Solar Radiometer: A Great Solar Educational Tool

The solar radiometer is a great solar educational tool that was actually invented all the way back in 1873 by an English physicist named Sir William Crooks. A solar radiometer is a glass globe that works as a sealed vacuum. Inside that airless vacuum are some vanes and a wheel. The idea behind this invention was that a solar radiometer would be able to measure the intensity of solar energy.

The solar radiometer was the first invention that could accurately measure the intensity of radiant solar energy. Crooks figured out that the key was to make sure that there was a near perfect vacuum inside the glass where at least 99% of the air had to be removed. Otherwise there would be too much drag and the vanes wouldn't spin at all. The complete lack of friction was what allowed the measurement of radiant solar energy to take place.

When everything in the solar radiometer is set to work correctly, what happens is that the actual photons from the sun bounce of the silver side of the vanes, which causes movement and rotation. Although the force is small, it was the first time that there was an invention that could actually measure to some degree the intensity of radiant solar energy.

While at the time this was a huge breakthrough for science, now it still plays a strong role as a great educational science tool. Many describe the radiometer as a light-bulb shaped device with a tiny weather vane in the middle, which is a fairly accurate description. The light energy from the sun or even lamp light causes the "weather vane" to spin, converting light energy into mechanical energy.

These are great for elementary science classes because they allow actual experiments to be done regarding solar energy, and show how light comes through. A science teacher can make mock homes with various covers to move between the light and the solar radiometer, or can shut the lights off completely and watch the solar radiometers slow.

Sir William Crooks definitely made a breakthrough with his invention of the solar radiometer, and it still helps bring young children into science and especially into solar energy even today.