The Passglas
Precision measure for drinking games
A few centuries ago in parts of Europe, a tall, graduated goblet was used for drinking games that tested one's ability to imbibe with great precision.
Carbon Dating
Decay rates create debates
Scientists can determine the age of very old organic artifacts using the clever process known as carbon dating. But how does it actually work, and why do some religious groups find it so problematic?
Megaplumes
The amazing underwater cyclones
When superheated water is rapidly discharged from a hydrothermal vent on the ocean floor, it can cause a huge, lenslike whirlpool that keeps swirling for months.
Cueva de las Manos
Ancient spray-painted art in Patagonia
Spray-painting (of sorts) is thousands of years old, and well-preserved examples of art using this technique are found on a rock face in Patagonia.
Titanium Art
The colorful process of anodization
By immersing titanium in a salt solution and applying electricity, artists can create pieces with a brilliant range of colors. But they're all optical illusions.
Passenger Pigeons
The great American extinction
The last surviving member of a bird species that once numbered in the billions died in 1914. Their extraordinary extinction is a sad commentary on human values.
Paris Catacombs
Man-made calcium deposits
Beneath the streets of Paris lies a vast network of catacombs, containing the bones of an estimated six million former residents.
The Hidden Lives of Sloths
Symbiosis in slow motion
All sloths have three toes, even the two-toed ones! That is just one of many surprising facts about these docile, slow-moving creatures often found in tropical rain forests.
Six Degrees of Separation
Is it a small world after all?
Scientific research suggests that the web of social relationships connecting you with any other person on the planet may involve as few as six steps.
The Tunnels of Moose Jaw
Underground legends
A Saskatchewan city with a funny name has some surprising history beneath its streets. From sweatshops to speakeasies, underground operations boomed in the early years of the 20th century.