Test 2. Flashcards
What is the theory that describes the relationship between space and time?
Special relativity
True or False: According to special relativity, the laws of physics are the same for all observers in uniform motion.
True
The postulates of special relativity
When two observers are moving at constant speeds relative to one another the will observe the same laws of physics
-the speed of light in a vacuum is the same for all observers
What is t’
Is the time always observed by the stationary observer observing the fast moving object
What is l’
Is the distance observed by the stationary observer observing the fast moving object
What is the Doppler effect
The Doppler effect is the change in the observed frequency of a wave when the source or observer is moving
The ______ effect is observed in _______ and ________
The Doppler effect is observed in sound and light
A wave source moving Toward then you _______ in the equation
Take away
Is the source is moving Away from them then the equation will
Addition
Sound moves towards you what happens to the frequency and wavelength. Is this red or blue shift
Higher frequency, lower wavelength, blue shift
Sound moves away from you what happens to the frequency and wavelength is the is red or blue shift
Lower frequency, higher wavelength, redshift
(Remember EM spectrum)
The spectra emitted by each galaxy where shifted towards the _____ by a specific amount. This ______ was due to the _________ moving_______ from the ______ at speed , causing the ______ effect to be observed. The bigger the _______ of the shift the _____ the galaxy was _____
The spectra emitted by each galaxy were shifted towards the red by a specific amount. This shift was due to the galaxy moving away from the earth at speed, causing the doppler effect to be observed. The bigger the magnitude of the shift the faster the galaxy was moving
What is the estimate age of the universe
13.7 billion years
What can lead us to the theory of the expanding universe
The measurements of the velocity of galaxy’s and their distance from us
What force is slowing down the expansion of the universe
Gravity
The eventual fate of the universe depends on its what
Mass-energy density
The suns orbital speed is determined by what
The gravitational pull of matter inside its orbit
The mass of the galaxy can be determined by what
The orbital speed of stars within it
The mass of the galaxy can be determined by what
The orbital speed of stars within it
What is dark matter
The estimations of the galaxies not adding up
The ________ is also expanding at a ______ rate than astronomers expect
The universe is also expanding at a greater rate to what astronomers expect
What does dark energy come from
The accelerating rate of expansion of the universe
What is evidence for the Big Bang theory and the expansion of the universe
Cosmic microwave background radiation
Additional support of the Big Bang theory comes from the relative _____ of ________and _________ in the universe
Additional support of the Big Bang theory comes from the relative abundance of hydrogen and helium in the universe
