Lecture #7InterludeInterlude
the birds and the bees
Lecture #7InterludeInterlude
the birds and the bees
Bird-flying problem…
• ferry boat / seagull issue
• albatross• albatross
• eagles et al.
• thermals: surface winds
flying problem…
ferry boat / seagull issue
thermals: surface winds
Possible solution?
• What keeps dust, pollen, volcanic ash in • What keeps dust, pollen, volcanic ash in the air?
Possible solution?
What keeps dust, pollen, volcanic ash in What keeps dust, pollen, volcanic ash in
+
Vertically oriented field…
earth’s surface+
_ Earth’s field:
_
__ Earth’s field:
100 volts per meter
reason?
For 0.1-kg object (e.g., bird)
Could bird be kept aloft – like dust
Required charge: 10
(bee: 100 mg – need 10
kg object (e.g., bird)
like dust -- by electrostatic charge?
Required charge: 1017 electrons
need 1014 electrons or 10 pC)
Do birds and insects contain charge?
• Yes – Warnke et al. (bee: 100 mg • Yes – Warnke et al. (bee: 100 mg
• Electromagnetic smog issue
Do birds and insects contain charge?
Warnke et al. (bee: 100 mg – 10 pC range)Warnke et al. (bee: 100 mg – 10 pC range)
Electromagnetic smog issue
How could birds acquire charge?
• cellular negativity• cellular negativity
• triboelectricity
• defecation
How could birds acquire charge?
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counter
1. Cellular: Recall how negativity might arise
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_
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+
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hydrophilic materials
Exclusion zone Zone beyond
counter-ions (protons or hydronium ions)
1. Cellular: Recall how negativity might arise
Zone beyond
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_
_ +
+
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counter
Similar for biological entities…
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_
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Protein (negative)
Exclusion zone
counter-ions (protons or hydronium ions)
Similar for biological entities…
What happens to the free protons (hydroniums)?
tissues (negative)
blood flow+ + + + +
What happens to the free protons (hydroniums)?
+++
lung
blood flow
lung
Result = net organismal negativity
vessel
Result
• Bird acquires negative ch
• Breathing significant for flying• Breathing significant for flying
• May explain birds’ unique respiratory system
Result
charge with each breath .
Breathing significant for flyingBreathing significant for flying
unique respiratory system
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+++
(Note: directional exhalation
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++
induced motion ++
++
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Protons, or hydroniums
motion ++
ion could contribute to motion
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++
exhale direction
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+
++
(very small force required)
Charge mechanism 2: Triboelectricity
• Rubbing two different materials separates charge• Triboelectricity: a field unto itself• Hair dryer….charges hair• Hair dryer….charges hair• Bird feathers rub air during flapping AND flight
– could it be significant?
Charge mechanism 2: Triboelectricity
Rubbing two different materials separates chargeTriboelectricity: a field unto itselfHair dryer….charges hairHair dryer….charges hairBird feathers rub air during flapping AND flight
Triboelectric series• Positive (+)• Air
• Human Hands
• Asbestos
• Rabbit's Fur
• Glass
• Human Hair
• Mica
• Nylon• Nylon
• Wool
• Lead
• Cat's Fur
• Silk
• Aluminum
• Paper
• Cotton
• Steel
• Wood
• Lucite
• Sealing wax
• Amber
Triboelectric series
• Polystyrene
• Polyethylene
• Rubber balloon
• Sulphur
• Hard rubber
• Nickel, Copper
• Brass, Silver
• Gold, Platinum• Gold, Platinum
• Sulfur
• Acetate, Rayon
• Polyester
• Celluloid
• Polyurethane
• Polyethylene
• Polypropylene
• Vinyl
• Silicon
• Teflon
• Saran Wrap
• Negative (-)
Triboelectric series• Positive (+)• Air
• Human Hands
• Asbestos
• Rabbit's Fur
• Glass
• Human Hair
• Mica
• Nylon• Nylon
• Wool
• Lead
• Cat's Fur
• Silk
• Aluminum
• Paper
• Cotton
• Steel
• Wood
• Lucite
• Sealing wax
• Amber
Triboelectric series
• Polystyrene
• Polyethylene
• Rubber balloon
• Sulphur
• Hard rubber
• Nickel, Copper
• Brass, Silver
• Gold, Platinum• Gold, Platinum
• Sulfur
• Acetate, Rayon
• Polyester
• Celluloid
• Polyurethane
• Polyethylene
• Polypropylene
• Vinyl
• Silicon
• Teflon
• Saran Wrap
• Negative (-)
Could triboelcectricity confer negative charge?
• Wing flapping
• Gliding, especially against wind• Gliding, especially against wind
• REASON why all birds have feathers and why feathers are only on birds?
Could triboelcectricity confer negative charge?
Gliding, especially against windGliding, especially against wind
all birds have feathers and why feathers are only on birds?
Are flying creatureby triboelectricity?
• birds
• bees• bees
• other insects
• also airplanes and “lifters”
res actually charged by triboelectricity?
also airplanes and “lifters”
Can charge induce forward motion?
field lines
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Can charge induce forward motion?
wingwing
Charge mechanism 3: Defecation
• The “white stuff” = highly positive
• Defecation prior to takeoff
• Inevitably hits your head because your • Inevitably hits your head because your head is negatively charged?
Charge mechanism 3: Defecation
The “white stuff” = highly positive
Defecation prior to takeoff
Inevitably hits your head because your Inevitably hits your head because your head is negatively charged?
Summary: proposedbased on electrostatic repulsion
• Earth is negatively charged• Earth is negatively charged
• Cells have negative charge (breathing enhanced)
• Friction induces negative
• Defecation increases negative charge (supercharging)
ed flying mechanism based on electrostatic repulsion
Earth is negatively chargedEarth is negatively charged
Cells have negative charge (breathing enhanced)
ve charge (flapping enhanced
Defecation increases negative charge (super-
Explains…
• Why gliding is VERY common (look up!)
• Why birds fly over Himalayas
• How birds can migrate for days (automatic)• How birds can migrate for days (automatic)
• Insect acrobatics
• Bird formations (like-
• Insect swarming (like
• Low energy usage– charge-induced lifting
– infrared radiation supplies energy
Explains…
Why gliding is VERY common (look up!)
Himalayas
How birds can migrate for days (automatic)How birds can migrate for days (automatic)
-likes-like)
Insect swarming (like-likes-like)
induced lifting
infrared radiation supplies energy