Fractions around U+2150 and elsewhere, intriguingly including 0/3.  Playing cards with 14(!) cards per suit at U+1F0A0.

There are a great many pairs of characters that could encode binary, e.g., ASCII ACK and NAK.

Are there any other bases commonly in use?  Base 60 in time and angles.  Base 20 seems likely.

Wednesday, January 31, 2018

[kfnmlrlk] Incompetence appearing as malice

Enumerate situations in which incompetence can strongly appear to be malice.  Gray area.

[luapmttv] Room temperature cheese

Cheese tastes radically different depending on what temperature it is.  Fats can melt in your mouth, like chocolate, releasing flavor dissolved in fat if not too cold.

Cheese sliced thin or shredded absorbs ambient heat quicker.

[xifpmmhs] Sukiyaki

The lyrics of the song Sukiyaki 上を向いて歩こう are powerfully bittersweet.  As it reached high popularity in the English-speaking world, were the listeners aware of the meaning of the lyrics?  In 1960s America, there were probably very few resources for translation from Japanese.  Does the sentiment carry through in the music even if you do not understand the lyrics?

The name Sukiyaki is of course ridiculous.  Much better would have been Hitoribocchi -- a word used repeatedly in the song -- meaning "lonely".

[cipzvuew] Other applications of the modularity theorem?

Are there other nice easily accessible corollaries to the Modularity Theorem other than Fermat's Last Theorem?

[nmcihzfy] More majuscule

We can add the digits 1 through 9, omitting zero which is difficult to distinguish from the letter O, to the list of capital (uppercase) letters, yielding 45.  Use lining figures (uppercase numerals) not text figures.

We assume that font and resolution sufficient to differentiate OQ can also differentiate 1I 2Z 5S 6G 8B etc.

There are also lowercase letters with ascenders but I don't feel they work so well in this collection.  In some fonts, J and Q (and maybe more) have descenders.

For base 45, it might be better to use zero and omit capital letter O so that the symbols can use a natural order: numbers, Latin letters, Greek letters.

Perhaps useful for a mysterious-looking wall of symbols like The Matrix.  Here is some random text: WVR4UFΞΨEII9R3L0JTHKΩVCG900BΨΘ367XLKDAPΛΨ82CΞ0N4MMR75XΛMEZLTNPQΩXW5K2ΘTΛVQVS154KWNBZ6XM7RMΞBKGVΨE7DR2ΘΣTW7VSΩΛXFG51ΛKRZ8UΓ6YUG9CNΠH1AΩLIW9EΨBBDNDΔZΩWFRACΓRTΔE07JNXFFVB7Ξ2ΨΩΛBIYDΣHDACWΘ551USHZWD3ΞΔΨ3JCABPDL0ΞYS3LAUKDMEDZLΦZΣΠE3ΨFΣBPΓΞΦΦ1S8ΞEΘLRΔΠ00ECΠRYQΨΔSQMΞ21ΛWΔVMB9F3MΠΓKFJΠFF139UZ6UΞQ1TΘΨQEKV5BLC8VΨ5ΛGESAGΓJ5E6GAΨBΓJNΔ161M1B5L1F8I5QΣΓNΔJNCΨ5ΛC6U8RL3V6ZVCΨ95Π9NKCTZ1ΨΩ8FILU3W38RFEEL7ΠKYLRΠRCE82GS8JMPQBBGGΠBG7B5N9NΔYSIFH6EQE5ΨΓPΣZRBDG8NMXΠLFPΩF0RDEΓL1ΛΔWLUPN8QVZΛΨΔ2BWΛ9KCΣΞΘ0RΞAΔ5CT1LGHGH0Z4PΔH5ΦSΞI27ΠXUNQΦURIFVΓΩA8VΞFA9EILΩFMΘΔL1VRAKCK4Θ0NRK1ALΩΦΓΣ5L4Ξ5ZΞQ0HRΠ0DΞΛ86ΓZTFX3ΓΠKH0E8XNΞZ5ΓΓYVY3IGNPGMFΦΔXVGIYRQΩSC0ΛGYZW85FJBΠQ5ΨIXΓUΨΘLΣ2RΘJP66VΨΓWΨD08SW0M0T8ΩCΩYΓACUΓ1KVLΠMJDKUFΠ9ΨΛΘKQΛΔΔ8INCWE0ΘΣBJN8AΛΨFΞX8RΨ6WDΞPΓRHLWTΣRΦNZWΦULGΩPΞΨV068RΨAW8XZ11E4ΛGUΨ8SPΠΨDMW55JHLTB96YF435UΠU8Φ4EZYJΩSFUF2JWGET1VXYΩWSFT4ΘΞFKKA49GYRΠΦF0ΓΓSKΛJΣZΨMXB3TMΔPKΔDMIDJMΦER596HG5YΨGJMXΓA730Γ9Φ17NG4MΓSU46SΛPBLΓDΨTDXΛFWFNEC5Y4PVΞΓCEDHWIΩWW5BHQT4I6NQ2NA2WHSIX2TΩMRLΦV5TH6ΣΔ4Σ12H0ΠBΨΩT1Q2GMKFBSΔEHΣGEFEBΠΣ64KA0LL8PΔTPMYΦ57J

