relativity theory

NOUN
17 LETTERS · STARTS WITH R

relativity theory is a valid 17-letter word worth 28 points in Scrabble and 27 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
R1E1L1A1T1I1V4I1T1Y4T1H4E1O1R1Y4
1 + 1 + 1 + 1 + 1 + 1 + 4 + 1 + 1 + 4 + 0 + 1 + 4 + 1 + 1 + 1 + 4 =28 PTS
DOUBLE WORD → 56TRIPLE WORD → 84
MEANING

What does relativity theory mean?