16 December 2015, 01:41 PM ET
Author and PBS host Robert Lawrence Kuhn brings his unique, mind-bending questions to the Expert Voices platform.
12 November 2015, 03:22 PM ET
In several small villages in the northwest of Spain, no one knew what made the water in their fountains turn a blood-like red.
21 September 2015, 08:50 AM ET
Even plants and animals like to leave a good impression.
13 July 2015, 07:27 AM ET
Stunning mosaics have turned up during an archaeological dig of a fifth-century synagogue in northern Israel.
13 July 2015, 07:18 AM ET
A pile of 2,000 tangled gold spirals that bring to mind heaps of the fairy tale princess Rapunzel's golden locks were recently unearthed in Denmark.
17 June 2015, 02:55 PM ET
Photos from a search expedition to solve the mystery of Amelia Earhart's disappearance.
12 June 2015, 11:13 AM ET
Astronomers have long known that galaxies spin more quickly than can be explained by the laws of physics.
30 May 2015, 08:27 AM ET
Blue-ice areas are patches of ice where wind and evaporation have scoured glaciers clean of snow.
29 October 2014, 06:51 PM ET
Amelia Earhart's disappearance during an attempt to fly around the world remains a mystery, but recent expeditions may have found clues to her fate.
08 September 2014, 08:43 AM ET
Most infants begin learning a spoken language from the moment they're born. But as the brain becomes less flexible with age, it's difficult for children to master the sounds and intonation of a second language.
02 September 2014, 02:44 AM ET
Until recently, no one had ever seen the moving rocks at Racetrack Playa, but a new video shows the stones creeping across the desert.
09 June 2014, 06:40 PM ET
Why is the sky blue? The light coming from the sun is made of many colors, each of which has a different wavelength.
14 May 2014, 04:58 PM ET
Today, on National Buttermilk Biscuit Day (May 14), a lot of people may be wondering, what exactly is buttermilk?
12 May 2014, 05:01 PM ET
Tornadoes are one of the most destructive natural forces on Earth. Though scientists don't entirely understand how tornadoes form, they do have a good idea about the conditions that cause tornadoes to develop.
12 May 2014, 04:17 PM ET
Contrary to what their name would suggest, sweetbreads are not sugary pastries. So, what are sweetbreads?
12 May 2014, 03:20 PM ET
Turtles, like the humans who love them, are a diverse bunch. There are over 300 species of this ancient reptile, and each one has its own preferred diet.
08 May 2014, 04:43 PM ET
It's proven that the caffeine in coffee stimulates the brain, but there's something in a cup of joe that can also jump-start the other end of the body. That's right: Coffee can make you poop.
08 May 2014, 03:17 PM ET
For pet cats, all the toys in the world can't compare to a simple cardboard box.
29 April 2014, 06:00 PM ET
Kosher food is not a style of cooking or a cultural menu (like Chinese or Italian food). Instead, "kosher" refers to foods that adhere to the dietary laws of Judaism, also called kashrut, as described in the Torah.
28 April 2014, 04:34 PM ET
It's commonly believed that dogs wag their tails to convey that they are happy and friendly, but this isn't exactly true.
28 April 2014, 03:33 PM ET
A contusion, or bruise, is a reddish-purple discoloration of the skin that doesn't blanch, or turn white or pale, when pressed upon.
28 April 2014, 03:26 PM ET
One of the fastest-growing sources of energy in the world, wind turbines generate electricity without emitting greenhouse gases into the environment (unlike fossil fuels).
26 April 2014, 08:52 AM ET
Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells.
26 April 2014, 08:48 AM ET
A byproduct of the metabolic breakdown of purines, uric acid is a human waste product that most people never think about.
14 April 2014, 04:53 PM ET
For humans, touch is a sense most often associated with the fingers. But man's best friend, the dog, touches the world a different way — with his face.
14 April 2014, 04:17 PM ET
Dolphins sleep with one eye open, and with half their brain wide awake, researchers have found.
14 April 2014, 03:43 PM ET
Found in the bark of the cinchona tree, quinine is a compound with many medicinal applications, including fever-reducing, painkilling and anti-inflammatory properties. It was also the first treatment for malaria.
11 April 2014, 03:19 PM ET
When the sun heats water in the oceans, rivers, lakes and other sources, some of it evaporates, or transforms from liquid water to water vapor. This is the first step in cloud formation.
11 April 2014, 02:50 PM ET
If you've ever had a tooth pulled, then you might be familiar with a severely painful — and aptly named — condition known as dry socket (alveolar osteitis).
11 April 2014, 12:33 PM ET
The FTC estimates that 9 million Americans have their identity stolen every year in credit-card skimming or similar kinds of scams. The ease with which skimmers operate, however, raises several questions about the security of card transactions.
09 April 2014, 03:20 PM ET
Xanthan gum helps salad dressing pour easily from the bottle, makes ice cream taste creamier and allows liquid cosmetics to stay blended while on the shelf.
31 March 2014, 04:52 PM ET
Despite their name and appearance, peanuts are not tree nuts like walnuts and pecans — they're part of the legume family of plants, which includes beans, lentils, peas and other familiar foods.
31 March 2014, 04:30 PM ET
Contrary to what some people think, pineapples don't grow on trees — they grow out of the ground, from a leafy plant.
31 March 2014, 04:07 PM ET
Blood sugar, or glucose, is an important source of energy and provides nutrients to your body's organs, muscles and nervous system.
31 March 2014, 01:19 PM ET
Itchy, contagious and in a place you'd rather not mention, jock itch (tinea cruris) is a fungal skin infection that affects the genital region.
27 March 2014, 05:34 PM ET
Peripheral neuropathy (often referred to simply as "neuropathy") refers to any condition that damages or disrupts nerves in the peripheral nervous system.