Earth Sci Chapter 1

Question 1

What observations led to the acceptance of the Big Bang theory?

Answer 1

Three Pillars of Proof
o Recession of stars/galaxies (Hubble’s Law)
o Characteristics of microwave background radiation
o Abundance of light elements

Question 2

What are the steps of the scientific method?

Answer 2

Hypothesis, Theory, Law

Question 3

What is hypothesis?

Answer 3

an educated guess based upon observation (sometimes only one observation)

cannot be supported or rejected
cannot be proven to be true

Question 4

What is theory

Answer 4

the foundation of science, and summarizes a hypothesis (or group of hypotheses) that is supported by repeated testing and observation

Question 5

what is law

Answer 5

explains a body of observations. no exceptions found

Question 6

What is a singularity

Answer 6

• No readily understood definition
• An area in space-time where gravitational force is so high that all known laws of
  physics break down and do not apply

Question 7

What is the Big Bang theory? What does it describe?

Answer 7

• The theory of how the universe was created

- It describes a gigantic expansion that was the beginning of space and time

Question 8

What are the three main lines of observation that support the Big Bang theory?

Answer 8

doppler effect, cosmic microwave background, abundance of light elements

Question 9

What is the big bang theory

Answer 9

an effort to explain exactly what happened at the beginning of the Universe

At the birth of the universe, time and space were created in a gigantic expansion that emanated from a ‘singularity’

Question 10

what is a gigantic expansion?

Answer 10

Think of an infinitesimally small balloon, which in the tiniest fraction of time, suddenly expands and keeps on expanding. In that tiny instant, time and space had a finite beginning inside the balloon

Question 11

Doppler effect

Answer 11

An object coming towards you making sound will have compressed sound
waves (louder)

­An object moving away making sound will have extended sound waves (lower)

Question 12

Cosmic Microwave Background (CMB)

Answer 12

The hot light photons from the big bang have lost energy and dropped into
microwave wavelength (out of visible light)
­
Appears as static noise when played by a sensitive microwave radio
receiver

Question 13

Abundance of light elements

Answer 13

Hydrogen (75%), Helium (25%), Lithium (trace)

can be explained only if they originated from one single ratio of the first subatomic particles of matter that can be formed from a super-hot environment

Question 14

What are the possible shapes of the universe?

Answer 14

Sphere, saddle shaped, and flat

Question 15

Sphere universe

Answer 15

• ­Positive curvature
• ­Closed universe
• Finite size but without boundary

Question 16

saddle shaped universe

Answer 16

• Negative curvature

- ­Infinite and unbound

Question 17

Flat universe

Answer 17

• Infinite and boundless

Question 18

What makes up the most matter in the universe, dark matter or stars?

Answer 18

Dark matter > stars

Dark matter: 27%
Stars, etc: 5%

Question 19

What is the difference between dark matter and dark energy?

Answer 19

Dark matter is unable to be seen, gives off no electromagnetic energy, has gravitational attraction

Dark energy is opposite of gravity, it repels matter, controls expansion of space

Question 20

What is the difference between dark matter and dark energy?

Answer 20

Dark matter is unable to be seen, gives off no electromagnetic energy, has gravitational attraction

Dark energy is opposite of gravity, it repels matter, controls expansion of space

Question 21

How can we know the age of the universe? (3 ways)

Answer 21

Radioactivity, Hubble’s Expansion Constant, Cosmic Microwave Background Radiation

Question 22

Radioactivity

Answer 22

• Radioactive elements that break down into other components are tracked
• Measure how long the process took based on which radioactive process produces said gasses from the first elements
• Between 11.5 and 17.5 billion years, at least 13.2 billion

Question 23

Hubble’s Expansion Constant,

Answer 23

• Using Hubble’s constant equation, there is a t variable
  ­- Possible to determine age of the most distant light sources
  ­- Between 13 and 4 billion years

Question 24

Cosmic Microwave Background Radiation

Answer 24

• Offer most accurate view of conditions in early Universe
  ­- A model based on the CMB signal map when first photons were produced
  by Big Bang
  ­- 13.80 +/- 0.04 billion years