Joe Phelan

There are about 1,350 potentially active volcanoes on Earth. Where are most of these volcanoes located?

When and where was chess invented and why is it still so popular around the world?

Here's a look at the world's largest cities by size, population and cultural impact.

A seashell held to your ear may sound like the ocean, but so does cupping your hand or holding a bowl at the same spot. Here's why.

Here's the science behind petrified wood, including what it is, how long it takes to form and whether it's useful in the research world.

What are air pockets and can they cause planes to crash?

Here's what happens in people's brains when they use tobacco products.

Can anything crafted by humans be viewed with the naked eye from space, or would astronauts need to use binoculars?

Here's what the science says about whether everyone or only those with the right genes can wiggle their ears.

Some people who visit Paris develop extreme symptoms — such as nausea, vomiting and hallucinations — when their expectations of the city do not jibe with reality.

Even when there is substantial evidence to the contrary, the allure of conspiracy theories may be too powerful for some to resist.

Did you know that the outline or the border of your lips is a special feature of humans only?

Due to a number of technical and logistical difficulties, as well as meandering through sparsely populated areas, there is no pressing need to build a bridge on the Amazon River.

Here's the science behind whether all bees die after stinging humans.

Here's the science behind the so-called "cat gap," a roughly 7 million-long period in North America in which there aren't any known cat fossils.

Here's a look at the science for why we haven't cloned any humans yet.

Here's a look at the science for why we haven't cloned any humans yet.

The atmosphere is vast and parts of it extend beyond the moon. But where does it technically end, according to scientists?

Here's the science behind whether anything can travel faster than the speed of light.

What cities, states and countries are most at risk from rising sea levels? What can they do to protect themselves?

The Mandela effect is when many people believe that something happened when, in reality, it never did.

Answers to how many nuclear weapons exist, who has them and how powerful are they.

Here's the science behind "shooting stars" and the best way to spot these meteors.