Hank explains the whole story about radiation - the good, the extremely helpful, and the bad.

LIGHT! Let's talk about it today. Sunlight, moonlight, torchlight, and flashlight. They all come from different places, but they’re the very same thing: light! It’s what makes it possible for us to see the world around us, so it’s worth...

The way light behaves can seem very counter intuitive, and many physicists would agree with that, but once you figure out light waves it all starts to make more sense! In this episode of Crash Course Physics, Shini shows us how we know...

In this video Paul Andersen explains how ray diagrams can be used to determine the size and location of a reflected image. Ray diagrams for plane, concave, and convex mirrors are included.

In this video Paul Andersen details the waves in electromagnetic radiation. There is an inverse relation between the wavelength and frequency of electromagnetic waves. Electromagnetic radiation includes gamma rays, x-rays, infrared...

Jessi and Squeaks are ready to go outside, but before they do, Jessi needs to make sure to put on sunscreen so that she doesn't get a sunburn!

Every year, tens of thousands of people have brain surgery without a single incision: there's no scalpel, no operating table, and the patient loses no blood. Instead, this procedure uses a machine that emits invisible beams of light at a...

Originally discovered by accident, X-rays are now used about 100 million times a year in clinics around the world. How do these magic eyes work? Ge Wang details the history and mechanics of the X-ray machine and CT scanners.

Proteins, and by extension our bodies, depend on the fact that atoms are arranged, spaced, and linked to each other in specific ways. And thanks to June Sutor, we have a better understanding of how those atoms come together and interact...

How did we get here? Well, in terms of Atomic Chemistry, Hank takes us on a tour of the folks that were part of the long chain of other folks who helped us get to these deeper understandings of the world. From Leucippus to...

This video is brought to you by the Child and Teen Checkups program of the Minnesota Department of Health.

Today Phil explains how telescopes work and offers up some astronomical shopping advice.<br/>

New ReviewWhen I was a kid, I remember people talking about putting on suntan lotion to help them absorb the sun's rays. Those days are over. Too much sun can be terrible for you. Besides the fact that it significantly increases the risk of skin...

Exoplanet TOI 1227 b is being bombarded by x-rays from its host red dwarf star, causing it to “shrink from the size of Jupiter with a thick atmosphere to a small, barren world,” according to the NASA Chandra team.



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Stars represent a celestial battle of two opposing forces, gravity trying to collapse the star, and radiation pressure trying to explode the star. But it comes to an end close to the time that it runs out of fuel. Gravity...

How important is it to wear sunscreen when out in the Sun. Find out with this simple experiment!

Howcast - There’s no reason you and your baby can’t have fun in the sun—as long as she doesn’t catch too many rays.

Howcast - Check out part 26 of this walkthrough for the third person action shooter "Warhammer 40K Space Marine" and beat Chapter 3 with this online demo.

Howcast - Learn seven cool facts about waxy monkey frogs from reptile and amphibian expert Jungle Bob in this Howcast video.

Howcast - Learn the difference between UVA rays and UVB rays from licensed esthetician Joanna Vargas in this Howcast video.

Howcast - Learn how to avoid a sunburn from licensed esthetician Joanna Vargas in this Howcast video.

It's breakfast time at the South Carolina aquarium's stingray tank.

It's breakfast time at the South Carolina aquarium's stingray tank.

Visit the stingray tank at feeding time and get a closer look at these creatures made up completely of cartilage.