Tuesday, January 23, 2018

[oemprfgv] Voronoi on a sphere

Voronoi diagrams on a plane always have regions of uncomfortably infinite area.  A Voronoi partition of a sphere does not have this problem.  Also, the torus does not have this problem.  Inspired by an animation of Voronoi partitions of moving points.

The Delaunay triangulation remains finite.

[csmdfofy] Sample only 1% of users

If you are collecting personal information to improve your service or software, uniformly sample only 1%.  Your statistics will remain valid, but the collected Big Data is unlikely to be misusable in a targeted attack against a particular person: any particular person has a 99% chance of having escaped your mass surveillance.

Services and software providers can advertise the percentage that they sample and compete with each other for the lowest percentage.  They can get certifications from trusted third parties that they are only collecting 1%.

[dglnfsxs] Carlsen improving others' endgame play

The story goes, Magnus Carlsen won a lot of chess games from drawn endgames which motivated his peers to improve their endgame play, so he doesn't win as many in that way anymore.  Test whether this story is true by objectively measuring the quality of moves of his opponents.

Previously, on impact.

[cgbeflff] Reordering chaconnes

Can the variations of a chaconne or passacaglia be reordered?  If so, this offers a relatively easy avenue to change or improve a piece.

[upivculb] Website checklist

How does your web page look in a very narrow browser window?  Do paragraphs of text reflow?

How does your web page look with the browser's default colors changed to white text on black background?

How does your web page look with JavaScript turned off?  Does it need to look as bad as it does (for JavaScript games, yes; for textual content, probably not)?

[ftzqznpc] Eulogy for Java applets

With the removal of NPAPI after Firefox 52, Java applets will no longer run.  This is unfortunate as Java was one of the few languages that had put some thought and effort into a security model and sandboxing, in contrast to the giant mess that is Javascript.  (Unclear whether Java's security model was any good.)  There were a great many fine Java applets (games, graphics demos) which did nothing but draw onto a canvas, requiring no additional privileges: it is a shame those will no longer run.

Can Java applets be resurrected in the brave new world without NPAPI?  Probably involves compiling a JVM into Javascript or Webassembly.

Also dead are Wolfram Demonstrations.

[qxyxntvs] List of escapes

Markdown requires backslash-escaping the following 15 characters: \ ` * _ { } [ ] ( ) # + - . !

LaTeX requires being careful about the following 10: $ # % _ { } ^ ~ \ &

HTML requires using an entity to denote the following 2: < &

C strings require a backslash escape for the following 2: \ "

This blog recently switched to Markdown-based composition.  Things may go wrong if I forget which characters need to be escaped when.

