Our friends at Numberphile provide a detailed look at how the game Connect Four is won or lost.

In this episode of SciShow Kids, Jessi talks about how solar eclipses occur, and why they can only be seen from certain locations.

Learn about the states of matter, solids, liquids and gases, how they're different and where they're found in everyday life.

This video takes a look at hydrothermal vents and the novel life forms that thrive there in the absence of sunlight, fueled by underwater volcanoes. One of these harsh environments is the Axial Seamount off the West Coast of the United States.

Within a deep and narrow cave in South Africa, paleoanthropologist Lee Berger and his team found fossil remains belonging to the newest member of our human family. The Homo naledi discovery adds another exciting chapter to the human evolution story by introducing an ancestor that was primitive, but shared physical characteristics with modern humans.

What happened when Expedition PROTECT and American Promise arrived at Jeffrey's Ledge, a marine protected area in the Gulf of Maine? The crew tells us about what they are doing and why.

In this final installment of the series, a white Kermode bear encounters a black bear while fishing. Observe their behavior. Look and see for yourself what ensues!

Romantic chemistry is all about warm, gooey feelings that gush from the deepest depths of the heart... right? Not quite. Actually, the real boss behind attraction is your brain, which runs through a very quick, very complex series of calculations when assessing a potential partner. Dawn Maslar explores how our five senses contribute to this mating game, citing some pretty wild studies along the way.

The salmon that make it upstream mate and then die of exhaustion. Meanwhile, many other animals are lurking and waiting to feed.

In this episode, we see how the bears coexist with other creatures in their environment, and also learn about the role of the bear in Tsimshian lore. Enjoy!

In order to fatten up before winter sets in, brown bears feast upon salmon migrating upstream to spawn. Enjoy!.

Catch glimpses of sockeye salmon, also called red salmon, as they make their way upstream in a migration known as the "red flood." Also included is footage of dippers, which are some of the only songbirds that search for food on the bottom of a body of water.

Young black bears need to be careful when encountering the North American porcupine. Enjoy more footage from Alaska and Princess Royal Island in British Columbia, where young raccoons are also out and about.

"Help us to complete development of the Ocean Energy Turbine designed to replace Fossil Fuel and Nuclear Energy Dependence." Back this project and make the world a better place.

In summer, mother bears and their young cubs can be spotted on the plains near Hallo Bay in Alaska's Katmai National Park.