Speed of Electricity
Yesterday on 4BC Afternoons, Lindsay asked how fast does electricity travel? Really fast we all thought. Not so. Not so. Electricity travels at less than 1 cm per minute – it is practically crawling! An electrical wire works a lot like a water hose which is full of water and the gun on the nozzle is deactivated. As soon as you pull the trigger water gushes out. Electricity is a lot like that. All the electrons are lined up and are under voltage pressure waiting to be released. As soon as you flick a switch the electricity is released.
Loretta also wanted to know “Is dry cleaning really dry, and if so how does it clean your clothes?” Interesting question. I’m sure a lot of people don’t really know how it works. With dry cleaning your clothes are immersed in a liquid (a solvent). The reason it is called dry, is the liquid is NOT “wet” with water.
In the early days of dry cleaning the solvent used was often kerosene or gasoline. Today perchloroethylene is almost universally used. The clothes are washed in this solvent and then the solvent is recovered in an extractor so it can be reused and not evaporate into the atmosphere.
Here is a video showing the “Dry” cleaning process. Like me, you will probably be amazed to see that your clothes are all tumbling around in liquid. Who knew?
A little history of dry cleaning: Dry cleaning was discovered in the mid-19th century by French dye-works owner Jean Baptiste Jolly, who noticed that his tablecloth became cleaner after his maid spilled kerosene on it. He subsequently developed a service cleaning people’s clothes in this manner, which became known as “nettoyage à sec,” or “dry cleaning”.