A couple of weeks ago I saw the video below explaining how energy really moved through electrical wires. I felt like it broke my brain and told me that everything I learned about current and electromagnetic fields was oversimplified. All that studying for ham radio tests was for nought.
The video presents a thought experiment with current flowing to a light bulb through wires 1 light-second long.
But now there seems to be a small cottage industry in replies to the above video. The video below (extremely entertaining!) clarifies how the first video presents a bit of a trick question. A wire that length acts like an antenna transmission line, and some energy bleeds through due to capacitance, even if the wire was cut at the ends.
THEN, I saw this third video. What’s better than a thought experiment? AN EXPERIMENT! He actually strings up a kilometer of wire, hooks it up to an oscilloscope, and shows what the electrons are doing in a real-world example. He even clips the wires and shows the small amount of current that appears at the resistor (light bulb) almost instantaneously.
Anyway, I know I just posted about an hour’s worth of science videos. If you watch any of them, watch the last one. I just wanted to say I love science. I’m fascinated by the complexities of trying to teach science to others. It’s great to see this worked out in detail on Youtube. In the end, the best way to demonstrate a scientific concept is with an actual experiment. That’s why hands-on science museums are so important.
It was also good to unbreak my brain.
