Our Dynamic Universe 6 Flashcards
What is the Doppler effect
The name of the naturally occurring phenomenon which alters the relative frequency of radiation
What does the Doppler effect do
Wen a sound source is approaching a observer the sound has a higher frequency and when a sound source is moving away from an observer the sound has a lower frequency and the Doppler effect can be observed for all waves including sound and light
Sources moving away from the observer will be …
Redshifted
Sources moving towards an observer will be
Blue shifted
What can the level of redshift / blueshift be used to calculate
The speed of moving galaxies
Is blue shift positive or negative
Negative
Is redshift positive or negative
Positive
On a line spectra the lines produced can identify ..
The light source
Redshift will show the lines shifted …
Towards the red end
Blueshift will show the line shifted …
Towards the blue end
What is the age of the universe
13.8 billion years
What is evidence to support the Big Bang theory
cosmological redshift - Hubble observations show galaxies are moving away from us and the light is redshifted
cosmic microwave background radiation - radiation is detected everywhere in space it is equally distributed in all directions this is the afterglow of the Big Bang theory
abundance of light elements - the simplest elements - hydrogen and helium _ were the first form after the big bag. The heavier elements were formed in the stars from these lighter elements
What is dark matter
Galaxies are rotating faster then predicted. This indicates there is matter that does not interact with or emit light
What is dark energy
If the universe is expanding and this expansion is accelerating there must be a source for all his extra kinetic energy.
What colour are hot stars
Blue
What colour are cold stars
Red
The hotter that star the more …
Energy emitted