[fnkttzox] Inspirations and imitations

Great pieces of art inspire derivative works, many more loosely than in the legal copyright sense.  Enumerate them for some art considered great.

Great pieces of art are usually built on ideas from previous art.  Enumerate them.

What came before; what came after.

[stqbglit] Keyboard layouts

Assume Dvorak's idea of all vowels on the home row on one side is a good idea.  AEIO should go directly under the fingers (where ASDF are), and U, the least common vowel, goes at G.

Some common letter should go where semicolon is now.  Or maybe backspace if you don't have a keyboard that can put it on the thumb.

Other common consonants on the right hand home keys.  TH being two of them seems like a good idea.

Remaining letters go in alphabetical order across the keyboard to make them easy to find, though there are many ways to do this.

[rahqenfa] Permuting a keyboard layout

Create keyboard layout which can be learned gradually as modifications to QWERTY: a series of small changes which can be learned over time.  Swaps of 2 keys are the smallest type of change, then cyclic 3-permutations.

Avoid any key from participating in multiple (successive) permutations.  Only a subset of permutations of the original layout are reachable.

[sgxtsbmn] Spectating blindfold chess

The audience watches a projected board with pieces while the players play blindfold chess.  What annotations on the audience's board would be interesting, perhaps hinting at where players might make a blindfold-induced mistake?

How long a piece has been there?  Where has it been recently?

[sngnlrug] After school

School gets out at 3.  Parents get home from work at 5:30.  That block of time in between is opportunity for the kids to get in trouble.  What are the consequences of that time structure?  Why is it structured that way?

Which types of parents / families can engineer a solution to keep their kids out of trouble?  Which cannot?  Probably socioeconomics has a lot of influence: who can hire a babysitter?

We assume getting into trouble as a child as lifelong consequences.  The time structure induces -- maintains -- social stratification in the next generation.  If the time structure is deliberate, it is quite sinister.

[werudmic] Passenger-side door

Create a car in which it is easy for the driver to exit out the passenger side door.  Probably the center island moves out of the way.

When parallel parked, it is more safe for driver who won't need to step into traffic to exit, and more safe for bicyclists riding next to parallel parked cars.

[vzqsukrs] Trebuchet trebuchet

How far can you launch a trebuchet?  Silly, of course: why provide your enemy with a weapon?  Broken parts might be repaired and reassembled.

[rtuzfhzb] Square in octagon in square

Draw a larger square around a smaller square.  What is an aesthetically pleasing margin?

Fit an octagon exactly between the larger and smaller so that 4 sides of the octagon are coincident with sides of the larger square and the corners of the smaller square are on midpoints of the other 4 sides of the octagon.

The ratio of areas between the larger and smaller squares is then 2:1; or linear dimensions sqrt(2):1.

[wtqdkweo] Large coats with large pockets

If the weather bad enough for a large coat, then you are probably also wearing a hat, gloves, scarf, etc., which need to be stored somewhere so as not to get separated or lost.  And, in a large coat, there is plenty of space inside for large pockets.

Inspired by a woman's large coat with small pockets.

[fcxchtsq] S&PR

A modern English version of the ancient Roman SPQR acronym would be S&PR (not SP&R which was the inspiration from elsewhere).  Curiously the ampersand is a modification of the Latin word for "and": "et".

[ahkvcwht] Keep Harry alive

Voldemort discovers in time that Harry is a horcrux, perhaps his last horcrux, so must keep him alive.

Probably boring: alive but disabled and imprisoned, though friends trying to rescue him could generate plot.  More weirdly, Harry lives free but with a very unusual guardian angel.

[pycttush] Dr. Jekyll or Mr. Hyde

Modify the story so that no one, not even the double-personality guy himself, can tell whether he is in the Dr. Jekyll or Mr. Hyde state until some stressful situation occurs and the character's true nature (at that moment) is revealed through good or evil actions.

