Changing Ideas About The Universe Flashcards
what is the geocentric model
a theory that suggested the sun, moon and all stars orbited the earth in perfect circles
why did people believe in the geocentric model
- because people didnt have telescopes at that time
- and only saw the sun and moon in the sky travelling in the same routes everyday day and night
how long was the geocentric model believed to have been the way the solar system worked
from the time of the ancient greeks to the 1500s
what was the next model after the geocentric model and what did it state
- next up was the heliocentric model
- this model stated that the earth and all of the planets orbited the sun in perfect circles
who found the best evidence for the heliocentric model and what did they find (short)
- galileo was the one who found the evidence
- the evidence he found was the moons around jupiter
what was galileo’s observations of the moons of jupiter
- whilst looking at jupiter through a telescope, he noticed some stars were in a line near jupiter
- he looked again and realised that the ‘stars’ never moved away from jupiter and seemed to be carried along with the planet
what did galileo’s observations allow him to draw to a conclusion
- it showed that not everything was in orbit around the earth
- proving that the geocentric model was wrong
how did evidence for galileo’s theory accumulate
- due to the increase in technological advancements
- allowing us to be able to accurately study our solar system
what does the heliocentric model state
- that all planets orbit the sun
- but that the orbits aren’t in perfect circles
- but they orbit in an elliptical motion
- and the sun isnt at the center of the universe as previously thought
what does the steady state theory state
- that the universe has always existed as it does now
- and it always continue to
what is the steady state theory based on
the idea that the universe pretty much appears the same everywhere
explain what the steady state theory states
- as the universe expands, new matter is constantly being created
- the means that the density of the universe as always roughly the same
- so in this theory, there is no beginning or end to the universe
what does the big bang theory states
- initially, all matter in the universe occupied a very small space
- the tiny space was very dense and so very hot too
- then it exploded and space started expanding, which is expanding to this very day
what is the difference between the steady state theory and the big bang theory in terms of time spans of the universe
- the steady state theory states that the universe is infinite and has no beginning or end
- where as the big bang theory gives a finite date for the existence of the universe, which is 13.8 billion years
which theory regarding how the universe began is widely accepted and why
- the big bang theory
- because of the evidence which supports it
- like background radiation
