Final answer:
The slowing of materials and particles after an explosion, such as in a supernova, leads to the transfer of energy to surrounding matter as shock waves, which emit radiation at longer wavelengths resulting in an 'afterglow' that can be observed over time.
Step-by-step explanation:
After the explosion materials and particles slowed down, the high-speed particles transferred their energy to the surrounding matter in the form of a shock wave. The subsequent radiation emission of longer wavelengths such as X-rays, visible light, and radio waves created an 'afterglow', where the glow's wavelength increases as the blast loses energy. This is a phenomenon observed in events such as supernovae when the collapse of a star's core rebounds and results in a shock wave that blows the star apart with immense energy.
The electromagnetic forces are significant here because they help bind electrons to the nucleus. In instances of extreme densities, as found in the collapse of a stellar core, these forces interact with matter to produce various types of radiation, including X-rays and gamma rays, which we can observe as different stages of the explosion or collapse evolve over time.