Inspired by the difficulty of self-measuring your own self-qi.  How destructive might you, or someone you are intimate with, be if the going gets tough?

[weallkmp] Constant curvature

Curved manifolds become interesting in at least 2 dimensions.  (Are there any interesting things to do on a 1-dimensional curved manifold?  Maybe serve as a baseline for text.)

Constant curvature is the simplest type of curvature.  A 2D manifold with constant positive curvature is the surface of a sphere.  Constant negative curvature is (I think) hyperbolic space, for example Escher's Circle Limit series.  Also pseudosphere.

Create software tools for working in these spaces, for example for a game: how to address a point, compute distances and angles.

[vkzutrjs] Drops and bubbles

We consider a function oscillating around zero, e.g., Riemann-Siegel Z function.  When the function is positive, a dropper above a pool of liquid fills a droplet with liquid at a rate proportional to the value of the function, so the size of the droplet is proportional to the area under the curve.  The droplet disconnects from the dropper when the function hits zero, and the drop falls to the surface of the pool of liquid below.  Similarly, a bubble is formed and rises to the surface for when the function is negative.  Drops and bubbles meet the surface in a rhythm corresponding to the zeroes of the function.

[bzxomrfi] Long adjournment

Consider a chess game in which each player is permitted to invoke adjournment once at any time, without a sealed move.  The adjournments are long, permitting development of significant theory from the adjourned position: maybe a week or month.  Players may consult their developed databases on resumption of play so as not to have to memorize it all.

This could also be done in a game between computers programs, though it would be more straightforward to simply set the time control to Game in 1 week.

[uhshclce] GO TO COME FROM

Consider a programming language, probably something like assembly or machine code, in which the target of a GOTO instruction must be a COME FROM instruction with the address of the GOTO.  If it is not, then something has gone wrong, maybe memory corruption, and the program should abort.  COME FROM instructions otherwise function as no-ops.  A subroutine has encoded in its header all the addresses which might call it.

A context in which something like this might be useful is a document with hierarchical text.  To skip over a section, the browser needs to know exactly how many bytes to skip.

[lacdlmwe] Ketchup

Ketchup is a condiment which hits many of the important fundamental flavors: salty, sweet, savory, and sour.  (But this combination is far from unique to ketchup.)

This suggests variations on ketchup which slightly alter the relative strengths of the flavors.

Major missing flavors are bitter and spicy.

Monday, January 22, 2018

[egweafzh] Game controller musical instrument

Create an electronic musical instrument whose input interface is a game controller.  They have been optimized to be good input devices.

[ccachxyd] Small semantic alphabet

A-Z, 0-9, Yes, No

Inspired by fingerspelling / American Sign Language.  With those signs one can communicate anything.

Monday, January 15, 2018

[tqlbtqsi] Surprisingly high revenue

People are always interested in learning about activities (businesses, portions of businesses) which generate surprisingly high revenue, though "surprising" is subjective.

At the same time, if an activity is generating high revenue, there will often be powerful mechanisms to conceal that fact, to deter competitors from entering and decreasing the revenue.

Create a system to gather and disseminate information about instances of surprisingly high revenue, perhaps rewards for whistleblowers.  It is a public good.

[lpbygtxf] Rubik's AR helper

Create an augmented reality application which provides directions to solve a Rubik's cube, watching your moves as you do them and providing a way to recover if you make a mistake.  (Often, if you make a mistake in the middle of an unassisted solve, it's as bad as needing to start all over again.)  This would be most useful for puzzles much larger than the Rubik's cube where a single mistake might undo hours of work.

It could also provide a way to quickly get back to a specific starting position (scramble) that you want to repeatedly solve, perhaps for practice or to investigate different ways of solving.  The backend could use Kociemba to find short sequences.  Having a way to easily get to certain positions vastly lowers the barrier to entry in learning to solve puzzles.  This was the motivation for the Lego Rubik's cube.

