After Galileo built his first telescope in 1609, he observed and described the landscape of the moon, discovered four of the moons of Jupiter, discovered the phases of Venus, and discovered sunspots. Galileo's discovery of sunspots supported the idea of heliocentrism, a model that places the sun at the center of the universe with the planets orbiting around it.Know More
Galileo studied and later taught mathematics at the University of Pisa. He helped to describe ballistics and presented his "Principle of Inertia." In 1632, Galileo presented his concept of basic relativity in physics, which later became the basis of Einstein's special theory of relativity.
In 1632, Galileo published a book openly supporting heliocentrism. He was later forced to publicly denounce his findings.Learn More
The Environmental Protection Agency outlines the protective measures people can take against ionizing radiation as being time, distance and shielding. Taken together, these three factors determine the severity of exposure to radiation, including gamma ray radiation, and the likelihood of long-term health effects.Full Answer >
Meteoroids are pieces of natural space debris that orbit around a larger solar body, such as the sun. They measure about the size of a quarter and are much smaller than other objects that typically orbit. Meteoroids are made from a mix of rock and metals: mostly nickel and irons.Full Answer >
The Earth's rotation means that the sun is visible during certain times and blocked during other times. When the sun is visible, it is daytime; when it is blocked, night has come.Full Answer >
According to Springfield Technical Community College, the visual receptor cells are located at the proximal end of the retina. These cells are called photoreceptor cells.Full Answer >