How large is the US 'green economy?'

One way to gauge a country's attention to the environment may be measuring how much of its economy is devoted to protecting, rehabilitating, and preserving the natural environment. While the U.S. has made prior attempts at ...

Unraveling the mathematics behind wiggly worm knots

For millennia, humans have used knots for all kinds of reasons—to tie rope, braid hair, or weave fabrics. But there are organisms that are better at tying knots and far superior—and faster—at untangling them.

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