walking

The Surprising Science of Walking

Delhi and many other cities in India are like massive construction sites, and the accompanying dust levels are very high. Credit: savioseb/Flickr, CC BY 2.0

What it Means to Take the Long View on Air Pollution in Delhi

Walking on two legs might be the more energy-efficient way to do it. Credit: giuseppemilo/Flickr, CC BY 2.0

Listen: How Come Humans Walk on Two Legs, Not Four?