My physics teacher says that centripetal force is caused by gravity. I'm not entirely sure how this works? How can force cause another in space (ie where there's nothing). 

My astronomy teacher says that gravity is (note: not like) a 3D blanket and when you put mass on it, the mass causes a dip/dent in the blanket and so if you put another object with less mass it will roll down the dip onto the bigger mass. Is this true and is this what causes the centripetal force. 


Question: Highlight Search (hls) matches of multiple search terms with different colors
Answer: With the 'hlsearch' option, no, they all have to appear in the same color.  However, you can use the :match feature instead.  For example:

:match TODO /var1/
:2match Type /var2/
:3match Comment /var3/


This, of course, is more cumbersome than straight 'hlsearch' matching, because it requires you to know what syntax coloring groups are already defined, or define your own.  Also, you can only do up to three separate matches this way.  If you need more, you'll have to use matchadd() instead.

See:

:help :match
:help :highlight
:help highlight-groups
:help matchadd()