Last week at a church social activity my wife and I were sitting with some friends - highly educated people - and the discussion turned to my profession. I explained what it is that I do and then came the question that always comes after I explain that I'm trying to understand dynamo action in sun-like stars, "so why does the government give you money to do that?" I tried to explain that there are economic benefits to funding basic research and then moved the conversation to something else. Today, however, I was reading about proposals to cut funding of the NSF is some of the latest debt-reduction proposals and I again thought of that conversation. Then I thought about some work that a good friend is doing trying to build compact, low-cost, reliable ways to diagnose exactly what strain of viral infection someone has, and I came up with an alternate idea. So I'm going to try it out on you guys.
In 1666 Issac Newton built a device that could take in sunlight, run it through a prism, and conclusively show that white light was made of all colors combined - what he termed "spectrum". The process of separating light into it's constituent colors or wavelengths can be done via diffraction. At the time there was absolutely no practical application to this.
Nobody was able to do much with it until 140 years later when two British guys were able to show that the sun emitted limit that wasn't visible to human eyes - including UV light. In the 1950's two guys used an understanding of how light diffracts to show that DNA is what encodes the instructions for how the cells in your body operate. There was no practical application for that at the time. In the 1970's scientists came to understand that UV light can damage DNA, which can lead to skin cancer. Now when you go out on a sunny day, you put on sunscreen to prevent sunburns and skin cancer. Why? Because Newton played with a prism in 1666.
After the discovery of UV light the next big thing anybody did with Newton's idea was to make the device for producing spectrum better. Pretty soon a guy named Joseph Fraunhofer in 1814 was taking much more accurate and detailed spectra of the sun. In this he noticed a bunch of dark lines - colors that were missing from the rainbow of light. There was no practical application for that discovery, but it seemed pretty cool. Before long people were taking spectra of other things and they noticed that different materials produced different dark lines. Eventually a guy named Kirchhoff figured out that you could use spectra to figure out what something was made of and that certain materials absorbed the light of certain colors or wavelengths. There was no practical application for this either, but it was still pretty cool. Then in 1945 another guy name Percy Spencer was working on radar for the military when he noticed that if he pointed the radar at a candy bar from his lunch it melted. Pretty soon he had figured out that water was really good at absorbing light at a certain frequency. He built a box with a radar transmitter pointed into it and found out that you could use it to heat food. Thus was the microwave oven was born. I ate popcorn on Sunday because Issac Newton played with light in the 1660's.
Why do we as a nation pay people like me to study how sun-like stars use convection, rotation, and stratification to build organized magnetic fields? Because we might figure something out that has no practical application, but somebody might think it's cool and so they'll play with it some more. Then they might figure out something with no practical application, but somebody else will think it's cool. Then that person might stumble onto something that saves lives, dinners, and/or planes.