Thursday, July 21, 2016

[aykigsev] High wattage electric tea kettle

The high prevalence of NEMA 5-20R receptacles (outlets) (with the T shaped hole on one side) makes me wonder why there aren't more consumer appliances with a NEMA 5-20P plug.  The 5-20P plug may draw 20 amps instead of 15 of the common 5-15P plug, or, multiplying by 120 volts, 2400 watts instead of 1800 watts.

More wattage could be especially useful for electric kettles, computer power supplies, hair dryers, space heaters, air conditioners.

Product packaging can prominently label that it has a 5-20P plug so requires a 5-20R outlet.  People who do sketchy things like use a plug adapter to plug a 5-20P plug into a 5-15R outlet will get what they deserve, probably a tripped circuit breaker.

One could draw even more power using a 208V/240V outlet and plug, but that's usually only present in at most one place in the home, for the electric clothes dryer.

[miclqdco] Letters to keep far apart

Take the N most common words and identify words that differ by only one letter.  Enumerate the letter pairs which should be kept far apart on a keyboard layout.

Inspired by problems with (if of) (this thus) (*es *ed) on QWERTY soft keyboards.

Alternatively, given a keyboard layout, score it against the top N most common words.  First, enumerate the adjacent letters in the layout, then count the number of pairs of words that differ by only one adjacent pair, then two adjacent pairs to break ties, etc.

[idtzcdrs] More transparent dating site

A dating site allows people to rank or filter people; this is common if not universal.  Add the additional feature of a person's ranking function or filters being features by which someone else can rank or filter by.  Filter people by their filters.

The canonical example of when this might be desirable is someone looking to date someone who restricts him or herself to a certain religion.

Sometimes, a person's filters are not explicit but are implicit in the choices they make on whom to contact or ignore.  Let such implicit filters also be criteria for others to rank; they may have to be derived through machine learning.  Presenting the learned results will be a UI (UX) challenge.  Essentially, one's entire behavior on the dating site is grounds for being judged.

Of course, this might lead to madness, lots of strategic or deceptive behavior.  Probably need to thwart people creating multiple accounts.

[kwmmtnvn] Delta angular momentum

We imagine a spinning object like the sun.  Each time period, it get hits by a comet coming from a random direction in 3D, imparting a small impulse of angular momentum.  Over time, the sun's axis and rate of rotation changes, a random walk.

This can easily be modeled with vectors.  The sun's angular momentum, or angular velocity, is a vector (encoding axis and rate), and each colliding comet is another vector.  Add the two vectors in the normal way to get the new angular momentum or velocity of the sun.  It seems almost too easy.

This yields an object which rotates whose axis of rotation constantly changes.

To avoid these Dirac delta function impulses, one can integrate bounded height infinitesimal vectors over time, maybe a rectangle or a triangle or a nice spline going up then down.

To avoid the object from spinning too fast, one can add a resistance term to the integration or differential equation.

[kiixetvf] Prerequisites for changing the world

In order to change the world, you need to (well, you should) understand how the world works.  The way the world works is often very ugly.  Are you prepared to understand such ugliness?

Sunday, July 17, 2016

[msnhydsl] Dangerous caustics

Most people can recognize that convex lenses and concave mirrors can concentrate sunlight to dangerous intensities, perhaps igniting fires.  However, are there other less famous shapes which can concentrate almost as well?

Inspired by the caustics of a glass cup.  By adjusting both the inner and outer shapes (while still keeping it a surface of revolution), it seems one could conceal lens-like concentrating power from certain angles.

Saturday, July 16, 2016

[uffggnqt] Sound is cheap

In the past, publishing a sound recording was expensive, consuming a physical medium with very limited space: vinyl record, tape, CD.  Typical limit was about 15 songs on a CD, and then there is the packaging and shipping cost of the medium.

Nowadays, both with much higher density media as well as digital downloads, the cost of publishing sound is much, much lower.

A performer records a song, and then a sound engineer mixes it to make it sound just right.  In the past with limited and expensive media space, it made sense to publish only that final mix.

Nowadays, however, also publishing lots of different versions, or even the unmixed studio recordings (a track for each microphone), costs but a minuscule amount more than publishing just one track.  Of course, this requires a very different artistic philosophy than before, perhaps embracing remix culture, one which not all artists may agree.  However, artists can continue publishing just the one gold master if they wish.

Inspired by, how many songs can be published on a DVD, using modern audio compression?

Friday, July 15, 2016

[ooxwtlbm] Accretion disks in higher dimensions

It is curious that in both 2 and 3 dimensions, matter converging toward a point, e.g., a black hole, forms a 2 dimensional accretion disk.  What happens in higher dimensions?  I speculate that in sufficiently high dimensions it is not a 2D disk; there is enough space for perturbations to cause a disk structure not to be stable.

[hkjjutrv] Riemann zeta convergence

Using tricks, namely analytic continuation, we can get the natural numbers 1 + 2 + 3 + ... to sum to a mindboggling finite value, namely zeta(-1) = -1/12.  However, no tricks can get the reciprocals of the natural numbers, the harmonic series, 1/1 + 1/2 + 1/3 + ... = zeta(1) to converge.  It is truly a pole.  This is surprising because the harmonic series seems less outrageously infinite than the sum of the natural numbers.

What characterizes divergent series which can be summed versus those which cannot?

[kvdnjiez] Longevity of magnetization

Magnetostratiography demonstrates that under certain conditions, magnetization can persist for a very long time, millions if not billions of years, much longer than (say) paper or engraving onto stone.  This might be good news for magnetic data storage if the medium is sufficiently sturdy, e.g., metal hard drive platters.

Design magnetic storage with a goal of extreme long term data storage.  The data must not rely critically on firmware or other special data hardcoded into the hard drive circuit board.

[pxdspbkq] Rotating sphere script

An easy way to do something similar to the moving star field alphabet is simply to have a sphere marked with some pattern rotating on one of several axes, perhaps the 20 vertices of a dodecahedron.

[cukfvjlv] Nuclear submarines are fish

Assuming nuclear submarines generate electricity then extract oxygen from seawater by electrolysis, it is quite a milestone human achievement: we have created a way for humans to never have to surface for air, at least until food or nuclear fuel runs out.  In principle, food and nuclear fuel could both be acquired underwater.

We finally became on par with fish.  In contrast, conventionally powered submarines presumably have to surface occasionally, so are like marine mammals.

[vfyiacyf] Generating surplus oxygen

Consider generating electricity using combustion (a common method), of course consuming oxygen in combustion.  Then, use that electricity to perform electrolysis of water, generating oxygen.  Can there be a net positive production of oxygen?  Such technology would be useful on a fossil fuel powered submarine.

Alternatively, instead of electrolysis, use the generated electricity to power some machinery which extracts dissolved oxygen from seawater, like the gills of a fish.  Can this be net positive?

[oyhsjfqv] Surviving magnetic field reversals

The earth's magnetic field protects us from charged particles of the sun's radiation and cosmic rays.  It is mysterious therefore that magnetic field reversals, during which there is evidence that the geomagnetic field significantly decreases in strength, do not correlate with mass extinctions.

Hypothesize that organisms on earth (probably land organisms) have evolved to survive higher radiation during magnetic field reversals.  This is amazing as it is a capability needed extremely rarely.

What are the survival mechanisms?  Of course, DNA repair and apoptosis are two.  Hypothesize that cancer is also counterintuitively a survival mechanism, inspired by "The final checkpoint. Cancer as an adaptive evolutionary mechanism".  During periods of high radiation, cancer kills off some mutated members of the species before they can reproduce.  The mutated ones which do reproduce pass on their mutated genes to the next generation, but we hypothesize that the offspring have higher susceptibility to cancer so they may not live long enough to reproduce.  In this way, the species survives, avoiding propagating harmful mutations.  Species which have lower susceptibility to cancer, while seemingly advantageous during periods of high radiation, actually end up mutating away from optimality and it will be a much slower path of evolution to recover it, during which time they might get killed off or crowded out by species which survived better.

Wednesday, July 13, 2016

[bmheuosv] Regulating razors and blades

Consider regulation requiring that goods sold with the razors and razorblades pricing model disclose that fact explicitly.

Might be tricky: the first good is sold at a loss, but a loss compared to what?

Perhaps must disclose the intellectual property protections, usually patents, of the second good.

Tuesday, July 12, 2016

[dltiqcyy] Optimizing counting in hardware

Incrementing a counter in a register either causes large latency (for a ripple carry adder) or large area (for carry lookahead), and possibly consumes the ALU which could be better utilized for more complicated arithmetic.  Can we avoid these by doing things differently?

For small numbers, e.g., counting to 63, unary.  For large numbers, maybe Gray code?  Add support in instruction sets and programming languages.  Need a type which supports incrementing and equality testing but not other arithmetic operations.

Might be a solution in search of a problem.  Is counting (ALU utilization) a significant bottleneck?

[lijlbmvi] Features for a generated language

What features of a computer language make things convenient for tools which generate output in that language?  (As opposed to make things convenient for humans programming in that language.)

Lack of forced indentation.  Identifiers of arbitrary length.  Lines of arbitrary length.  Ability to create fresh namespaces whose names which are guaranteed not to collide other names already in scope.  Function definitions do not need to be topologically sorted, and may be mutually recursive.

Inspired by languages which compile down to C or C++.

Continues a UI idea that UIs should be usable by both humans and machines.

[hzsvabya] Searching and retrieving encrypted data

Consider encrypted data stored on a cloud storage service that charges per amount of data stored and per the amount of data transfered in and out of the cloud.

Naively searching the encrypted data by downloading it to a secure machine where it is decrypted and searched would incur large data transfer costs.  On average, half the data would need to be downloaded.

