In this video Paul Andersen explains how an object with mass placed in a gravitational field experiences a gravitational force. On the Earth this gravitational force is known as weight. The gravitational force is equal to the product...

Today is the anniversary of the best-worst day of your life. The best part was discovering a subterranean city on Mars. The worst part was when you lost contact with Earth. You and the other 99 scientists have spent the year engineering...

In this video Paul Andersen explains how the linear momentum is equal to the product of the mass of an object and the velocity of the center of mass. He uses video analysis software to calculate the velocity of an object and therefore...

In this episode we explain why fire is red, gas flames are blue, and why you're too cool to glow.

The science of the multicolored dress.

Paul Andersen explains how X inactivation works in mammals. This process was first described by Mary Lyon. Each cell in a female will have on activated and one inactivated X chromosome. This explains why almost all calico cats are...

How worried should you be when your urine isn't yellow, but instead it's green, red, or even black?

Conventional wisdom might have you believe that human beings only really start showing empathy after a few years of learning social norms and morals. However, some research suggests that this kind of compulsion to do good might be...

Why is the sky blue? It's a question that you'd think kids have been asking for thousands of years, but it might not be that old at all. The ancient Greek poet Homer never used a word for blue in The Odyssey or The Iliad, because blue is...

This is Not a Rainbow

HAS SPACE ALWAYS BEEN BLACK? As long as we've been around, YES. But the universe gets much more exciting, AND much BRIGHTER, as we start winding our clocks back to the early days of the universe. Near the beginning of the universe, when...

Jessi helps Squeaks learn about why foods can be so many tasty-looking colors!

The evil wizard MoldeVort has been trying to kill you for years, and today it looks like he’s going to succeed. But your friends are on their way, and if you can survive until they arrive, they should be able to help stop him. Can you...

The sky is blue, but according to whom? Could the rules of our language affect the way we perceive color?

Fire it up! We explain hot stuff.

To the average tongue, the color "red" doesn't have a flavor or a smell. But color can affect how we perceive the world in so many ways - including how things taste and smell!

Paul Andersen explains how natural selection is a major mechanism in evolution. The video begins with a discussion of Charles Darwin and the details of natural selection. The data of the peppered moth during the industrial revolution...

Autumn means leaves are turning different shades of red, orange, and yellow and falling to the ground. But why? Jessi takes you deep inside a leaf to explain!

We all know that the Earth is huge, but what is it made of? Join Jessi and Squeaks for a fun activity to learn about Earth's layers, and to make your own model of Earth!

New ReviewIt's a cavalcade of color!

New ReviewSmall problems can be surprisingly annoying—but these clever tricks make them disappear in seconds. From fixing a broken flip-flop with a simple bread clip to removing permanent marker from a whiteboard like magic, these smart hacks will...

New ReviewThe Doctor will be coloring herself! Let's color her, shall we? The pants in blue and the blouse in yellow. Let's color her hair too. Oh, the Doctor colored her hair purple. Naughty girl! Let's fix it. That leaves the hat, hands, and...

In this math video we will interpret the graph of a proportional relationship. We are given a graph the represents a real world relationship. We will discuss what the variables x and y represent to the real world situation. We will...

In this video, you will learn how to change the background color of a web page.