On Fri, 4 Mar 2016 07:20 am, alister wrote: > On Thu, 03 Mar 2016 11:03:55 -0700, Ian Kelly wrote:
>> Antimatter has positive mass. > > Are you sure? > mix 1 atom of hydrogen + 1 of anti hydrogen & you end up with 0 mass (+ > LOTTS of energy) > > To be honest it is all over my head It's good to be honest :-) Yes, anti-matter has positive mass. There was still some tiny lingering doubt up until (by memory) 20 years ago, at which time physicists actually managed to make sufficient anti-matter that they could assemble it into slow-moving atoms and observe the effect of gravity on it, and sure enough, anti-matter falls due to gravity the same as regular matter. (There wasn't really any serious doubt about this, since you can pull and push anti-matter with electric and magnetic fields and it behaves exactly the same way as regular matter. But if gravity had turned out to be different, it would have been a truly paradigm-changing discovery.) As far as the reaction of matter and anti-matter, we've known for about a century that mass and energy are related and freely convertible from one to the other. That's the famous equation by Einstein: E = m*c**2. Even tiny amounts of energy (say, the light and heat released from a burning match) involve a correspondingly tiny reduction in mass. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