More clever would also store encrypted indices to aid search, incurring additional storage cost while decreasing data transfer costs.

Optimize the system, the construction of the indices, for given data storage and bandwidth prices.

With indices, even encrypted, access patterns can leak information to an adversary.

[kjfgtkwv] Engineering the solar system

Look for evidence that the arrangement of the planets in our solar system is artificial, highly unlikely to have occurred by chance.  Someone with vast astroengineering abilities put them there during the early formation of the solar system, perhaps part of a long plan to engineer life on earth.

Inspired by evidence that Uranus and Neptune have switched places.

[wvsyuwhe] Large finite remaining sources of energy

How many joules of energy will the sun emit over its remaining main sequence lifetime, if it could be collected with a Dyson sphere?

What is the Earth's remaining total geothermal energy (from radioactive decay)?

What is the rotational energy of the earth?

What is the gravitational potential energy of Jupiter in its orbit around the sun?  That is, how much energy could be extracted from Jupiter via gravitational slingshots, with the end result of crashing Jupiter into the sun?

[webbffll] Who gets off the planet?

At some point, the earth will become uninhabitable, at the very latest, due to white dwarf sun.  Intelligent life, it it still exists, will need to get off the planet in order to survive.

Will everyone who wants to leave will be able to?  Or will the less fortunate be forcibly left behind to die, reminiscent of the American evacuation of Saigon?

On one hand, transporting even the current population off the planet and out of the solar system will require gargantuan quantities of rocket fuel.  On the other hand, over a time frame of millions of years, with solar powered space elevators and lots of gravitational slingshots around Jupiter, it doesn't seem so bad.

It may be difficult to precisely define whether someone who wants to leave is able to leave in a migration that takes generations, and the human (or whoever inherits the earth) population might dwindle naturally due to harsh conditions.  There will be a last ship: will everyone left behind be people choosing to remain voluntarily?

[pcuviwfu] 1x1 Rubik's cube puzzles

First, we enumerate ways of describing moves of a standard color scheme 1x1x1 Rubik's cube (an object typically presented as a joke).  Rotating any face of the cube of course rotates the entire cube.

Standard move notation: Rotate the {Up, Down, Left, Right, Front, Back} face by a {quarter, half, three-quarter} turn clockwise.

Rotate the {White, Yellow, Blue, Green, Red, Orange} face by a {quarter, half, three-quarter} turn clockwise.

Rotate the cube by a quarter turn so that the {Up, Down, Left, Right, Front, Back, White, Yellow, Blue, Green, Red, Orange} face takes the place of the {Up, Down, Left, Right, Front, Back, White, Yellow, Blue, Green, Red, Orange} face.

Next, a series of puzzle templates of increasing difficulty:

The cube has {U,D,L,R,F,B} face of color {W,Y,B,G,R,O} and {U,D,L,R,F,B} face of color {W,Y,B,G,R,O}.  What is the color of the {U,D,L,R,F,B} face?  Or, where is the {W,Y,B,G,R,O} face?

The cube has {U,D,L,R,F,B} face of color {W,Y,B,G,R,O} and {U,D,L,R,F,B} face of color {W,Y,B,G,R,O}.  We do the following sequence of moves {move possibilities listed above}.  After this sequence, what is the color of the {U,D,L,R,F,B} face?  Or, where is the {W,Y,B,G,R,O} face?

The cube has {U,D,L,R,F,B} face of color {W,Y,B,G,R,O}. We do the following sequence of moves {move possibilities listed above}.  After this sequence, the {U,D,L,R,F,B} face has color {W,Y,B,G,R,O}.  We then do another sequence of moves {move possibilities listed above}.  After this sequence, what is the color of the {U,D,L,R,F,B} face?  Or, where is the {W,Y,B,G,R,O} face?

The constraints could be harder: The {U,D,L,R,F,B} face at time point T1 in this sequence of moves ... has {the same, a different} color as the {U,D,L,R,F,B} face at time point T2.  Or dually, the {W,Y,B,G,R,O} face at time point T1 is in {the same, a different} location as the {W,Y,B,G,R,O} face at time point T2.

All of these are easily solvable by considering all 24 possible orientations of the initial cube.  Doing 3-dimensional rotations in one's head is the challenge.

Sunday, July 10, 2016

[zercxrvz] Mathematics without proof

Consider radically deemphasizing the importance of proofs in mathematics.  If it is true most of the time, it is good enough.  If it is true all the time, then that is just an extra bonus.  Characterizing some of the exceptions of something that is true most of the time is nice.  Characterizing all of the exceptions (if any) is just an extra bonus.

How far could we go with this approach?  To a certain extent, it is already being done, for example, for the great many results that rely on the Riemann Hypothesis being true.

Avoids some of the aesthetic ugliness of proofs, which might impede education.

[jtjwognm] Superhero mind control

At first, it seems the superhero maintains his or her secret identity with a change in costume, a common trope.

Later, it is revealed that the superhero has mind control powers and is disturbingly erasing knowledge of his or her secret identity from those who learn of it.

Even later, the character's status as a hero begins to be doubtful as the character is revealed to be able to exercise vast mind control over the entire population.  The tales of heroic deeds might be being narrated by an unreliable narrator, also subject to the mind control.

[mukpsdue] Augmented reality world grid

Using virtual reality or augmented reality, one can see the grid lines of a geodesic global hash.  No practical purpose so far: it makes the world look like Minecraft.

[qdkhaonz] College as signaling

The story goes, graduating from business school serves as a signaling mechanism in an imperfect information game, signaling something useful for potential employers.  You don't actually learn anything useful in business school; it only the act of getting past its artificial hurdles that matter.  And this observation ironically won a business school dean a Nobel Prize in Economics.

Apply the same reasoning to undergraduate college education, where the arguments that you don't learn anything useful are even stronger.  If true, the vast government expenditure to increase access to college education, e.g., financial aid, predicated on the assumption that college teaches something useful, was for naught.  We do nowadays see evidence that a college education is worth far less than it used to.

We need to know, we should have known, exactly what that "something" is that graduating from business school or college signals.

Hypothesize that it is the financial and social support structure around a person, kind of a continuation of "it takes a village to raise a child".  When an employer hires someone, they are also hiring the entire financial and social support structure around a person.  Getting through college, in the absence of government intervention, required a large support structure, which a later employer can count on, or "exploit", to yield a high productivity employee.

[qevzlbxs] Small electric generator

Create a small electric generator powered by easily available fuel, perhaps butane, gasoline, or candle, which provides enough power to recharge a phone, USB 5 V 1.5 A (or 3 A for 2 simultaneously).

Surprised this doesn't already exist commercially.  Existing portable generators typically produce much more power (and are big, loud, and heavy), while fuel cell versions are highly experimental technologies including failed companies.

Stirling engine.  Should the cool side of a Stirling engine be blown by a fan powered mechanically by the engine, or powered by the electricity generated?

[rllgtwrb] Elegant theorems, messy proofs

A proof often resembles a Rube Goldberg machine of parts -- lemmas -- strung together in whatever way works to accomplish the task, perhaps leaving doubt: does that actually work?

This is the aesthetics of professional mathematics, an aesthetic which might not appeal to some people.

Even the most beautiful proof is messier than the theorem it proves, because it must necessarily state the theorem as part of the proof.

[zmwgsbxu] Not making one's bed

Making your bed after you wake up locks in between the sheets the moisture released by your body overnight, providing a better more humid environment for dust mites to live, ultimately aggravating the dust allergy.  Leaving your bed uncovered allows the moisture to dissipate.

However, making your bed, in many people and cultures, defines a person's value.

[lguyocsu] Faking out a camera

Consider placing a screen depicting a scene in front of a camera, say security camera, so that it records the screen scene instead of the real scene behind the screen.

The problem is, the camera's lens has been set to focus on the real scene further away from the screen, so recording a scene depicted on the screen will be out of focus.

This could be mitigated by placing another lens in between the screen and camera.  Design this lens.  This might be easy.

[kwbsmebr] Signing camera

Create a camera that signs (not encrypts) images and video it records with a cryptographic key baked into the camera.  A picture can therefore be authenticated as taken by the camera, and not edited with Photoshop.

It must not be possible to extract the private key from the camera, or else fake images could also be created and signed with the camera's key.  It must not be possible replace the camera's key with another key.  This might be a good use for DRM, though they could also be accomplished by a physical tamper-evident seal protecting the hardware.

Saturday, July 09, 2016

[rkxzutjd] Burning the world for real

Some people just want to watch the world burn.  If you are such a person, consider as a career in nuclear weapons research and development.

How true is this of those in the highly classified field?

[isroiojg] Seemingly drawable losing positions

Compose a chess position which seems at least drawable to a human on cursory analysis but which is actually losing.  The human should not notice that some line is "uncertain".

This is a rare type of chess problem, but it could be constructed from a similar and common type, the seemingly drawn position which is actually winning.  Take one of those positions and, if possible, go one ply retrograde while not destroying the outcome.

Could be a contest: a human is asked to classify positions as won, lost, or drawn, also permitting expressing degree of certainty (perhaps as odds).

Friday, July 08, 2016

[ebzgthrf] Dihedral angles in real life

If the earth were, say, a regular icosahedron, there would be ridges at edges.  Build such a ridge at human scale.  This should be easy.

Depending on exactly how gravity works, the ridge could be symmetric, approached from both sides at the same slope, or horizontal with a downhill slope on the other side from the point of view of the observer (gravity abruptly changes on the other side, probably for a game).

[bocgioqu] Peace and War

Peace causes social institutions, especially institutions of power, to become calcified.

War disrupts them.  This disruption can occur even if the war does not occur on the soil that the social institutions exist: war causes changes in an economy, then changes in economic supply and demand, especially labor supply and demand, induce changes in society, as seen in the United States during world wars 1 and 2.

