It is still an open question as to whether anti-matter falls up or down - e.g. negative gravitational mass.<p>The ALPHA experiment is using anti-hydrogen at CERN to find out.<p><a href="https://www.nature.com/articles/ncomms2787" rel="nofollow">https://www.nature.com/articles/ncomms2787</a><p>So far they have made some, but not enough to rule out experimental error.
Is this the same story as posted here:<p><a href="https://news.ycombinator.com/item?id=14147264" rel="nofollow">https://news.ycombinator.com/item?id=14147264</a> (0 comments)<p>Or here: <a href="https://news.ycombinator.com/item?id=14135929" rel="nofollow">https://news.ycombinator.com/item?id=14135929</a> (0 comments)<p>Or here: <a href="https://news.ycombinator.com/item?id=14131417" rel="nofollow">https://news.ycombinator.com/item?id=14131417</a> (1 comment)<p>Or here: <a href="https://news.ycombinator.com/item?id=14130945" rel="nofollow">https://news.ycombinator.com/item?id=14130945</a> (2 comments)<p>Or here: <a href="https://news.ycombinator.com/item?id=14093860" rel="nofollow">https://news.ycombinator.com/item?id=14093860</a> (40 comments)<p>If it's the same as that last one, the comments there are pretty scathing about the whole thing, so some scepticism advised.
I think I used the term "negative mass" on a physics pop quiz once. Had something to do with matter-antimatter reactions. Appears I was 23 years ahead of my time.