Antimatter is a misnomer. Antimatter is material with no, or negative, mass. Antimatter would be better understood if referred to as 'antimass'. I think that we will learn that the material with mass and the material without mass, either balance out, or explain the economy of the weak force.
Actually, antimatter has mass, it just created with subatomic particles that have the opposite charge of "normal" particles. So instead of protons and electrons, antimatter is made up of anti-protons and positrons. (see https://www.livescience.com/32387-what-is-antimatter.html)
The concept of negative mass is intriguing. Both general relativity and quantum mechanics have subtleties embedded in them that could be describe as negative mass. There's actually been a bit of news recently about scientists creating negative mass "stuff" or at least demonstrating that this "stuff" has the illusion of negative mass. So yeah, it's a pretty neat fridge area of science that might just be grounded in reality.
Mathematically at least, an electron moving in a wire has negative mass. But these things get complicated. There is also negative temperature - negative Kelvin that is! How can you have less than no motion?!?! But really it is more a mathematical beast from thermodynamics. Anti-Catholics have negative mass.
The recent news was that negative mass could exist. It isn't disallowed by General Relativity. https://medium.com/the-physics-arxi...e-mass-can-exist-in-our-universe-250a980320a7 Something funny that I noticed. They used the equations for a fluid to help obtain a solution of General Relativity, Einstein's son was known for his work in fluid dynamics. https://en.wikipedia.org/wiki/Hans_Albert_Einstein
This all reminds me of a favorite quote There's a solution of the equations of general relativity called the Aichelburg-Saxl solution, which describes massless black holes moving at the speed of light. There's no experimental evidence that these actually exist, but they're fun to think about nonetheless, since you can use the equations of general relativity to figure out what they would do if they did. – Dr. John Baez
Actually, believe it or not, so far no one has ever carried out an experiment to see if anti-matter falls downward in earth's gravity. Pretty much the consensus of almost all scientists in the field is that they are sure it would, but they do not really know this for certain. Although it may sound strange to most of you, actually carrying out the experiment has a few technical difficulties, mainly because the force of gravity is so weak in comparison to other forces acting on these tiny particles. http://cerncourier.com/cws/article/cern/67455 https://www.livescience.com/29164-antimatter-antigravity-fall-up.html
It is a manifestation of the energy distribution from Quantum Mechanics. It has been a many years ago but IIRC, when you write the equation for the particle, the total energy is a function of the mass energy, the electric field energy of the particle itself, and the potential energy of the electric field. As the electron moves along the lattice, the energy is all found in the fields, and then some, and the mass goes negative. Energy is conserved but manifests differently. It is fair to say that the electron is acting like a wave as it travels.
AFAIK there is no negative on the Kelvin temperature scale, only Absolute Zero. I prefer the Celsius temperature scale over Fahrenheit because water freezes at Zero rather than .32° Fahrenheit, the Kelvin temperature scale obviously being better suited to Laboratory work involving Cryogenics.
So now you've learned something. The definition of temperature gets complicated at the atomic level. This is not something that can be measured, only calculated. IIRC, it has to do with a population inversion of atomic states, where you have atoms in a reduced energy state, that would normally not occur. About the only classes that are as bad as the 400 level Quantum Mechanics series, for physics seniors, is the 400 level Thermodynamics series.
I have used the standard of molecular activity as temperatures affect, and super conduction becomes possible at close to absolute Zero.
That gets complicated What kind of activity? There are low temperature superconductors but only certain materials. Scientists in Fairbanks Alaska discovered a material that is superconductive at room temperature. Then they realized room temperature was near absolute zero.
For any system of molecules or particles, in order to quantify temperature, one needs to consider the degrees of freedom. This not only includes the 3 directions of motion - translational motion - but also the number of axes of rotation the molecules have - rotational motion, and vibrations. That depends on the structure of the molecules. Degrees of freedom of gas molecules[edit] https://en.wikipedia.org/wiki/Degrees_of_freedom_(physics_and_chemistry) But here is the real kicker - that is only a classical model that yields to a much more complex Quantum Mechanical model for temperature