Im waterin' ur car.

My mom sent this to me the other day. It's Fox News Houston story about a man who's invented an engine powered by (gasp) WATER! It was added to YouTube a year ago, and it's been added a few times since then. Naturally, it took even longer to circulate amongst the old folks who still e-mail each other WindowsMedia attachments (yeah, my mom emailed me a WMV file).

Now of course, this story is just silly. It's not a hoax exactly, but we are not getting water powered cars anytime soon. Sure, getting power from water through electrolysis is perfectly feasible, just not terribly efficient. Wikipedia explains why:

Where designs that claim to be water fuelled engines have been made public, they often involve obtaining hydrogen from water by electrolysis. The usual scheme is to use electricity (from a battery) to split water into hydrogen and oxygen — then to burn the hydrogen in a more or less conventional engine — then use some of the power of that engine to recharge the battery and thus electrolyse more water. The end result would once again be water because that is what you get when you burn hydrogen in air. In effect, you'd have a perpetual motion machine.

In practice, none of the processes involved are 100% efficient. This means that some electricity is wasted in the electrolysis stage, some heat is wasted in burning the hydrogen in the engine and some of the power of the engine is lost in generating electricity. This means that the amount of power available for recharging the battery is considerably less than the amount of electricity needed for continued electrolysis — and the engine rapidly comes to a halt when the battery runs out of charge.

When the hydrogen is burned, the heat it creates can be converted into work by a conventional piston engine (car engine), but the efficiency of such engines is limited by the second law of thermodynamics and is likely to be of the order 30%. Because a conventional electric motor does not use heat, it can theoretically have an efficiency close to 100% and 80% efficient motors are commonplace.

The best part of the e-mail came from the guy who forwarded the video to my mom:

Subject: Fwd: Fw: Water as fuel??

THIS IS INCREDIBLE.  ONLY ON FOX....MAKES YOU WONDER WHAT ELSE THE MEDIA IGNORES...  EB 

A revolutionary invention!..Let's pray for it to be available soon.
Why isn't the media talking about this incredible discovery.

Only on Fox, indeed. Our local affiliate, too. I'm Houston Proud, for sure. Also, I'm going to pray that people one day figure out Fox is also the media. When you turn on your television, THAT IS THE MEDIA. Fox is a multinational, billion-dollar corporation. They own freaking MySpace. They're trying to buy DowJones. Fox is the media.

Sheesh.