Electrons and photons seem to behave as half-way imaginary or invisible, and halfway material. They can disappear and reappear, even elsewhere, without intervening communication. Actually that is quite like our experiential reality. An emotion, and some accompanying action. But the root of everything is actually invisible laws, principles, and emotion.
Heart is a kind of emotion.
It is very personal, not at all impersonal or cold or detached. It is, on the other hand, very involved with you and me and our feelings and doings. In other words, the universe cares about us. Heart is the foundation of the universe. So that is one task of the Unified Field Theory.