What Is Radiation?

Where does it come from? How can it hurt you? How can we avoid it? Quick and Dirty Tips' newest expert, Everyday Einstein, answers these and many other questions about radiation.

Lee Falin, PhD ,
March 22, 2013
Episode #001

What is Radiation?


The word itself sounds ominous. It conjures up images of toxic waste fields and superheroes with strange powers. Most of the time it isn’t something that we think about unless we have to.

The 2011 Tohoku earthquake and tsunami led to the meltdown of one of the Fukushima nuclear reactors in Japan. The meltdown caused widespread concern about possible radiation poisoning. But what exactly is radiation and how can it poison you?

What Is Radiation?

Technically, any energy that moves through something is called radiation. Light from the sun traveling through space, radio waves from your local station traveling through the air, and heat traveling from a hot iron to your hand are all forms of radiation.

It’s handy to sort the different forms of radiation based on how much energy each one contains. If you were to take all of the different kinds of radiation in the universe and arrange them from lowest energy to highest energy, you would have what scientists call The Electromagnetic Spectrum or EM Spectrum, for short.

Radiation on the lower end of the EM spectrum, things like radio waves, heat, and visible light, are sometimes lumped together in a group called “non-ionizing radiation.” The nastier sounding types like ultraviolet rays, X-rays, and gamma rays on the high end of the EM spectrum are collectively called “ionizing radiation.”

At this point you might be thinking, “Great. This radiation stuff is everywhere. It’s only a matter of time before it gets me!” Fortunately...


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