Yestarday we saw that a cycle does not fall because of the rotation
of its wheels
Today we will see some places where MASSIVE objects/phenomenon is caused/affected by rotations and thus angular momentum .
a) Accretion Disks in Binary Systems : Our Sun is a single star . But most
of the stars in the Universe occur in Pairs . They form what is known as
Binary systems . Now lets suppose that there are 2 stars in a binary
pair : A HUGE star with a low atmosphere density . Lets call this dude S
and we have a compact star s which is the companion of S . If s and S are
close to each other then it might happen that s may begin to attract
the gases that form the atmosphere of S . so the gases of S start moving
towards s . Now as they move they loose energy because of collisions .
So to conserve the Angular Momentum the gases start whirling around
s and form a disk/ring around s . This is called the accretion disk .
The ring is flat and rotates very fast . The ring is perpendicular to
the axis of rotation of the star s . This is because the gases at this
place experience more centrifugal force and can resist the gravity of s .
This is again in accordance with the consevation of Angular Momentum .
For a beautiful picture of this Phenomenon see :
http://physics.angelo.edu/~msonntag/physics1301/binarymasstransfer.htm
b) Formation of Galaxies :
Imagine : A HUUUUUUUUUUGE cloud of dust and gas spinning . IT collapses
because of the gravity of its individual parts or some local irregularities.
Now as mass falls towards the inside it starts rotating very rapidly.
THis is to conserve angular momentum . Again it collects in a disk shape
perpendicular to the axis of rotation . Now places where there is more
gas/dust mass start falling withn themselves to form stars . Again these
starts are rotating . The total angular momentum of the galaxy is
the sum of the rotational motion of the galaxy and the sum of angular
momentum of its parts( starts , dust etc ) .
So we see that the same theory that explains tops also explains
things zillions of miles across .
