1.
What is a Massive Compact Halo Object (MACHO)?
Correct Answer
A. Dim objects, intermediate between stars and planets
Explanation
A Massive Compact Halo Object (MACHO) refers to dim objects that are intermediate in size between stars and planets. These objects are typically found in the halo of a galaxy and can include objects such as brown dwarfs, black holes, or even rogue planets. They emit very little light and are difficult to detect, making them a challenging subject of study in astrophysics.
2.
What percentage of the universe is baryonic matter?
Correct Answer
B. 4.6%
Explanation
The correct answer is 4.6%. Baryonic matter refers to the ordinary matter that makes up atoms, such as protons, neutrons, and electrons. This includes everything we can see and detect, such as stars, planets, and galaxies. However, the majority of the universe is made up of dark matter and dark energy, which are not included in the baryonic matter. Therefore, baryonic matter only accounts for a small percentage, which is 4.6%, of the total mass-energy content of the universe.
3.
Scientists believe that Dark Energy
(Select all the answers that apply)
Correct Answer(s)
A. Repels gravity
B. Is responsible for the expansion of the universe
C. Is large majority of the total content of the universe
Explanation
Dark Energy is believed to repel gravity, as it counteracts the force of gravity and causes the expansion of the universe. It is also thought to be responsible for the expansion of the universe, as its presence leads to the acceleration of this expansion. Additionally, Dark Energy is believed to make up a large majority of the total content of the universe, indicating that it has a significant presence and influence. However, there is no mention of Dark Energy being WIMPs (Weakly Interacting Massive Particles) in the given information.
4.
Scientists believe that black holes are made of
Correct Answer
A. Dark matter
Explanation
Black holes are believed to be made of dark matter because dark matter is a hypothetical form of matter that does not interact with light or other electromagnetic radiation, making it invisible and difficult to detect. It is thought to make up a significant portion of the universe's mass and is believed to be responsible for the gravitational forces that hold galaxies together. Since black holes are known for their extremely strong gravitational pull, it is logical to assume that they are composed of dark matter.
5.
Neutrinos have a ________________ charge.
Correct Answer
C. No charge
Explanation
Neutrinos have no charge because they are electrically neutral particles. Unlike protons, which have a positive charge, and electrons, which have a negative charge, neutrinos do not have any charge. This means that they are not affected by electromagnetic forces and can pass through matter without being deflected. Neutrinos are only subject to the weak nuclear force, which allows them to interact with other particles in certain ways.
6.
The expansion of the universe is
Correct Answer
C. Speeding up
Explanation
The expansion of the universe is speeding up. This is supported by observational evidence, such as the measurements of distant supernovae and the cosmic microwave background radiation. These observations indicate that galaxies are moving away from each other at an accelerating rate. This phenomenon is attributed to the presence of dark energy, a mysterious force that counteracts gravity and drives the expansion of the universe. The exact nature of dark energy is still not fully understood, but its existence is necessary to explain the observed acceleration.
7.
The density of the universe is
Correct Answer
A. 5.9 protons per cubic meter
Explanation
The density of the universe is measured in protons per cubic meter. The correct answer is 5.9 protons per cubic meter, as it represents the average density of protons in the universe. This means that in every cubic meter of space, there are approximately 5.9 protons.
8.
What instrument is NASA using to gather information about the composition of the universe?
Correct Answer
C. Wilkinson Microwave Anisotropy Probe
Explanation
The Wilkinson Microwave Anisotropy Probe (WMAP) is an instrument used by NASA to gather information about the composition of the universe. It measures the temperature of the cosmic microwave background radiation, which is the afterglow of the Big Bang. By studying this radiation, scientists can learn more about the early universe, the formation of galaxies, and the distribution of matter and energy.
9.
The universe is ________________________ .
Correct Answer
B. Flat
Explanation
The correct answer is "flat". This suggests that the universe is not curved or spherical in shape, but rather has a flat geometry. This is supported by various theories in cosmology, such as the concept of a flat universe in the context of the Big Bang theory. It implies that the universe extends uniformly in all directions, without any curvature or bending.
10.
Material made of protons, neutrons and electrons is called _______________ by scientists.
Correct Answer
D. Baryonic matter
Explanation
Baryonic matter refers to material that is composed of protons, neutrons, and electrons. This term is used by scientists to describe substances that are made up of these fundamental particles. Hydrogen, for example, is a type of baryonic matter because it consists of a single proton and an electron. Neutrinos, on the other hand, are not considered baryonic matter as they are elementary particles that do not have any charge or mass. Non baryonic matter refers to other types of matter that do not consist of protons, neutrons, and electrons, such as dark matter.