Sunday, March 12, 2006

Age of Altruism

Babies as young as 18 months old can tell when adults need help and will
often do their best to assist.

Lifting things, opening doors, picking up objects.

These early signs of helpfulness is a sign of humsns' altruism.. This is
rare in the animals. Chimps also display such kind of helpfulness. This
suggests that the evolutionary roots of altruism go back to common
ancestors shared beteen humans and chimpanzees.

Tests also show that if an adult struggles to pick up a dropped
clothespin in front of an infant, it quickly crawls over picks up the
clothespin and hands it over to the adult. Chimpanzees performed a
similar task. But human babies were found to perform better at opening
up doors and stacking books in case the adult had his ands full.

Saturday, March 11, 2006

Motion - Gravity - Geometry

Gravity is not due to force, but it is a manifestation of curved space
and time, the curvature being produced by mass-energy content of the
spacetime.

One of the defining features of general relativity is the idea that
gravitational force is replaced by gravitational geometry. The
phenomenon in classical mechanics which were ascribed to the actions of
force of gravity are taken in general relativity to represent inertial
motion in curved spacetime.

Inertial observers, that is the observers in inertial motion, for
example freefalling objects, can accelereate w.r.t each other. For
instance, if we take the case of two freely falling balls, same mass,
same shape, on the opposite sides of the earth, they'd accelerate w.r.t
each other as they approach other.

So their acceleration, or more precisely their motion, would be a
manifestation of the geometry of spacetime in which they exist.