solar shstem pi Flashcards
what is red shift / blue shift and what does it mean
2’ what does it mean
3) further away galaxies?
4) how does this suggest the big bang theory
- different chemicals absorb frequencies of light, and reflect the rest, this is how colour . THIS CAN BE SHOWN ON AN ABSORBTION SPECTRUM with black lines, and a certain pattern
- these same LIGHT observed from distanter galaxy produce the same pattern of absorbtion spectrum but woth lower frequency towards left than should be
- in other words the observed wavelength is increased , where light is shifted towards red end of spectrum- this is CALLED RED SHIFT
= MEASUREMENTS TELLS US THAT RED SHIFT MEANS GALAXIES ARE MOVING AWAY FROM EACH OTHER
3) further away galaxies have a higher red shift, meaning they are expanding away faster than the close ones
4) blue shift means they coming to you
5) finally the fact that they are expanding suggest they started in a concentrated dense high temp mass, and then expanded into universe today= BIG BANG THEORY
what suggests the universe is expanding even more?
what did they asusme
that gravity would cause the rate of universe expnsding to slow doen
- het observations of supernovae suggest RATE IS ACTUALLY INCREASING of expansion
- scientists cant explain why universe gradually expanding faster rather than slowing down
- recent years suggest there is matter and energy we cant detect= dark. this could be potential reason ti why universe is expanding faster
what is the big bang theory
2) two evidences?
- scientists belived that universe started frim something small dense smaller than atom
- exploded then expanded
- still expanding
2) - cosmic microwave background radiation
- red shift galaxies expanding
what is cosmic backgroudn radiation snd how evidence for big bang
1) scientists have observed low frequency MICROWAVE radiation coming from all directions in universe
2) when big bang explosion happened , nigh frequency and high energy radiation was released
3) overr expansion and cooling , this has been STRETCHED so frequency decreased such that it in microwave region. this is called cmbr
- thought to be leftover radiation and energy from big bang so supports it
what does solar system consist of
5
- sun = star at centre of our galaxy
- planets = objects spherical due ti gravity orbit sun
- moons = objects orbit planets
- minor planets dward = ANYTHING THAT NOT KRBIT AROUND SUN, so asteroids and pluto
- comets = ice dust orbit sun but small thin orbits
lifecyle of a star basic
1) cloud of dust and gas
2) protostar
3) main sequence star
4) red giant or red supergiant
5) small star
- planetary nebula
- white dwarf
or large star
- supernova
- then neutron star or blackhole
advanced life
1) cloud of dust and gas to protostar?
1) stars formed from HUGE amounts of cloud of dust and gas. the huge gravity here thus draws the gas and dust and they join to firm PROTOSTAR.
Then the temperature rises as the star gets more dense meanign particles collide more with more force= increase temp.
- when temp gets high enough, hydrogen nuckie have condtions to undergo nuclear fusion, producing HELIUM NUCLEI.
- fusion gives out huge energy, and a star is born
2) main star sequence?
how long it last
- the star immediately enters a period kf equkibroum, the energy released by fusion expanding outwards is countered by the force due to grsvity acting inwards
- this makes it STABLE, and here it called MAIN SEQUENCE STAR
- lasts several BILLION YEARS, our sun is in it rn
3) then red giant /supergiant how?
- eventually hydorgen runs out and instead fusion of heavier elements occur
- swells up and SURFACE COOLS , becoming red. small to medium stars become red giants
- bigger stars form red supergiants - they can undergo more fusion if heavier elements snd expand and contract several times
4) then small stars, what happen to them?
after nebulla?
- red giant will run out of elements to undergo fusion , so energy no longer counter gravity and unstable
- gravity will eject outer layer kf dust and gas and become A PLANETARY
nebulla
2) this eventuwlly leaves a hot dense white core = white dwarf , which will evenitwlly cool and fade away
5) what happen to big stars tho
neutron and black
what happens to remaining dust thrown out
- red supergiants , when run out if fuel, they collapse in on themselves to form MASSIVE EXPLOSION = SUPERNOVA
- this theows outer layers of dust and gas into space , leaving dense core = NEUTRON STAR
2) this will become another star one day - but if so big it will form even denser point = BLACK HOLE, so dense that even light cant escape from it.
difference between jnner wnd outer planets
inner rocky and atmosphere like ewrth mercury venus mars
outer gas giants m kce giants, have bare moons and rings