[qpabsroz] Things going wrong

How well could you handle "things" going wrong right now?  Answering this question may help measure your own self-qi.

Perhaps you would break.

[fhgafiff] Mental Mr. Glass

Consider the character of Mr. Glass in M. Night Shyamalan's Unbreakable who is physically very frail.  Next, imagine someone who is very frail not physically but mentally, perhaps a relatable psychological state: one is just one piece of straw away from mental breakdown.  This would be an example of low self-qi, or high stress level.

[jjlxkffg] Angry or sad

Both irritability and sadness are markers of low self-qi.  However they seem very different moods, causing a person to behave and perceive the world in very different ways.  What causes the difference?  Possibly a flaw in this theory.

[oaabzyay] Rat Park seems less fun

Assuming true, Rat Park is both unsurprising and surprising:

It is unsurprising because it seems obvious socialization and the availability of other entertainment affect addiction.

But it is surprising because socialization and alternative entertainment probably don't provide anything close to the intense high that heroin can provide (though not sure what dosages the rats were provided or whether that statement is true for rats).  It would seem that rats ought to still crave the thing that's better even with other things available.  Why not?

Saturday, January 13, 2018

[hfqrhxdw] Generalizing Fermat's Last Theorem

The equation a^n + b^n = c^n easily has lots solutions with real numbers.  With monumental effort, Wiles et al. showed it has no solutions with integers n>2, and a trivial corollary is that it has no solutions with rational numbers either.

It easily has lots of solutions with algebraic numbers (just take the nth root).  Where is the boundary, the threshold size of the subset of reals, where it changes from having lots of solutions to few or none?  Constructible numbers, quadratic surds?

[sqezqapp] Editor emits a patch

Open a file with an editor.  On exit, the editor emits to standard output a diff between the original file and the new version after your edits.

[wdnbrppj] Kill all humans quickly

The humans will adapt and organize a resistance if the AI killbots don't act quickly.  How quick is quick enough that we won't be able to respond and survive?  (Assume the killbots actually want to kill all humans relatively quickly, not just doom them to a slow death, for example in a radioactive wasteland after salted nuclear weapons.)

I'm guessing about 5 minutes.

It'll be tricky for the killbots to position themselves (especially tricky without arousing suspicion) so that they are within 5 minutes reach of every human on earth, particularly those in very remote, very isolated locations: mines, Antarctica, International Space Station, submarines.

Submarine crews might be especially difficult to locate and kill because the location of submarines tend to be very closely guarded military secrets.  The original thought was was, they surface to find everyone else dead, so they must repopulate the earth.  It's a good thing the crews were recently made coed.

[suamrgsy] Transparent tax

It's surprising that retailers of items subject to high additional taxes, e.g., alcohol, tobacco, do not label the prices of individual items on their shelves in a way that makes clear how much of the price is tax, e.g, (base price X, + tax Y = you pay Z).  This would be a form of speech encouraging political action among customers to lower the tax.  The retailer would benefit from lower tax, gaining customers who were on the bubble, those whom the tax had caused them to choose not to purchase the good.

Is such speech forbidden?

[xynljlpz] Nazi Nazi Nazi Nazi nazi nazi Nazi Nazi.

A sentence with similar structure as with repeated "buffalo".  "Nazi" as an adjective is common.  We use "nazi" as a verb to mean "act in the way of a Nazi toward" (this is an example of "Verbing weirds language.").  Finally we use "Nazi" as a plural or collective noun (again unusual compared to the more usual pluralization "Nazis"): perhaps the mind is fooled into believing Nazi is a Latin-style pluralization of something like Nazus or Naz.

The sentence does have useful semantic meaning: white nationalist groups fight amongst themselves (perhaps a strategy ultimately to prevent any from gaining significant power).

