4 ms·
I'm not sure about negative mass, but negative energy density can be achieved with the Casimir effect. https://en.wikipedia.org/wiki/Casimir_effect https://en.
by axblount 3y ago
I'm not sure about negative mass, but negative energy density can be achieved with the Casimir effect.
https://en.wikipedia.org/wiki/Casimir_effect https://en.wikipedia.org/wiki/Casimir_effect
- sandworm101 3y agoMy understanding is that this is not really negative energy, rather only energy lower than the quantum background. There is still an absolute zero energy as a hard floor, akin to how negative temperatures just mean lower than an agreed norm and one cannot have true negative temperature.
- _Microft 3y agoThere are actual negative temperatures (Kelvin scale!). One example are lasers in which a population inversion facilitates lasing. https://en.wikipedia.org/wiki/Laser https://en.wikipedia.org/wiki/Laser https://en.wikipedia.org/wiki/Population_inversion https://en.wikipedia.org/wiki/Population_inversion https://en.wikipedia.org/wiki/Negative_temperature#Lasers https://en.wikipedia.org/wiki/Negative_temperature#Lasers (Negative thermodynamic temperature has very unintuitive effects in general, so maybe read all of the last article to get an idea)