Cosmology

Question 1

Is the universe expanding?

Answer 1

yes, light waves are doppler shifted indicating that it is being stretched by looking at light in space (other stars, etc)

Question 2

what is the doppler effect?

Answer 2

the compressing sound waves to make a higher pitch and higher frequency
(nascar driving by)

Question 3

What are the two concepts of light?

Answer 3

Wavelength– makes up waves and troughs and measures the distance between identical parts

Frequency– the amount that it happens

Question 4

What is the red shift when it comes to the doppler effect?

Answer 4

Red light has a longer frequency than blue light

Moving light waves compress (blue) or expand (red) depending on
whether the light is moving towards you or away from you (and galaxies are red shifted, therefore moving away)

Question 5

What happened during the big bang?

Answer 5

the creation of the universe: exploded with all of the known energy inside 13.7 billion years ago

Protons and neutrons form and then combine to form other elements

Question 6

What is Big Bang Nucleosynthesis?

Answer 6

about 3 mins after the big bang, hydrogen atoms fuse to form LIGHT ELEMENTS (He,
Be, Li, B) by nuclear fusion

Question 7

what is nuclear fusion?

Answer 7

the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy

(how the sun is powered and makes heat, etc)

Question 8

What is Stellar Nucleosynthesis?

Answer 8

produces heavy elements (atomic # 6-26; C to Fe)

Elements with atomic numbers >26 form during supernovae

Question 9

How was the sun formed?

Answer 9

Atoms and molecules come together to form a gaseous nebula

Gravity causes the nebula to collapse
(resulting in increased density, increased temperature, rotation)

Eventually a star is formed at the center of the disk (due to nuclear fusion)

Question 10

What is the order (of terms) of planet formation?

Answer 10

• planetesimal
• protoplanet
• planet

Question 11

How do planets heat up and grow?

Answer 11

• The energy of other things colliding with the planet as it orbits (making it own path)
• Gravity forming the mass into a sphere with a hot core
• Radioactive decay

Question 12

What is differentiation (density stratification)?

Answer 12

Distribution of mass on the planet

Heavy elements (Fe, Ni) sink to the center
Light elements (Si, Mg, Al, oxides) remain near surface

Question 13

How did the Earth and the moon form (Giant Impact Hypothesis)?

Answer 13

Another planet-like body (Theia) collides with Earth and they combine

Rings from the wreckage form in orbit and eventually condense into the moon

Question 14

What is outgassing and how was it important to Earth’s formation?

Answer 14

Outgassing: release of a gas that was dissolved, trapped, frozen, or absorbed in some material (the crust)

The gasses form clouds and the atmosphere and it is very hot on the planet (resembles the planet that obi wan and anakin fought on)

Question 15

What was Earth’s source of water?

Answer 15

asteroids, water in the gaseous nebula

Question 16

Why was Earth considered a “cloud planet” and why was that important?

Answer 16

It was a cloud planet because no light could really get through, the sun couldn’t really penetrate.

It was so hot that water was unable to form in pools and was just evaporating and raining over and over again

Question 17

What did water do to the planet once it was cool enough to form into liquid?

Answer 17

water accumulates in surface basins and begins to dissolve crustal rocks

CO2 dissolved in water and also helped to break down the crust

Question 18

What happened when sunlight began to penetrate through the clouds?

Answer 18

O3 broke down to form O2 and O
Other elements broke down or combined with them

Question 19

What was the oxygen revolution (oxygen photosynthesis)?

Answer 19

Cyanobacteria produce enough oxygen to oxidize minerals
dissolved in the ocean and sediments
Oxygen accumulates in atmosphere

CO2 + H2O + photons ——> CH2O + O2

Question 20

Why do all living organisms need water?

Answer 20

• retains heat
• moderates temperature
• universal solvent (dissolves chemicals)
• transports nutrients and waste

suggests common ancestry among all living things and that life probably started in the ocean

Question 21

Where is there water in our solar system?

Answer 21

Jupiter moons: Europa, Ganymede
Saturn moon: Enceladus
Mars

Question 22

What is the Goldilocks Zone?

Answer 22

The ideal conditions of the spacing of the planet where water and life could be found