Electromagnetic Spectrum

Written by: Paige Leal

The electromagnetic spectrum is basically all types of light energy, even the ones we can’t see. It goes from low-energy waves like radio waves all the way to super high-energy gamma rays. Humans can only see a tiny part in the middle called visible light .

Starting with the lowest energy, radio waves have the longest wavelengths. These are used for things like communication through phones or radios, but we can’t see them at all. After that are microwaves, which are slightly higher energy and are used for cooking and technology. They are also invisible to us. Then comes infrared radiation, which is basically heat. Even though we can feel it, like from the sun or a heater, we still can’t see it.

The part we actually see is visible light. This is only about 400–700 nanometers in wavelength, which is super small compared to the whole spectrum. Our eyes have special cells that detect this range and turn it into color. Each color is just a different wavelength. Red has the longest wavelength, and violet has the shortest. The colors go in order starting with red then orange, yellow, green, blue, indigo, and violet. Together, they make white light.

We see color based on what light is reflected. For example, if something looks red, it’s because it reflects red wavelengths and absorbs the others. Also, our brain mixes signals from red, green, and blue receptors to create all the colors we see.

After visible light comes ultraviolet (UV) rays. These have shorter wavelengths and more energy than visible light. We can’t see them, but they can affect us, like causing sunburns. Beyond UV are X-rays, which have even more energy and can pass through soft tissue, which is why they’re used in medical imaging and have saftey procedures before using them.

Finally, at the highest energy end are gamma rays. These have the shortest wavelengths and the most energy in the entire spectrum. They’re produced by things like nuclear reactions and are very powerful and dangerous in large amounts.

Overall, the electromagnetic spectrum shows that light isn’t just what we see, it’s a huge range of energy. Our eyes only catch a small piece, but that little section is what creates all the colors we experience every day.