Oct. 12 – 2B03 12/10/2011 9:29:00 AM
General relativity – more mass, more curved spacetime is
Spacetime tells matter how to move.
o As well as light – light moves through curved space-time.
GR - all that Newton did not predict.
Gravitational waves – fundamental prediction of GR.
Haven’t observed any.
Quantum gravity – combining large and small scales, in order to understand
extreme things in the universe.
Black holes ex.
tides due to tidal forces – differential gravity
o prof standing – gravitational pull different than her feet and
head (tiny effect). If she stood close to black hole, it would be
really strong and you would be stretched out. These
differential forces have dramatic effects of earth.
o tides on earth due to moon’s gravity.
Finding planets not in our solar system, don’t orbit about or sun.
Some stars can burn deuterium.
IF you have nuclear burning, you are a star.
o You are not a planet.
Finding Planets around other stars is very difficult
Reason – stars – big, bright. Planets are way smaller and dimmer –
trying to see them is incredibly difficult.
The Transmit method - watch a given star for a long time and you
measure how bright that star is over time. If star has planet
orbiting, for a short period of time, planet going to block some of
the star light. o Technique simple, but hard to do, because the dip (when
planet goes in front) is often unmeasurable.
o For it to work, star needs to be big and EDGE ON
Edge on - Has