Topic 8- Space Physics (Pre 2018) Flashcards
What does this increase in wavelength tell us about the movement of most galaxies
moving away
Explain how this observation (galaxies moving away w increasing wavelength) supports the Big Bang theory of the formation of
the Universe.
the furthest galaxies show the biggest red shift
(meaning that) the furthest galaxies are moving fastest
(so the) Universe is expanding
the Universe started from
an initial point
State one piece of evidence that supports the Big Bang theory of the
formation of the Universe.
cosmic microwave background radiation
In 1965, scientists rejected the ‘steady state’ theory in favour of the ‘big bang’
theory.
Suggest what might cause scientists to stop supporting one theory and to start
supporting an alternative theory.
(new) evidence that supports / disproves a theory
Why are telescopes that detect different types of electromagnetic waves used to observe the Universe?
stars / galaxies / sources emit all / different types of electromagnetic waves /
radiation
What is red-shift?
wavelength (of light) increases
or
light moves to red end of
spectrum
What does the measurement of its red-shift tell scientists about this star?
it is the star (detected) furthest from the Earth
or
it is moving away the fastest
Describe the ‘big bang’ theory.
all matter compressed to / starts at / comes from a single point (massive) explosion sends matter outwards
Suggest what scientists should do if new evidence were found that did not
support the ‘big bang’ theory.
check validity / reliability of the evidence
How do the wavelength and frequency of the light from Andromeda seem to have
changed when viewed from the Earth?
wavelength is decreased
frequency is increased
Explain why scientists believe that the Solar System was formed from the material
produced when earlier stars exploded.
solar system contains heavy elements / elements heavier than hydrogen
and helium
these (heavy) elements are / were formed by (nuclear) fusion
n a super nova / when stars explode
Explain how the spectrum ‘shift’ of the dark line supports the theory that the
Universe began from a very small point.
line shifts towards red end of spectrum
wavelength (appears) to increase
galaxy is moving away
When considering the origin of the universe, what is the difference between the ‘big
bang’ theory and the ‘steady state’ theory?
big bang theory – universe started at one point (then expanded)
steady state theory – universe has no origin / has always existed
Why does red-shift provide evidence to support both the ‘big-bang’ theory and
the ‘steady state’ theory?
red-shift is evidence / supports idea of expanding universe
both theories use the idea / accept / explain why the universe is expanding
The light arriving from distant galaxies provides scientists with evidence to
support the ‘Big Bang’ theory.
Explain how
light shows a red shift
galaxies moving away (from the Earth)
What should scientists do when a theory does not appear to be supported by new
data?
check reliability / validity of data
amend theory
How does the red-shift from distant galaxies provide evidence for the beginning of
the Universe?
red-shift shows galaxies are moving away
more distant galaxies show bigger red-shift
suggests single point of origin (of the universe)
What do scientists believe is the origin of CMBR?
(radiation produced shortly after) ‘Big Bang’
Why was the discovery of CMBR so important to the scientists believing the
‘Big Bang’ theory to be correct?
can only be explained by ‘Big Bang’
How is the wavelength of CMBR likely to change, if at all, over the next billion
years?
Give a reason for your answer.
increase
universe continues to accelerate outwards
Which type of electromagnetic wave has the shortest wavelength?
gamma
State one difference between an ultraviolet wave and a visible light wave.
- (ultraviolet has a) higher frequency
- (ultraviolet has a) greater energy
- (ultraviolet has a) shorter wavelength
What information can scientists find out about a galaxy when they measure
the size of the red-shift the galaxy produces?
distance
speed galaxy is moving
Give one other way in which the Moon is different from the other satellites
- it’s natural
Describe how stars are formed.
(enough) dust / gas (from space)
are pulled together
by gravitational attraction
What is the relationship between the masses of the dust and gas in the cloud
in Stage 2 and the force of gravity between them?
the bigger the masses (of the dust and gases then) the bigger
the force / gravity (between them)
What is the relationship between the distance apart of the dust and gas in the
cloud in Stage 2 and the force of gravity between them?
the greater the distance (between the dust and gases then) the
smaller the force / gravity (between them)
What happens in Stage 4?
- hydrogen runs out / is used up
- nuclei larger than helium nuclei formed
- (star expands to) / become(s) a red giant
Describe what will happen to the Sun from the time the hydrogen is used up until the
Sun “dies”.
- fusion decreases or stops
- collapses rapidly causing the (core) temperature to rise
- (inward) gravitational forces no longer balance (outward) pressure
- expands
- and becomes a red giant
- it cools
- then becomes a white dwarf
- helium may fuse
Over billions of years the amount of hydrogen in a star decreases. Why?
converted into helium
The inner planets of the solar system contain atoms of the heaviest elements.
(i) Where did these atoms come from?
supernova
Explain how stars produce energy.
- nuclei / atoms of light elements fuse
- each (fusion) reaction releases energy / heat / light
- lots of reactions occur
What evidence is there to suggest that the Sun was formed from the material
produced when an earlier star exploded?
presence of nuclei of the heaviest / heavy / heavier elements
Explain what is meant by the term black hole.
(matter / mass) with such a high density / strong gravitational (field)
electromagnetic radiation / light is pulled 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 other/lighter atoms/elements
during super nova/explosion of star(s
Explain how, and when, atoms of different elements may be distributed throughout
the Universe.
explosion of star(s)/super nova
at the end of the ‘life’ of star
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
