How did a relative of the red panda end up in North America? What can this tell us about how long ago – and how many times – North America was connected to Europe and Asia?

Relativity Isn't Relative

This video is chapter 6 in my series on special relativity, and it covers the topic of relativistic addition of velocity: aka, how things that are moving relative to one inertial reference frame, which is moving relative to another...

Ever wonder how Einstein proved E=mc2? This is how. Pi day (3.14) is Albert Einstein's Birthday! To celebrate, we'll explain 4 of his most groundbreaking papers from 1905, when he was just 26 years old

How Einstein (& others) discovered Special Relativity. Pi day (3.14) is Albert Einstein's Birthday! To celebrate, we'll explain 4 of his most groundbreaking papers from 1905, when he was just 26 years old.

Have you ever wondered why 75% humidity in the summer feels sticky, but 75% humidity in the winter feels super dry? Turns out, the common definition of humidity is inconvenient and confusing. But there is a better way!

Mercury, a.k.a. quicksilver, is famous for being a liquid at room temperature...and also below room temperature. But you can't use a high school chem class to explain why. Instead, we need a little help from Einstein.

Neils Bohr said, “It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we can say about Nature.” Well it turns out that if we pay attention to this subtle difference, some of the most...

This video is about Bell's Spaceship Paradox of Special Relativity, wherein a pair of rockets (or spacecraft) connected by a weak thread accelerate with uniform acceleration, maintaining the same separation, and the question is: does the...

Have you ever wondered why 75% humidity in the summer feels sticky, but 75% humidity in the winter feels super dry? Turns out, the common definition of humidity is inconvenient and confusing. But there is a better way!

From wasps nests to nuclear reactors. Here are just a few clever ways archeologists figure out how old something is.

Do you have an old children’s book you love? Well, there’s a good chance that it might be racist, says kids’ author Grace Lin. She offers her humble opinion on how you can keep loving your favorite classics while acknowledging the...

A new drug reduces the risk of heart attacks by 40%. Shark attacks are up by a factor of two. Drinking a liter of soda per day doubles your chance of developing cancer. These are all examples of a common way risk is presented in news...

The bizarre Arrow's Impossibility Theorem, or Arrow's Paradox, shows a counterintuitive relationship between fair voting procedures and dictatorships.

This video is about the Portal Paradox - a paradox in the video game Portal (and Portal 2) regarding whether or not a companion cube passing through a moving portal plops out of the other end with no speed (velocity,...

Our friend the Giant Squid inspired a SciShow Kids viewer to write us and ask, 'What is squid ink, and can you write with it?' Jessi has the answers!

Since the days of Ancient Greece, philosophers and scientists have been wondering: What is space? Is the absence of things.... a thing? These questions continued to fascinate physicists in the modern era, leading Isaac Newton, Ernst...

Ever wonder how Einstein proved E=mc2? This is how. Pi day (3.14) is Albert Einstein's Birthday! To celebrate, we'll explain 4 of his most groundbreaking papers from 1905, when he was just 26 years old

The sun may have thousands of stellar siblings, many of them probably just like it, elsewhere in the galaxy. Find out how astronomers are looking for them, and learn about a match that could be our star's long-lost sibling!

This video is about the definition of a day, and how it applies (or not) on the sun. Solar day, sidereal day, universal coordinated time (UTC) day, etc. Length of a day.

12,000 years ago, the earth was very different, and so were some of the animals living on it! Here are 5 giants creatures you might have seen back then.

There’s a massive black hole next door that appears far too big for its host galaxy! And in another galaxy, TWO supermassive black holes formed, giving us a glimpse at a true rarity in astronomy!

Statistics are persuasive. So much so that people, organizations, and whole countries base some of their most important decisions on organized data. But any set of statistics might have something lurking inside it that can turn the...

We all know about inter species animal hybrids - Napoleon Dynamite's favorite animal, the liger, is a typical example. But could a human and our closest primate relative the chimpanzee also breed a living hybrid? Hank explores this ......