What is death? What do we see?

Let's think about this:

Up quarks and down quarks make protons and neutrons. Together with electrons they build an atom. Atoms are building blocks of molecules, in which is building blocks of proteins. In which help build an organelle. There, creates a cell. In which are the building blocks of tissues. In, which are building blocks of organs. Organs make and organ system, in which makes an organism. You are at that stage of complexity.

Death is when the functionality in one of these and lower levels begin to fail and loses the battle against equilibrium. 

A cell undergoes death if the organelles begin to fail. You won't die, unless if you are a single cell. However, you die if your organs (that are akin to organelles in your cells), begin to fail. So why the difference?

The problem here is that in trying to survive life, this system is robust enough through time. Cells divide and your nervous system will try and avoid death. We don't think about it, for our brains are wired so that we don't think about death to avoid it. However, everything is different. We now have a layer on top, called civilization. Now we can think about it. Thats how religion forms. Death still happens, yet the civilization is robust enough to keep going. 

So, what this mean? Let's go back to the cell analogy.

A malfunction of a protein if severe enough can break the organelles. There the cell will die or turn into cancer. If a cell is cancerous, it can destroy the tissue and by proxy the organs. If an organ dies, then the system relating to the organ is damaged. There, if the system dies, the organism dies.

It's akin to a tower. Parts will break and fall, yet there are workers to avoid the collapse of the tower. However, the tower isn't sentient. So, by that logic we are not sentient, but why are we sentient?

Our nervous system, the brain helps with having sentience. Our brains are the reason why we exist. The body will die without the brain. What happens there after?

When the person dies, the lower structures are also going to fall apart. If you die, first, the organ system will fall apart. There cells, won't have any food. In which the atomic realm will fall apart. There your cells and by proxy your brain will die. You are not conscious. Death is noting. When you die you don't exist. So, death is akin to losing consciousness permanently. You just see nothing. As your body continues to fall apart in realms.

Civilization is part of an ecosystem. Ecosystem build biomes. In which earth is built in which is a planet. There planets build solar systems. solar systems build galaxies. There Galaxies build cluster. Cluster build Superclusters. Which is the universe is built upon. Death by this definition extends to all. At some point there is nothing left. No black, just void. Nothing Less, Nothing More.