Light is energy, and it can be defined by four things: intensity (how bright), frequency (or wavelength), polarization (the direction of the electric field), and phase (time shift). We’re going to look at different ways to produce light as well as its properties....

When it’s too hard to count ‘em up and too much time to calculate, it’s time to guesstimate the answer. I use this technique all the time to “ball park” my answer so I know if I've made a mistake with my final answer. Download the student worksheet that goes with this...

You can’t just shine a flashlight through a lens and call it a laser, because the way a laser generates light is what makes it a laser in the first place. The word LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers are optical...

If you hate long division like I do, then this lesson will be very useful in showing you how to make the most out of your division tasks without losing sleep over it. It’s easy, quick, and a whole lot of fun! If you haven’t already mastered your multiplication tables,...

A meteoroid is a small rock that zooms around outer space. When the meteoroid zips into the Earth’s atmosphere, it’s now called a meteor or “shooting star”. If the rock doesn’t vaporize en route, it’s called a meteorite as soon as it whacks into the ground. The word...

Spectrometers are used in chemistry and astronomy to measure light. In astronomy, we can find out about distant stars without ever traveling to them, because we can split the incoming light from the stars into their colors (or energies) and “read” what they are made...

How do astronomers find planets around distant stars? If you look at a star through binoculars or a telescope, you’ll quickly notice how bright the star is, and how difficult it is to see anything other than the star, especially a small planet that doesn’t generate...

The Sun illuminates half of the Moon all the time. Imagine shining a flashlight on a beach ball. The half that faces the light is lit up. There’s no light on the far side, right? So for the Moon, which half is lit up depends on the rotation of the Moon. And which part...

Today you get to learn how to read an astronomical chart to find out when the Sun sets, when twilight ends, which planets are visible, when the next full moon occurs, and much more. This is an excellent way to impress your friends. The patterns of stars and planets...