power of matter Flashcards
(10 cards)
what is the nebula
overtime, the hydrogen gas in the nebula is pulled together by gravity and it begins to spin, as the gas spins faster it heats up and becomes a prostar
what is a main sequence star
the fusion of hydrogen to form helium changes the interoior composition of a star which in turn results in changes in its temperature, luminosity and radius
what is a supergiant
the core of the red supergiant continues to fuse heavier and heavier elements. This process stops when iron builds up in the core of the star
what is a supernova
when stars run out of hydrogen to fuse in their cores they run out of fuel and collapse due to their own gravity
what is a neutron star
when the central core becomes so dense that electrons and protons begin to form neutrons, it collapses to form a neutron star
what is a black hole
stars that do morph into black holes usually go through the death throes of a core collapse supernova but some are too big for even that. They directly collapse into the invisible mouths of the universe, slowly drawing dust and gas and occasional passing stars towards them with gravity.
explain nuclear fusion
Changes the number of protons inside the nucleus as the original element is changed into a new element. At very high temperatures, a nuclear reaction called fusion occurs in stars. It is the joining of two nuclei to make a bigger nucleus. This destroys a little bit of mass which turns into a large amount of energy
the steady state theory/model
the theory that the universe looks the same from every spot in it and at every time. There could have been no beginning or end
The big bang theory/model
the theory that in the instant, a trillion-trillionth of a second, a singularity created the big bang, the universe expanded with incomprehensible speed from its pebble size origin to astronomical scope. Over the ensuing billions of years the expansion has continued to expand but much slower
what is the red shift
occurs when a light emmiting body moves away from us. Light waves at the end trail and stretch out which are said to be red shifting due to their longer wavelengths which means that stars and galaxies are moving away- supporting the BBT
