Conservationists take a radical approach to save rhinos from extinction. The popular webcomic xkcd gets representation in academia. And the nature of reality is explored by philosophers and scientists. It's Earthy Thursday, our weekly segment on science and Earth-related news! All this and more for the Pagan News Beagle!

Are you interested in permaculture? The form of agriculture first advocated publicly by David Holmgren and Bill Mollison in 1978 as a sustainable alternative to modern agriculture has gained increasing support from environmentalists and counterculture activists over the years since its original inception. Now, Oregon State University lets you apply for a 4 week course in the practice form anywhere in the world. You can find out more about the program here.

What's "radical conservation?" According to geologist Ed Warner, it's a form of conservationism that focuses on working with local landowners to increase communal and economic incentives to conserve local species. As black rhinos face increasing threats in their native homelands, some groups are looking to adopt Warner's ideas as a new strategy.

If you're familiar with webcomics or geek culture you may well have heard of the comic xkcd, which writer-artist Randall Munroe describes as a "webcomic of romance, sarcasm, math, and language." Frequently dealing in subjects relating to science the webcomic is now getting representation in actual science textbooks.

How much of our perception of color is really accurate? Astronomer Phil Plait takes a look at a photograph of the Canary Islands off the coast of Africa to illustrate how what might look green can actually also be red.

Speaking of perception and reality, how do we know the world we live in is "real" at all? An increasingly popular idea in philosophy circles is the concept that what we might all be living in a virtual reality simulation created by scientists in the "real world." But is there any evidence for this? Scientific American takes a look.

Top image by Philip Ronan