Wordsmith.org: the magic of words

Wordsmith Talk

About Us | What's New | Search | Site Map | Contact Us  

Previous Thread
Next Thread
Print Thread
Page 5 of 6 1 2 3 4 5 6
Joined: Sep 2001
Posts: 6,296
W
Carpal Tunnel
Offline
Carpal Tunnel
W
Joined: Sep 2001
Posts: 6,296
And it's not really belaboring the obvious. It's pointing out interesting evidence. (I don't know anything about the history of clock making, but your point is interesting enough that I'm about to google the subject. )


#94771 02/07/03 09:20 PM
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
Offline
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613
I have been privileged to see the famous bat colony of Austin, Texas, emerge--once. I was too awed by the sheer numbers (up to a million and a half) to actually notice whether they wheeled clockwise or not, but as I cast my mind back, the image seems to be clockwise.
Here's a link that explains about drag, lift, and thrust. Possibly these are subject to the Coriolis effect.
http://www.ucmp.berkeley.edu/vertebrates/flight/physics.html
Here is a link to the first of 5 or 6 pictures of them emerging. But if anyone can tell which way, you're a better observer than I am.
http://www.pbase.com/image/264541


#94772 02/07/03 10:54 PM
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
Offline
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803
Possibly these are subject to the Coriolis effect.


The reason that small scale phenomena don't show a noticeable correlation to Coriolis forces is that the Coriolis forces are small compared to other conditions. In the case of the sink drain, filling the sink from an off center tap will set up motion in the water that will not damp out before the drain is opened. If the water is circulating clockwise it will go down the drain clockwise. In the case of tornadoes, local topography will have a greater effect on the air flow than Coriolis forces will. The same is true for any aerodynamic forces that the bats will experience.


#94773 02/07/03 10:59 PM
Joined: Jan 2001
Posts: 13,858
W
wwh Offline
Carpal Tunnel
Offline
Carpal Tunnel
W
Joined: Jan 2001
Posts: 13,858
Here is a very long list of links to bat sites. Well worth browsing. I found one picture of a lot of
bats flying at dusk, but they did not appear to be circling.
http://www.batbox.org/old_bat_house.html


#94774 02/08/03 12:43 AM
Joined: Sep 2001
Posts: 872
M
milum Offline OP
old hand
OP Offline
old hand
M
Joined: Sep 2001
Posts: 872
Jackie, the Austin bat colony of 1,500,000 that you saw is said to rise from their roost in the bridge counterclockwise. And so says this from the National Park Service...

"Hundreds of thousands of Mexican free-tailed bats, whirling counterclockwise, spill forth from a gigantic hole in the earth and are silhouetted against a colorful desert sky ... this is the bat flight experience at Carlsbad Caverns National Park."

And faldage, yes the coriolis effect is small on small sized structures but it tugs with unrelenting persistence. Animals that fly especially need every economy of energy that they can get.

By-the-way, in the morning after the night of feeding, the northern hemisphere bats fly back home, but they don't screw themselves (clockwise) back into the cave, instead they dive in a straight line to the mouth of the cave and on to their roost.


#94775 02/08/03 12:57 AM
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
Offline
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803
Animals that fly especially need every economy of energy that they can get.

The point is that other forces swamp the Coriolis forces. It's not that it isn't there or that the samll animals can afford to ignore it; it's the fact that other things are more important at that scale.


#94776 02/08/03 01:56 AM
Joined: Jan 2001
Posts: 13,858
W
wwh Offline
Carpal Tunnel
Offline
Carpal Tunnel
W
Joined: Jan 2001
Posts: 13,858
Dear Milo: I have looked at a lot of the sites. I finally saw a picture of the narrow gaps between
the concrete blocks that make spaces the bats can use in large numbers. I wondered how it
could be possible for the narrow range of temperatures the bats need.
One thing: I wonder how far the bats have to fly for all of them to find enough insects. It must
be quite a distance, covering a very large area.

Dear Milo: I have a new theory for you. One of the sites said the bats are classified as primates.
Is is possible that like humans they are right "handed", and have the right wing slightly more powerful
than the left, which would tend to make them circle to the left, counterclockwise? (taking my tongue
out of my cheek.) i'm sure Faldage will agree with me that is more probable than the Coriolis force.


#94777 02/08/03 03:17 AM
Joined: Mar 2001
Posts: 4,189
Carpal Tunnel
Offline
Carpal Tunnel
Joined: Mar 2001
Posts: 4,189
anti-clockwise here, although the main clock in my house runs in the direction traditoinally called anti-clockwise.

That's because you guys Upunder dwell in counter-matter!




#94778 02/08/03 03:20 AM
Joined: Mar 2001
Posts: 4,189
Carpal Tunnel
Offline
Carpal Tunnel
Joined: Mar 2001
Posts: 4,189
Well, milum, you could always look at it this way...no matter which direction the bats fly in...guano is still guano!


#94779 02/08/03 10:53 AM
Joined: Sep 2001
Posts: 6,296
W
Carpal Tunnel
Offline
Carpal Tunnel
W
Joined: Sep 2001
Posts: 6,296
Here's an elementary bat quiz that none of us here would have any problem in scoring 100% on.

The quiz is set up so that you can pretty much tell the answer without knowing it, but you might have a child somewhere who'd like to take the quiz.

Do not go to this site if you're not curious about elementary bat quizzes!

http://www.cccoe.k12.ca.us/bats/quiz.html


Page 5 of 6 1 2 3 4 5 6

Moderated by  Jackie 

Link Copied to Clipboard
Forum Statistics
Forums16
Topics13,912
Posts229,283
Members9,179
Most Online3,341
Dec 9th, 2011
Newest Members
TRIALNERRA, befuddledmind, KILL_YOUR_SUV, Heather_Turey, Standy
9,179 Registered Users
Who's Online Now
0 members (), 302 guests, and 2 robots.
Key: Admin, Global Mod, Mod
Top Posters(30 Days)
Top Posters
wwh 13,858
Faldage 13,803
Jackie 11,613
tsuwm 10,542
wofahulicodoc 10,510
LukeJavan8 9,916
AnnaStrophic 6,511
Wordwind 6,296
of troy 5,400
Disclaimer: Wordsmith.org is not responsible for views expressed on this site. Use of this forum is at your own risk and liability - you agree to hold Wordsmith.org and its associates harmless as a condition of using it.

Home | Today's Word | Yesterday's Word | Subscribe | FAQ | Archives | Search | Feedback
Wordsmith Talk | Wordsmith Chat

© 1994-2024 Wordsmith

Powered by UBB.threads™ PHP Forum Software 7.7.5