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.
Answer:
The Amazon rainforest in Brazil lost an area about 12 times the size of New York City from August 2018 through July of this year, according to government data released Monday, which shows that deforestation in the biome has shot up significantly since the election of President Jair Bolsonaro.
The 3,769 square miles of forest cover lost during that period represents a 30 percent increase from the previous year and the highest net loss since 2008.
While there are always multiple direct and indirect drivers of deforestation, the largest contributors in Brazil, by far, are cattle ranching, demand for commodities, and logging (Butler, 2019). Cattle ranching is, as it sounds, the issue of large areas of forest being destroyed for cattle farms. This relates to the demand for commodities, as Brazil is the largest exporter of beef in the world (Yale University, 2015). The other largest commodity in the Brazilian Amazon is soybeans. In fact, Brazil is the largest exporter of soybeans in the world (Simoes et al., 2011). Soybeans require large plots of land in order to be farmed, and this land is obtained largely through deforestation. Lastly, logging, the process of obtaining wood for timber and other uses, is a very large contributor to deforestation.
Explanation:
A belief in the eightfold path
Supply and demand!
If you want a lot of something cause its in high demand.