physcis space test
Red shift
life cycle of stars
How are stars formed
Fate of the universe
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what is dark energy and dark matter
how will the universe end
what decides how the universe will end
Dark energy is a kind of anti-gravity that wants to push everything apart
Dark matter is a invisible substance that makes up most of our universe
Big crunch
Big yawn (heat death)
If the universe is over a particular density it big crunch will ensue but if it is below that particular density the big yawn will happen
The galaxies will gradually get pushed away as all the stars and galaxies will die off making the universe a dark and cold place
Everything will come into a singularity and be squeezed together. Like a reverse big bang
nebula - this is a gas cloud made of remnats of other stars
protostar- it is on the verge of igniting to a fully fledged star
Main sequence star- they are the most stars in the universe. Has the mass of 1.5x the sun
Red giant- the main sequence will expand due to it fusing heavier elements
white dwarf - this is the core of a star. It is about the size of a planet
Black dwarf - the white dwarf will fade away making a black dwarf
Massive star - this is a star that is 100x the size of our sun
Red super-giant - the star expands due to it fusing heavier elements
Black hole - this is an object that has the greatest gravitational pull in the universe, not even light can escape from it
neutron star - this is all the star's mass condensed into an object the size of a city
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what is nuclear fusion
How does the star become stable
where do stars from from
stars form from nebula which are clouds of mainly hydrogen gas
Nuclear fusion is when you combine 2 nuclei of an atom to make a new heavier one
the force of gravity and the radiation that is being emitted due to nuclear fusion are at equilibrium so therefore the star doesn't fluctuate in size so therefore it is stable
what is red shift?
red shift is the distortion of light when an object is moving away from us
How can we prove that dark energy exists with red shift
Most object in the universe appear to be moving away from us. From their point of view, we are moving away from them too. This suggest that an invisible force is pushing the galaxies away. This is dark energy
How does a stable star become a red giant
This is because the star starts to fuse heavier and heavier elements meaning the radiation given out by the nuclear fusion is greater than the gravity of the star meaning that it will swell up
The Big bang theory
What is the big bang theory
What is the evidence of the big bang theory
Are there any other theory to the creation of the universe
The theory suggests that the universe was originally a ball of energy that eventually exploded out to the universe
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