General Colloquium:
March 30, - 4:00pm Phys 223
(Coffee at 3:30p.m. in room 242)
Professor Margaret Geller
Harvard University
Department of Physics
Title: "Mapping the Universe"
Abstract
A revolution in detector technology
has made ours the age of mapping the universe. There are now more
than 200,000 galaxies with measured redshifts in the nearby
universe. These large surveys have taken us a long way toward
describing the arrangement of galaxies on very large scales at the
current epoch. Detection of fluctuations in the cosmic microwave
background provide tight constraints on the cosmological parameters
and on the initial conditions for galaxy formation. HST and large
telescopes on the ground now enable direct observation of the
evolution of galaxies large-scale structure. Observations of the
universe at large redshift, increasingly detailed observations of the
nearby universe, and sophisticated n-body simulations provide a
coherent (though very incomplete) picture of the physics of
structure formation from the scale of galaxies ~
105
light years to the scale of large-scale voids and walls ~ 3 x
108
light years.