Answer:
A New Kind of Light in the Universe? “Super-Planckian” Material Emits Light That Exceeds Limits of Natural Law
Answer:
b. flat rotation curves in spiral galaxies
Explanation:
Dark matter accounts for majority of the matter in the universe (about 85%). It is considered to be composed of subatomic particles which are yet to be discovered. Dark matter cannot be observed because it does not emit light that can be detected. Only its gravitational effect is visible.
Astronomers when calculated the mass of the visible matter and tried to account for the observed speed of stars in the galaxy, there was a mismatch. To understand what caused this mismatch, astronomers gave name to the invisible matter as the Dark Matter.
The expected velocity of stars should decrease away from the near the center of the galaxy but a constant velocity of stars was observed that is a relatively flat rotation curve was obtained.
Thus, flat rotation curves in spiral galaxies in an evidence of Dark Matter.
The solutions to environmental problems are “coordination of environmental efforts between sectors”, “enforcement of environmental regulations”, “sustainable land management practices”.
<u>Explanation:
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The environmental problems in any region can be a threat to that region since it may affect their health to a greater extent. In order to eradicate any environmental problem in a region there must be a good coordination existing between sectors which will result in solving an environmental problem easily and quickly.
Strict enforcement of environmental regulation acts and policies also plays a major role in solving the environmental problems. Land management practices are those that combine the land management, water bio diversity and other resources in environment for meeting the needs of human beings.
