John M wrote:

Jesse and George: the cobbler apprentice speaketh: you, mathematically high-minded savants look for a primitive realization of 'negative mass' etc, while you find it natural to use negative numbers. If I was 185lb last week and now 180 lb, then I have 5 lb in negative. Of course I cannot physically identify the 'missing mass', but mathematically it exists and I can calculate with it, speak about it, think about it: it 'exists'.

`Well, you're free to define "negative mass" however you like, of course--but`

`this is not how physicists would use the term. When you plug negative values`

`of mass or energy into various physics equations it leads to weird`

`consequences that we don't see in everyday life, such as the fact that`

`negative-mass objects would be gravitationally repelled by positive-mass`

`objects, rather than attracted to them. Likewise, in general relativity only`

`negative mass/energy would be able to hold open a wormhole, there'd be no`

`way to arrange positive mass/energy to do that.`

Jesse