How did ancient Greeks such as Aristotle know that Earth is round?
A) From the ancient manuscripts of authors such as Homer.
B) By noting that ships drop below the horizon as they go out to sea.
C) By triangulation (measuring the distance between 2 points, and measuring 2 angles, to determine the distance to a 3rd point).
D) Careful measurements of the distance, along Earth's surface, between two widely separated points showed it to be longer than the straight-line distance.
E) Actually, the ancient Greeks thought that Earth is flat.
Question 2
A rocket is moving at 1/4 the speed of light relative to Earth. At the center of this rocket, a light suddenly flashes. To an observer at rest in the rocket
A) the light will reach the front of the rocket at the same instant that it reaches the back of the rocket.
B) the light will reach the front of the rocket before it reaches the back of the rocket.
C) the light will reach the front of the rocket after it reaches the back of the rocket.
The greenhouse effect: heat trapping by earth's atmosphere.
Ancient Giant Virus
Cutaway Model of Earth
Tides on Earth
After excavation, recovered remains are screened to ensure that even tiny fragments are retrieved an
Formation of the Early Earth