Negative mass??  

shywolf
Member

NegativeMass

Instead of trying to undo the biting of the old apple/I bite a new one instead/And with a toothless grin/Become a Dionysian among Christians.

ReplyQuote
Posted : April 21, 2017 2:45 am
e-griff
Member

So, what do you think? 

ReplyQuote
Posted : April 21, 2017 6:52 am
shywolf
Member

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.)

Your thoughts?

Instead of trying to undo the biting of the old apple/I bite a new one instead/And with a toothless grin/Become a Dionysian among Christians.

ReplyQuote
Posted : April 21, 2017 11:09 pm
e-griff
Member

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. 

ReplyQuote
Posted : April 23, 2017 12:51 pm
sirat
Member

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:

https://iai.tv/video/gravity?utm_source=Institute+of+Art+and+Ideas&utm_campaign=f3d46ee707-Gravity+IAI+TV+Release_2017_04_18&utm_medium=email&utm_term=0_33593fe9fa-f3d46ee707-47010841

ReplyQuote
Posted : April 23, 2017 4:41 pm
shywolf
Member

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.

Instead of trying to undo the biting of the old apple/I bite a new one instead/And with a toothless grin/Become a Dionysian among Christians.

ReplyQuote
Posted : April 24, 2017 4:48 am
  
Working

Please Login or Register