Archive for the ‘electricity’ Category
Mystifying Marconi
Guglielmo Marconi in 1909
My attention was recently drawn to an article in the Provincetown Independent entitled The Marconi Mythology. This makes the claim that “His ideas were derived from spiritualism, a pseudo-religious movement of the late 19th and early 20th centuries by which people sought to commune with the spirit world.” It also claims that Marconi believed that “sound never disappears from Earth” and that one could potentially construct a device to recover the sound of the angels singing in Bethlehem!
This last claim is the more extrordinary. But I can find no evidence that it is true. Not only can I find nothing to connect Marconi with these ideas, I can find nothing online to suggest that the possiblility of recovering “lost sounds” is even a known belief.
The idea that he might have been interested in spiritualism is at least plausible. A number of well-known figures of the day were receptive to the idea of communicating with the dead including Sir Arthur Conan Doyl, biologist Alfred Russell Wallace, and English physicist and radio pioneer Oliver Lodge. But Marconi does not seem to have been one of them.
Radio Shack brand may return online
The Radio Shack stores played a big role in my childhood. My first memory of Radio Shack is from around 1975 when I was six. I went with my dad when he bought new speaker cables. We went others times whenever our TV stopped working. Dad would take the back cover off, pull out some vacuum tubes, and take them in to Radio Shack to use the tab tester. Sometimes there would be a line for the tester. If the tester said a tube was weak, dad would go over to a counter and ask the man there for a new one.
Review of the Sun Joe CJ603E Wood Chipper
Ever since I first saw them in a catalog years ago I have wanted own one of those garden waste chippers. Those I saw 30 years ago were made of metal and cost far more than I could justify paying. But consumer goods are getting cheaper and home wood chippers are no exception. One reason they are cheaper is that the stamped and folded bodies of heavy-gauge sheet metal have been replaced by molded plastic. Still the prices seemed too low for a useful machine. Surely they would break and jam unless the openings had been made deliberately small enough that nothing which would put a strain in the mechanism could be inserted in which case the machine would be of little practical value.
Electrical Power and Power Loss
Basic Electrical Units
A volt is a unit of electrical potential. Electrical potential in turn is the force which a power source (such as a battery) applies to a connected device in order to push electrons through it. Electrical potential (voltage) is comperable to the presure which a pump applies to a plumbing system in order to push water through the pipes.