“The equality 0.999… = 1 has long been accepted by mathematicians and is part of general mathematical education. Nonetheless, some students find it sufficiently counterintuitive that they question or reject it, commonly enough that the difficulty of convincing them of the validity of this identity has been the subject of several studies in mathematics education.”

0.999… – Wikipedia

/via @notch: “To people telling me it’s NOT the same number; you are wrong.”

text-mode:

Alchemical Symbols from Le vray et methodiqve covrs de la physiqve resolvtive : vvlgairement dite chymie …  by Annibal Barlet (Paris, 1657).

STL File Viewing on GitHub

…once time had turned 1984 from dystopy to past, the year 2000 claimed back its role as embodiment of the future. All our hopes and fears and crazy ideas about future technology received the timestamp 2000.

Looking back, it never fails to amaze me how distant this past future appears.

Urup Island, Russia

/via /r/EarthPorn

SimCity: The Intersection Trap /via Rock, Paper Shotgun

Trees take hold as permafrost thaws near the Altai Mountains in Russia.

From NASA, via /r/EarthPorn

One does not simply walk into Mordor. /via @JohnDCook

Permafrost: The Tipping Time Bomb

One of the most feared of climate change “feedbacks” is the potential release of greenhouse gases by melting arctic permafrost soils. New research indicates a critical threshold of that feedback effect could be closer than we once thought.
Pangaea separation animation.