Humans have traveled to the moon and uncovered the secrets of the Taos Hum, the Devil's Kettle, and maybe even the pyramids of Egypt. But there are still plenty of phenomena that science can't explain yet. Although scientists may have theories about the following phenomena, no one can say for certain why they occur. Here are nine mysteries of life that still stump experts everywhere.
Scientists aren't sure why people yawn.
Yawning is something you likely do every day, but, oddly enough, scientists still aren't sure why.
Recently, the scientific community has moved toward the idea that yawning is a thermoregulatory behavior that cools down the brain, but its true biological function is still unclear.
What's more, scientists aren't entirely sure why it's contagious among social animals, such as humans. A 2005 study published in Cognitive Brain Research found that the networks in your brain responsible for empathy and social skills are activated when you see someone yawn. Researchers have also observed that chimpanzees can "catch" yawns from humans.
"Copying the facial expressions of others helps us to adopt and understand their current state," said Matthew Campbell of Yerkes National Primate Research Center at Emory University.
This is why, according to one study, psychopaths aren't as susceptible to contagious yawning.
This mushroom grows only in Texas and Japan, and scientists can't explain it.
The Chorioactis geaster is the only mushroom species in the Chorioactis genus, and it's found only in Texas and Japan.
The two locations are on the same latitude, but mycologists have not been able to figure out why these mushrooms grow only in these two spots. A 2004 study of the mushrooms' DNA, published by Harvard University Herbaria, suggested that the populations were separated into two lineages about 19 million years ago.
In Texas, the mushroom is known as the "devil's cigar," since it looks like a cigar before it opens into a star shape.
No one knows why Saturn's north pole has a swirling, hexagon-shaped storm.
No one knows why Saturn's north pole has a swirling, hexagon-shaped storm.