Download Semicircular Canals

Aristotle’s Law (c. 350 BC)
• An object in motion
will eventually come
to rest, which is its
natural state
• A force is necessary
to keep an object
moving
Galileo’s Observations (c. 1600)
• A ball rolling down a
very shallow ramp is
slowed by friction
• Without friction, the
ball would roll forever
Newton’s First Law (c. 1700)
• An object at rest tends
to stay at rest, and an
object in constant
motion (that is,
constant velocity) tends
to stay in constant
motion unless acted
upon by an
(unbalanced) outside
force.
Semicircular Canals
Circular tubes of fluid
As head rotates, fluid
tends to stay in place
Inertia of fluid causes
cupula to bend