Chip's Technical Blog

Tech commentary of thoughts, challenges, how-to's, and the mundane.

Archive for August, 2007

Mutt error message: “Message XXX UID YYY less than ZZZ”

Wednesday, August 22nd, 2007

If you are constantly getting this error message in Mutt (seemingly every time Mutt checks for new messages, or you change folders), then I may have a solution for you. You see, when I tried to lookup this message, I found two things:

  • Pages saying the message was harmless and to be ignored
  • Pages giving a technical explanation of the error message (which also tend to fall in the first category too)

Two pages in particular are this one from the Pine users group, and this one from the IMAP FAQs which give technical explanations. Basically, the UID’s must be increasing in a mailbox, and someone detected a dis-order. Typically, clients take the opportunity to re-order the UIDs to correct the problem.

But in my Mutt instance, this persisted restarting the client, moving messages, and more. I could not get the message to go away. After understanding the technical side, I went to find the problem. But I couldn’t find it. It did not occur in the mailboxes themselves.

Finally, I realized it had to do with the header cache. I deleted the header cache, and now I don’t have the error message anymore.

Good Luck!

3-D IMax Movies

Thursday, August 16th, 2007

So I went to see “Harry Potter and the Order of the Phoenix: An IMAX 3D Experience” Saturday. I was a little disappointed that only the last 20 minutes were in 3-d. Perhaps if I’d read up before, I would instead have been excited that a whole 20 minutes were in 3-d, but such is life. Those 20 minutes were quite impressive, and I did appreciate seeing them in 3-d.

So since then, I’ve been wondering why the rest of the movie wasn’t in 3-d. I tried to search Google for the answer, but only came up with stories about how there would be 20 minutes, and nothing about why not the other minutes.

What’s the reason? Possibilities I’ve come up with are:

  • Perhaps it’s too expensive
  • Maybe the technology doesn’t work as well on non-action scenes
  • Possibly people become disoriented with a full-length 3-d feature

I also found a nice article describing the different IMAX varieties, and in particular how the 3-d technology works [Wikipedia’s IMAX page]. First, the scenes are filmed simultaneously by two different cameras, about 2.5 inches apart (mimicking our eyes), and then project both images simultaneously. To keep it from confusing your eyes, the two projections are polarized at perpendicular angles. Then the glasses you wear cancel out one of the two images for each eye, reproducing the depth of feel. Of course, for a movie like HP, they are actually dealing mostly with animations, and use the patented computer graphics technologies to artificially create the two projections. This gives them the further advantage of being able to correct imperfections in the dual recording to give a more natural depth of feel. To read more about it, I recommend reading the linked Wikipedia page. I think it would be fascinating to find people who work on this kind of graphics to hear more about the technology.

Whatever the reason they only ran 20 minutes 3-d, I for one am looking forward to the day when watching movies is a full 3-d experience, whether through glasses, holograms, or otherwise.

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