Mad Scientist Equipment

That V-shaped thing, with a little electric arc that starts at the bottom, moves to the top and disappears, over and over again? You know, that goes, “Bzzzzzzzzzzzt”?

What’s that called?

Jacob’s ladder

A transformer?

Jacob’s Ladder it is.

http://www.bio.miami.edu/rob/tesla.html

Out of curiosity (since we’ve answered the OPs question), what is a Jacob’s Ladder used for? Does it have a function or is it just there to look cool?

Looks cool. No practical function, unless you thinking looking cool is an important function.

Find a properly insulated skewer.

There is no cooler way to roast marshmallows.

      • You can sometimes get a similar effect if you open high-voltage switches under load: here’s a film of a switch (on top of some substation electrical towers) being opened, and the same type of arc happens:

http://205.243.100.155/frames/mpg/345kV_SWITCH.MPG

(-I dunno whose site this is, or how long it’ll be there…)
~

By combining an enclosed ladder with a source of butane, you can create a convenient, and practical source of fireballs in your own home. This obviates the need to buy balloons, and mess around outside with matches, in all kinds of nasty weather.

Another practical use for a Jacob’s Ladder is disrupting AM radio for everyone on your block.

The things blast out RF garbage like nobody’s business. I’ve not tried, but I imagine the sheer quantity of RF these things put out would “swamp” anything within a few yards, including cell phones.

A Jacobs ladder does have a practical application. When making neon tubes, high voltage electricity is passed thru the tube while the vacuum is applied. The Jacobs ladder is used as a overload indicator in series with the tube. If you increase the voltage on the bombarding transformer too much, the spark will jump the gap and let you know you are a little too hot.

A Jacobs ladder does have a practical application. When making neon tubes, high voltage electricity is passed thru the tube while the vacuum is applied. The Jacobs ladder is used as a overload indicator in parallel with the tube. If you increase the voltage on the bombarding transformer too much, the spark will jump the gap and let you know you are a little too hot.

Where have all the science writers gone?!? There’s no reason why “plasma” should be in quotes there. The little zappy things climbing the wires aren’t “sort of” plasma, or approximately plasma. They are plasma, plain and simple. And they’re not “volts”, either. It is a high voltage device, but while the zappy things might be called “bolts”, or even “jolts” (neither of those being a technical term), they’re sure not volts.

Ya just can’t get good help anymore!