Ice Age 3: Dawn of the Dinosaurs is set on a distant world undergoing
a prolonged, and uncharacteristically warm, ice age. Wooly mammoths and saber-toothed
cats roam the snowy, and sometimes not so snowy, planes; while odd shaped and
poorly bathed sloths make futile attempts to utilize their cognitive array. All
is well; except maybe in the instance of the tiny Scrat, whose acorn woes know
no bounds... I often wake in the depths of the night, covered in cold sweat, perused
by nightmarish visions of acorns; for in my dreams I have peered in to the cold
eyes of despair and touched the cackling hell that is acorn ownership.
Rather than subject oneself to that kind of adversity, one
could alternatively invest in the geological sector. Say what you will but you probably
won’t find yourself climbing a tree in a thunderstorm to save a plot of land,
which inadvertently rolled away while you were on the phone with the in-laws. In this world porous formations dominate the
geological landscape which has a number of benefits. When thrown out of your
high rise apartment by an angry wife one could fall with relative peace of
mind, knowing that upon impact the small cells making up the terrain will
collapse and absorb ones kinetic energy.
Timecode [00:03:10] shows our wayward hero meeting the floor
of a canyon, face first, after a speedy plunge. He walks away unscathed but
leaves a detailed extrusion in the topology. On the other hand a large force
distributed over a large area results in stable support. Timecode [00:03:18] shows
a wooly mammoth run by without making holes in the ground.
Timecode [01:25:42] shows the female Scrat push an acorn in
to the ground. It goes in suddenly with force but quickly stops as the energy
is dissipated by the crumpling lattice of the geological formation. When more
force is applied the ground breaks up in wide spreading cracks, suggesting the lattice
becomes denser with depth; when sufficient force is applied the lattice shears
along the plane of weakest connections. This behavior is consistent with a porous
structure.
Inertia seems to hold in this world. While falling from your high rise apartment, having aforementioned peace of mind, one does not have to worry about landing in the thorny bushes covering the perimeter of ones fine domicile. Knowing that your wife gave you an initial velocity in the horizontal direction one can be sure ones future does not include an awkward conversation with a doctor regarding extraction of things from other things.
Timecode [00:13:49] shows the sloth, while sliding down the
mountain, let go of two eggs above his head prior to entering a hollow log. Upon
exiting the log he finds them where he left them; above his head. Since no different
forces acted in the negative X direction on the eggs they continued to travel
horizontally at the same speed as the sloth. In the Y direction the forces
acting on the sloth and the eggs are the same however, the eggs are in free
fall while the sloth is sliding down a hill. Part of the force due to being in
the gravitational field is converted in to horizontal motion for the sloth.
However because the log was very short the fact that the eggs were accelerating
downward at a faster rate than the sloth can be ignored as there is not enough
time for them to drop a non-trivial amount.
As a corollary; momentum is conserved. Timecode [01:17:40]
shows the tiger saving the sloth by knocking him out of harms way. Because the
tiger has a large mass relative to the sloth, and because momentum is conserved,
when the tiger hits the sloth he experiences a small acceleration and continues
virtually unimpeded on his trajectory. The sloth on the other hand, having a
smaller mass, is violently accelerated out of harms way.
This world also features exaggerated paths of action. When
the wife reaches for a household appliance of significant mass and acceptable
geometry to launch in your direction, one could exploit the fact that her hand
will travel far back before beginning its inevitable motion forward. This could
be critical in giving one a chance to successfully dodge the projectile by
providing an early warning system.
Timecodes [01:25:24] and [00:47:09] show characters follow through
with the motion of their limbs and facial muscles in a way that would indicate
high inertial mass. The inertial mass isn’t necessarily equal to the
gravitational mass in this world and could be very high for most elements. As a
result it requires more time to slow a moving limb, resulting in it traveling
on its original trajectory for a longer period of time. The same could apply to
facial muscles. Once your bushy eyebrows and floppy ears are in motion it takes
time to stop them.
On a few occasions this world does not conform to our laws
of physics. Timecode [00:20:39] shows what I call the impossible soap bubble. The
male Scrat tries to catch up to the female Scrat by jumping inside his soap
bubble and hitting the top with his head to translate it vertically. This would
not be possible in our universe because during the jump the Scrat would apply a
force to the bubble in the negative Y direction; causing it to go down. His
momentum upward would be equal to the momentum of the bubble downward. When his
head would impact the top the momentums would cancel out; him and the bubble
will return to accelerating downwards at “1g”. At best if there was no gravity
he would break even but with it he won’t even get that.
Timecodes [00:36:40] and [01:25:45] show objects and
creatures stretch greatly under relatively low forces. The Scrat fight scene
and the Scrat goo scene show relatively weak molecular cohesion. The attractive
forces between molecules are weak enough that one can stretch once own body. In
addition these forces are not proportion to 1/r^2 like our universe; they
stretch yet hold. I would say that while the forces are weak they are more
proportional to 1/r^1 as they do not wane at a distance as quickly as in our
universe.
Animators seem to hold on to the majority of probable
physics to create an environment the average person can relate to. They alter
specific scenes to bring comedy or emotion in to the work or to otherwise
emphasize something. I think creating physics that are drastically different
works well in abstract games but in majority of the films, shows and games a
fair amount of our physics has to be present to make a connection with the
audience. Much like one designs an audio amplifier to give the most accurate
reproduction possible, then colors the sound with a specific harmonic
distortion signature, animators create a realistic landscape and alter it in
specific ways to communicate better with the viewer.
