For thousands of years, philosophers have pondered cardinality: knowing “how many.” Using a series of crude estimates, the ancient Greek mathematician Archimedes worked out the approximate number of ...

A new study involving more than 100 scientists from across the globe and the largest forest database yet assembled estimates that there are about 73,000 tree species on Earth, including about 9,200 ...

WEST LAFAYETTE, Ind. — One person can’t measure all the trees in the world, but when many people come together, a global view becomes possible. A worldwide collaboration of scientists has produced the ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

Here are some self-evident truths: Humans need to produce less carbon dioxide—assuming we care a fig about our children’s well-being. But even that’s no longer enough. CO 2 levels in the atmosphere ...