So-- Please--- to clear up a squabble here at home. ....

We have just been to see Star Trek (bear with me here all you scientists) and I asked if red matter was true! Silly me.. but it led to a schism of the group into those who believe dark matter is 'out there' and those ( well one really!) who doesn't. I have been reading these posts and am amazed that something a lay person like me takes for granted may not be actually real. Is it?