CHAPTER SEVENTEEN

How Much Electricity Is in the Sky?

The passive method rests on a single claim: that the atmosphere holds free electrical energy and that a wire can deliver a useful amount of it to a plant. This can be checked with numbers, and the numbers have been known for a century.

The fair-weather field

The earth and its atmosphere form a great electrical circuit. Thunderstorms around the world, a couple of thousand of them at any moment, pump charge upward, leaving the upper atmosphere a few hundred thousand volts positive with respect to the ground. In fair weather that voltage shows up near the surface as a vertical electric field of roughly 100 to 150 volts for every meter of height.

That sounds like a great deal. The top of a six-foot pole stands in air nearly three hundred volts above the ground. Why can you not light a lamp with it? Why does it not shock you?

Because voltage is not energy. Air is an excellent insulator, and almost no current flows through it. The fair-weather current that drifts down from the sky to the ground is about two picoamperes on each square meter, two millionths of a millionth of an ampere. The moment you touch that three hundred volts with anything conductive, it collapses, because there is nothing behind it. Your own body, standing in the garden, is at ground potential from head to foot, and so is every plant.

The arithmetic

Multiply it out. The electrical power passing through the air above one square meter of garden in fair weather comes to less than a billionth of a watt.

Now compare. Full sunlight delivers about a thousand watts to that same square meter. The sun is supplying the plant with roughly a trillion times more energy than the fair-weather electricity of the air. Even if a copper coil could capture every bit of the atmosphere’s electrical power over an entire garden bed, which it cannot, it would be delivering energy on the scale of a single flea’s jump per day.

So the common statement that an antenna “harvests atmospheric energy to feed the plants” is false as a matter of quantity. There is not enough there to harvest.

What a rod actually does

A grounded metal rod in the open does have real electrical effects, and it is worth knowing what they are.

In fair weather it does almost nothing. It sits at ground potential, and the air around its tip is not ionized. If anything it slightly shields the ground immediately around it, the opposite of what is claimed.

Under a thundercloud, things change. The field can rise to thousands of volts per meter, and then the tip of any pointed, grounded object begins to leak a discharge into the air. Trees do this from their leaves and twigs. The currents are real and measurable, on the order of a millionth of an ampere for a tree. That is a million times the fair-weather figure, and still a very small current, flowing only while the storm is overhead.

Could a brief, tiny current like that matter to a plant? If Goldsworthy’s storm-signal idea is right, plants may indeed respond to the electrical signs of a storm. But in that case the plant’s own leaf tips already do the job that the antenna is said to do, and the storm is providing the signal with or without the copper.

And lightning?

Lightning does fertilize the earth, as Bertholon’s farmers believed. The heat of the stroke joins nitrogen and oxygen, and rain carries the product down as nitrate. Worldwide this fixes several million tons of nitrogen a year, a small but real contribution, roughly a twentieth or less of what fertilizer factories produce. It is spread thinly over the whole planet by rain. No garden device increases your share, and a device that did attract lightning would be a hazard, not a help.

The physics, then, gives a clear answer about one kind of electroculture. Powered systems supply real fields and currents and may do something. Passive collectors have almost nothing to collect.