PrintMay 23, 2007
Arnold confronts his most powerful enemy ever: the laws of physics
The Governator, a.k.a Arnold Schwarzenegger, is now talking up "the hydrogen economy of the future," which will supposedly save us from our energy woes. Or maybe it'll be electric cars, biofuels and solar. Or all of the above. If this were a wrestling match, Governor Arnold would have that dirty old oil economy down on the wrestling mat, begging for mercy.
The trouble is that the stern laws of physics are different from pro wrestling and Hollywood action epics.
Because the current crop of "solutions" have one thing in common. They require more energy to manufacture than they yield. They are lousy energy conversion and transport methods, not new energy sources.
High school physics students are supposed to know that energy sources can only be converted from one kind to another, but there's no "conventional" way to create it. Only in your dreams, Governor, Sir.
Science knows of only two ways to obtain energy on this planet. Either we convert it from the fusion reactor of the sun --- using solar collectors or green plants, or through sun-made oil, coal, methane, shale sands, water flow, wind, or tidal power. Or, we can produce energy from a radioactive mass, like the sun itself. That's nuclear energy, which produces radiant heat from uranium or plutonium.
It is still true that oil, coal and nuclear are far and away the biggest and best, most cost-efficient methods available. The United States is fortunately rich in coal, shale, and natural gas, but because of environmentalist overkill, the country has a declining future in oil. You can convert any energy source into a different form, as long as you don't mind slipping down the efficiency hill, step by step, with all the finality of the Frankenstein Monster clumping downstairs. There's nothing we can do about it. We can turn oil into hydrogen, and coal into electricity --- and end up running "clean" electrical or hydrogen cars. Trouble is, you lose BTUs at every single step. And you get more total pollution, because now you're using even more coal, oil, and nuclear input for the same energy output. There's no free lunch, in economics or physics.
You can always dream of efficiency improvements that could theoretically make up for these basic facts of physics. So maybe hydrogen fuel cells will let us store energy at high efficiency. Great, but we still have to get the energy from the same old sources: coal, oil or nuclear. So Reuters was far out into Fantasyland the other day when it claimed that new hydrogen storage discoveries will help us get to energy paradise. But hydrogen storage won't help energy production. We still have to get it in the first place. Too bad, but the media flunks high school physics. (Just like most of them probably did the first time.)
Or we could make everybody drive small cars and motor scooters --- and be at the mercy of bigger vehicles. That's also basic physics: Mass times velocity equals force, so bigger cars crush smaller ones. They have more mass. The smaller your car, the more vulnerable you are.
Bottom line for Arnie's hydrogen-electric cars? Barring a scientific miracle, they are inherently much worse than gas-powered cars. It's the Tinseltown "solution" to reality --- expensive and wasteful, much dirtier to start with, but cleaner once we see it. It looks great, as long as you don't peek behind the cardboard scenery. So this is a shell game, covered up by hype and scientific ignorance. The end users think they're not using those bad old fuels. In fact, they are still using them and getting less for their money. Millions of people will end up using more petroleum and coal - it'll just be out of sight somewhere in Nevada.
So the next time Governor Arnie talks up a "hydrogen economy" for California, will somebody please ask him what energy sources he is proposing to use, to free up hydrogen molecules from water or methane? Reporters never seem to remember basic physics --- it would get them fired. But somebody please ask. If the Goobernator is an honest man, he will say:
Hydrogen will be produced from oil, coal, and nuclear power at a big loss in efficiency. It's going to take billions and billions of dollars in tax money to create a Giant Monument to My Ego, and it's not going to pay for itself in the foreseeable future. Solar energy isn't ready, and won't be for years.
If he doesn't say that, he's ignorant or lying. Even the Governator can't fake out the laws of physics.
James Lewis blogs at http://www.dangeroustimes.wordpress.com/
Update:
Update:
Be Careful With the Laws of Physics
Considering that James Lewis taunts the "Goobernator" with the laws of physics, I think it wise if Mr. Lewis would correct the error in his post. Mr. Lewis states that "Mass times velocity equals force, so bigger cars crush smaller ones. They have more mass. The smaller your car, the more vulnerable you are". This is incorrect on at least three counts.
First, from Newton's second law of motion, force (F) equals mass times acceleration (F=ma). By definition, momentum (P) equals mass times velocity (P=mv). Force and momentum are not equivalent. They are different because acceleration is defined as the rate of change in velocity, which naturally also drives a difference in the units of measure.
Second, the stated conclusion, "so bigger cars crush smaller ones", does not even follow from the correct equation, F=ma or P=mv, take your pick. Bigger cars crush smaller ones because the collision is inelastic. In an inelastic car collision, some kinetic energy of the two vehicles is absorbed, and some is observed as residual motion (kinetic energy) of the two vehicles after collision. We observe that the less massive car increases in density (is crushed) more so after collision than the more massive car. The less massive car absorbs a disproportionate amount of the total pre-collision kinetic energy.
Third, if the collision were elastic (which it is not), then regardless of difference in mass of the two vehicles, there would be no crushing of the less massive car. By definition, an elastic collision conserves the kinetic energy after collision, and there is no absorption of kinetic energy released to crush anything.
Occupants of smaller cars are more vulnerable due to the nature of the collision, not due to the car being smaller; this from the laws of physics, whether you like being corrected on it or not.
James D. Baker
Littleton, CO
