Step 1: Do You Have the Psychic Power?
To see if you are one of the few, concentrate very hard on the TV picture and think of making it jitter. At the same time, you should hum a low note which will aid the concentration. Vary the tone of the hum, and at some point you may see the screen begin to wobble as your psychic energy synchronises with the TV signal.
Step 2: Using the Power.
Frustrate your friends (as long as they have the right type of TV) by making their telly jitter for a while, then stopping when they get up to try and fix it. As with all Super Powers, you should use this one wisely and in moderation.
Only read on once you have become a True Master Of The Power.
Step 3: Denouement.
Forget the "psychic powers". The trick is in the humming, and as you may have guessed, only you can see the effect.
An old CRT type TV set has a dot which sweeps lines across the screen, working its way down to the bottom. This happens 50 times a second for UK sets, 60 times a second for US ones. This is called the 'refresh rate'. The humming causes your head to vibrate and your eyes to wobble ever so slightly. When you get near the refresh rate of the TV (50 or 60 Hz) what is called a 'beat frequency' is set up, which is the difference between the pitch of your humming and the refresh rate of the TV. If you are humming at 65Hz (in the US), the picture will appear to move at a rate of 5 times a second.
The real trick with this is to tell a friend about the Super Power. Go along with it a bit, Tell him you can see a bit of movement and suggest he hums louder, until you have him humming like a maniac.