In life, the human body comprises matter and energy. That energy is both electrical (impulses and signals) and chemical (reactions). The same can be said about plants, which are powered by photosynthesis, a process that allows them to generate energy from sunlight.
But what if instead of looking at death from a biological perspective, we examine it from a physics standpoint? More specifically, let’s look at how our energy is redistributed after we die.
Even though it’s an inexorable part of life, for many people, death — or at least the thought of ceasing to exist forever — can be a scary thing. The disturbing things that happen to the body during decomposition — the process by which cells and tissues begin to break down post mortem — are bad enough.
When we die, our energy is redistributed throughout the universe according to the law of conservation of energy. While this should not be confused with our consciousness living forever, our energy continuing after we’re gone could make death a less scary prospect.
The process of energy generation is much more complex in humans, though. Remarkably, at any given moment, roughly 20 watts of energy course through your body — enough to power a light bulb — and this energy is acquired in a plethora of ways. Mostly, we get it 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.
As we know through thermodynamics, energy cannot be destroyed. It simply changes states. The total amount of energy in an isolated system does not, and cannot, change. And thanks to Einstein, we also know that matter and energy are two rungs on the same ladder.
The universe as a whole is closed. However, human bodies (and other ecosystems) are not closed — they’re open systems. We exchange energy with our surroundings. We can gain energy (again, through chemical processes), and we can lose it (by expelling waste or emitting heat).
In death, the collection of atoms of which you are composed (a universe within the universe) are repurposed. Those atoms and that energy, which originated during the creation of the Universe, will always be around. Therefore, your “light,” that is, the essence of your energy — not to be confused with your actual consciousness — will continue to echo throughout space until the end of time.