I ran the entire text of this article through XKCD&#x27;s simple writer tool (<a href="http:&#x2F;&#x2F;xkcd.com&#x2F;simplewriter&#x2F;" rel="nofollow">http:&#x2F;&#x2F;xkcd.com&#x2F;simplewriter&#x2F;</a>) and it pointed out that &quot;movement&quot; is not among the 1000 most common English words. The word &quot;movement&quot; is used exactly once in this article.<p>So I guess this should be Theory of relativity explained using the 1000 most common English words and one additional word :)