SS Connection

My PBL projects are the Plasma Ball and the Radiometer. Both inventions were made in the late 1800's. During this time, in the nineteenth century, with industrial growth Western and central European countries were developing a middle class of industrialists and professionals. There was confidence in human progress and the human ability to do virtually anything. This confidence was characterized by the belief that man was reasonable and able to make choices with free will. It also emphasized toleration of others and respect for science and reason.

In 1894, Nikola Tesla received a patent for his Incandescent Electric Light that was the basic design for today's plasma ball. Tesla invented this light as a way of studying high voltage phenomena. A plasma globe or plasma lamp (also called plasma ball, dome, sphere, tube or orb, depending on shape) is (usually) a clear glass orb filled with a mixture of various noble gases with a high-voltage electrode in the center of the sphere. Plasma filaments extend from the inner electrode to the outer glass insulator, giving the appearance of multiple constant beams of colored light (see corona discharge and electric glow discharge). Plasma globes were most popular as novelty items in the 1980s.

The Crookes radiometer, also known as the light mill, consists of an airtight glass bulb, containing a partial vacuum. It was invented in 1873 by the chemist Sir William Crookes as the by-product of some chemical research. In the course of very accurate quantitative chemical work, he was weighing samples in a partially evacuated chamber to reduce the effect of air currents, and noticed the weighing were disturbed when sunlight shone on the balance. Inside are a set of vanes which are mounted on a spindle. The vanes rotate when exposed to light, with faster rotation for more intense light, providing a quantitative measurement of electromagnetic radiation intensity. The reason for the rotation has historically been a cause of much scientific debate. Today the device is mainly used in physics education as a demonstration of a heat engine run by light energy.