[qmijmsbv] Obsolete superheroes

Superheroes who have been obsoleted by commonly available technology hang out and commiserate in the style of HISHE Superhero Cafe: The superhero who can start fires, obsoleted by a lighter.  The superhero who can "bend" aluminum ore to extract aluminum metal.  The superhero who can form a protective bubble around him or herself that cannot be penetrated by the smallpox virus and so avoids becoming infected with smallpox.  The superhero who can communicate wirelessly with other superheroes.

[sxhydedb] Why are integers special?

Fermat's Last Theorem seemed silly and trivial to me when I first encountered it as a child: it was very obviously false with plenty of counterexamples with real numbers.  Later, I learned of the restriction to integers, but it still seemed a little bit silly: the restriction seemed artificial and arbitrary just to make the problem difficult.

Why restrict yourself to integers, especially for an equation like Fermat's which can easily accept reals?  One could argue that the integers are merely points on the real number line that happen to have compact names, but there isn't anything more special about them, assuming the primacy of the reals.

I want to travel the world but restrict myself only to national capitals.

[trfunfyl] Mechanical with self-repair

Create a mechanical device, probably something very large, which includes some ability to repair itself autonomously, perhaps remove and replace some of its broken parts with spare parts in storage.

Pair of robots which can repair each other.

[ozsirofg] Alphabet for dyslexia

Dyslexic people have trouble with reflections of letters. Design an alphabet (not necessarily related to the Latin alphabet) whose characters are different, ideally very different, after reflection.

Also avoid characters which look similar after rotation, translation, scaling, topological deformation.  Perhaps use one from each row of this alphabet.

Although inspired by dyslexia, such an alphabet could make everyone's reading more efficient.

[afrovnkj] AlphaZero chess

AlphaZero is an intriguing new chess evaluation function.  It is not a full chess engine because it does not do time management, a significant component of a full chess engine.

Here are some recommendations on how to compare a new evaluation function against an existing chess engine such as Stockfish.  This was inspired by how poorly the AlphaZero paper did it; these would be improvements:

  1. Record and publish the exact version of Stockfish used, including compilation options.
  2. Set Stockfish to use 1 thread only and a search depth of a fixed number of nodes per move (the "go nodes" UCI protocol command).  This allows others to exactly replicate Stockfish's evaluation.  (Using only 1 thread only avoids the nondeterminism of multithreading.)
  3. Adjust the level of Stockfish (number of nodes per move) or the level of your new evaluation function (assuming yours is tunable) so that games played between them result in about 50% score: both sides achieve approximately the same number of wins as losses.  If the new evaluation function is very strong, Stockfish might have to be given a huge time advantage to achieve a 50% score.  A 50% score allows highlighting strengths and weaknesses of both sides.
  4. Report the strength difference between your evaluation function and Stockfish as the difference in time consumed by each side in achieving the 50% score.
  5. If you want to show off how strong your evaluation function is, and your evaluation function is tunable, repeat tuning your (presumably stronger than Stockfish) evaluation function for a 75% score, keeping Stockfish's settings the same.

[dymjdwyn] Time-synchronized movie

Design a system to play a movie or other time-indexed media so that a dramatic point in the movie happens exactly at a specific time.  A little bit tricky because real-time.

Coincide some countdown in the movie with the New Year's Eve countdown.  Or replay of sports.

Previously, earthquakes.

[vjzkikzl] It's Lupus

Another way they could have played with the "it's not lupus" running gag on House: set it up so that the audience knows it's lupus but the characters believe, even conclude, that it is not.

[smzoiwzk] Face-turning octahedron

The face-turning octahedron, whose simplest example is the Diamond Skewb, has the interesting feature that the face overhangs the plane that turns, allowing more leverage and possibly a better grip.  Does this allow nice finger tricks?

The cubical Skewb and the concave Rubik's cube also have this feature.  In contrast, in the Megaminx the turning face slants inward so it is harder to get a grip on it, inspiring innovative features like ridges.

