Space Flashcards
Suggest what is likely to cause a theory to be dropped.
New evidence or observations that cannot be described by the theory
Explain how galaxies moving away from each other supports the Big Bang theory.
the furthest galaxies show the biggest red-shift
and are therefore moving the fastest
so the universe is expanding
extrapolating backwards, this suggests the universe started from a single point
Describe how stars are formed.
When dust and hydrogen gas
get pulled together
by gravitational attraction
Why are telescopes that detect different types of electromagnetic waves used to observe the Universe?
stars and galaxies emit different types of electromagnetic waves
What is red-shift?
when the wavelength of light increases
If a galaxy has moved away the furthest…
it is moving the fastest
What should scientists do if they found new evidence that did not support the Big Bang theory?
they should change the theory to match the evidence
What is meant by red shift and what does it tell us about distant galaxies?
longer wavelength waves
galaxies are moving away from the earth
What did Hubble discover through red-shift?
that galaxies are moving away from the earth
reliability
consistency of measure
accuracy
how close you are to the final value
validity
accuracy of measure
Explain why scientists believe that the Solar System was formed from the material produced when earlier stars exploded.
solar systems contain heavy elements
which are formed by nuclear fusion
in supernova explosions
Suggest a reason why scientists were keen to carry out new research into the universe.
to find evidence to prove or disprove a theory
What should scientists do when a theory does not appear to be supported by new data?
check the reliability of the data
adapt/amend the theory
Why was the discovery of CMBR so important to the scientists believing the ‘Big Bang’ theory to be correct?
can only be explained by the Big Bang theory
v = fλ
wave speed (m/s) = frequency (Hz) x wavelength (m)
What information can scientists find out about a galaxy when they measure the size of the red-shift the galaxy produces?
distance from the earth
speed galaxy is travelling
Why is fusion so important?
it produces energy
What is a black hole?
is extremely dense
that pulls light in
What is produced as the gases from a star spiral into a black hole?
x-rays
Explain how atoms of very heavy elements, such as gold (Au), were formed.
fusion of lighter elements
during a supernova explosion
Explain the difference between a protostar and a main sequence star.
a protostar is at a lower temperature
as nuclear fusion reactions have not started in its core
Where does nuclear fusion take place?
in stars
in a supernova
