“I heard there was, like, a car that runs on water … “
“Dude, no, there’ve been, like, six of them. But oil companies bought all the patents.”
A lot of the people who attend my poetry class in jail believe in freaky conspiracy theories. Somebody started telling me that the plots of various Berenstain Bears books are different from when he was a child, which is evidence that the universe bifurcated and that he’s now trapped in an alternate timeline from the path he was on before …
(New printings of some Berenstain Bears books really are different. Take Old Hat New Hat, a charming story about shopping and satisfaction: after the protagonist realizes that he prefers the old, beat-up hat he already owns to any of the newer, fancier models, a harried salesperson reacts with a mix of disgust and disbelieve. This scene has been excised from the board book version that you could buy today. Can’t have anything that tarnishes the joy of consumerism!)
I’ve written about conspiracy theories previously, but I think it’s worth re-iterating, in the interest of fairness, that the men in jail are correct when they assume that vast numbers of people are “breathing together” against them. Politicians, judges, police, corporate CEOs and more have cooperated to build a world in which men like my students are locked away. Not too long ago, it would have been fairly easy for them to carve out a meaningful existence, but advances in automation, the ease of international shipping, and changes to tax policy have dismantled the opportunities of the past.
Which means that I often find myself seriously debating misinterpretations of Hugh Everett’s “many worlds” theory (described midway through my essay, “Ashes”), or Biblical prophecies, or Jung-like burblings of the collective unconsciousness.
Or, last week, the existence of water cars.
In 2012, government officials from Pakistan announced that a local scientist had invented a process for using water as fuel. At the time, I was still running a webcomic – one week’s Evil Dave vs. Regular Dave focused on news of the invention.
When scientists argue that a water-powered car can’t exist, they typically reference the Second Law of Thermodynamics (also discussed in “Ashes”). The Second Law asserts that extremely unlikely events occur so rarely that you can safely assume their probability to be zero.
If something is disallowed by the Second Law, there’s nothing actually preventing it from happening. For an oversimplified example, imagine there are 10 molecules of a gas randomly whizzing about inside a box. The Second Law says that all 10 will never be traveling in the exact same direction at the same time. If they were, you’d get energy from nothing. They might all strike the north-facing wall at the same time, causing the box to move, instead of an equal number hitting the northern and southern facing walls.
But, just like flipping eight coins and seeing them all land heads, sometimes the above scenario will occur. It violates the Second Law, and it can happen. Perpetual motion machines can exist. They are just very, very rare. (Imagine a fraction where the denominator is a one followed by as many zeros as you could write before you die. That number will be bigger than the chance of a water-fueled car working for even several seconds.)
When chemists talk about fuel, they think about diagrams that look roughly like this:
The y axis on this graph is energy, and the x axis is mostly meaningless – here it’s labeled “reaction coordinate,” but you wouldn’t be so far off if you just think of it as time.
For a gasoline powered car, the term “reactants” refers to octane and oxygen. Combined, these have a higher amount of energy stored in their chemical bonds than an equivalent mass of the “products,” carbon dioxide and water, so you can release energy through combustion. The released energy moves your car forward.
And there’s a hill in the middle. This is generally called the “activation barrier” of the reaction. Basically, the universe thinks it’s a good idea to turn octane and oxygen into CO2 and H2O … but the universe is lazy. Left to its own devices, it can’t be bothered. Which is good – because this reaction has a high activation barrier, we rarely explode while refueling at the gas station.
Your car uses a battery to provide the energy needed to start this process, after which the energy of the first reaction can be used to activate the next. The net result is that you’re soon cruising the highway with nary a care, dribbling water from your tailpipe, pumping carbon into the air.
(Your car also uses a “catalyst” – this component doesn’t change how much energy you’ll extract per molecule of octane, but it lowers the height of the activation barrier, which makes it easier for the car to start. Maybe you’ve heard the term “cold fusion.” If we could harness a reaction combining hydrogen molecules to form helium, that would be a great source of power. Hydrogen fusion is what our sun uses. This reaction chucks out a lot of energy and has non-toxic byproducts.
But the “cold” part of “cold fusion” refers to the fact that, without a catalyst, this reaction has an extremely steep activation barrier. It works on the sun because hydrogen molecules are crammed together at high temperature and pressure. Something like millions of degrees. I personally get all sweaty and miserable at 80 degrees, and am liable to burn myself when futzing about near an oven at 500 degrees … I’d prefer not to drive a 1,000,000 degree hydrogen-fusion-powered automobile.)
With any fuel source, you can guess at its workings by comparing the energy of its inputs and outputs. Octane and oxygen have high chemical energies, carbon dioxide and water have lower energies, so that’s why your car goes forward. Our planet, too, can be viewed as a simple machine. High frequency (blue-ish) light streams toward us from the sun, then something happens here that increases the order of molecules on Earth, after which we release a bunch of low-frequency (red-ish) light.
(We release low-frequency “infrared” light as body heat – night vision goggles work by detecting this.)
Our planet is an order-creating machine fueled by changing the color of photons from the sun.
A water-fueled car is impractical because other molecules that contain hydrogen and oxygen have higher chemical energy than an equivalent mass of water. There’s no energy available for you to siphon away into movement.
If you were worried that major oil companies are conspiring against you by hiding the existence of water-fueled cars, you can breathe a sigh of relief. But don’t let yourself get too complacent, because these companies really are conspiring against you. They’re trying to starve your children.