To explain the retrograde motion of planets, Ptolemy introduced the concept of ________.
Fill in the blank(s) with the appropriate word(s).
epicycles
You might also like to view...
A certain radioactive isotope placed near a Geiger counter registers 120 counts per minute. If the half-life of the isotope is one day, what will be the count rate at the end of four days?
A) 30 counts/min B) 15 counts/min C) 10 counts/min D) 7.5 counts/min E) 5 counts/min
Two thin layers of material with different indices of refraction are coated on a glass plate. The outer first material has n1 = 1.461, the inner second material has n2 = 1.544, and the glass has nglass = 1.62 . If light is incident from air on the first layer, what is the phase change for light that reflects from the glass?
a. 180° b. 0° c. 360° d. 540° e. 720°
What is the probability of rolling either a 7 or 11 on a single roll of a pair of dice?
a. 1/6 b. 2/9 c. 3/8 d. 1/3 e. 1/2
What is a stalactite and how does it form?
What will be an ideal response?