Question 1 (1 point) Which of the following is an example of the Doppler Effect? a The increase in the volume of sound waves as you walk towards a playing radio b The change in frequency of an ambulance siren as it speeds away from you c The decrease in the brightness of a candleflame as someone carries it into the next room d The ability to hear the sounds waves of a singer far away as they reverberate off the walls of an empty hallway Question 2 (1 point) Why is the Doppler Effect when concerning space objects often called "Redshift" and "Blueshift"? a Red is the color produced by objects moving faster and blue is the color produced by objects moving slower, so you measure the speed of objects by their color b Red and blue are temperature gradients. Warmer objects appear more red, while cooler objects appear more blue c The Doppler Effect is about the sound waves produced by the motion of the stars, so the stars that generate more sound waves appear more blue and the stars that produce less sound appear more red d The Doppler Effect changes frequency depending on the motion of objects and frequency changes the color of light to either redder or bluer hues. Question 3 (1 point) What is the evidence that the Universe is currently expanding? a There is more area of the Universe today than there was one hundred years ago. If the Universe has more area in it than before, it must mean the Universe is expanding b Over 90% of all objects in the Universe are red-shifted, meaning they are moving away from us. If everything is moving away from everything else, it must mean the Universe is expanding c All objects in the Universe are increasing in acceleration, which they could not do unless there was a force pulling them outward. If there is a force pulling all objects outwards, then there must be a force spreading the Universe, therefore, it must mean the Universe is expanding d The majority of the objects in the Universe are increasing in size, due to gravity constantly attracting matter into localized clumps. In order for these clumps to get larger, there must be more space for them to take up. The only way that can happen is if the Universe is constantly expanding Question 4 (1 point) Why do scientists believe the Universe began as one singlularity (A single point)? a The rate of expansion of the Universe could only be possible if the explosion of the Universe came from a single point b The Universe's shape is spherical, which means that the original origin of the Universe had to be a spherical point like a singularity c The gravity of the Universe is always pulling towards a single point in the center of the Universe, which must be the location of the original singularity d Since the Universe is expanding now, it must have been closer together in the past. At the start of time, the Universe must have been as close together as it possibly could be Question 5 (1 point) Which of the following was released immediately after the big bang? a Spiral Galaxies b Cosmic Background Radiation c Hydrogen Plasma d Black Holes Information for notes The Universe began as a single point of nearly infinite mass. The reason scientists conclude this is because almost every object in the Universe is moving away from every other object. This is found because of the red shift of these objects A Red Shift is the term given to objects undergoing a Doppler Effect for light. When objects move father away from each other, their light frequency decreases, making them appear 'redder' than they actually are. Since almost every object in the Universe is red-shifted, this means almost every object in the Universe is moving away from each other. In other words, the Universe is expanding So if the Universe is expanding now, is must have been close together at one point at the beginning of time. This point was what is called the 'singularity'. The expansion of the Universe began when the singularity exploded, an event called the Big Bang. The Big Bang, like all explosions, released a large amount of energy. This energy from the beginning of time can still be detected today. It is called the "Cosmic Background Radiation" Question 6 (1 point) What is the difference between baryonic matter and dark matter? a Baryonic matter can be seen, dark matter cannot be seen b Baryonic matter has mass, dark matter has no mass c Baryonic matter is produced by stars, dark matter is produced by black holes d Baryonic matter produces the effect of gravity, dark matter produces the effect of electromagnetism Question 7 (1 point) Why was the Coma Cluster's rotational speed used as the main evidence for the existence of dark matter? a The Coma Cluster doesn't have enough visible mass to be moving as fast as it is b The Coma Cluster doesn't have enough visible mass to be as energetic as it is c The Coma Cluster doesn't have enough visible mass to have the gravity it must have d The Coma Cluster doesn't have enough visible mass to be as bright as it is Question 8 (1 point) Why can't scientists confirm the existence of dark matter? a Dark matter does not emit, reflect or absorb any known electromagnetic radiation b Dark matter moves faster than the fastest scientific equipment can detect c Dark matter remains unable to be detected because it has no mass d Dark matter cannot generate force, therefore it cannot interact with anything else Information for your notes Dr. Fritz Zwicky analyzed the motion of a cluster of galaxies called the Coma Cluster. In this cluster, Dr. Zwicky's calculations found that the rotational speed of the Coma Cluster was too fast. Much like a box on a merry-go-round, when the merry-go-round turns too quickly, the box gets thrown off. This was happening to the Coma Cluster, it was moving so fast, its stars and galaxies should be thrown off the cluster as well. The thing that could stop this is the force of gravity. Gravity is pulling the stars and clusters together to keep them from being thrown off. But there is a problem with the Coma Cluster. Gravity is produced by matter, yet the Coma Cluster does not have enough baryonic matter to produce the gravity needed to keep it together. Baryonic matter is matter that can be detected. Dr. Zwicky theorized that there must exist a large amount of matter that we cannot detect that is providing the missing amount of gravity. He called this matter, Dark Matter. Dark Matter is matter that cannot emit, absorb or reflect electromagnetic radiation. Since all of our scientific equipment is designed to collect some form of electromagnetic radiation, dark matter is invisible to all known scientific equipment. We only have indirect evidence of its existence, such as the case of the missing gravity with the Coma Cluster Question 9 (1 point) What is the link between dark energy and dark matter? a Both are found in galaxies and can be detected with sonar equipment b Both were created during the Big Bang and both are undetectable by modern science equipment c Both were created during the Big Bang and both expand the Universe d Both expand the Universe and both are undetectable by modern science Question 10 (1 point) Why was the significance of detecting Supernovae with explosion sizes larger than expected? a It provided evidence that supernovae are much stronger than predicted b It provided evidence that black holes were not created entirely by dying stars c It provided evidence that star cores use fusion for their energy d It provided evidence that the Universe's expansion is accelerating Information for your notes When the Big Bang occurred, the Universe continued to expand at a constant rate, since there was no force outside the Universe to stop it. However, gravity is constantly attempting to pull the Universe back to the original singularity. Since gravity cannot be stopped, it has continued pulling against this expansion When scientists observed a large supernova, they found the blast radius to be far larger than their models predicted. This can only mean the Universe expanded during the time the supernova started and when it ended. This was faster than previously calculated, so the only explanation is that the expansion of the Universe is actually accelerating. In order to do this, it needs energy, yet this energy was never recorded. Scientists named this energy "Dark Energy" since, like Dark Matter, it was created at the beginning of the Big Bang and cannot be detected by any known scientific equipment