Limitless imagination and physical limits

Originally posted on

Written by Community Solutions Fellow Kurt Cobb

Humans can imagine lots of things. They can imagine angels and demons. They can imagine whole worlds unlike ours with beings unlike us. They can convey these products of imagination in art, in literature and in film.

They can imagine flying machines, armored cars, diving suits, machine guns and human-like robots. Leonardo da Vinci imagined all of them hundreds of years before they became everyday reality. Hero of Alexandria, a Roman citizen and engineer, described a steam engine 1700 years before Thomas Savery obtained the first patent for one.

It didn't occur to the ancient Romans to refine the idea of the steam engine for transport or industrial work. They lacked the imagination for such a move and perhaps the necessity. After all, they had built a thriving empire without the steam engine, and the Mediterranean already offered quick, wind-powered transport to practically any part of the empire.

How do we distinguish those ideas that are forever going to remain in the realm of fiction and those that can become concrete reality? Of those that are possible how do we determine which won't destroy us? Both questions are very difficult ones indeed.

We are "moderns". We believe we have thrown off the burden of superstition and can now see in the clear light of day all the rational possibilities in the world that were previously hidden from our understanding. In this era of enlightenment the rush of invention and the power it has given us have resulted in the conceit that there is no limit to the power we can ultimately have.

That has given rise to an entire genre of fiction we call science fiction. Much of it concerns itself with space travel, particularly encounters with faraway alien civilizations. And, there is some reason to believe, just based on the immense size of the universe, that such civilizations exist even though we have never heard from them.

The science fiction genre and the enormous technological flowering of our age has encouraged the notion that anything we can imagine, we can achieve or invent. With regard to invention, the trouble with imagination as prediction is that if our imagination were vivid enough to detail the workings of a futuristic invention, those details would be tantamount to having created the invention itself.

All too often, we have objects with mere capabilities, but with no specifications. We have energy-matter transporters, but no specifications and no reason to believe based on the laws of physics that there could be any. We have ships that travel faster than the speed of light. There are theories about how to achieve such speeds. But, the amount of energy required is so enormous--by one calculation the energy contained in all the matter of the planet Jupiter to propel a 1,000 cubic meter ship--that it is hard to imagine how such an energy burst, if achieved, would not destroy the object it was trying to propel.

And, here we get to the crux of the matter. The above illustration is probably the most extreme one we could conjure of what actually constitutes technical prowess. Technology requires energy to run. What we've essentially been doing so far is substituting fossil fuel energy for human labor to run the technology that makes us feel so powerful. This has allowed productivity per person to skyrocket in the industrial age, but at a cost. That cost is the rapid depletion of fossil fuels and the climate effects of burning them.

Technology has given us the illusion of increasing "efficiency" in labor, when, in fact, this "efficiency" has been achieved through the wildly inefficient use of energy from the burning of fossil fuels. That inefficiency is the reason we are burning through so much fossil fuel so fast and creating climate change and depletion problems. (I am indebted to Nate Hagens for this insight.)

So, here I would like to propose a check on every "miracle" technology we are expecting in the future to do everything from making work optional (robots) to solving the climate problem (scrubbing the air of carbon dioxide). If the proponent of any yet-to-be-invented or yet-to-be-widely-deployed technology cannot explain where he or she will get all the energy needed to run it at scale in ways that 1) won't destroy the climate and 2) are in accordance with the known laws of physics, you should be very skeptical that it will ever be widely used.

A society that is ruined by climate change will cease to be technologically adept. So far, the best information we have about how to avoid a climate catastrophe is summed up in two principles: 1) Stop emitting greenhouse gases and 2) stop destroying things such as forests which absorb them.

Many of the technofixes which I've seen such as scrubbing the atmosphere of excess carbon involve enormous energy use. I know that the fantasists will protest that we will do all the things we want to do with "clean" energy. They must believe we have a lot longer for such an energy transition than we actually do. And, they likely don't understand the vast differences in energy density between fossil fuels and renewable energy. So far, "clean" renewable energy is only adding to our capacity rather than replacing our existing fossil fuel infrastructure.

The human imagination is an amazing thing. Its expression in literature, music and art can delight us and also be a mirror for our deepest selves. But it can lead us as well to mistake all our internal yearnings--for love, power and excitement--for external possibilities that have technological solutions which may not be possible or which may have serious downsides.

I am not trying to stop innovation. I am only trying to distinguish helpful innovation that betters our chances of survival and increases our overall quality of life from that which only sends us further down the road of climate instability and resource depletion and thus puts our very survival as a species at stake.