Origin of the universe Flashcards
What does the universe seem to be doing?
Expanding
Where are galaxies moving?
Away from eachother
Light from other galaxies is…
Red-shifted
What do different chemical elements absorb?
Different frequencies of light
What does each element produce?
A specific pattern of dark lines at the frequency it absorbs in the visible spectrum
What do you see when you look at light from distant galaxies?
The same patterns at lower frequencies
Shifted towards the red end of the spectrum
What is red shift?
When frequencies are lower so they are shifted to the red end of the spectrum
What is the Doppler effect?
Lower pitch when passed and moving away from you
What happens when something emits waves towards or away from you?
Wavelengths and frequencies are different compared to when the source is stationary
What is the frequency of a source moving towards you?
Higher
Shorter wavelength
What is the frequency of a source moving away from you?
Lower
Longer wavelength
What does the Doppler effect happen to?
Longitudinal waves
Transverse waves
What happens to the red shift when a galaxy is further away?
Greater red-shift
What does red shift suggest?
All galaxies are moving away from us quickly
What does red shift provide?
Evidence the universe is expanding
What does it mean if a galaxy is further away from us?
They are moving faster
What was the big bang?
ALL matter and energy compressed into a small space
It exploded from a single point
What is the estimated time the bang occurred?
14 billion years ago
What is the steady state theory?
States the universe has always existed as it is now
Suggests that matter is being created in the spaces as the universe expands
What is evidence proving the big bang?
Discovery of cosmic microwave background radiation
CMBR
What have scientists detected?
Low frequency electromagnetic radiation coming from all parts of the universe
Where is low frequency electromagnetic radiation in the EM spectrum?
Microwave
What is the only theory which can explain CMBR?
Big bang
What happened just after the big bang?
The universe was extremely hot and emitted high frequency radiation
What happened as the universe expanded?
Cooled and the radiation dropped frequency
Now seen as microwave radiation
What does the big bang theory predict?
The universe expansion is slowing down however it is actually speeding up
What does the big bang theory not explain?
What caused the explosion
What conditions were like before
