The electric and/or magnetic patch does not move in a straight line. It moves along the surface of the sphere, and therefore accelerates as it does so. This is the key. It is the accelerating patch(es) of electric and/or magnetic fields on the surface of a ball-of-light that induces the balls-of-light that peel away from the surface.
Weak patches of would not have enough energy to create a ball-of-light, but would still create a photon.
Relatively weak patches induce relatively small elementary particles. For example, the electric and magnetic patches on the surface of the core of normal star are relatively harmonic and weak. Therefore, they induce relatively small elementary particles such as electrons or protons.
Stronger patches will induce larger elementary particles. For example, the electric and magnetic patches on the surface of the core of galaxy are much stronger and would have the power to induce the core of a star! But even here, there is a range. Relatively harmonic galactic cores induce small stars in spherical patterns -- see elliptical galaxies. Relatively nonharmonic galactic cores induce larger cores of stars -- see spiral galaxies.
In general, the less harmonic a decaying ball-of-light is, the greater in magnitude would be the moving patches of electric and magnetic, and the greater in magnitude would be induced particles that peal away from the core of the decaying particle.
One implication of this is, we want our star -- the sun -- to remain stable. If there is the possibility of something colliding with the sun and making it unstable, then we should do everything in our power to prevent it -- prevention -- or protect ourselves from the result -- protection. (See also Extinctions.)