Assuming one wanted to remove this feature (as an exercise in geometry) from the Skewb and Diamond Skewb and have the cutting planes be precisely orthogonal to where they meet the faces (like a Rubik's cube), what should be the shape of the polyhedron?  (Because it is deep cut, a sphere would also work, but that is boring.)  Answer might be the regular or rhombic dodecahedral shape mods of the Skewb.

[uzgewhha] UI log

The nice thing about command-line interaction is it automatically gives you a log of your actions and the subsequent effects of your actions.  You can see, and later review, what you did and the effects.  This is useful for learning and understanding a system.  It is also useful for teaching: you can easily publish, "this is how I solved the problem: ..." by publishing the log.

(Previously, modifying an editor to enhance this effect.)

Can a GUI be enhanced to provide these features?

[oafmpxgd] Fun with acting

Take your favorite scenes from movies or theater and reenact them, producing very short theater or film/video.  Possibly modify as you see fit.

Inspired by selectionless.

More ambitiously, do a bunch of them and string them together in some vaguely coherent fashion.  Possibly kind of a dual of a jukebox musical, in which the scenes are simply filler to connect unrelated songs.  Here we need filler to connect unrelated scenes.

Wednesday, January 10, 2018

[klavsdjb] Buffalo buffaloes Buffalo buffaloes buffalo buffalo Buffalo buffaloes.

The original sentence with repeated "buffalo" only works because of an unusual use of the word as a plural noun (agreeing with the plural verb) instead of the more common pluralization buffaloes.

Brown cats [that] black dogs buffalo buffalo white mice.

Or buffalo could be interpreted (again unusually) as a collective noun.

Jewish people [that] German people buffalo buffalo Palestinian people.

Tuesday, January 09, 2018

[sbnglams] Vertical Morse code

Draw 3 dots vertically.  Connect some adjacent pairs with vertical line segments (dashes). Of the remaining isolated dots, erase some of them.  (Some may mean all or none.)

There are 13 possibilities.  We use a comma to denote an isolated dot, a period to denote an erased isolated dot, and an underbar to denote a dash.  We describe the character from bottom (the baseline) to top.

  1. ,,,
  2. ,,.
  3. ,.,
  4. ,..
  5. .,,
  6. .,.
  7. ..,
  8. ...
  9. _.
  10. _,
  11. ._
  12. ,_
  13. __

#8 is a completely blank character.  Omitting this blank character leaving 12 seems attractive for expressing base-12 (duodecimal/dozenal).  These characters are very narrow so can be packed densely.

There are 8 possibilities (1 2 3 4 9 10 12 13) if we require the baseline to be occupied (not an erased dot).  These 8 seem attractive for octal.  There are 5 possibilities (1 3 10 12 13) if we require the character be "full height", both the baseline and top line occupied.

Starting with only 2 vertical dots, the numbers of possibilities are 5/3/2.  The 2, namely a colon and a vertical bar, seems attractive for binary.

Starting with only 1 vertical dot, the numbers of possibilities are 2/1/1.

Starting with 4 vertical dots, we need an additional character, e,g, hyphen, to denote an empty space between two dashes, e.g. ( - ).  The numbers of possibilities are 34/21/13 assuming I counted correctly.

  • ,,,,=16+ _,,=3*4 __,=2*2 _-_ ___ 34
  • 8+ _,, _., _,. _.. ,_, ,_. ,,_ ,._ __, __. ,__ _-_ ___ 21
  • 4+ _,, _., ,_, ,,_ ,._ __, ,__ _-_ ___ 13

These counts are Fibonacci numbers, though not clear why.

Monday, January 08, 2018

[iblofees] Calendar Facts

Here is a machine readable version of xkcd #1930 "Calendar Facts", perhaps useful for followup projects like creating a random fact generator.  Further notes follow.

