References

REFERENCE A device that sanitizes the air to remove impurities and pollutants is an appealing prospect, but just how do air purifiers work?

REFERENCE We know it's good for fitness, but is running good for weight loss? We look at the science.

REFERENCE Yes, it's good for cardio, but does running actually burn fat? We dive into whether running can help you shed excess weight

The Paris Agreement is an international plan to address climate change.

Antioxidants are powerful protective chemicals found in fruits, vegetables and many other foods.

Also known as "the sixth sense" or "psi," extrasensory perception, or ESP, encompasses a wide range of paranormal abilities, including mind reading and predicting the future.

In addition to being a delicious snack, sweet, juicy oranges contain a multitude of nutrients.

The Greenland shark is the oldest known shark, with one individual estimated to be 392 years old.

Learn all about different types of galaxies in the universe and how they came together.

Multiverse theory suggests we live in one of an infinite number of universes.

The hippocampus is a small region of our brain responsible for memory, learning and navigation.

In healthy children and adults, the virus typically causes mild, cold-like symptoms; but it can cause more serious disease in infants and the elderly.

Tetanus, also called lockjaw, is caused by bacteria found on rusty metals and many other surfaces.

Many parents experience postpartum depression. Here's what it looks like and how it can be treated.

Huntsman spiders are long-legged predators that hunt down their prey. One species of huntsman spider has a leg span that's as big as a dinner plate.

Sperm whales are the largest toothed whales, with enormous square-shaped heads and the biggest brains of any animal on Earth.

Here's what immunodeficiency means.

Polar bears are the largest bear species and are supremely adapted to their Arctic habitat, whether they are prowling the ice or swimming in the sea.

Information about asteroids, where they come from and whether one might hit Earth.