Comments on: Light-detecting backpacks record the complete migration routes of songbirds http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/ Mon, 26 Nov 2012 12:00:51 +0000 hourly 1 http://wordpress.org/?v=3.4.2 By: Stagyar zil Doggo http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2397 Stagyar zil Doggo Wed, 18 Feb 2009 18:18:07 +0000 http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2397 Nathan: Length of day would tell you latitude if you were stationary. Each time of sunrise or sunset puts you somewhere on a great circle, which is inclined to the equator at a (known) angle between 66.5 deg and 90 deg depending on time of year. I don't see how you can locate yourself on said circle. You could apply some heuristics (conservative estimates of distance traversed from last known location, etc.) and constrain your path to pass through known points but it would be very iffy. Nathan:
Length of day would tell you latitude if you were stationary.
Each time of sunrise or sunset puts you somewhere on a great circle, which is inclined to the equator at a (known) angle between 66.5 deg and 90 deg depending on time of year. I don’t see how you can locate yourself on said circle. You could apply some heuristics (conservative estimates of distance traversed from last known location, etc.) and constrain your path to pass through known points but it would be very iffy.

]]> By: Nathan Myers http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2396 Nathan Myers Wed, 18 Feb 2009 06:14:44 +0000 http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2396 Stagyar: the length of the day tells you the latitude. Me, I'm astonished they were able to get enough precision out of such measurements. Stagyar: the length of the day tells you the latitude. Me, I’m astonished they were able to get enough precision out of such measurements.

]]> By: Stagyar zil Doggo http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2395 Stagyar zil Doggo Tue, 17 Feb 2009 09:47:53 +0000 http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2395 <blockquote>By measuring rising and falling light levels, these miniature contraptions revealed the timings of sunrise and sunset wherever the birds happened to be flying.</blockquote> Um, sunrise and sunset timings will give you longitude provided latitude is known. How did they determine latitude? Also, what do the colors of the lines and dotted versus solid lines indicate in the figures you've shown?

By measuring rising and falling light levels, these miniature contraptions revealed the timings of sunrise and sunset wherever the birds happened to be flying.

Um, sunrise and sunset timings will give you longitude provided latitude is known. How did they determine latitude? Also, what do the colors of the lines and dotted versus solid lines indicate in the figures you’ve shown?

]]> By: B. Will http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2394 B. Will Sun, 15 Feb 2009 22:32:13 +0000 http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2394 It's very interesting how technology is advancing science. We learn new information every day thanks to such devices as this "bird backpack". It’s very interesting how technology is advancing science. We learn new information every day thanks to such devices as this “bird backpack”.

]]> By: Ed Yong http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2393 Ed Yong Sun, 15 Feb 2009 20:55:08 +0000 http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2393 HP - the headline's hilarious. Along similar lines, I cite you <a href="http://www.medicinenet.com/script/main/art.asp?articlekey=90467" rel="nofollow">this</a> and <a href="http://abcnews.go.com/Health/Story?id=2913194&page=1" rel="nofollow">this</a>. Well of course they are... ;-) HP – the headline’s hilarious. Along similar lines, I cite you this and this. Well of course they are… ;-)

]]> By: Lilian Nattel http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2392 Lilian Nattel Fri, 13 Feb 2009 20:26:34 +0000 http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2392 Very interesting--thanks--and a university close to home. Very interesting–thanks–and a university close to home.

]]> By: HP http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2391 HP Fri, 13 Feb 2009 17:40:35 +0000 http://blogs.discovermagazine.com/notrocketscience/2009/02/13/light-detecting-backpacks-record-the-complete-migration-routes-of-songbirds/#comment-2391 I read about this this morning in -- of all places -- <a href="http://languagelog.ldc.upenn.edu/nll/?p=1138" rel="nofollow">Language Log</a>. It seems that MSNBC gave this story a rather <a href="http://www.msnbc.msn.com/id/29167346/" rel="nofollow">unfortunate headline</a>. (Still up as of 12:30 EST.) Thanks for giving us the story without distractions. I read about this this morning in — of all places — Language Log. It seems that MSNBC gave this story a rather unfortunate headline. (Still up as of 12:30 EST.)
Thanks for giving us the story without distractions.

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