Sequence [Atom "Did you know that",Choice [Sequence [Atom "the",Choice [Sequence [Choice [Atom "fall",Atom "spring"],Atom "equinox"],Sequence [Choice [Atom "winter",Atom "summer"],Choice [Atom "solstice",Atom "Olympics"]],Sequence [Choice [Atom "earliest",Atom "latest"],Choice [Atom "sunrise",Atom "sunset"]]]],Sequence [Atom "Daylight",Choice [Atom "Saving",Atom "Savings"],Atom "Time"],Sequence [Atom "leap",Choice [Atom "day",Atom "year"]],Atom "Easter",Sequence [Atom "the",Choice [Atom "Harvest",Atom "super",Atom "blood"],Atom "moon"],Atom "Toyota Truck Month",Atom "Shark Week"],Choice [Sequence [Atom "happens",Choice [Atom "earlier",Atom "later",Atom "at the wrong time"],Atom "every year"],Sequence [Atom "drifts out of sync with the",Choice [Atom "sun",Atom "moon",Atom "zodiac",Sequence [Choice [Atom "Gregorian",Atom "Mayan",Atom "lunar",Atom "iPhone"],Atom "calendar"],Atom "atomic clock in Colorado"]],Sequence [Atom "might",Choice [Atom "not happen",Atom "happen twice"],Atom "this year"]],Atom "because of",Choice [Sequence [Atom "time zone legislation in",Choice [Atom "Indiana",Atom "Arizona",Atom "Russia"]],Atom "a decree by the Pope in the 1500s",Sequence [Choice [Atom "precession",Atom "libration",Atom "nutation",Atom "libation",Atom "eccentricity",Atom "obliquity"],Atom "of the",Choice [Atom "moon",Atom "sun",Atom "earth's axis",Atom "equator",Atom "prime meridian",Sequence [Choice [Atom "International Date",Atom "Mason-Dixon"],Atom "line"]]],Atom "magnetic field reversal",Sequence [Atom "an arbitrary decision by",Choice [Atom "Benjamin Franklin",Atom "Isaac Newton",Atom "FDR"]]],Atom "? ",Atom "Apparently",Choice [Atom "it causes a predictable increase in car accidents",Atom "that's why we have leap seconds",Atom "scientists are really worried",Sequence [Atom "it was even more extreme during the",Choice [Sequence [Choice [Atom "Bronze",Atom "Ice"],Atom "Age"],Atom "Cretaceous",Atom "1990s"]],Sequence [Atom "there's a proposal to fix it, but it",Choice [Atom "will never happen",Atom "actually makes things worse",Atom "is stalled in Congress",Atom "might be unconstitutional"]],Atom "it's getting worse and no one knows why"],Atom ". ",Atom "While it may seem like trivia, it",Choice [Atom "causes huge headaches for software developers",Atom "is taken advantage of by high-speed traders",Atom "triggered the 2003 Northeast Blackout",Atom "has to be corrected for by GPS satellites",Atom "is now recognized as a major cause of World War I"],Atom "."]

Including the mouseover text, the grammar encodes 780,000 facts.

The above grammar is the output of "show" by a Haskell program where we typed the grammar slightly more compactly, using/abusing the OverloadedStrings language extension and a Num instance.  OverloadedStrings is a nice language extension for when we have a large number of literals in the source.  Excerpts of the full source code below:

{-# LANGUAGE OverloadedStrings #-}

data Grammar = Atom String | Choice [Grammar] | Sequence [Grammar] deriving (Show,Eq);

instance IsString Grammar where {
fromString = Atom;
};

instance Num Grammar where {
(+) x y = Choice [x,y];
(*) x y = Sequence [x,y];
abs = undefined;
signum = undefined;
fromInteger = undefined;
negate = undefined;
};

facts :: Grammar;
facts =
    "Did you know that"
    *(
      ("the"
       *((("fall"+"spring")*"equinox")
         +(("winter"+"summer")*("solstice"+"Olympics"))...