The universe Flashcards
what is the heliocentric theory
proposed by Copernicus based of the moons of Jupiter that the sun is the centre of our universe
main methods of looking into space using the visible spectrum
naked eye
reflecting telescope
reflecting telescope
telescopes outside the atmosphere
why do we need telescopes in out of space
because some parts of the EM spectrum are absorbed by our atmosphere
what is a SETI
an extra terrestrial
probes and satellites
satellites around the earth observe the universe without interference and absorption caused by the atmosphere
probes in the solar system allow us to look more closely at planets and moons
landers and rovers land on objects collecting images and samples
pros of orbiters
simple to build and run, cheap and easier the get back or move onto other planets
pros of landers
allow us to find out more about an object, can collect more samples and detailed pictures but are more complex and expensive
life cycle of a small star
stellar nubula star red giant planetary nebula white dwarf
life cycle of a giant star
stellar nebula massive star red supergiant supernova neutron star or black hole
how is a stellar nebula formed
from gases and dust pulled together due to gravity its pressure and increases
how is a red giant formed
when a star has fused most of its hydrogen causing it to expand and cool
what is the Doppler effect
the Doppler effect occurs when there is relative movement between a source of waves and the observer
when an object is moving towards you the waves
are compressed have a shorter wavelength have a higher frequency sounds appear in higher pitch light shifts towards blue end of spectrum
when an object is moving towards you the waves…
are stretched have a longer wavelength have a lower frequency sounds appears lower pitch light shifts towards the red end of the spectrum
red shift explanation for the universe expanding
nearly all the galaxy’s are redshifted
which means the galaxies are moving away from us and eachother
the universe is expanding and started at some point
the steady state theory
the universe looks the same from all directions from Earth, the universe looks the same from any view point and has always looked like this
the universe is continually getting bigger and more matter aka hydrogen is being produced HOWEVER new matter cannot be detected
the Big Bang theory
the universe started from a really tiny point called singularity, it had an extremely hot temperature, don’t know what triggered it but 15 billion years ago it began to expand
as it expanded it cooled quickly
after 1 second e,p and n and after three hydrogen and helium formed
no new matter is being formed
CMR
is evidence for the Big Bang theory, when the BB occurred it produced a lot of radiation, over time the EM radiation stretched to microwave wavelength
what is the geocentric theory?
that the earth is the centre of the universe, it was proposed by Aristole
