Hi! Nice piece of text! I have only a little comment, on one paragraph with which I disagree.

One of the major discoveries of the twentieth century was Einstein’s realization that energy and mass are equivalent: mass has energy and energy has mass. In the right circumstances, they are interchangeable. Any energy change means a mass change.

This is not totally correct. It is better to say that mass is just a form of energy, like kinetic or potential energy are. It is misleading (and actually wrong) to say that energy has mass.

For instance, a photon of 100 GeV has a lot of energy. It is still a massless particle. If our photon gets more energy, it will still stay massless.

I hope this clarifies. Please consider updating your post.