Sometimes war occurs as a revolt by those feeling deprived of power in calcified social institutions.

Can this cycle, this need for something hugely destructive to disrupt calcified social institutions, be avoided?

[pjofckhw] Borrowed ladder

People have a mental model of social order.  Examine what that mental model is and how and why it forms.  Probably some aspects of social class, some aspects of Us versus Them.

When people perceive that someone is in the wrong place in that social order, and that that wrong place has been achieved by cheating, they react with hate and violence.  Examine what defines cheating, and the psychological mechanism leading to violence.

Post title inspired by Gattaca.

Thursday, July 07, 2016

[rqnvuujp] Pipe bombs

It's kind of surprising pipe bombs work at all, as a bunch of the energy of the explosive is spent turning the pipe into shrapnel.  How does it compare with a cardboard or PVC tube packed with the same amount of explosive surrounded by an outer shell of "pre-minced" shrapnel with equivalent mass as the pipe?  Does the compressive effect of the metal pipe enhance destructiveness or lethality, perhaps through higher shrapnel velocity, despite the energy wasted?

Of course, pipe bombs are more convenient (the pipe provides sturdy packaging) and easier to construct: no need to obtain or create shrapnel.

[exayhpao] Keyboard arrangements

Let "finger" be shorthand for the 4 fingers excluding the thumb.

3 rows of 4 buttons for the 4 fingers = 12.  1 button for thumb = 13.  2 hands = 26 which is the number of letters in the alphabet.  More thumb buttons for space, punctuation, etc.

5 buttons for the thumb.  2 hands = 10 which is the number of digits 0 through 9.  Maybe 6 buttons adding backspace and escape.  Perhaps for smartphone soft keyboard.

2 rows of 4 buttons for 4 fingers = 8.  2 hands = 16 for hexadecimal input.

Tuesday, July 05, 2016

[zzjjrpky] LED streetlamps

New LED streetlamps emit a bluer light (consequently whiter) than the yellow low pressure sodium streetlamps that used to dominate.  This might cause sleep disorders.

However, reverting to a yellower light will likely run into resistance, as the whiter light is likely perceived as more classy than the ugly outdated technology of yellow sodium lamps.

Ironically, yellow LEDs existed long before the blue ones which power white LEDs, or mix red and green LEDs.

[hxkdpnkr] Longest thunderstorm

Given time and location data about lightning strikes (easy to do with triangulation), compute the location that experienced the longest thunderstorm, where thunderstorm could be defined something like at least one lighting strike within N miles every M seconds.

[jupydyij] Flipping the color sphere

Consider the surface of an RGB color cube.  Project the surface of the cube onto a sphere.  Do a sphere eversion.

Consider an RGB image.  Somehow -- and this is unsolved -- map the color sphere eversion to colors shifting in the image.  I think one of the results is Red Green Blue switching from going clockwise to counterclockwise around the hue circle.  A rainbow will flip the direction of its colors in a picture.

[osaqzafp] Knight distance diagram

Create a diagram of a chessboard marked with the distance of each square in chess knight moves from the starting square of a knight, or maybe from f3.

This should be easy, though we seek creative presentations.

[nmzhizcn] Slideshow programs on Linux

Cursory research into programs in Linux which (might) show a slideshow of a bunch of images:

eog (especially consider the "Slideshow Shuffle" plugin in eog-plugins) qiv pqiv feh gnome-photos gthumb gwenview mirage phototonic viewnior xscreensaver

Selected pqiv which is small and did what I want.  Fading between images works, though is very CPU intensive and a little bit jerky for a slow 6 second fade.  Ought to use vector instructions, wherever they may be.

[ejovwvyz] Torus coloring

7 colors suffice to color any map on a torus.  This suggests interesting puzzles about whether it can be done with fewer than 7 for a given map.  For a plane, the only interesting number is 3, an NP-complete problem.

Draw a seven color tessellation on a plane and provide a rectangular (or parallelogram-shaped) unit cell which defines a flat torus with opposing edges glued together.

I think hexagons work, as well as diagonal strips truncated to the height.

[agxoruxx] Villarceau circles on a torus

A physical model of a torus with Villarceau circles marked would be nice.  Turn it around in your hands to convince yourself they actually are circles.  Clear model.  Perhaps wireframe constructed solely out of Villarceau circles.

Tori of many different shapes.

[nprbevpw] This car climbed

Bumper sticker.  Many local hills or preposterous mountains to choose from.  Inspired by "This car climbed Mt. Washington".

[btfjayig] Encoding data in poetry

Devise a method to encode arbitrary data, for example, a cryptographic key, in poetry.  Number of syllables in a line, pattern of stress and unstress in a line, vowels or consonants.

Such constraints still provide the author a lot of freedom to compose something memorable.

Prose constrains words which limits the author.

[nbpqtzeu] Two linked tori with no gap

Consider a torus with tube diameter equal to the hole diameter, so outer diameter 3 times the hole diameter.  Can 2 such tori link, rotated 90 degrees from each other, each through the hole of the other?

Or do the surfaces intersect by just a little bit?  If so, what ratio of hole to outer diameter does allow the tori to interlink?  Alternatively, what cross section, not a circle, madr a surface of revolution allows linking with no gap and no overlap?

[hhthezxg] Dress versus costume

When you put on clothes, under what conditions does it feel like you are putting on a costume?

[hhthezxg] Recognizing unsolvable 2x2

Create an algorithm that will recognize whether a given scrambled 2x2 Rubik's cube is solvable or unsolvable because of a corner twist.

[qwrzdobf] Humor

People have different preferences about humor.  In those differences is reflected all of society, especially its boundaries and social conflicts.  People often have strong feelings of love or (especially) hate toward certain kinds of humor, reflecting -- revealing -- social conflicts.

Inspired by controversy over "low", sophomoric, humor, appreciated by lower classes, targeted for censorship by the upper classes.

Previously, on horror.

[ixqtkzio] Muggings versus pickpockets

Both crimes deprive the victims of their wallet.  Is there something interesting going on where one crime is more prevalant than the other?

[egbsuyde] Correcting training examples

Machine learning will identify training examples that may have been misclassified.  Ask the human again on these examples.  If the human insists the examples are not errors, then there is something deeper happening.

Monday, July 04, 2016

[vuqzjhmd] Heptagon

rainbow heptagon

Rainbow-shaded regular heptagon.  The source code below draws it in two different ways. It is unfortunate that the JuicyPixels Codec.Picture generateImage mapPixels encodePng pipeline (implemented in the function heptagonpic) is not lazy.  A 32000 by 32000 image ran out of memory.  The alternative route, outputting a Netpbm PPM (implemented in the function heptagon) then piping standard output to pnmtopng worked just fine.

There is a curious optical illusion of radial spikes, especially in the red and cyan.

Source code in Haskell.

Sunday, July 03, 2016

[mngsrgaq] Challenge-response authentication with Google Glass

The external computer which knows your public key presents a challenge in the form of a generated QR code.  You, wearing Google Glass, scan the challenge.  Your Google Glass, knowing your private key, computes the response, and projects it into your augmented reality as a series of numbers.  You type the visible numbers into the external computer, authenticating yourself.

Of course, this could be done without Google Glass, for example, just with a smartphone with a barcode reader app.  And the response could also be communicated by other methods than typing: speech, or the phone generating a response QR code which the external computer reads with its barcode reader, or one of the many forms of wireless communication.

If typing, then 2048 bit RSA involves typing some 600 digits, probably more with error correcting codes.  Elliptic curve cryptography is a little bit more compact.

We need standardized protocols to define the format of challenges and responses.  They might not all fit in one QR code, so a protocol to animate multiple in succession to transmit multiple chunks of data.  If we permit animation, then QR might be overkill, EAN-13 (aka UPC) requires less sophisticated scanners.

The inspiration was, human-computer authentication would be so much easier if people could quickly do kilobit modular arithmetic and modular exponentiation in their heads.  With augmented reality, they can.

We need a way so that someone cannot use a stolen or confiscated Google Glass or smartphone to authenticate.

[sqdxacek] Lisp with newlines

Consider modifying Lisp to be able to interpret lines as having parentheses around them.  The goal is to decrease the amount of parentheses.  We introduce a very special form "do":

do foo bar

which when occurring on a single line with "do" at the beginning of the line (possibly preceded by whitespace) gets rewritten by a preprocessor as

(foo bar)

Without "do", things remain the same; no parentheses get added.  Some tricky cases:

do (foo bar)
is ((foo bar))

do (foo bar
is ((foo bar)

do (foo bar
is ((foo bar) baz)

do (foo bar
do baz)
is ((foo bar) (baz))

do (foo bar
do )
is ((foo bar) ())

The code gets littered with "do" everywhere, though that's not so different from other languages littered with semicolons or forced newlines everywhere.  The keyword "do" could be replaced with some more unobtrusive symbol, perhaps even a semicolon at the end of the line (analogous to "do" at the end of a line), though I dislike languages with excessive reliance on punctuation.

Exploring semicolons in the middle of lines:

foo bar ;
is (foo bar)

foo bar ; baz quux ;
is (foo bar)(baz quux)

foo bar ; baz quux
is (foo bar) baz quux

foo bar ; (baz quux
is (foo bar)(baz quux

foo bar ; (baz ; quux)
is (foo bar)((baz) quux)

(foo bar ;
is ((foo bar)

(foo bar ; )
is ((foo bar))

(foo bar ; ) ;
is ((foo bar)) ()

Alternatively, the default behavior on lines could always be to surround with parentheses, and there could be a very special form that indicates when not to.  I think this would be more confusing: invisible nothingness means something.

