“Snow Cleaning” Keeps This Giant Telescope Mirror Perfectly Pristine


“Snow Cleaning” Keeps This Giant Telescope Mirror Perfectly Pristine
The James Webb Space Telescope is the most powerful space telescope ever built, and its mirrors must be kept squeaky clean. Any debris, even tiny flecks of dust, could impact its science. Ergo, “snow cleaning:” the use of carbon dioxide snow to clean the mirrors thoroughly yet gently.

May 11, 2015 at 10:05AM
via Digg http://ift.tt/1K085ND

Can you touch an electron? The weird metaphysics when states try to tax digital goods


Can you touch an electron? The weird metaphysics when states try to tax digital goods
In March, Alabama announced it would start taxing streaming services like Netflix and Spotify the same way it taxes rental stores that deal in physical discs. The law says that the state will levy a 4 percent tax on rentals of “tangible personal property.” So in order to tax a Netflix subscription, Alabama’s tax collectors have been forced to argue that streaming movies are somehow exactly that — tangible.

May 10, 2015 at 05:33PM
via Digg http://ift.tt/1zR40Yw

The Playboy Centerfold At The Centre Of Computer Science


The Playboy Centerfold At The Centre Of Computer Science
Alexander Sawchuk, the assistant professor of electrical engineering, his graduate student and the SIPI lab manager were frantically looking for a new image for a research paper. They had already exhausted the stock of usual test images. It was at this moment — according to legend — that a colleague walked in with the November 1972 issue of Playboy.

May 10, 2015 at 04:32PM
via Digg http://ift.tt/1F7Mtf8