Flashcards in 7 Deck (29)
What is a geocentric model of the solar system?
Where the earth is in the middle and the planets and sun orbit teh earth.
Who came up with the first geocentric model of the solar system?
Order of planets in our solar system:
Mercury, Venus, earth, mars, Jupiter, Saturn, Uranus, Neptune.
What are there in solar systems?
There are moons, planets, asteroids, meteoroids and comets.
What is a heliocentric model?
Where the sun is in the middle.
Who changed the model from geocentric to heliocentric?
Who invented the first telescope?
What are the two different types of orbits?
Geostationary and polar orbit.
What are satellites and what are there uses?
They are things which orbit a moon or planet. Some are natural like moons however some are artificial like man made machines.
They are used for communication, GPS and space telescopes.
What is a geostationary orbit.
Where a satellite gets put into space and it stays in the exact same place above earth.
What is a polar orbit?
Where you can see the whole world in a very short space of time and doesn’t need a continuous link.
As the speed of an orbit has increased what happens to the centripetal force?
As the centripetal force increases what happens to the radius?
It would increases.
When the speed of an orbit increases what happens to the radius?
How do stars start?
With a star nebular when he gravity pulls together to form a protostar.
Smaller star lifecycle:
Main sequence - red giant - planetary nebular - white dwarf.
Bigger star lifecycle.
Main sequence - red supergiant - supernova - neutron star or black hole.
When a larger star is a red supergiant what elements do they fuse.
All elements up to iron. Starting with Hydrogen to helium.
What do stars fuse in main sequence stars?
Hydrogen to helium.
How are elements heavier than iron formed?
In supernovas where the red supergiants implode.
What do stars do to repel gravity?
The sun produces almost all the colours that make up white light, however very few are missing? Why is this?
They are absorption lines which correspond to the elements hydrogen and helium which the sun fuses.
When galaxys are moving further away from us we know this as the absorption lines from hydrogen and helium do what?
They shift towards the red end of the light spectrum. This is called redshift.
When galaxys are moving towards what occurs with absorption lines?
Blueshift where the lines move to the blue side of the colour spectrum.
The further away the galaxy is what happens differently in redshift?
The lines shift more to the red side.
What is redshift proof of?
1. The Big Bang theory
2. The universe is expending.
What is the steady state theory?
- an alternate view to the BBT
- was founded in 1948
- says that the universe in expanding but it stays a constant density.
- redshift proves that the universe is expanding.
- however whole theory is disproven by the cosmic microwave background theory.
What’s the Big Bang theory?
Where the universe started by one big ball of energy and then it exploded and its still expanding.
- proven by comic microwave background theory
- also proven by redshift.