If I say from a physics standpoint : It seems as our energy is redistributed after we die.
We know that 'Energy cannot be created or destroyed. It simply changes states'
We get energy through the consumption of food, which gives us chemical energy. That chemical energy is then transformed into kinetic energy that is ultimately used to power our muscles.
In death, your atoms become repurposed. Those atoms and that energy, which originated during the Big Bang, will always be around. Therefore, your “light,” that is, the essence of your energy — not to be confused with your thoughts or actual consciousness — will continue to echo throughout space until the end of time.