May the force be with you - electromagnetic fields generated by human thoughts

Empty space is full of invisible force fields, and we can detect electromagnetic fields from the farthest reaches of the universe. So couldn't our thoughts generate electromagnetic fields that might be sensed by other people? Here's the problem.

You gotta love this place. Every day is like Halloween!

- Fox Mulder

Early in the first film of the Star Wars trilogy, Obi Wan Kenobi, urges Luke Skywalker to feel the Force!" To no one s surprise, Luke does, eventually, and it is very very good to him. It was also very, very good to George Lucas. A billion dollars and twenty years later, the Force is still with us.

Tell me that you have not, at some time in your life, looked up at the night sky and shuddered at the vast loneliness of our existence. Or, sitting alone in a darkening room, perhaps in a remote cabin in the woods, have you never, as a barely perceptible chill breeze brushed your skin, had an idea that there might be some "thing" in the room with you, which you cannot see? What are the things that go bump in the night?

Dark side or not, there's something particularly cozy about an invisible Force that ties the universe together and gives it meaning, coherence, legitimacy. Pondering the existence of aliens may be how we ease our innate human loneliness nowadays, but pondering the existence of invisible forces is nothing new. Such musings are, after all, at the heart of most of the world's religions, whose annual gross stretches back for millennia and makes Lucas's look like chicken feed.

In fact, invisible forces are not merely the stuff of revelation: they are everywhere! Turn on your radio, and suddenly there is music, borne by invisible radio waves. Leap into the air, and the force of gravity pulls you back to Earth. Pluck a couple of magnets off the refrigerator and feel them push away from each other. As a matter of fact, there is almost no such thing as a visible force! I say "almost" because, of course, if a piano falls on your head, the source of the force you feel (before you feel nothing anymore) is eminently visible! Or is it? What is it about the piano that makes it "material"? Why does it crush your skull?

This might seem like a silly question; after all, what could be more solid than wood, ivory, metal, all the things from which a piano is fabricated? Well, a piano, at the fundamental level, is made of billions and billions of atoms. You can therefore reasonably assume that the particles in the atoms in the piano smack up against the atoms in your head and the multiple collisions are what cause one of these atomic aggregates to spatter.

Ah, nothing could be further from the truth. No particle in any atom in the piano - no proton, neutron, or even electron - ever gets close, on an atomic scale, to any particle in any atom in your skull. Most of what we like to think of as "matter" is actually empty space. The region in which electrons orbit an atomic nucleus is more than 10,000 times as large as the nucleus itself. It's the invisible electric forces emanating from the charged particles in the atoms in the piano that repel the charged particles in the atoms in your head and do such a good job of making both your head and the piano seem solid.

Physicist Richard Feynman used this idea to relate the strength of the electric force to the gravitational force. I will repeat his argument here, changing it slightly so we can continue to speak in terms of your head and the piano. But instead of dropping a piano on your head, let's drop your head on a piano from, say, 100 floors up. Let's assume you are at the top of the Empire State Building, which I seem to remember from my youth has 102 stories. And say that you manage to climb over the high fence around the observation deck and do a swan dive toward the ground below. At the same instant, some piano movers have taken a union-required break from their chore of moving a new concert grand into the lobby of the building. The piano is still in several pieces, which are lying on mats on the sidewalk. Suddenly the movers look up, and to their horror they see you hurtling earthward. You land on the instrument's elegant, polished wooden lid, which is lying flat on the ground.

Now, says Feynman, gravity has been accelerating you for 102 stories, but you don't continue your descent toward the center of the Earth: The electrical force - in this case between the atoms in the lid (in turn supported firmly by the sidewalk) and the atoms in your head - stops you cold in a fraction of an inch! Despite its spectacularly noticeable effects, gravity is the weakest force in nature.

Even this example doesn't do justice to how weak gravity really is compared to the electric force. Here's another one: Take a single electron, which has a small electric charge associated with it. If I put another electron near it, they are repelled by the electric force between them. In empty space, where no other forces were around to balance this force, they would fly apart. Now, say I wanted to pin the second electron down by putting a large mass on top of it, so that the gravitational attraction of the large mass (plus the electron) toward the original electron would exactly balance out the electric repulsion between the two electrons. How big a mass would I need?