Particle nature

This equation is often taken to mean that matter and energy are two sides of the same coin. . . . 

One of the simplest examples of this is electron-positron annihilation. " 

CREATING MATTER FROM LIGHT

If you can convert matter entirely into energy, you should be able to do the reverse. It’s known as the Breit–Wheeler process and involves colliding two photons to create an electron-positron pair.

In 1905, Einstein wrote a paper that was changed Particle Physics forever.

Einstein,  E = mc^2

In 1927, Dirac clarified Einstein’s idea as dualistic particle: E=±MC²      

 (matter – antimatter are two sides of the same coin)