[amrogoed] No smoking

Smoking falls roughly along class lines in the United States.  Mentally rewrite "No Smoking" signs as "Whites Only".  One can see class warfare in action.  The signs and their enforcement are a politically correct way of making certain classes feel uncomfortable and unwelcome from a place.

Of course, one can look at the present and be ashamed at history repeating itself.  Beyond that however, I suspect understanding the present allows us to far better understand the past.

"No Smoking" in the present is not intended to be class warfare; it is ostensibly intended to ally a specific, tangible, real health concern: second-hand smoke.  Similarly, "Whites Only" in the past I suspect was not a manifestation of simple hatred of race but of something far more specific, tangible, and real.  I suspect the conflict was over something deeper, which only happened to correlate well with skin color.  (Perhaps what some nowadays call "safe space".)  Racism isn't racism, and thinking it is is what causes history to repeat itself.

[efnadktz] Political simulations

Soon computers may be able to simulate a mass of humans well enough to do accurate political simulations of specific real-world campaign tactics.

Everyone can see, and simulate for themselves, just how shallow and easily manipulatable people are.  Will this inspire people not to be so shallow?

Friday, July 01, 2016

[khionoak] Armageddon Game, part 2

O'Brien and Bashir (Star Trek: Deep Space 9) recreate the Harvesters biological weapon, with devastating consequences to, say, life in the galaxy -- perhaps Halo's Flood or Stargate's Wraith -- proving the original aliens correct that they should have assassinated everyone with technical knowledge of the weapon.

Perhaps the Federation reached a time of desperate times calling for desperate measures.

Also, the reason the Harvesters resisted so strongly efforts at destruction was because they were intelligent: O'Brien and Bashir committed genocide in the name of peace.

[tmwtbmok] Slideshow of what you own

Take a picture of everything you own, which could be useful for many purposes.  Have a constantly running slideshow in your home so you get reminded of what you own.  Avoid the feeling of "Oh I forgot I owned that" when unpacking things from storage.

Unsolved problem: when discarding an item, take another picture of it, then use automated object recognition to find the original picture of it and remove the original picture from the slideshow.

[soipwdxx] Focus and scale

Recording the focus, i.e., the distance from the lens to the image, especially if the lens distance adjusts perhaps by autofocus, I think helps establish the scale of objects (in focus) in the image.  This is very useful metadata for image understanding.

This is probably already done with EXIF.

[mmzqoeda] Playing catch with yourself

Throw a ball.  Run / jog / walk to where it landed, and throw it again.  Avoids the monotony of just running as exercise, and maybe gets some cross training in there with an upper body workout of throwing.  You are not pointlessly running, you are running to something interesting, namely the ball.

Baseball, with otherwise empty diamond: throw it toward the backstop, then toward the outfield.

Inspired by basketball shooting baskets: one needs to run to go get rebounds.

[nirurjwf] Dots and boxes with passes

Consider modifying the game of dots and boxes to permit passing.  On two consecutive passes, the game is scored in its current state.  Probably need to define who wins ties in order to avoid games ending with a 0-0 tie.

[yzjzdbid] Toddler instinct

Toddlers instinctively go through a phase in which they test limits, perhaps testing the laws of physics or what their body can do or withstand, but more famously, testing social rules much to the annoyance of parents and caregivers.

In most people, this instinct turns off, and the kid, later adult, learns to behave properly.  Examine the mechanism by which this instinct exists, and how it gets turned off.

The advancement of science depends on people testing limits.  But keeping social order depends on people not testing limits.

[wjiscipu] Playing for a safe draw

Given a chess position, find the safest draw if possible, one that offers the opponent the least chances for complications.  Traditional chess engines cannot do this because it requires quantifying safety and complications.  There is demand for this computation, famously for the grandmaster draws amidst rules forbidding draws.

[gliatcmb] Incoming interstellar transmission

To accomplish seemingly realtime communication across vast distances of space, encode yourself as a computer program, then transmit at the speed of light that computer program to the recipient.  It may take years for the program to reach the recipient.  The recipient runs the computer program locally and interacts, in real time, with "you".

[rmknucgo] Dance is addictive

Social dancing is literally addictive (for some people), likely hitting the same pleasure centers in the brain as other addictive drugs, and causing similar withdrawal symptoms on quitting.

Also, we see peddling "First one's free!"

Should it be regulated?

Also similarly, it inspires extremely strong feelings in people, including causing people to attack each other.

[vrbgaeeo] Failure to communicate well

Person A tells not the truth but the words strategically chosen most likely to achieve his or her goals.  Person B, listening, game theoretically assumes everyone communicates this way, so does not trust Person A's words.

No one assumes good faith; entire communication breaks down; communicating truth plainly becomes impossible.  Examine if, when, and where this is occurring.

Game theoretically, we would expect signaling mechanisms for imperfect information.

[joirdkvu] Enumerating strings matching a regular expression

Given a regular expression, list, in order of length, the strings that match it.  This may be an infinite list.  I think this is easy, though possibly tricky if the expression is not anchored.

[jvcgfudl] Fun with retina displays

Create a game taking advantage of the extremely high pixel resolution of some modern displays, perhaps rewarding keen short distance eyesight.

Object approaches from very far away (perspective projection), rewarding identifying it correctly first.

[wflaumdd] Certificates only as bootstrap, then WoT

Certificates are good for bootstrapping, but after that, things should mostly use Web of Trust.  Maybe both, verifying one against the other.

The reason is it is highly likely that powerful entities have compromised root certificate authorities (or can, on a whim), and are simply holding on to the capability for use when needed.  Distributed web of trust seems far more difficult for such an agency to compromise.

[bvnkegdi] Guest login with screen lock password

Log in to a guest account, as seen on Mac OS X and Ubuntu.  Add the feature of a logged in guest being able to set a password for their session.  This password is used by screen lock and unlock, allowing a guest user to lock the screen (even automatically) when away from keyboard.

I frequently use guest even on my own computers to increase privacy.

Upon logging out, the guest account, including its password, is wiped.

Upon finding a guest session with screen locked, can another user also wanting to use guest, force log out and wipe the previous guest?  Probably yes.

[ebdkngyk] Base hundred-thousand

Organizing vocabulary to express large number as powers of 10^3 (short scale), powers of 10^6 (British long scale), powers of 10^4 (Japan), or powers of 10^2 (India) is silly.  The right way to do it is powers of 10^5 or 10^10, because the rest of the number system is based on our number of fingers.

The Indian number system conveniently has a word for 10^5, lakh, from which could derive bilakh 10^10, trilakh 10^15, (a switch from Greek to Latin happens here) quadrilakh 10^20, quintilakh (10^25), sexilakh (10^30), septilakh (10^35), octilakh (10^40).  Or, Hindi prefixes.

Incidentally, novem is the Latin word for cardinal nine; nonus is the Latin word for ordinal ninth.  It is surprising that the words differ so much, compared to eight and ten.

Does any language have a good root word for ten billion (10^10)?

Previously, on expressing large numbers.

Thursday, June 30, 2016

[paouesqw] aeiouwy

Vowels and soft consonants: a e i o u w y

Any arrangement can (sort of) be pronounced, though people may not agree on the pronunciation.

Inspired by the vowel cluster in Faneuil Hall.

Wednesday, June 29, 2016

[msmzfnmj] Tricky chess

2 possibilities: the best move is not one of the obvious ones, or seemingly good moves are subtly not.  Both could happen.

Automatically detect these situations, for creating problems, either as a puzzle generator or as a computer opponent tuned to win against humans.

Tuesday, June 28, 2016

[wnjsemlg] Bug zapper hopper for chickens (or fish)

The bug zapper kills a lot of bugs at night and scatters the vaporized insect bodies over a large area below the device.  Chickens can come and feed on the bits in the day (as seen in one YouTube video).

Unfortunately, ants, active at night, might get to the bug bits before the chickens wake up (as seen in another YouTube video).

Create some sort of bug bits collection hopper shielded from ants that can hold the chicken feed until morning.  Difficulties: the bugs explode and get propelled at high speed, so the hopper must either be large or enclose; however, we do not want to obstruct the path for bugs to enter, or their view of the light.  Exploded bugs are sticky, so we need a way for the bugs to be scraped off the surface of the hopper.  Maybe the chickens can do it themselves.

An alternate idea (seen elsewhere) is to hang the bug zapper over a pond and let the bug bits feed fish, then harvest the fish.  The bug zapper needs to periodically be cleaned and maintained, so we need some way of accessing it: perhaps some swinging pole or line with pulley, like for laundry.

[cvxgcxbv] Compress then random pad then encrypt

Compression before encryption used to be unambiguously recommended because it conceals structures in the plaintext like letter frequency that could aid cryptanalysis.  However, exploits like CRIME and BREACH cast doubt on whether compression is such a good idea, as information about structure of the plaintext gets visibly leaked as length of the ciphertext.

The acceptability of block ciphers in counter mode suggest that structure of the plaintext does not need to be concealed at all, so long as you aren't doing something silly like ECB mode.  (People used to be wary of counter mode.)

Consider compressing the plaintext, then padding the plaintext with random data to the length of the original plaintext.  There may be clever ways involving the encrypting cipher itself to generate the padding.  The purpose of the compression is not to decrease transmission cost, but to conceal plaintext structure, just in case that is still useful to do.

[bypppggg] England versus Germany, part III

Mr. Einstein called: he would like to know what weapons are going to be used.

Inspired by Brexit.

[bbjtgbib] Clear before console login prompt

The Linux computer boots, displaying boot messages to console, then displaying a console login prompt.  As of Ubuntu 16.04 Server, the screen clears before displaying the console login prompt.

This is a terrible idea: the last few boot messages become unreadable because they flash by and are immediately cleared.

