ScienceCasts: The Sounds of Interstellar Space

As Voyager 1 recedes from the solar system, researchers are listening for "interstellar music" (a.k.a. plasma waves) to learn more about conditions outside the heliosphere.

 

Electric Flame

Is a flame really a plasma? Well it depends on your definition of plasma, but there are certainly ions in a flame, formed as molecules collide with each other at high speed, sometimes knocking electrons off of their atoms. Special thanks to the Palais de la Decouverte for helping me perform this experiment. Using tens of thousands of volts on two metal plates, we created a strong electric field around the plasma. This pulled positive ions in one direction and negative ions in the other direction elongating the flame horizontally and causing it to flicker like a "papillon" (butterfly). Then we showed that much longer sparks can be made through the flame than through air since the ions increase the conductivity.

Other Veritasium videos

Plasma in a magnetic field

Demonstration of spinning plasma in a magnetic field from a permanent magnet.

Plasma: The 4th State of Matter

Plasma is widely considered to be the fourth state of matter due to its unique properties. Plasma is a gas in which the atoms are ionized, meaning there are free negatively charged electrons and positively charged ions. This collection of charged particles can be controlled by electromagnetic fields and this allows plasmas to be used as a controllable reactive gas. The electronics industry uses this concept to etch very small patterns into silicon to make our modern day devices smaller and more efficient.

This movie was produced by students Bobby Bruce and Michael Sweatt for the A. James Clark School of Engineering's 2008 Vid/Terp competition.