Law, Theory, Hypothesis
Hypothesis: educated guess with observation. -WHY
Theory: summarizes hypothesis by testing. - WHY
Law: explains observations - HOW
Singularity
an area in space-time where gravitational force is so high, all known laws of physics break down.
Evidence of Bi...
Singularity - Answer an area in space-time where gravitational force is so high, all
known laws of physics break down.
Evidence of Big Bang - Three Pillars of Proof - Answer 1. Hubble's Law
2. characteristics of cosmic microwave background radiation
3. abundance of light elements
1. Hubbles Law - Answer - there are many galaxies
- the universe is explaining
- measure distance in space
- v=Hod
Doppler Shift - Answer The apparent change in wavelengths.
2. Cosmic Background Radiation - Answer As the universe expanded it cooled
3. Abundance of Light Elements - Answer - hydrogen 75%, helium 25%, lithium
- observed abundance can be explained if they ORIGINATED FROM ONE SINGLE
RATIO OF THE FIRST SUB ATOMIC PARTICLE OF MATTER
Shapes of the universe - Answer 1. sphere - closed, finite size, contract in a "big
crunch"
2. saddle shape - open, negative curve, expansion rate never reaches 0.
3. flat - can expand/contract forever, no boundaries, reaches 0.
Dark Matter - Answer - cannot see as it gives no energy
- can detect its gravitational attraction
- 27% of matter
Dark Energy - Answer - Repels matter
- controls expansion of space
- 70% of universe
Age of universe - Answer 1. radioactivity
2. cosmic microwave background radiation
, 3. hubbles expansion constant
Radioactivity - Answer breakdown of elements. Determines universe age by :
a) observing components of gasses around the stars.
b) knowing radioactive processes.
c) knowing time factors involved in breaking down a component.
How old is the universe? - Answer 13.8 Years based on CMBR Model
Light Years - Answer measure distances in space. You are looking at a star that started
its journey 1 million years ago.
Measuring Light years - 0 to 500 - Answer trigonometric parallax: object is at a different
place relative to background.
Measuring Light years - 500 to 500 million - Answer Hertzprung Rusell DIagram:
matches brightness of stars compared to their temperature (colour).
Distance of Apparent brightness Calculation - Answer AB=Intrinsic
Brightness/(4*pi*distance^2)
Cepheids - Answer stars with pulsing brightness that peaks
The Local Group - Answer the Milky way galaxy, the andromeda galaxy, the triangulum
galaxy
Density - Answer mass per unit of volume
supernova - Answer explosive death of a massive star
Nebular Hypothesis - Answer suggests that the solar system formed over a brief span of
time from a giant nebula (cloud of interstellar gas).
Fusion reactions - Answer releases more energy to create a star. (Heat of Gas).
Red Giant - Answer Dying Star, sun loses mass and runs out of hydrogen fuel.
Momentum - Answer measure of an objects tendency to move at a constant speed
along a straight path.
Angular Momentum - Answer measure of the amount of spin of an object.
Conservation of angular momentum - Answer if no outside force acts on a spinning
object, the objects angular momentum will not change with time.
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