Worse yet, there seems to be a cron job that periodically clears the console.  This obscures previous failed login attempts.

All this is presumably to keep things looking nice, in line with Ubuntu's style of concealing as much potentially useful information as possible from the user, probably a misguided attempt to emulate Apple.

[krauckdc] Snooze

Create a device acts like a short extension cord most of the time, passing through AC power.  However, pressing a button turns off power for a timed interval, and it automatically turns back on after the interval.  (Alternatively, turns on temporarily.)

Wanted for a loud air filter to be run when people are not in the room: people push the button when present.

Sunday, June 26, 2016

[lxgoonnr] Umlaut

Incorrectly for fun: umlaût


Friday, June 24, 2016

[vvflcgjx] RSA by hand

How long would it take for a human to perform 2048 bit RSA by hand using pencil and paper?  Elliptic curve cryptography?  AES and SHA2?

Thursday, June 23, 2016

[etmmywoj] Sex as an icebreaker

Suppose two consenting people wish to engage in having sex as an icebreaker.  What is some advice for success?

It will probably only mutually work, i.e., be an icebreaker successfully, for certain kinds of people.  What kinds of people?  It probably depends heavily on what sex means to each person.

Probably the goal is to have a long conversational cuddling session afterwards.  So don't do it too late in the day when people might fall asleep immediately afterwards.

Biochemically, we are probably wanting certain hormones to become active, perhaps pair bonding.  What causes those hormones to be released?

Wednesday, June 22, 2016

[lyjmnyjg] Restaurant advance purchase

Somewhat surprising is the lack of prevalence of restaurants, especially delivery, from which one can order (and pay) days or weeks in advance, for a discount.

Ordering in advance allows the restaurant better inventory management: how much ingredients to order and avoid wasted food.  People often know their meal plans or desires in advance, so would be glad to have a discount.

[ezlejzxb] Layered societies and at large voting

In some locations, there exist multiple distinct societies layered on top of each other, living in geographically the same area but otherwise not mixing and barely interacting.  Most commonly class divisions in dense urban settings.

Such locations are not suitable for geographic-based political boundaries, i.e., legislative districts.  Instead better would be multiple legislators "at large" from a single district.

In contrast, geographical districting is useful to subdivide a very large area of homogenous society: the residents of each district can have a legislator who is physically close to them, perhaps for face-to-face discussions.

[efrbnnpw] Stay clear of white women

To what extent does the experience of growing up as an African-African male include informal education to steer clear of white women, or some certain subset of white women, who can wield much political power (playing the victim card) when accusing rape or other sex crimes against them?  (This would be similar to the informal education teaching African-Americans to steer clear of cops.)  If true, it would be a good subject for a documentary.

If you don't want to be hanging by your neck from a tree next morning, don't even risk interacting with them.  Many historical lynchings were about sex crimes, or broadly unacceptable sexual actions that the official justice system could not prosecute to the death that the lynchers deemed necessary.

(If the lynchings induced the current (hypothetical) education, then it is another case of terrorism actually working as planned.)

The issue is probably much larger than a race boundary, probably class warfare also, despite seemingly fewer actual lynchings not at a race boundary.  If the issue is common, then if one is a person (stereotypically a middle or upper class white woman) bearing social class markers indicating that people will listen to, and believe, an accusation of rape or other sex crime, then courtship life will be lonely: rationally, no one wants to risk their neck.  Game theoretically, such women will seek to conceal or shed such social markers, though this may be difficult because those markers may define identity.

Inspired by the extrajudicial social and online lynchings seen these days against sex crimes.

[exfuzqhm] Getting shit past the censors

Create a TV show depicting behind the scenes of producing another (perhaps fictional) TV show, and in particular the behind-the-scenes discussion of providing the audience with the entertainment they crave (to make the most money) but obliging the legal, political, and moral censors.

In the past with the Hays Code: (implied) premarital sex was permitted so long as it was depicted as bad, that the characters doing it suffered punishment in the plot.

Modern similar example: (implied) child pornography depicted only as bad -- the criminals who do it getting punished -- on Law & Order SVU, but indirectly satiating that demand.

[bltothha] Testing equality of algebraic expressions

Given an algebraic expression, test whether it is identical to zero for all possible assignments of variables.  How difficult is this problem?  It probably depends on the operators and functions in the expression.  I wouldn't be surprised if it is Turing incomputable.

Suppose we limit to asking whether it is zero for all but a set of measure zero, where it could be undefined or take a value different from zero.  For example, (x/x)-1.  Is the problem easier?

For all but a set of finite measure (area)?  Probably look at asymptotic behavior.

Pick a few random values and plug them into variables.  Evaluate and test if the result is equal to zero (this is potentially tricky).  If it is nonzero on a set of measure zero, then one has to have been tremendously unlucky to find a nonzero.

Difficult cases: a expression that is nonzero only for small neighborhood around the first hypothetical counterexample to the Riemann hypothesis.  Or around all counterexamples, perhaps summing up to an infinite area.

An expression which zero outside of a sphere of radius G, where G is some huge finite number.

Zero for all irrational numbers, nonzero for rationals (Dirichlet function).  Or, zero for all non-computable numbers, nonzero for computable numbers.

[pgvgjznf] Learning to intimidate

Intimidation is an important skill for success in various cultures and subcultures.  Where do people learn it, and in particular, practice it during the process of learning?

For many things, one enters the world in the most subservient status, so not an appropriate venue for practicing intimidation: child subservient to parent, new employee subservient to bosses.  Then, one can imagine lack of opportunities for first-hand practice in intimidation preventing advancement, so a feedback loop.

Learning by intimidating younger siblings.  Or perhaps male siblings learning on female siblings.  Not everyone has siblings.

Obviously, schools.  But policies against bullying may prevent people learning this socially important skill.

Of course, the fact that it is an important and socially useful skill is a larger problem.

Previous similar, learning cheating and deception as life skill.

[swpqjgej] Romiet and Juleo

Variations on spoonerizing Romeo and Juliet:

Romulet and Judeo
Romulus and Julia
Roma and Julius

(The last hinting at the classical allusion to Caesar hidden in the original names.)

[mghvqkqf] Luddites as a protected class

Technology marches forward at (seemingly) exponentially faster rates.  Network effects, broadly, might induce everyone to adopt some technology.  However, the effect of a technology might require generations to properly evaluate.

Consider making people who refuse to adopt some technology a protected class, with the government providing them social assistance, in order to generate socially useful data about the delta effect of the technology.

(We currently already get such differential data from third-world countries who simply lack access to some technology.)

The protection lasts only a generation or two from the introduction of the technology, probably invalidating protection for most instances of people stupidly refusing vaccines.

[viuowpxi] NP superhero

Tell the story of a superhero whose one superpower is the ability to solve all NP problems in polynomial time.

As a comic superhero with a mostly useless power, maybe the exponent of the polynomial is extremely large (but finite).

[pchtgjiu] League of mutual trust

What competitive sport offers the greatest opportunities for surreptitious cheating?  Hypothesize correspondence chess with a prohibition against external assistance including computers.  Then, form a correspondence chess league among friends who trust each other not to cheat.

More interesting than the game is the trust network.  When will such trust networks form?  Can they be leveraged for something else?

[agicfnee] Extracting a scrambled tar file

Consider a tar file, or some other archive format of many files, which is becoming available as blocks in random order, perhaps through bittorrent.  Unpack the files in the underlying archive as they becomes available, instead of storing the whole thing then unpacking it.  This is to save disk space.

Blocks corresponding to incomplete files will require some overhead.

Bittorrent itself however already has a mechanism for distributing collections of files as one torrent.

[bocuoafx] Surface of a hypercube

Probably the easiest non-Euclidean 3D manifold to model, perhaps for flying around in virtual reality, is the surface of the hypercube.

What happens at the corners?  Probably easiest is you can see into neighboring cubes, but you cannot see "around the corner" into neighbors of neighbors.  Or maybe you can; things get weirdly replicated as if some strange mirror.

[obwwlxut] Gluing polyhedra

Consider gluing matching faces of polyhedra, building structures.  For example, regular dodecahedra will not tesselate space, but I suspect one can build interesting helices (spirals).  Boerdijk-Coxeter helix.

Limit to polyhedra with faces with regular polygons of unit side length to keep things simple.  Though star faces and star polyhedra could be included.

Hinges if relaxing to join only at an edge. Joints for joining only at a vertex. Restrictions of faces to regular, and edges to be unit length, can correspondingly be relaxed.

Previously similar in 2D.

Easiest to do it in virtual reality.  In 2D or 3D we seek user interface tools which provide nice feedback when a polygon or polyhedron clicks into place correctly next to another one.

[gigcoraf] Gluing unit line segments

Consider a drawing or modeling program in which the unit line segment joining others at its endpoints is the only primitive.  Shortcuts for regular polygons.  Also including stars, apeirogons.  Shortcut for rhombus of useful angles, probably constructing an edge parallel to another one, or complete a rhombus given two edges meeting at a vertex.  Shortcut for a polygonal arc between two points.

Higher dimensions (wireframe nets), hyperbolic spaces.  Abstract polyhedra.

[zhqntonf] Animations for documentation

In a Rubik's cube program controlled by keystrokes, useful would be animations depicting what each key does.  Alternatively, click on an animation to operate (awkwardly) by mouse.

12 quarter turns of faces, 6 whole cube rotations.  More for slices, 2 layer turns.

[nmimkviw] Political philanthropy

Where should one donate to maximize the amount of political support in return, from recipients of the donation or their supporters?  This has probably been worked out by the rich.

One scenario is money which has been obtained through nefarious means.  Donate (some of) it in return for political support in case you get in trouble for the nefarious means by which you obtained the money.

