Download The Merger of Two Disk Galaxies

This animation begins with a collapsing
interstellar cloud of gas and dust. Most of
the material becomes part of the young Sun,
but some debris forms a disk. Within this
disk form the planets, moons, comets,
asteroids, and meteoroids. Note that this
process is repeated on a smaller scale in the
outer solar system, where miniature disks
form around the Jovian planets.
Within the Orion Nebula—a giant cloud
of gas and dust some 1500 light-years
from Earth—new stars, and perhaps
new planets, are being formed.
The final closeup is a young star
surrounded by a dark disk of material
within which planets may be forming.
(HST images).
The Merger of Two Disk Galaxies
This supercomputer simulation shows the collision and merger of
two disk-shaped galaxies. Stars in the disk of each galaxy are
colored blue, while stars in their central bulges are shown in
yellow. Red indicates dark matter that surrounds each galaxy. The
total elapsed time for this simulation is one billion years.
This supercomputer simulation shows six galaxies merging to
form a single giant galaxy. Toward the end of the simulation a
large galaxy forms that "devours" other, smaller galaxies, a
process called galactic cannibalism. (In ordinary galactic mergers,
galaxies of about the same size are involved.) Galactic
cannibalism may explain how giant elliptical galaxies form near
the centers of rich clusters of galaxies, where galactic collisions
are frequent.
The centre of our Galaxy: Sagitarius A*
Curved Spacetime
Physics can reconstruct the history of the
universe up to the Planck-time ~ 1.35 .10-34 sec
Before that time QM and RT contradict
2D-Analogy: inflation of a baloon
• All points move apart a la Hubble
• There is no centre of the universe
• Space itself expands
Critical density :
crit = 2.10-27 kg/m3
 = /crit
Up to 300,000 yrs
Hot and opaque
Matter and radiation coupled
Universe cooled by expansion:
matter and radiation become suddenly decoupled
Universe becomes transparant
This is the oldest radiation
and the farthest we can possibly see
This radiation is the Cosmic Background
Radiation (CBR)
Because of subsequent expansion the the
universe this is now cooled to ~ 2.7 Kelvin
Since january 2003 a entire map
of the CBR is available
CBR
Isotropy Problem
Isotrope 1:10,000
Newest measurements indicate that space is
almost flat and isotrope
Solution: inflation theory
Short after Plancktime space grew
during about 10-24 seconds a factor 1050
Newest measurements also indicate that redshift
grows stronger than Hubble’s law
The expansion is accelerating !!!
Possible solution:
reintroduction of Cosmological Constant ?
What would Einstein say ???
Big Crunch : not likely
Big Sleep : 1036 yrs from now only lowenergy radiation