science

observation, concepts, based on perspective

Describe the position from which an observation is made 

Observation from above or aerial view

The distance above the earth's surface

The motion of the earth spinning on it's axis

Earth's eliptical rotation

When day and night have equal amount of hours, occurs in March and September (spring and fall)

Imaginary point

When there is more hours in either the day or the night, June 21st or December 21st