So, what do you think?
It does have a symmetry to it, like so many other symmetries in physics such as matter/anti-matter, positive/negative charge, etc., but it's so counterintuitive, that I can't wrap my head around it. Imagine pushing a ball made of negative mass, and instead of accelerating away from you, it accelerates toward you! However, this is certainly no weirder than quantum mechanics in which a particle can have two diametrically opposite properties at the same time until observed (thus, Schrödinger's famous satirical gedankenexperiment involving his poor cat), among many other examples.
I can see the implications of negative mass within the context of Newton's famous F=ma equation, I'm wondering what they are within the context of Einstein's famous E=mc^2 equation. It would predict negative energy, which is connected to wormholes and would allow 'time travel' as well as faster than light space travel. Again, I find it hard to wrap my head around those exotic concepts. I'm a diehard the-speed-of-light-must-be-a-universal-limit fan. The reversal of cause and effect engendered by 'time travel' is just too upsetting to my view of the universe. (I must be getting old. ;-) )
(We must bear in mind that all this is just hypothesis at this point. They've only created a fluid that behaves as if it were made of negative mass.)
Generally same as yours. It's not just counter intuitive it's counter the whole of mechanics. I think your last observation is valid.... A fluid that behaves as if....
We shall see.
Unfortunately I don't think this field is particularly simple, and 'intuition' isn't much use here. This is a nice discussion of the whole subject of universal gravitation:
That was indeed a very interesting discussion, David (although it was rudely halted once I reached my monthly video limit). I particularly enjoyed the contrast between the string theorist's view of gravity, with emphasis on general relativity's problem of not accounting for the speed of galactic rotation which requires the postulation of dark matter to solve, and that of the staunchly GTR oriented theoretical physicist. I think the string theorist articulated the two approaches quite well: is gravity a fundamental force we need to assume right from the beginning and then describe it, or is it possible to derive it first without assuming it? He sides with the latter (string theorists would love to arrive at a theory of everything through the derivation from fundamental entities called strings). Fascinating. Needless to say, I joined the site and will view the rest of the video later. Thanks for sharing.
I thought it was a particularly good one. The material isn't easy, you can't really make it simple, but I think they did a very good job.
My science writer hero of the moment (along with a few million others) is Carlo Rovelli. He's best known for Seven Brief Lessons in Physics (only 78 pages long) which is great, and apparently sold more copies than Fifty Shades of Grey in his native Italy, but didn't really tell me anything new, but his more recent Reality Is Not What It Seems is brilliant IMO, particularly the last three or four chapters. I had the book with me on my last long holiday and kept re-reading those. I can't really summarise them but you get a real grasp of how his theory of Loop Quantum Gravity works and how much it seems to explain. I've reviewed it in the coming Gold Dust. Can't recommend it too highly.