How did Dutch artist Leon Keer create a 3D illusion on a street in chalk? The same way they created perspective in Renaissance Florence

"Computers enable artists to calculate such effects with new precision – just as they enable 3D film-makers to achieve similar illusions. But all these modern wonders go back to the Renaissance when the closest thing to a computer was a set-square. The science improves. The locations change from churches and palaces to cinema screens and street surfaces. Our capacity for wonder lives on." (BBC) - http://bit.ly/zwfkuz

These are becoming more popular these days - it seems - but this video gives a little insight into the creation of an anamorphic street image.

http://www.youtube.com/watch?v=lm3bUEePRMU&feature=player_embedded

Spiralling into a trajectory?

"An Australian biology professor is causing a rumble in the academic jungle by suggesting that his country should import elephants and other foreign species into its wild interior.

"Take so many big species out of an ecosystem, and there are bound to be changes all the way down to its bottom.

"'We have a very unbalanced ecology and it's all just spiralling into a trajectory', lamented Prof Bowman."

I would love someone to provide a diagram or equation that would represent this 'spiralling into a trajectory'.

Read more at the BBC: http://bbc.in/wLStPv