Tree Mountain

http://www.flickr.com/photos/amymyou/518300581/
Image: Flickr

Twenty years ago, 11,000 people planted 11,000 trees on an artificial mountain near Ylöjärvi, Finland. The trees were planted in a mathematical pattern based on the golden section; in time they will grow into a virgin forest each tree of which has a designated custodian. The trees can change ownership, but they can never be removed from the forest, and the mountain itself can never be owned or sold.

Artist Agnes Denes conceived the project in 1982, and the Finnish government undertook it 10 years later. The site is legally protected for the next 400 years.

| Art

Lifeboats for All

In 1993, I attended a technology and art conference, ‘Ars Electronica,’ in Linz, Austria, where my former postdoctoral student Pattie Maes gave a talk titled ‘Why Immortality Is a Dead Idea.’ She took as many people as she could find who had publicly predicted downloading of consciousness into silicon, and plotted the dates of their predictions, along with when they themselves would turn seventy years old. Not too surprisingly, the years matched up for each of them. Three score and ten years from their individual births, technology would be ripe for them to download their consciousness into a computer. Just in the nick of time! They were each, in their own minds, going to be remarkably lucky, to be in just the right place at the right time.

— MIT roboticist Rodney Brooks, Flesh and Machines, 2003

| Technology

The Halkett Boat

https://commons.wikimedia.org/wiki/File:Halkett_Boat_Cloak.jpg

Royal Navy officer Peter Halkett designed this lightweight “boat cloak” in 1844. When deflated, its hull could be worn as a cloak, the oar used as a walking stick, and the sail as an umbrella, but a portable bellows could inflate it in four minutes into a craft that could carry eight people.

Explorer John Richardson, who had nearly died of hypothermia trying to cross an arctic river during John Franklin’s disastrous Coppermine Expedition of 1819, wrote that “Had we been possessed of such a contrivance in our first expedition, I have little doubt of our having brought the whole party in safely.” But the navy saw no use for Halkett’s boats, and his efforts to promote them to outdoorsmen similarly failed. The two remaining specimens reside in museums.

https://commons.wikimedia.org/wiki/File:Halkett_Boat_Cloak_in_use_cropped.jpg

| Technology

Bootstrap Percolation

grid infection puzzle

On a 12 × 12 grid, some squares are infected and some are healthy. On each turn, a healthy square becomes infected if it has two or more infected orthogonal neighbors. (In the example above, the black squares are infected, the white squares are healthy, and the gray squares will be infected next turn.) What’s the smallest number of initially infected squares that can spread an infection over the whole board?

Click for Answer
| Puzzles

Naturally

Steven Bartlett and Peter Suber’s Self-Reference: Reflections on Reflexivity contains a bibliography of works on reflexivity.

It includes an entry for Steven Bartlett and Peter Suber’s Self-Reference: Reflections on Reflexivity.

| Science & Math

Unquote

http://commons.wikimedia.org/wiki/File:Redrosedust_wright_f2000.jpg

“Whether you can observe a thing or not depends on the theory which you use. It is the theory which decides what can be observed.” — Albert Einstein

“When we observe nature, and especially the ordering of nature, it is always ourselves alone we are observing.” — G.C. Lichtenberg

| Quotations

Counterfeit Redux

A more challenging version of the Counterfeit Coin puzzle from 2011:

You have 12 coins, one of which has been replaced with a counterfeit. The false coin differs in weight from the true ones, but you don’t know whether it’s heavier or lighter. How can find it using three weighings in a pan balance?

Click for Answer
| Puzzles

Moving Images

By turning the traditional rules of perspective inside out, the paintings of British artist Patrick Hughes induce a compelling illusion in three dimensions.

“Reverspectives are three-dimensional paintings that when viewed from the front initially give the impression of viewing a painted flat surface that shows a perspective view,” he writes. “However as soon as the viewer moves their head even slightly the three dimensional surface that supports the perspective view accentuates the depth of the image and accelerates the shifting perspective far more than the brain normally allows.

“This provides a powerful and often disorienting impression of depth and movement. The illusion is made possible by painting the view in reverse to the relief of the surface, that is, the bits that stick farthest out from the painting are painted with the most distant part of the scene.”

See Termespheres.

| Art