79 AD Vesuvius eruption heat pyroclastic flows

Vesuvius heat may have killed many

The 79 AD eruption of Mount Vesuvius likely killed many people with heat rather than ash suffocation. After about 18 hours of falling pumice, most inhabitants had escaped. Later hot flows could kill instantly, even inside buildings 10 km from the volcano, at temperatures of at least 250 °C.

An octopus can flash a warning without changing color

Under ⅓ Second

A blue-ringed octopus can reveal its brilliant blue warning rings in less than a third of a second. But it does not need to create new pigment. Tiny muscles uncover reflective structures that were hidden beneath its skin. The rings were there all along—the octopus simply switches them into view.

The Arctic tern makes the longest known bird migration

At Least 19,000 Km

An Arctic tern flies at least 19,000 kilometers from its Arctic breeding grounds to Antarctica and back each year. By moving between the far north and far south, it experiences two summers every year.

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79 AD Vesuvius eruption heat pyroclastic flows

Vesuvius heat may have killed many

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