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- Hi, I'm Lauren, this is Brain Stuff
and I have a topically relevant scenario
for your consideration.
Let's say you wanted a change the scenery
so you set out with the
clothes on your back,
your innate knowledge of the world
and zip all else,
no map, no smart phone, nada.
Would you be able to travel
tens of thousands of miles
across oceans and continents
and then get back home a few months later?
Because hey, lots of
birds do this every year.
It's called migration
and often these birds
go to the exact same
summer and winter spots
using nearly the exact
same routes every time.
Ornithologists have speculated
that birds might use a number
of sights, sounds, smells
and learned social cues
to get where they're going
but young birds making their
trip for the first time
have been observed migrating successfully
with no chaperones.
What gives?
Research has revealed that migratory birds
have vision-based magnetoreception.
They can see magnetic fields.
And earth is lousy with magnetic fields.
See, earth's molten outer core
is made up of iron alloys
which are swished around
by heat coming up off
of the solid inner core
and by the rotation of the earth.
That motion plus the fact
that iron is really good
at conducting electricity
creates a dynamo,
a generator of electric
and magnetic fields
which basically makes the earth function
like a giant bar magnet.
North is positive, south is negative
and our planet is wrapped
in slopes and curves
of magnetic fields arcing in between them.
And migratory birds
can sense those fields.
Experiments over the past couple decades
have shown that birds
prepare to migrate south
will align themselves with magnetic south
even if you create an
artificial south in a lab.
And furthermore, these
birds see magnetic fields.
Around 2010, researchers
fit European robins
with clear or frosted goggles
and found that the birds
needed clear vision
in their right eyes to
navigate magnetically.
Why not the left eye?
No one knows.
Scientists are now studying
what biological mechanism
might be responsible for this.
The popular theory goes
that magnetic fields cause a
chemical reaction in birds eyes
that affect their sensitivity to light.
So magnetic fields might show up
as brighter or darker patterns
spread out over everything the bird sees
like a map on a heads up display.
More research needs to be done
to determine exactly how this works
but in the meantime,
here's a question for you,
if you could get an eye or brain implant
that would let you see magnetic fields,
would you?
Let me know in the comments.
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