
20211210: 2021 End of Year AMA!
 00:02: ... there a required a type of energy that doesn't exist and that is uh a negative energy density so as far as we know energy can only be positive um in you know ...


20210421: The NEW Warp Drive Possibilities
 04:48: We can summarize this by saying that it requires a negative energy density, which should be impossible except perhaps on the tiniest, quantum scales.


20200422: Will Wormholes Allow Fast Interstellar Travel?
 08:42: ... common way to think of exotic matter is anything with negative energy density. Something with negative mass could produce the required negative ...
 09:44: ... existing in that region. The gap between the plates will then have a negative energy density relative to surroundings. Unfortunately, the Casimir effect is very, ...
 10:15: ... the wormhole would have to pass through this region of extremely high negative energy density, which probably wouldn’t be healthy. Matt Visser, who literally wrote the ...


20191021: Is Time Travel Impossible?
 05:37: Really what we need to open the wormhole is a negative energy density.


20190109: Are Dark Matter And Dark Energy The Same?
 08:02: Well a constant NEGATIVE energy density – like the one proposed by Farnes, gives a negative cosmological constant.
 10:16: Does a universe with a constant negative energy density fit the observations?
 11:00: ... an age for his universe of 13.8 billion years assuming a very low negative energy density, but that really just corresponds to the very first straight part in the ...


20151028: Is The Alcubierre Warp Drive Possible?
 03:24: ... do this for the warp field, you find that you need to produce a ring of negative energy density in a band around the ship to produce the right warp ...
 06:18: Now, this would be a field created by positive, not negative, energy density.
