Lecture #7 Interlude

Lecture #7InterludeInterlude

the birds and the bees

Lecture #7InterludeInterlude

the birds and the bees

Birds and fish

How do….

• birds (and insects) fly? .

• fish swim? • fish swim?

How do….

birds (and insects) fly? .

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?

_

_

_ +

+

+

counter

1. Cellular: Recall how negativity might arise

_

_

_

+

+

+

hydrophilic materials

Exclusion zone Zone beyond

counter-ions (protons or hydronium ions)

1. Cellular: Recall how negativity might arise

Zone beyond

_

_

_ +

+

+

counter

Similar for biological entities…

_

_

_

+

+

+

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

Exhaling generates negativity

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

++

+++

(Note: directional exhalation

+

++

induced motion ++

++

+ +

Protons, or hydroniums

motion ++

ion could contribute to motion

+

++

exhale direction

++

+

++

(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”

• from Warnkefrom Warnkefrom Warnke

from Warnke

from Warnke

Can charge induce forward motion?

field lines

------

--- --

Can charge induce forward motion?

wingwing

Forward motion

field lines

------

--- --

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