Photon vs Electron (Jerz’s Literacy Weblog)

My son at age 8 is turning out to be quite the science geek. While I was driving him home from piano lesson today, he asked me whether an electron is the smallest thing in the universe.

I took at stab at it and guessed that maybe a photon is smaller, since its the smallest possible measurement of light. I remembered that light sometimes acts like a wave and sometimes acts like a particle. A photon has properties that are similar to a wave, right? And a wave can be endlessly long, and the wavelength of the electromagnetic spectrum varies quite a bit, with the measurements extending to the very small and the very large.

Thinking about it logically, I suppose that photons have to be comparatively large, since they can be blocked by fairly thin sheets of matter.

I’ve checked Wikipedia and a few other sites, and now I’m realizing that asking about the size of a photon is like asking how big is blue, or how smooth is a loud sound. We can measure the wavelength of blue light, or we can convert a loud sound into a signal with peaks and valleys we can measure.

Here is a good collection of articles: The Nature of Light.

I’m not sure I’m ready to explain quarks and superstrings to my son, but as soon as I publish this, I’m going to go tell him that I was wrong about the photon.