Why do exams always tell you to use a number 2 pencil? What happens if you don’t? Quick Questions explains!

Dinosaurs were huge—it's common knowledge. So why aren't modern mammals anywhere near that size? In this episode of SciShow, Hank gives a quick run-down of the reasons scientists think the land mammals of today are nowhere near the size...

Airplanes are one of the quickest ways to get anywhere, but commercial jets haven't gotten much fast since the 1950's. Why is that?

Hank describes some of the best explanations that neurologists have come up with to account for the strange sensation we know as déjà vu.

Hank describes some scientific advances in the field of mind reading.

Caves are fascinating, but these ones are some of the most fascinating, both in and out of this world. Hosted by: Stefan Chin

We’ve sent thousands of things into space over the years! Many of them just orbit the Earth, and some are flying out past the edges of the Solar System. In this episode, we present our favorite currently active space probes!

More than 30 million people in the US are eligible to have their arrest and conviction records cleared -- but most people who qualify either can't afford it or simply don't know it's an option. In this gripping talk, second chance...

Want to learn more about the topic in this week's video? Here are some keywords/phrases to get your googling started: - Mass Extinction Event: a significant, global decrease in the diversity of life - "Big 5": The five biggest mass...

More than a billion people worldwide, mostly children, do not have a legal identity. In many countries, this means they can't get access to vital services like health care and education, says legal identity expert Kristen Wenz. She...

A huge and diverse subfamily of dogs, the bone-crushers patrolled North America for more than thirty million years, before they disappeared in the not-too-distant past. So what happened to the biggest dogs that ever lived?

In 1944, amateur astronomer Hisako Koyama's latest endeavor was sketching the sun's shifting surface. She spent weeks angling her telescope towards the sun and tracking every change she saw with drawings. Little did she know, these...

Foraminifera - tiny, single-celled marine life forms - build gorgeous houses that record how much ice there is on the planet.



FYI: We try to leave jargon out of our videos, but if you want to learn more about this...

If you go to the gym often enough, you might be familiar with protein powders and shakes, but one study thinks that the secret to big gains might actually be your gut bacteria.

Why are some athletes able to crush world records when other records remain unbroken for years? The answer has to do with the kind of materials used in the competition and the type of athletic event one is competing in. Hank Green...

Some of the oldest galaxies we’ve ever seen are small, faint satellite galaxies orbiting the Milky Way, and they're providing us with a glimpse of how the universe evolved.

The origin story of turtles is a mystery that has perplexed many for centuries, but thanks to more recent studies, we might be one step closer to figuring out their lineage.

In the wake of Hurricane Sandy, Hank answers some frequently asked questions about it, and how it got to be so crazy. What is up with this storm? Has this ever happened before? This is global warming right?

SciShow News explains the latest climate weirdness, and why the Global Warming Hiatus wasn’t really what it sounded like. Plus, see how humans have harnessed the climbing power of the gecko!

The revolution that made music more marketable, more personal and easier to pirate began ... at the dawn of the 19th century. José Bowen outlines how new printing technology and an improved piano gave rise to the first music industry.

Hank describes some scientific advances in the field of mind reading.

These days it seems almost trivial to cool atoms down to near absolute zero temperatures in a lab, but what is the lowest possible naturally occurring air temperature on this planet?

Airplanes are one of the quickest ways to get anywhere, but commercial jets haven't gotten much fast since the 1950's. Why is that?

The record for the fastest thing ever created by humans is a tie between the Helios 2 probe and a manhole cover.