Inspired by Sandy Jenkins, Collins Street Bakery.

Probably the best is to donate to political campaigns, though there are some devils in the details.  Does this help explain why there is so much money in politics?

Probably not donate to the poor, because the poor have little political power.

Donate to something people like, and attach your name prominently to it, in hopes of political support from them later. Conversely, if you see a name prominently attached, hypothesize the money was obtained by nefarious means.

[rkadsatq] Random samples of infinite precision floating point

Using a stream cipher in the background, one can simulate uniform random samples of infinite precision floating point numbers within a bound, e.g., between 0 and 1.  Behind the scenes, only a random key for the stream cipher is being sampled.  The sampled infinite precision floating point number can have as many digits or bits as needed generated on demand.

Comparing such a number against another, or against a rational number, is easy.  Arithmetic is harder, including radix conversion.

Can one do non-uniform random samples, e.g., normal distribution?

[tkcnbjxy] Time indexed random slideshow with varying time per slide

Consider slides in random order for which the time serves as an index.  However, if slides take varying amounts of time to display, things become tricky.

One way to do it is to schedule blocks of slides at a time.  Perhaps an hour worth of slides is precomputed from that hour's random seed.  The total number of slides shown in the hour is varying, depending on which slides took longer.  One can later know what slide was shown when from recovering the random seed computed from the hour, then linear search by time.

Avoid repeats between blocks by the following approximation: compute not just the current hour but the blocks 2 and 1 hour before.  Assume all slides were shown 2 hours before: this is an approximation.  Compute the approximated block 1 hour before avoiding repeats with the approximated block 2 hours before.  Compute the current block avoiding repeats with approximated the block 1 hour before.  We must use approximations and not reality to avoid an infinitely long Markov chain into the past.

Need to do slight fudging to cause each block to be exactly 1 hour.  For example, scale everything by time.

Saturday, June 18, 2016

[tpshqjtc] Scale constraints

Additional possible features or constraints on scales: No more than 2 consecutive semitones.  No more than 1 consecutive augmented second.

[mdmpfmxv] Learning the derivative work first

Traditionally, learn, or be exposed to the source work first, then the derivative work, to understand and be able to enjoy the context.

But people can and do do it the other way around, an interesting mental task, perhaps mentally filling in the gaps or remaining not unpleasantly confused.

Sometimes the much later derivative work has been better adapted to a modern audience.

Watch the movie based on the classic book first, or after?

The cover of an old song?

[ontfqsow] Find the geodesic

A player races through a manifold, seeking the shortest path.  Unlike most racing games, speed does not matter.  Animation could depict where other past racers were for your current distance.

Perhaps race through a tube of varying curvature and width.  The racecar travels "in a straight line" if given no input, though that might be a tricky concept on curved manifolds.

Even finding the shortest path between two points on the surface of a cube is nontrivial.

Perhaps different skill classes for corresponding to the minimum speed permitted.  Higher minimum speed is harder.

2D and 3D manifolds.

Friday, June 17, 2016

[ekqxqqlx] Crowd sourced improvements

An artist publishes a work, then solicits suggestions for improvement.  The artist then incorporates some of the suggestions into additional versions of the work.

Most ambitious would be to do it for a movie, after it comes out in theaters.  The released DVD contains additional scenes filmed from the suggestions, that the audience can splice in if they want.

Some sort of crowdsourcing platform in which the good ideas get voted up.  Need ability for collaboration, but also forks and merges, an unholy union of git and reddit.

Issues of copyright: Creative Commons CC-BY, or ambitiously CC-BY-SA probably works.  Cannot have NC.

[guoaramf] Nightclub mass shooting

Nightclubs, by design, induce in their attendees the extremes of human emotion: extreme joy and extreme sorrow.  Hopefully more of the former, which is why people attend, but there are sort of zero-sum or conservation law effects that can occur.

If a nightclub doesn't have a mass shooting every once in a while (where once in a while might be something like once in a thousand years), it's probably doing it wrong.

Inspired by Orlando.

[lggcstux] Enforcing black market contracts without guns

How are contracts and other rules enforced in regions that have strict gun control?  There remains a mutual demand for some system of dispute resolution in parts of society, usually the bottom or untouchable classes, not adequately served by the normal justice system.

[ecabziqn] Base 100

Create a character set to express numbers from 0 to 99, as two small characters stacked vertically, so they take up no more space than a single typical Latin character.  We want it to be legible at low resolutions, so traditional numbers reduced in size probably won't work.  Here is an idea based on various accents:

ring (angstrom)
single double grave acute accents
circumflex hacek
left right wedge

[zzmvhoye] Button push energy

What can be done using only the energy of a human pressing a button?  For example, how much computation?  For more energy, pull a lever.

[taejefur] Gruntled

Rate yourself as an employee on a scale of disgruntled to gruntled.  The company gruntling activity will be tomorrow.  To gruntle or disgruntle, that is the question.

[tshdekbn] T ball

Consider radically modifying baseball by eliminating the pitcher.  Instead, the ball is hit off a tee, like in youth leagues.

Probably also eliminate the home run.

Need some way of making hitting harder, so the batter cannot easily control where the ball will go.  This difficulty exists in golf driving.  Maybe lighter, more textured ball.

Ball could be levitated by Bernoulli effect: it bobs in the air.

Base stealing either no longer happens, which would be sad, or needs to be significantly modified.

[sbodhkvz] Bug zapper webcam

A live webcam of a bug zapper in action would be entertaining.  ("You might be a redneck if...")  Difficulties / desired features:

Brightness and contrast: ideally the camera's vantage point would be from inside, so the light is behind the camera.  And cylindrical fisheye, probably synthesized from multiple cameras.

If not filming from the inside of the device, one way to avoid the brightness of the light is to have it flicker at a very high rate, then have the camera shutter synchronized to be open when the light is off.

Desirability of slow motion and magnification.  The sound it makes could be a useful cue of what to replay in slow motion.

12 hour replay, 6 month replay.

Some sort of machine learning to detect when the bugs are out and the lamp is most effective.  Of course, a light sensor can be one component.  Some reports that it can also be effective during they day when it rains the the bug zapper is covered from the rain: bugs seek shelter from the rain.

Some way of cheaply attracting mosquitoes.  Attractant (octenol) is reportedly expensive.  Generating warm CO2 should be easy.

Some way of easily cleaning it, including the bug bits that get splattered on the camera lens.

[btwrpvds] Ecology of bug zappers

Electric bug zappers preferentially kill bugs attracted to the light.  It could therefore increase bugs not attracted to light, for example mosquitoes, as they expand to fill the ecological niche made empty.  Also, as it decreases bugs, it decreases food for bug predators, so decreases bug predators, which do not preferentially eat bugs attracted to light.  The decrease in predators could increase the prevalence of certain bugs.

Monday, June 13, 2016

[qzjqopja] Slow fade

In a slideshow, when switching from a very bright image to a dark one, or vice versa, the fade should be slower.

Problem was observed between regular and inverted astronomical images.

[qzjqopja] Autonomous DJ

The advantage of listening to music at a music venue, e.g., dance venue, is that someone else, a DJ or music director, picks the music for you.  A sophisticated DJ could program on the fly, adjusting the playlist by observing the audience.  A less sophisticated DJ could incorporate feedback offline for the next iteration of the event.

The task of observing and incorporating feedback into music selection seems like a very human task; I don't see machines (e.g., machine learning) ever doing a good job at it.  People rarely give obvious and useful feedback about how they feel about the overall music selection, unless it is really bad.  There are even sociological and political decisions to be made: some people may be happy about the music, some people may be sad: which group is more important?

[gfyiiqdh] Controlling your account

Desired generic features for account access (authentication):

Multiple keys, probably challenge-response with public-key cryptography.  Making it look like password authentication can be delegated to a trusted third party.

Set and run arbitrary policies regarding how keys must be used to access the account.  Perhaps several keys are needed simultaneously, some controlled by 2 factor authentication mechanisms using a trusted third party.

Set and run policies regarding how keys must be used to modify the account access policies, for example, revoking a key.  Perhaps more keys are needed than mere account access.

Logs for key usage, sent off site to a trusted third party.

Devil in the details of these trusted third parties.

Sunday, June 12, 2016

[ahnojrec] Context free matching

We don't seem to have easy to use tools like grep or regular expression libraries for the next step up in the Chomsky hierarchy, namely context free grammars.  (Bison and yacc, happy, parsec, etc., exist, but they are rather cumbersome compared to regular expressions.)

Two cubic time parsing algorithms: the Earley algorithm and the Cocke Younger Kasami algorithm, with plenty of opportunities for optimization.

It might be lack of demand.  Regular expressions might be enough, especially with non-regular extensions like matching backreferences in perlre.

Regular expression matching by default is unanchored: look for a match anywhere in the string.  Context free grammars are by default anchored at the beginning of a document.

Regular expressions typically process one line at a time.  Context free grammars typically process the entire document at once.

[cogormuc] Interactive live music

In response to the advancement of technology in recorded music, live music, or live entertainment in general, should push what live can offer but recorded cannot.

Generically, one of those things is interaction between the performer and audience, though the devil is in the details.

Sometimes, perhaps often, people psychologically want to passively consume entertainment without interacting.  The performer could still passively observe the audience, but this may also be unsettling to people not wanting to be observed.

[rscsprka] Molecule T-shirt

Create a T shirt with a molecule depicted on it (of course, not an original idea).  There are many, many different molecules to suit different people's different preferences.  Probably custom one-off printing.

We need a searchable database of chemicals: these already exist, though not targeted to the general public seeking images for a T-shirt or other art.

