Module 1A Flashcards
Astronomy
the scientific investigation of the Universe.
The Universe
All that exists
laws and principles of science,
the relationships between matter and force particles,
big G,
the universal gravity constant, a measure of the strength of the gravity
force,
little k,
Coulomb’s constant, a measure of the strength of the electromagnetic
force,
multiverse
(multiple universes),
physics
what is happening here on Earth,
What is astronomy about?
whereas astronomy is
mostly about what is happening “out there”
cosmology
the study of the evolution of the Universe, past, present and future.
13.8 billion years ago.
The universe began
the average mass-energy density of the Universe
ultimately determines the geometry of the Universe, and whether it is finite or
infinite in extent.
Flat geometry
The geometry of the universe
The universe is expanding into
it’s infinite self
The striking uniformity of the CMB temperature implies
an immense and rapid “blowing up” or “inflation” for less than a trillionth of a second after the Big Bang, with the observable Universe growing from the size of a proton to the size of a grapefruit (about 26 orders of magnitude enlargement).
CMB temperature
3000°
“cosmic inflation,”
slight increases in matter density were “seeded” into the then grapefruit
sized observable Universe.
the force of gravity started to dominate the fledgling Universe, and
matter naturally started to clump together around these “seed” points of slightly higher density put into the Universe during the “cosmic inflation” period. These “seed” points grew into the stars and galaxies we see today.
The expansion rate of the universe
is speeding up
three kinds of matter or energy:
ordinary matter, dark matter, and dark
energy.
The universe is 4.6%
atoms
The universe is 71.4%
Dark energy
The universe is 24%
dark matter
ordinary matter
the regular matter we encounter every
day, matter composed of protons,
neutrons and electrons.
Dark matter
dark matter is more than 5 times more abundant than ordinary matter in the visible Universe.
dark energy.
energy that permeates all of space and causes space to expand as if there were a repulsive gravitational force present.
the more space that is added by space expansion,
the more dark energy there is.
