reply to post by JohnySeagull
Interesting information about the geese. Thanks for sharing that. I also have never seen migratory flights of geese where two groups have actually
collided and/or there has been apparent confusion. That's very odd and a touch disturbing.
Some members have asked or commented on how birds might be able to sense the planet's magnetic field, so I'd like to provide some references to back
this up in case anyone is dubious or skeptical about it. (And it's not only been scientifically evaluated in birds, either.)
It's a fact that some species of birds are able to see magnetic fields (meaning via their eyes). A report in
National Geographic News dated Sept 27, 2007 says in
part:
Scientists already suspected birds' eyes contain molecules that are thought to sense Earth's magnetic field. In a new study, German researchers
found that these molecules are linked to an area of the brain known to process visual information. In that sense, "birds may see the magnetic field,"
said study lead author Dominik Heyers, a biologist at the University of Oldenburg. [...] The finding strongly supports the hypothesis that migratory
birds use their visual system to navigate using the magnetic field.
More recent research has been able to expand on this knowledge. Referring to a report published in
Current Biology, an article in
Indiana Public Media says in part:
Scientists have known that birds can detect the Earth’s magnetic fields since 1968, but a new study published in this month’s issue of Current
Biology asserts that birds can actually see them.
European robins were outfitted with “somewhat unflattering goggles” that helped researchers determine how the magnetic fields appear to the
subjects.
The experiment showed that robins’ sight of magnetic fields uses a molecule called cryptochrome found in avian retinas.
There are other studies discussing the fact that some birds have trace amounts of a mineral called magnetite in their brains, and there is a
hypothesis that this might also have some effect on their ability to sense magnetic fields. Lab tests done on pigeons found they had behaviour
patterns that varied in relation to magnetic fields, but it's unclear if this is just an anomaly relating to Pigeons or not. Studies have also shown
that
rainbow trout manage migration via the use of magnetite in their olfactory cavities! Refer to
The Compasses of Birds in the
Science Creative Quarterly for more details.
Now here's something
very interesting: bats
also use magnetite to find their way! In an abstract from the research paper entitled
Bats Use Magnetite to Detect the Earth's Magnetic Field,
found on Plosone.org's website, it says in part:
The results demonstrate that the big brown bat Eptesicus fuscus uses single domain magnetite to detect the Earths magnetic field and the
response indicates a polarity based receptor. Polarity detection is a prerequisite for the use of magnetite as a compass and suggests that big brown
bats use magnetite to detect the magnetic field as a compass.
What makes this so interesting is that bats are mammals. So are we... And yes, there is research that shows we also have magnetite in our brains. At
the present time, its precise purpose or value (if any) has not been definitively determined. All the same, it's worth bearing in mind (pun intended)
that if some animal species are apparently showing behavioural changes that might be related to magnetic field fluctuations -- especially the planet's
-- then it's not completely unreasonable to hypothesize that there might be some effects on us as well.
Getting back to JohnySeagull's comments that the sun appears to be rising and setting in a narrow range, and setting much more south, I'd like to
offer the following map, which I created using a resource on NOAA that can be found
HERE :
[atsimg]http://files.abovetopsecret.com/images/member/19202456aaa1.jpg[/atsimg]
Johny, all I know is that you're in Ireland somewhere and in a rural area. I simply chose a location between Dublin and Limerick as an example. The
actual angles for sunrise and sunset won't vary a great deal if you're elsewhere in Ireland. The main thing is to note the basic directions. As you
can see, sunrise (the green line) from the position I've marked appears to be off in the direction of Kilkenny, while sunset (the red line) is over
past Tipperary. If you use the link I've given and try it for yourself with your real location then you can see if what they give you corresponds to
what you actually see. It ought to... If you then put a Summer date (say July 1st) you'll see that the sun appears to rise up towards Kildare and sets
over in the direction of Loughrea. Oh, please make sure you set the time zone correctly. (Right now it should be a "0" as I have it because you use
GMT).
Observation is made more difficult if you're in a valley with high hills close by. It cuts down on the line of sight and can make it hard to get a
good fix on "true horizon" sunrise and sunset positions. In that situation, it's best to observe sunrise and sunset from a hilltop so you can see a
good distance. Then the actual angles will be more apparent.
Anyway, I hope this helps to clarify the matter.
Best regards,
Mike
edit on 25/11/10 by JustMike because: O Tempores, O Mores, O Typos!