Actually it's all quite plain; the lamps electrical current is enhanced by a property in the human body called capacitance, which is the ability to store an electrical charge. The properties in the human body utilized are temperature (heat), resistance (water in our bodies conducts electricity), and radio reception (we are human antennae). The charge your body introduces causes an oscillator in the lamp mechanism to change frequency and toggle the light on and off. Usually these lamps have three brightness settings, plus an "off" switch. So, each touch causes the lamp to switch from Off, Dim, Intermediate, Full, and back to Off. Simple huh?
So, who invented this wonder? Good question. Nobody seems to know for sure. J. D. Porter was said to discover and market touch lamps before discovering the quartz Damsonite in 1977. There were also patents issued in 1987 to Scott Kunen, and in 1988 to Cline and Gouldy. These appear to have been for the electronic module that regulates the power in the lamp; that little oscillator. Or, you could go with some people who claim that your touch causes a partial earth disturbance in the wiring. And then there are those who just figure the aliens, or future man time-traveling, brought us the "gift."
Those latter versions are often cited due to the occasional "odd" behavior of these lamps. Mainly, switching on by themselves. One man complained that his thrashing around in bed at night caused his touch lamp to go on at times. But those rare instances are generally believed to be caused by inexpensive or faulty units that respond too easily to changes around them.
People love the convenience and charm of the touch lamp and children are forever fascinated by them, getting a little science lesson along the way.
These table lamps are not only lovely, but can provide inspiration as well as beauty. Some of the decorative glass shades available now are commemorative as well, such as Fallen Heros, POW/MIAs, and Semper Fidelis lamp shades that can provide life-long remembrances. In a lighter touch, others glow with delicate flowers, butterflies, and hummingbirds. Children can take delight in having their very own fairy, unicorn or dragon on the table by their bed. There are Tiffany style touch lamps to illuminate a room with warmth and exquisiteness. Or, if you prefer a fabric shade on your lamp, you can have that also. Marvelous varieties are available to choose from.