Monday, December 28, 2009

Pocohontas Retold

Spoiler alert: I discuss the movie Avatar below.

When I read the Pocohontas story to my kids (we have the Disney version), we usually have a little discussion when we get to the page where Pocohontas attempts to dissuade her father (the local Indian chief) from starting a war with the settlers. The kids are interested in the idea that both people are trying to do the right thing, but they have completely different ideas about what the right thing is.

For those of you not familiar with the story, Pocohontas has fallen in love with a mercenary on the voyage (John Smith), and the two of them want to establish peace between the settlers and the natives. The book suggests that peace involves the settlers staying in North America. Powhatan, her father, is assembling a war party to drive the settlers away.

We can look back in history to better understand who was "right".
  • As the book makes clear, a war between the settlers and the Indians is going to lead to many Indian casualties, since the settlers have guns and the Indians do not. Furthermore, most of the settlers are not intending to do harm to the Indians, as they've been told they are settling land that has no ownership yet. Pocohontas' efforts end up saving many well-intentioned people's lives.
  • These same settlers would probably understand that, had they landed anywhere in England and built a village where they landed, they would be summarily evicted by whomever owned the land they were on. The racism here is lightly touched on in the book, but it's helpful because it's pretty easy for the kids to see how convenient it is for the settlers to suppose that nobody in North America owns anything yet.
  • I usually tell the kids what little I know of the Mauri, the indigenous people of New Zealand. As I understand it, they immediately made war with white folks who arrived. I suspect that the Mauri were territorial in a way that worked better with the White conception of property, and because of that Mauri today have a significant representation in the New Zealand constitution and legislature, and own very large amounts of New Zealand's real estate. I expect many Native Americans would prefer the Mauri outcome to their own.
I recently went to see Avatar. It's basically the Pocohontas story, but the ending has changed and the natives switch from the Pocohontas to the Mauri approach. The change comes from two differences:
  1. The Na'vi are territorial. They have a few specific high-value trees. My understanding is that most of the North American natives had a much less specific sense of property.
  2. The movie has the natives resisting under human leadership, which is interesting to think about. It seems a bit condescending (especially the bit where the human, after 3 months of training, is outperforming the best of the natives), but historically North American natives really did not grasp the nature of the European threat fast enough to organize a massive resistance in time, and it seems at least possible that a charismatic European might have communicated the continent-level consequences of the European idea of property to enough of them to organize a resistance.
Although the movie doesn't make it clear enough, guns are a big advantage, but a multi-year supply line is an even bigger disadvantage. Although some of the dialog is a bit trite, I think the story is probably going to be a useful place to start interesting discussions. Hopefully they'll have some story books out at some point, because the PG-13 movie is far too violent for my kids to watch.

I once asked a friend who is a lawyer if all property rights, at least in North America, trace back to peace treaties of some kind, or if some (particular the French claim to the center of the continent that was then sold as the Louisiana Purchase) are based on bald assertions of authority without even a war. I never did get a decent answer.

If, in reading this post, anyone is wondering if I'm willing to cede my house to a Native American, the answer is no.

Monday, December 14, 2009

Powered Roadways

If it weren't for the battery problem, an electric vehicle could be a fairly reasonable vehicle today: electric motors are powerful, small, and cheap enough, etc. There are two parts to the battery problem, getting enough power and storing enough energy. Both can be solved by delivering power to the EV from the road. This has been considered many times before, and there are electric street cars that do it in Bordeaux.

The usual idea, however, is very expensive because
  • most sections of roadway or railway see little traffic and so the benefit of the high-cost infrastructure is spread over few vehicles.
  • the third rail power delivery system is made safe by expensive grade separations, fences, or electronic switching
  • the vehicles are very specialized and aren't built in large numbers.
So, to the extent that I'm advocating a new idea, it is... electrify urban highways. By which I mean, install a pair of metal strips flush against the paving in one of the lanes, such that ordinary cars aren't affected, but electric cars can lower a suitable pickup onto the strips and receive a few dozen kilowatts. Both the power and the energy storage demands on an electric vehicle's battery are dominated by the demands of highway operation.

Urban freeways are quite unusual as roads go.
  • They see quite a lot of traffic: The San Francisco Bay Bridge moves 270,000 vehicles a day across 10 lanes = 1 vehicle every 3.2 seconds over a 24-hour average.
  • They see quite a lot of the traffic: 24% of all traffic is on interstate highways, and I'll guess that most of that is on urban interstate highways.
  • They are short: in the entire US, there are just 15,300 miles of interstate highway in urban areas (same link)
  • They already have limited access. The safety hazards of a high-voltage electrical system out on the road are relatively minor compared to the existing vehicles using the roadway.
I don't have sources to verify the following claim, but I'm fairly sure that in many urban markets, most trips over 10 miles include some freeway. So, if the freeways in your urban area (e.g. Los Angeles or the Bay Area, or both) were electrified, you could make trips anywhere in that area in an electric car with a battery range of just 10 miles.

And, if all we want is 10 miles of range, with no need to deliver dozens of horsepower for minutes on end, existing battery technology is good enough.

The usual counterargument to big infrastructure is that it costs too much. However, electrifying freeways does not because the freeways are just not that big. Consider the Bay Area:
  • 300 miles of freeway
  • 7 million cars
If, over 10 years, we got to 10% of the cars being EVs with electric pickups, that would be 700,000 EVs, or, one for every 26 inches of freeway. Can 26 inches of roadway be upgraded for less than the cost of equipping an EV with a huge battery? Definitely.

There are many schemes for electrifying roadways, and some are quite complex. Although a simple pair of flush steel rails at 1000V is probably a reasonable implementation, it might be easier to sell to the public if the rails were safe enough to be touched by hand. This too is possible.

Imagine each rail is a hollow box, insulated on three sides, but with a nonmagnetic and top surface. Inside the box is a lightweight, magnetic, conductive cable (probably aluminum and steel), with a small gap between it and the underside of the top surface. The conductive top surface is broken at short regular intervals by an insulator. The bottom of the rail is probably a large conductor for moving electricity thousands of feet.

Without a magnet, the top surface is not electrified, and you can place your hand on it safely. The car's pickup would have a magnet which would ride on the strip, picking up the lightweight inner cable slightly, so that it contacts the top surface and conducts to the car.

Other variations would have a magnetic top surface with a flux gap, such that flux going from one side to the other shorts through the cable and picks it up that way.