[diolwckq] Boring sex as a way of driving people away

Consider a hypothetical society in which no one explicitly says no to sex: the lack of desire for (further) sex is communicated by lack of enthusiasm and bad chemistry during sex.

Could such a society exist?  If so, what allows it to be possible?  Does it exist?  If this is the accepted custom of both sides of sexual interactions, it will interact poorly with some expecting consent culture.

It exists in dance culture: people tolerate one bad dance, then the nonverbal message is don't dance again with someone you have bad dance chemistry with.

[jpctmsco] Fun with racism

Let's not be racist, we say, and we enact civil rights reform.  Then we're racist again with the War on Drugs.

Distill this human fallibility of making this same mistake over and over again, despite the best of intentions, into a game, to illustrate it and highlight it and maybe prevent it.

I strongly suspect it is repeating again in "safe space" and "consent culture".

[peonnolm] Piece power in large chess

We consider large square board chess variants which are formed by simply increasing the number of rooks and bishops (and pawns).  For random positions (leaving unspecified what is "random"), what percentage of squares are attacked?  How does the percentage change as the board size increases?

The worry is that as the board size gets larger, because the relative portion of the board a single ranged piece can attack shrinks (curse of dimensionality), so the game will devolve into a boring game with relatively weak pieces.

What percentage of the board can be attacked in 1 move (the above was considering attacking in 0 moves)?  On an empty board, a rook can attack any square in 1 move, no matter the size of the board.  For large boards, the relativity sparsity of pieces might aid the ranged pieces.  Is being able to attack in 1 move useful?  The defender can often escape in 1 move as well.

If we need more powerful pieces, we could consider pieces that can fly or do hook moves or drops, though drops are similar to attacks in 1 move since you cannot simultaneously drop and capture.

[frbdkpfx] Shadows for the flying piece

A flying chess variant piece may move to any square in a region, perhaps the whole board, perhaps a portion.  Modify it so pieces in the way can cast shadows, blocking flight.  A piece at the same rational slope but closer blocks flight to a further square.

[rgqohbgl] Nuclear warfare for fun and profit

Nuclear weapons are seemingly only defensive weapons: if a country uses one offensively, they will suffer a devastating nuclear counterattack from either the country attacked or its nuclear allies.  Iran, say, cannot offensively launch nuclear strikes against Israel or Saudi Arabia without incurring its own immediate obliteration.

That said, devise a means for a country to surreptitiously use nuclear weapons offensively against an enemy country.

First idea: give the weapon to a terrorist which cannot be traced back to the offensive country.

Second idea is more dramatic: stage a "fake" invasion by the enemy country, then use nuclear weapons against the invading enemy in the guise of defense and counterattack.  The "fake" invasion is militarily real; it's fakeness derives from the surreptitious political engineering done beforehand by the offensive country to induce the enemy country to launch a real military invasion.  This "fake" invasion could even be a nuclear attack, somehow convincing the enemy that incurring nuclear counterattack is "worth it".  This is the kind of intrigue I could imagine the Mossad or CIA doing: both supporting Iran's nuclear program enough to build one bomb (survivable for Israel or Saudi Arabia or the United States), as well as supporting the growth and popularity of religious extremism ("worth it") in Iran, all for engineering an excuse to literally wipe Iran off the map.  Perhaps ultimately to control the oil below.

Inducing a country to become extremist is not difficult: people become nasty when there is only a small piece of pie to fight over:  economic sanctions should work.

[xklbsncv] White actors

American political correctness (in arguments such as cultural appropriation) likes to place non-white actors in films, but have them act in a way that white audiences can relate to (because making money off white Americans is the bottom line).  Inspired by Western remake of Ghost in the Shell.

However, more interesting from an acting and screenwriting standpoint would be the opposite: white actors accurately acting non-white.  Someone from another culture watches the film and thinks, "That's me / my culture!  I've never seen me accurately depicted on screen (in an American film)!  Even though of course the racial features are of course not accurate."  This is, of course, not a good way to make money off of white Americans, who will not appreciate it, and may even find it unpleasant.  Even foreign viewers unable to suspend disbelief might find the cognitive dissonance unpleasant.

Reversing again, we might see it in foreign films aimed at the American audience, those that do well with Americans.  Though we do need to distinguish between a foreign film doing well universally (because it appeals to something universal in humans) or specifically for Americans.

[swgdfuit] Chinese literate cube vlogger

Youtube Rubik's cube and twisty puzzle video bloggers, for unboxings, inevitably say they cannot read the packaging and inserts written in Chinese.  The world waits for a bilingual vlogger to read and translate.

[mltmrseb] Importance of sexual orientation

For some people, their sexual orientation matters only for the type of porn they prefer to watch (and is just one of the many preferences affecting which of the zillion categories of porn one can watch).  For others, it means much, much more, strongly affecting major life decisions.  What causes this difference in people?  Probably (among other things) differing social structures around courtship and marriage.

[cfevdefa] Yulong mix and match

The stickerless versions of the YJ Yulong speedcube come in several different shades: original colored version, fluorescent colored version, pink version, and transparent version.  Can they be disassembled and pieces from different shades combined?

[kifeqdlu] Random uniformity in selection with replacement

Keep track of how many times each element of a set has already been selected.  To select the next item, first uniformly select a subset of N items, then choose the one among the N which has been selected the least.  Increment the counter of that one.  Replace to do the next selection.

What kind of probability distribution does this induce?  Parameter N.

Not memoryless.

[rpaorwrc] Lingua franca for science

Through various times in history, Greek, Latin, and English have been the lingua franca of science.  Possibly others: Arabic, French, German.  What are desirable features for a lingua franca for science, assuming we could switch away from, or modify, English?

Ability to coin new words, with guessable meanings, for new concepts.  English reaches for Greek and Latin roots: not great because it requires knowledge of Greek and Latin, but it works.

Easy to write.  Modern printed English has this; logographic languages like Japanese and Chinese are much harder to write, both for human input and for typesetting.

Machine readable with OCR.  Again, modern printed English is pretty good, though mathematics is difficult.  This is a vague vision of the future in which computers may be doing a lot of knowledge mining.

Ability to be precise in meaning.  I'm not sure any language is any better than any other language on this point, especially because languages are living, so can be modified as necessary for when precision is demanded.

Easy to learn, at least the subset used to communicate science.  English, with its tricky grammar and spelling, gets criticized on this point, though all living languages accrue complexity making them difficult to learn.

Easy to translate, especially machine translation.  Of course, this depends of the distance between the two languages.

Easy to speak well enough for others to understand.  Most languages do not have the unvoiced and voiced th sounds of English, but substituting s and z is still intelligible.  Other difficulties: r/l, r-colored vowels.  In contrast, I suspect tonal languages would not be easy for nontonal native speakers to learn.

[odbusmig] Shadow QR

Create a representation of a QR code in which the dark pixels are the result of shadows.  This should be easy.

Readable only when the light is just right.

[fzlbdedr] Dirty QR code

Write a QR code with a medium in which the dark pixels gather dirt at a faster rate than the light pixels.  Maybe outdoors.  It becomes more readable over time, perhaps starting out invisible.

Maybe plants growing or not growing.

[awivvish] Slice only Rubik's cube

A Rubik's cube limited only to slice moves is a relatively easy, though not trivial, puzzle.  Having a nice speedcube helps, not an original Rubik's cube.

Can every state in which the corners have not moved but the edges have be reached only though slice moves?  I'm guessing not: superflip is one such position.  How many distinct orbits are there?

[mbzbnejs] Transmitting whispers and shouts

Create a communication device with which the speaker can speak extremely softly, e.g., whisper or mumble, and a listener on the other end can hear it intelligibly.  However, if the speaker were to speak loudly, the listener's can also comfortably hear it without getting eardrums blown out.

Can the speaker speak softer than a whisper?  Perhaps some lip reading sensor as the speaker simply mouths the words.

[fjplwwta] Soccer with hands

Consider modifying soccer (association football) so that touching the ball with one's hands is permitted if one is not in contact with the ground, i.e., only when one is jumping.

Partially inspired by reports of injuries and brain damage from heading the ball.

[bafalspi] Midichlorian long game

If we are to believe George Lucas's story, the midichlorians saw or foresaw that Palpatine was, or was going to become, too powerful, so they engineered the conception of Anakin Skywalker to assassinate him, to bring balance to The Force.  Their plan did eventually work, though through tremendous convolutions: Anakin had to become the Emperor's confidante, beget a son (Luke), and only though his love of his son would he find motive and opportunity to turn and kill the Emperor.  Killing the Emperor came at extremely high cost: the deaths of almost all the Jedi as well as a galactic civil war.  The midichlorians are either extremely cold hearted in how they achieve their objectives, or the Emperor must have been extremely important to kill.  (One wonders how much worse things would be, or could be, if their plans failed and The Force became extremely unbalanced.  Maybe the universe would have ended.)

And through all this, the Emperor, both possessing prescience and knowledge of The Prophecy, was still unable to foil the midichlorians' plan, and in fact walked right into their fatal trap.

[diqmmpkm] 3D rotations game

Create a game based on the mental challenge of visualizing compositions of rotations in 3 dimensions.  Rotations in 3D do not commute.  Such visualization is something people can get better at with practice.

Two people, one cube with distinctly marked faces.  They take turns rotating the cube according to some rules about what rotations are permitted for a given player on a given turn.  Whoever achieves the goal orientation state wins.  Or dodecahedron.

Rotations of a sphere (a Lie group).  Perhaps some mechanical device that limits the rotations permitted from the current state.

[qupzduyt] Best case scenario boundaries

Everyone has sexual boundaries (this is knowingly an incorrect assumption) that vary case-by-case, depending on some characteristics of the person being interacted with.  Then, consider a person's most permissive boundary, the best case scenario, for a class of interactions, for example, hook-ups with people one has just met.

