Artists sometimes change or improve paintings by painting over old versions. Through careful examination or special imaging, we can sometimes see these ghosts of lost art again.
In Norse mythology Fimbulwinter is the great winter immediately preceding Ragnarök. It may have been inspired by the horrifying real-life events of 536 CE.
The esoteric programming language Whitespace uses only three characters: tabs, spaces, and line breaks. That makes it effectively invisible to the naked eye.
Somewhere in the sky, obscured from our view by the Milky Way, an unknown anomaly called the Great Attractor pulls a hundred thousand galaxies around.
Something creepy for your Friday: attaching electrodes to animals’ brains so their movements can be controlled remotely.
Where do black diamonds come from? We don’t actually know.
Some Australian birds make compost heaps.
Where do the elements come from? Nuclear astrophysics proposes several origins, depending on the element: the Big Bang, dying and exploding stars, and cosmic rays.
Who keeps the metric system down? In the United States, pirates do.
Animals have some of the best old-timey disease names, including heartwater, foulbrood, bluetongue, glanders, scrapie, camelpox, and bumblefoot.
When a double rainbow happens there’s a dark shadow between the bows. This is Alexander’s band.
In Myanmar you can drink tea or you can eat it.
The historian A. Roger Ekirch has argued that in Medieval Europe, and in many places prior to the Industrial Revolution, people would habitually wake up for an hour in the middle of the night.
When a human dies, they go through several distinct stages. In order: pale, cold, stiff, mottled, putrefied, decomposed, skeletonized.
A tree in New Zealand grows downwards-facing spikes for the first 15 or 20 years of its life; this is thought to be a remnant defence against gigantic now-extinct birds.