In a car, the generator-like action of the alternator occurs while the engine is running and keeps the battery fully charged. The headlights would discharge an old and failing battery quickly if it were not for the alternator. Why does the engine of a parked car run more quietly with the headlights off than with them on when the battery is in bad shape

from 1609, galileo galilei used the recently invented telescope to observe the sun, moon and planets. he saw the mountains and craters of the moon, and for the first time revealed the planets to be worlds in their own right. galileo also provided strong observational evidence that planets orbited the sun.

his discoveries about the moon, jupiter's moons, venus, and sunspots supported the idea that the sun - not the earth - was the center of the universe, as was commonly believed at the time.galileo turned his gaze toward venus, the brightest celestial object in the sky - other than the sun and the moon.