I have several sheetfed scanners. They are great in many ways -- though not nearly as automatic as they could be -- but they are expensive and have their limitations when it comes to real-world documents, which are often not in pristine shape.

Tonight I watched the debut of FlashForward, which is based on the novel of the same name by Rob Sawyer, an SF writer from my hometown whom I have known for many years. However, "based on" is the correct phrase because the TV show features Hollywood's standard inability to write a decent time travel story. Oddly, just last week I watched the fairly old movie "Deja Vu" with Denzel Washington, which is also a time travel story.

Hollywood absolutely loves time travel. It's hard to find a Hollywood F/SF TV show that hasn't fallen to the temptation to have a time travel episode. Battlestar Galactica's producer avowed he would never have time travel, and he didn't, but he did have a god who delivered prophecies of the future which is a very close cousin of that. Time travel stories seem easy, and they are fun. They are often used to explore alternate possibilities for characters, which writers and viewers love to see.

But it's very hard to do it consistently. In fact, it's almost never done consistently, except perhaps in shows devoted to time travel (where it gets more thought) and not often even then. Time travel stories must deal with the question of whether a trip to the past (by people or information) changes the future, how it changes it, who it changes it for, and how "fast" it changes it. I have an article in the works on a taxonomy of time travel fiction, but some rough categories from it are:

• Calvinist: Everything is cast, nothing changes. When you go back into the past it turns out you always did, and it results in the same present you came from.
• Alternate world: Going into the past creates a new reality, and the old reality vanishes (at varying speeds) or becomes a different, co-existing fork. Sometimes only the TT (time traveler) is aware of this, sometimes not even she is.
• Be careful not to change the past: If you change it, you might erase yourself. If you break it, you may get a chance to fix it in some limited amount of time.
• Go ahead and change the past: You won't get erased, but your world might be erased when you return to it.
• Try to change the past and you can't: Some magic force keeps pushing things back the way they are meant to be. You kill Hitler and somebody else rises to do the same thing.

Inherent in several of these is the idea of a second time dimension, in which there is a "before" the past was changed and an "after" the past was changed. In this second time dimension, it takes time (or rather time-2) for the changes to propagate. This is mainly there to give protagonists a chance to undo changes. We see Marty Mcfly slowly fade away until he gets his parents back together, and then instantly he's OK again.

In a time travel story, it is likely we will see cause follow effect, reversing normal causality. However, many writers take this as an excuse to throw all logic out the window. And almost all Hollywood SF inconsistently mixes up the various modes I describe above in one way or another.

Spoilers below for the first episode of FlashForward, and later for Deja Vu.

Update note: The fine folks at io9 asked FlashForward's producers about the flaw I raise but they are not as bothered by it.

I have put up a gallery of panoramas for Burning Man 2009. This year I went with the new Canon 5D Mark II, which has remarkable low-light shooting capabilities. As such, I generated a number of interesting new night panoramas in addition to the giant ones of the day.

In particular, you will want to check out the panorama of the crowd around the burn, as seen from the Esplanade, and the night scene around the Temple, and a twilight shot.

Two years ago, I discussed solutions for Burning Man Exodus. The problem: Get 45,000 people off the playa in 2 days, 95% of them taking a single highway south which goes through a small town which has a chokepoint capacity of about 450 cars/hour. Quite often wait times to get onto the road are 4 hours or more, though this year things were smoother (perhaps due to a lower attendance) and the number of people with 4 hour waits was lower.