Dotted LIGHT from one single wire … a simple electric circuit • low voltage power - supply • and a thin wire Suppose the current is large enough to make the wire glow, what would you expect ? A B and this is what you will see : Look closer … … and guess a reason for this • You see the shape of the glowing spots • And think of the space between them • Have you seen this before ? You are right ! • It’s a standing wave • And how to get this ? • All you need is … • A magnet ! and of course …. an alternating current in addition: …with a direct current both of these pictures A and B are wrong ! What you really get … …is this Think HOT !!!