Physics: Space Physics

Question 1

what is the first stage of a star’s life cycle

Answer 1

form from a cloud of dust and gas called a nebula

Question 2

what is the second stage of a star’s life cycle

Answer 2

gravity pulls the dust and gas together to form a protostar. Temperature rises and the protostar gets denser as there are more collisions between particles. Eventually it is hot enough for the hydrogen nuclei to undergo nuclear fusion and form a helium nuclei which releases lots of energy and keeps the core of the new born star hot

Question 3

what is the third stage of a star’s life cycle

Answer 3

star enters long stable period where outward pressure caused by nuclear fusion that tries to expand is balanced by inward pressure acted on by gravity. This is called main star sequence and lasts for billions of years

Question 4

what happens to stars that are the same size as our Sun

Answer 4

becomes a red giant then white dwarf then black dwarf

Question 5

what happens to stars that are much bigger than our Sun

Answer 5

becomes a Red Super Giant then Supernova then either a Neutron Star or a black hole

Question 6

how does a star become a Red Giant/Super Red Giant

Answer 6

The hydrogen runs out causing the star to swell. It becomes Red because the surface begins to cool

Question 7

what happens to Red Giants

Answer 7

they become unstable and eject the outer layer of dust and gas leaving the hot dense solid core becoming a white dwarf

Question 8

what happens to a white dwarf

Answer 8

The white dwarf begins to cool down emitting less energy until it no longer emits enough energy to be visible becoming a black dwarf

Question 9

what happens to Red Super Giants

Answer 9

starts to glow brightly again as they undergo more fusion and expand several times until they explode as a supernova releasing several elements into the universe to form new planets and stars

Question 10

what happens when a supernova becomes a Neutron star

Answer 10

the explosion leaves behind a very dense core called a neutron star

Question 11

what happens when a supernova becomes a Black Hole

Answer 11

If a star is massive enough it will become a black hole

Question 12

what is a black hole

Answer 12

Super dense point in space that not even light can escape from

Question 13

what are planets

Answer 13

Large objects that orbit a star. They must be large enough to have pulled in every nearby objects apart from their natural satellites

Question 14

what are dwarf planets

Answer 14

Planet like objects that orbit stars but dont meet all the rules for being a planet

Question 15

what are moons

Answer 15

type of natural satellite that orbit planets

Question 16

what are artificial satellites

Answer 16

satellites that orbit planets that humans have built

Question 17

what force provides orbits

Answer 17

gravity

Question 18

what does the size of the orbit depend on

Answer 18

the object’s speed

Question 19

how does the speed of the orbiting object change the closer you get to the object it is orbiting

Answer 19

the speed increases the closer you get

Question 20

what is red-shift

Answer 20

whee the wavelength of light increases shifting towards the red end of the spectrum

Question 21

what does the universe appear to be doing

Answer 21

expanding

Question 22

what is the Big Bang theory (simple as possible)

Answer 22

initially all matter in the universe was confined in a small meaning it was very dense and very hot. Then suddenly it exploded and space started expanding

Question 23

what is dark matter

Answer 23

unknown substance that holds galaxies together but doesn’t emit EM radiation

Question 24

what is dark energy

Answer 24

Unknown energy thought to be responsible for accelerated expansion of the universe