Have you ever seen a show or movie about a spy? If so, you may know spies use special glasses to see in the dark. These tools are called night vision goggles. Today’s Wonder of the Day takes a closer look at how they work!

Are you WONDERing whether night vision goggles really work? Yes, they do! In fact, they work very well. On a cloudy, moonless night, the best night vision goggles can help people see over 200 yards away.

First, it’s important to understand something about light. Did you know that not all light is visible? It’s true! The light we can see is called visible light. It’s only a part of the electromagnetic spectrum. There are other types of light that can’t be seen by the naked eye. This includes infrared and ultraviolet light.

How do night vision goggles work? That depends on which ones you’re using. There are two types of technology used in night vision goggles. They are image enhancement and thermal imaging.

Image enhancement amplifies existing light. This makes images easier to see. Even on the darkest nights, tiny bits of light are present. Some of this light may be infrared light that people can’t see. Night vision goggles using image enhancement technology collect all the available light. Then, they amplify it so that you can easily see what’s going on in the dark.

The other night vision technology is called thermal imaging. Have you ever heard the word “thermal”? If so, you know that this technology has to do with heat.

Hot objects, including human bodies, give off some heat in the form of infrared light. Night vision goggles use thermal imaging technology to capture that infrared light. This way, you can see an image of what’s going on in the dark. It’s based on the amount of heat being made by objects.

Thermal imaging works well when trying to see people in the dark. It’s also better suited for the darkest conditions. Most night vision goggles, however, use image enhancement technology.

Night vision technology has many uses for the military and law enforcement. For example, it can be used to find people in the dark. It’s also helpful for navigation and surveillance. Night vision can also be used for hunting and watching animals after dark.

Have you ever seen a night vision image? If so, you probably noticed that it had a green glow. Night vision goggles are made with screens that produce green pictures. That’s because human eyes are better suited to looking at green pictures for long periods of time.

Have you ever needed to be able to see in the dark? Night vision goggles can definitely help with that problem! They’re not just for spies and soldiers. Everyday people use night vision goggles for many purposes. Maybe you’ll get to try a pair on yourself one day!

Standards: NGSS.PS3.B, NGSS.PS4.B, NGSS.PS4.C, CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.SL.1

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Tomorrow’s Wonder of the Day combines history and geology!