So we might need some anti-matter to get enough energy to make singularities for our time machine.
Why do we need antimatter in a "normal" matter universe to make a time machine? I've heard theories that require exotic matter, but exotic matter isn't anti-matter.
Over the past 70 years we haven't been able to produce anything even close to a gram of anti-matter in the totality of all of mankind's reactors and colliders combined. In fact, we can virtually count the individual anti-particles one-at-a-time that we've been able to produce since the 1930's.
We live in a photonic universe where the natural laws of physics dictate a slight, but significant to us, preference for "normal" matter over antimatter. We see this in the evidence. Matter, in the form of subatomic particles, is the anomaly while photons are the norm. Matter is an otherwise slight bit of pollution in a universe mostly comprised of photonic energy. Antimatter in such a universe is unstable, highly reactive to any other form of matter and almost impossible to produce in anything but single particles.
An antimatter universe would look just about the same as our universe - mostly photonic with a slight pollution of antimatter worlds, stars and interstellar/galactic dust. People who would populate such a universe would call antimatter matter and refer to a universe such as ours as being made of antimatter.
BTW: Simply switching the signs in a simplistic matter-antimatter log of particle decay doesn't mean that such reactions actually occur. Making that assumption also assumes that the physical laws of the universe are perfectly symmetrical. We know that they aren't. If they were we wouldn't be here (unless we were photonic energy without matter). A universe where the laws of physics are perfectly symmetrical implies that all matter and antimatter was created equally and that after all reactions were completed (within about 10^-37 seconds after the Big Bang) nothing remained but photons.
The test of the theory isn't in the math alone. The proof is in experiment. The main three symmetries, C, P & T (charge, parity and time reversal) are well documented not to be symmetric at the quantum scale even though they appear on larger scales to be so.
