ISF Logo   IS Forum
Forum Index Register Members List Events Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology
 


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Tags dinosaurs

Reply
Old 9th August 2019, 06:09 PM   #41
sphenisc
Illuminator
 
sphenisc's Avatar
 
Join Date: Jul 2004
Posts: 4,832
Originally Posted by rjh01 View Post

Owls have almost a million rods per square millimeter (1,550 per square inch). Humans have about 200,000 rods per square millimeter (310 per square inch).
Those conversions seem to be way off.
__________________
"The cure for everything is salt water - tears, sweat or the sea." Isak Dinesen
sphenisc is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 9th August 2019, 07:42 PM   #42
RecoveringYuppy
Philosopher
 
Join Date: Nov 2006
Posts: 8,978
Originally Posted by sphenisc View Post
Those conversions seem to be way off.
They are correct.
__________________
REJ (Robert E Jones) posting anonymously under my real name for 30 years.

Make a fire for a man and you keep him warm for a day. Set him on fire and you keep him warm for the rest of his life.
RecoveringYuppy is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 9th August 2019, 08:07 PM   #43
JimOfAllTrades
Muse
 
Join Date: Aug 2011
Posts: 508
Originally Posted by RecoveringYuppy View Post
They are correct.
They appear to be backward.
JimOfAllTrades is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 10th August 2019, 04:55 AM   #44
rjh01
Gentleman of leisure
Tagger
 
rjh01's Avatar
 
Join Date: May 2005
Location: Flying around in the sky
Posts: 24,693
Originally Posted by JimOfAllTrades View Post
They appear to be backward.
You appear to be right. The error is in the original article. Swap the number around and you get a more reasonable answer. However the text appears to be ok.
__________________
This signature is for rent.
rjh01 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 10th August 2019, 07:54 AM   #45
RecoveringYuppy
Philosopher
 
Join Date: Nov 2006
Posts: 8,978
Originally Posted by rjh01 View Post
You appear to be right. The error is in the original article. Swap the number around and you get a more reasonable answer. However the text appears to be ok.
Oh I see. Yes, it's incorrect. But both the numbers and text are OK after swapping the sq mm values for sq in values.

ETA: https://en.wikipedia.org/wiki/Bird_vision

Quote:
The tawny owl's retina has about 56,000 light-sensitive rods per square millimetre (36 million per square inch); although earlier claims that it could see in the infrared part of the spectrum have been dismissed
__________________
REJ (Robert E Jones) posting anonymously under my real name for 30 years.

Make a fire for a man and you keep him warm for a day. Set him on fire and you keep him warm for the rest of his life.

Last edited by RecoveringYuppy; 10th August 2019 at 08:03 AM.
RecoveringYuppy is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 12:45 AM.
Powered by vBulletin. Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.

This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.