Do people differ significantly among where their most permissive boundary is?  Or is everyone boringly the same, anything goes, in the best case scenario?  If people differ, what causes the difference?  Presumably some social indoctrination mechanism, the details of which we seek.

"I pledge to be monogamous to you, except for the following list of celebrities..."

Of course, the other critical question is, what characteristics of the other person cause someone's boundaries to be more restrictive than their best-case-scenario boundary?

[szxvamew] Lebensraum and Japan

In the Lebensraum arguments that convinced Nazi Germany to invade the Soviet Union, did they correctly predict, and give the correct mechanisms for, the economic stagnation and demographic problems now seen in Japan?  Did anyone in Japan correctly predict the current economic state of Japan?  (Predicting the low birth rate would have been quite a radical prediction.)

Germany itself so far does not seem to have suffered gloom and doom from not having room to live.

[zyzvfioh] Antipodal scramble

A rough idea of judging whether a scramble, perhaps hand scramble, of a Rubik's cube has been done long enough is that "things" have gone through a state that is as far from the solved state as possible.

For example, every cubie has an antipode: during the scramble, every cubie must have passed through its antipode position at least once.  Or, every cubie must have passed through its original position, but in an incorrect orientation.  Or both of the two conditions, in either order.

Other variations possible, including the very difficult diameter of the full Rubik's cube graph (God's number).  Or, always start scrambles from Superflip.

[wgqpqyrk] Journalism providing the choice to avoid preconceptions

An online news article can provide options to hide people's names, genders, locations, and other markers that people use to form preconceptions based on stereotypes.  Hidden is the default; the reader has to actively choose to see those things, actively admitting that he or she wants to judge by those features.

[cnmvmhvm] Chess position evaluations priority queue

The next iteration of chess opening play out will probably not play until end of game; instead, concentrate on just the opening phase.  Instead, it will explore a much wider set of openings.  Rough idea is that the outcome of the game is sometimes obvious when the middlegame rolls around, and computers of the future will easily be able to play out the remainder of the game.

Put the unevaluated positions in a priority queue.  Components to calculate priority: total weight of position using chess piece values, move number, distance from main line (number of calculated moves).

[fzvwljod] i18n

For what software is it important to translate a (say) English UI into the local language?  For what software can the user figure it out, either by translating from English themselves, or figuring it out by intuition or similarity to other interfaces?

Proportion of the software's users who have learned English as a second language.  How many different things does the program do?  Is what it does obvious?

Tuesday, June 07, 2016

[jqjbsphx] Economic ties preventing war

Hypothesize that close economic ties prevent war.  Because war is a negative sum game, we should obviously get on implementing this as soon as possible.  But we aren't.

Is the hypothesis wrong?  The devil is in the details of the implementing the economic ties: are the details too difficult?

[lvbilfti] Computer safe

Create a container in which to keep a running computer so that it will do an action if it detects that it is being tampered, e.g., in a law enforcement raid, perhaps wipe cryptographic keys.

The container could be the size of a computer case, or the size of a room or house.

Previously, for data centers.

[mnzboovz] Developing opening theory

Optimistically, one can describe the development of chess opening theory as a vast distributed computing project spanning centuries, seeking ground truth.  Computers can continue this computation, and they do it well.

Pessimistically, and realistically, theory develops in the direction of offering the best "chances" against an opponent unfamiliar with the position, while also minimizing risks if the opponent is familiar with the position.  It is a psychological struggle about the familiar and unfamiliar, human fallibility, a risk-benefit analysis with probabilities.  This is very different from how computers play the game, at least currently.

The original idea was, chess at the highest level, with paid competitors and widely published and studied games, should pursue the noble optimistic goal above, advancing the state of knowledge about ground truth.  The game at the highest level should be modified to best further the search for truth: probably incorporate computers and databases into at least the opening phase of the game, e.g., Advanced Chess.

However, chess at the highest level (and every other level) is actually mostly played according to the pessimistic interpretation above: how can I trick my opponent, for one game only?  I mostly cannot see how that can be changed, except maybe for matches.

Incidentally, correspondence chess, despite computers, is also closer to the pessimistic interpretation: how can I avoid the weaknesses in my chess engines and exploit the weaknesses in my opponent's engines?

Actual ground truth in chess is probably that it is a draw.

[xixnyibs] Predictions of behavior based on appearance

Look at someone, for example, how they dress.  Make predictions of how they will behave based on how they dress.  (Continues the idea that a person is concretely their actions.)  When are the predictions accurate?  When they are, why are the predictions accurate?  That is, what common cause directs both how a person dresses and how that person behaves, yielding correlation?

Inspiration was gender conventions of dress: masculine and feminine dress.  If you see someone in feminine dress, what can be accurately predicted about their behavior?  If you see someone else otherwise similar but not in feminine dress, how is their behavior predicted to be different?  Many people have an intensely strong compulsion to dress according to their gender convention: not doing so is intensely uncomfortable or distasteful.  Whatever mechanism programmed that compulsion, what other behaviors did it program?

The markers of masculinity or femininity are complicated social constructions, but they are just the surface.  Looking deeper: Why does, say, femininity matter?  Why do the behaviors correlated with femininity matter?  Wild guess: imperfect information signaling mechanism to convey "I will be a good parent".

Often dress communicates social class.  However, masculinity and femininity seem separate concepts from social class.

[qhxkqcjf] Recording the hashes of web objects

A reputable web crawler creates and makes available an index of (URL,hash of content) tuples.  Maybe also add size.

Later, a user, wanting the content of a URL that is dead, looks up the URL in this index and gets the hash.  The user then offers a prize to anyone on the internet who can supply content that hashes to the given hash.  This can be verified automatically, though the details might be tricky.  Probably need reputable broker or escrow.

[afjmfoiy] Hopes versus reality

The people you are attracted to represent your hopes.  The people you can get along with in a relationship, people you are compatible with, represent reality.  Conflict and turmoil abound if hopes do not match up with reality.

Examine the mechanisms by which attraction and hopes form and reality occurs, and why they diverge.

The canonical example is people hope to marry up in social class, but habits and behavior makes them compatible with only their social class.

[hpgosidz] Arc length parametrization

Given a vector valued function F(t), derive its arc length parameterization, that is a function T(s) such that F(T(s)) moves along the arc at constant speed as s increases at a constant rate.  We need automatic or numerical differentiation, quadrature, and root finding to invert the arc length integral.  There might be a trick of inverting before integrating (implicit differentiation) to avoid needing root finding.

The motivation was for a color wheel (future post), needing to have a path that moves in CIELab color space at constant speed along a path that was specified in RGB space.

[keqnlqpx] Foods that are MSG

Ajinomoto (of course)
Nutritional yeast
Sazon de goya
Hydrolyzed vegetable protein
Tomato sauce
Fish sauce
Bonito flakes
Worcestershire sauce
Soy sauce
Liquid aminos
Cured meat, aged meat
Cheese (e.g., Parmesan)

It's not that these foods merely contain MSG -- they do -- rather, the entire point for the existance of these foods -- why they got processed from their original state -- was to break down their proteins to release glutamate, the source of the savory or umami flavor.

(OK, for some things, preservation may have been a higher priority.)

[smbspqku] Salsa20 is not quite block cipher

The Salsa20 cipher core is reversible, so it almost looks like a weird block cipher running in counter mode to yield a stream cipher.  It takes 128 bits of plaintext (the nonce and block counter) and yields 512 bits of ciphertext.

(Exercise: implement Salsa20 "decryption" by reversing its steps.)

Unfortunately, running the Salsa20 core backwards from the 512-bit ciphertext can be done without knowing the key.  And doing so yields not just the plaintext but also the key.

[ggafstnp] OH

One handed puzzles are surprisingly gratifying because they leave the other hand free to do something else, e.g., eat or operate a phone.

What is the best one-handed mechanical puzzle?  The classic is a small, loosely tensioned Rubik's cube, but that is a considerable dexterity challenge.  2x2 is easier.

[kdcvedsi] Completeness of the half turn universe

Restricting oneself only to half-turns (no quarter turns) on a Rubik's cube results in each face having at most two colors, the colors of opposite faces.

Is every reachable state (allowing quarter turns) that has such a coloring reachable with half turns only?

[kssyiyrg] Spherical sheep

Consider the task of generating random pretty images like the Electric Sheep project, but on the surface of a sphere.  Enjoy the presentation on a spherical display, or with virtual reality from the inside of the sphere.

With virtual reality one can also add depth, perhaps wisps of colored translucent gas or kaleidoscopic polyhedra flying around.

There remains the details of encoding images and video for the surface of a sphere, though astronomers have already solved this with HEALPix.

[wcqswupy] Extracting the recursive image

Given pixels organized recursively, extract a rectangular, or polygonal, region, grouping together consecutive reads.

[uzuxktcw] Table with indexed notes

Table cells are too small to hold large amounts of text.  The standard technique is instead to put in the cell a numeric or symbolic footnote reference, and then have footnotes below the table.

We could do a little better than just a number: a several letter code or abbreviation can give a hint or summary of the contents of the footnote.  The abbreviations are given in alphabetical order below the table.

Inspired by Wikipedia tables, which make numbered footnotes easy, perhaps too easy.

[syyzxjtl] Turn of the wind-powered screw

An endorheic lake, or one with very slow outflow, stratifies, most obviously by temperature.  Consider installing a screw-like pump to mix the layers.  The screw can easily be powered by wind, or possibly even by the temperature gradient.

This may of course drastically affect the pond's ecosystem.  A solution in search of a problem.  What flux thoroughly mixes the pond?  Very slow might still be effective.

Stuff from the bottom of the pond getting caught in the pump is of course a problem.