8 - space physics Flashcards
1
Q
1st life cycle of a star (like out sun)
A
- cloud of dust and gas/ nebula
- protostar
- main sequence star
- red giant
- white dwarf
- black dwarf
2
Q
2nd life cycle of a star (much bugger than our sun)
A
- cloud of dust and gas/ nebula
- protostar
- main sequence star
- super red giant
- supernova
- neutron star // black hole
3
Q
- hows a protostar formed
A
- gravity pulls the dust and gas together
- temp rises and dense as
- hydrogen nuclei undergo nuclear fusion
- gives out loads of energy v hot
4
Q
- hows a main sequence star formed
A
- outward pressure from nuclear fusion tries to expand the star but the inward pressure of gravity keeps it balanced
- this lasts several billions of years
5
Q
- hows a red giant or red super giant formed
A
- hydrogen runs out
- fusion of helium occurs
- heavier elements up to iron are created in its core
6
Q
5a. hows a white dwarf formed
A
- red gaint becomes unstable and ejects outter layer of fust and gas
- leaves a hot dense soli core - white dwarf
7
Q
6a. hows a black dwarf formed
A
- as white dwarf cools it emits less and less energy
- black dwarf - no energy
8
Q
5b. hows a supernova formed
A
- more fusion and nuclear reactions
- eventually explode forming elements heavier than iron and ejecting them into the universe forming new planets and stars
9
Q
6b. how is a neutrons star and black hole formed
A
- putter layer from supernova gone
- this leaves very dense core - neutron star
- if star is big enough it will become black hole - a super dense point in space no light can escape from
10
Q
4 things that orbit the sun
A
- planets
- dwarf planets
- moons
- natural and artificial satellites
11
Q
explain how planets orbit the sun
A
- planets travel in a circle shape around the sun
- this means that they are constantly changing direction
- and therefore constantly accelerating and changing velocity (not changing speed)
- for something to keep accelerating it needs a force and this force is gravity between the sun and the planet
12
Q
what keeps our planets orbiting the sun in a circle shape
A
instantaneous velocity
13
Q
the theory of the red shift
A
- the wavelengths of the light from distant galaxies has increased
- they are longer than they should be and have shifted to the red end of the spectrum
- this shows that the source of light is moving away from us and we get the same result which ever direction you look in
- more distant galaxies have greater red shifts than closer ones which shows they are moving away at a faster rate
- overall this shows that the universe is expanding
14
Q
red shift balloon concept
A
- balloon covered in pompoms
- each pompom represents a glaxaxy and as the balllon (universe) expands, the galaxys appear further away
15
Q
the big band theory
A
- all matter in the universe took up a very small space which was v dense and v hot
- ## it then exploded - space started expanding and now this is still going on
