Re: Do atoms make shadows?

Cecilia,

This is an excellent question and a little more complicated than you might think. This is beacause atoms are so small that visible light (red, green, blue, etc.) interacts strangely with atoms. To understand why this happens, you need to know that light is like a wave and vibrates at various frequencies. Coincidentally, the wavelength of light (or the distance from the peak of the first wave to the peak of the wave behind it) is similar to the size of an atom. That's right, we're talking about very tiny/dense waves! This is why when we see light coming from a light bulb it doesn't look "wavy": The waves are so close together, we can't tell with our eyes.

But because visible light has wavelengths similar in size to atoms, we use an electron beam to image atoms instead. This technology is called an electron microscope and there's an entire field of research dedicated to trying to look at tiny things such as atoms. You might be particularly interested to know that one of the techniques these researchers use is called "shadow casting" and involves focusing an electron beam on atomic-sized objects to cause a shadow of them to be cast and then imaged, so we can understand how the atomic objects are shaped.

Keep asking good questions,
Amber