Doppler effect
What is the doppler effect
The Doppler Effect is the apparent change in frequency or pitch when a sound source moves either toward or away from the listener.
What happens to the frequency of a radio wave when a car moves towards the radar?
The frequency of the radio wave increases.
It is a branch of astronomy that studies the origin, evolution, and fate of the universe, from the Big Bang to the present and beyond.
Cosmology
It is a poor cluster of galaxies that contains about 40 galaxies, including dwarf galaxies.
-Local Group
What does Hubble’s Law say about galaxies?
The farther away a galaxy is, the faster it moves away from us.
What happens to the frequency of a sound when the source moves towards the listener?
The frequency of the sound increases.
What happens to the frequency of a radio wave when a car moves away from the radar?
The frequency of the radio wave decreases.
It i s a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity.
Galaxy
Why do the raisins stay the same size even when the dough expands?
Because the raisins (galaxies) are not stretching, only the dough (space) is expanding.
What is the Hubble constant? (Include numeric equivalent.)
It is a number that tells us how fast the universe is expanding. It is about 71 km/s per megaparsec (Mpc).
What happens to the frequency of a sound when the source moves away from the listener?
The frequency of the sound decreases.
What formula would you use if the source and the observer are at rest?
Write the answer on the board. Plus 500 points will be given to the group that is able to answer the follow up question.
What are the three large spiral galaxies?
Milky Way Galaxy, Andromeda Galaxy, and Triangulum Galaxy.
What do the raisins in the dough represent?
The raisins represent galaxies in space or universe.
What is dark energy?
A mysterious force that makes the universe expand faster.
How is the Doppler Effect used in radar?
The Doppler Effect is used in radar to measure the velocity of detected objects.
What formula would you use if the source is moving towards the observer that is at rest?
Write the answer on the board.
How do astronomers determine the structure of the universe?
Astronomers determine the structure of the universe by detecting and analyzing electromagnetic waves from galaxies to understand their distribution and movement.
How does the analogy explain how galaxies move in space?
Just like the raisins, galaxies in space move away from each other as the universe expands.
What are the main parts of the universe?
68% dark energy, 27% dark matter, and 5% ordinary matter.
How is the Doppler Effect used to measure the speed of cars?
The Doppler Effect is used to measure the speed of cars by sending a fixed-frequency radio wave to a moving car.
What formula would you use if the source is moving away from the observer that is at rest?
Write the answer on the board.
How are clusters and superclusters different in terms of structure?
Clusters are groups of galaxies bound by gravity, while superclusters are larger structures that contain multiple clusters of galaxies.
What mixture in baking that is used in the analogy that represents space in the universe? Why does it use that as the analogy?
The raisin bread dough represents space in the universe, which grows bigger over time.
How do scientists calculate the age of the universe?
They use the formula Age = (9.78 × 10¹¹) / H, where H = 71 km/s/Mpc. This gives an age of 13.8 billion years.