There are all sorts of conservation laws in the Universe: for energy, momentum, charge, and more. Many properties of all physical systems are conserved: where things cannot be created or destroyed.
We’ve learned how to create matter under specific, explicit conditions: by colliding two quanta together at high enough energies so that equal amounts of matter and antimatter can emerge, so long as E = mc² allows it to happen.
For the first time, we’ve managed to create particles without any collisions or precursor particles at all: through strong electromagnetic fields and the Schwinger effect. Here’s how.