Fact 1: The moon revolving around the Earth causes the phases of the moon.

Fact 2: Tides also calculates the moon phases and the tide's coefficients.

Given the two facts above, answer the question "What can the moon revolving around the earth be used to calculate?" with the following options: 
- seasons
 - pain
 - magnetism
 - tides
 - voltage
 - Length
 - weight
 - motion


 

    tides     