Plasma is commonly thought of in connection with flat panel TVs. The technology is cool and the picture is great, but odds are good that you don’t really know much about the very plasma that makes these TVs possible. So, care to find out what plasma is?

Stay calm; there is going to be a little science involved in the explanation, but it’s pretty simple, honest.

Plasma is actually a fourth state of matter. Remember when your grade school teacher taught you about the three states of matter (solid, liquid and gas)? Well she might not have mentioned that there was another state of matter, probably because it was far more likely for a 10-year-old to come in contact with solids, liquids and gasses than with plasma.

Plasma is actually a gas that has been ionized. Ionizing gas means adding enough energy to make individual atoms give up an electron (the part of the atom that helps determine energy levels and conduct electricity). So the gas atoms float around missing an electron and the free electrons buzz about looking for somewhere to go.

This results in a lot of complex interactions, but here’s what you need to know: it makes plasma conduct electricity very well. That’s why it’s used in plasma TVs. The plasma allows the TV to excite phosphor that gives off a specific color, and the plasma even allows the intensity to vary, giving a plasma TV billions of shades of color.

Even though you’re more used to running into the other three states of matter in your everyday life, plasma is actually the most common state of matter in the universe. Stars consist mainly of plasma, and there is even a sparse amount of plasma in empty space. You’ve even seen plasma here on earth every time you’ve seen lightning because all the energy ionizes the surrounding air. The Northern Lights (aurora borealis) are another good example of plasma in nature.

Plasma was discovered clear back in 1879 by a man named Sir William Crookes, but it hasn’t experienced widespread use until recent decades. Rudimentary plasma TVs were created in 1964, but they didn’t start to become feasible for home use until the 1990s. Plasma is also used in other areas of commerce. For instance, plasma is used to sterilize fruits and other foods that have delicate skins or can’t be cleaned with chemicals.

It’s likely that you won’t think about plasma other than when you look at your flat panel plasma TV, but that’s okay. The next time somebody talks about the three states of matter, you’ll still sound pretty knowledgeable when you respond, “Actually, have you heard about the fourth state…”