fluorescent bulb lights up when near a plasma bulb a science with bobert video short

just what light is made of? All light consists of two oscillating waves that are perpendicular to each other. (animation) One of the waves is an oscillating magnetic field and the other is an oscillating electric field. (add labels) If we are going to build a cell phone signal blocker, we need to find something that will block these fields! (plasma ball movie starts) when a fluorescent light is placed close to a plasma ball the electric and magnetic fields of the plasma ball excite the gases inside the fluorescent bulb and these excited gas molecules strike the fluorescent sides of the bulb generating light! Isn’t that cool! .................. So if we place a material between the fluorescent bulb and the plasma ball and the bulb fails to light up then that means we have found a material that blocks electric and magnetic fields! Let’s try some different materials....let’s first try a glass lid....nope.....how about a metal lid?......It works.......how about aluminum foil?......it works!........

experimenting with a radio
Recall radio waves are very close to cell phone signals on the electromagnetic spectrum. (show again EM spectrum) That gives me an idea for another experiment. If we turn on a radio and surround it with a radio wave blocking material, the sound from the radio has to stop! (animation of radio with music signals coming out, thick square around it then music stops) AND if the material can not block radio waves the sound from the radio has to continue! Here are a bunch of experiments, (EM disappears) which ones do you think will block radio waves from being received by the radio? (circle ones that work, X out ones that do not) Let’s try each material and see which ones work!

plastic box aluminum foil under water
kettle with glass lid kettle with metal lid mylar birthday balloon
What about holes?
Looks like aluminum foil would be a great material.

But aluminum foil tears easy. what if we get holes in the aluminum foil, can it still effectively block radio signals? What do you think? Let’s try it and find out.....................Let’s try it again but with an even bigger hole using an aluminum clothes dryer exhaust tube! It still works! that’s because radio waves are huge! remember radio waves have a wavelength that is the size buildings down to around six feet. (EM diagram) the holes in our foil are not that big! So the radio waves can not fit. however, look at microwaves, they are a lot smaller! (arrow) The presence of holes may be a serious problem when building a cell phone signal blocker!
It is the electric field from the plasma ball that causes gas molecules in the fluorescent bulb to strike its inside coating emitting light!