Why human is mortal
Cells like ours have several "bugs" that cause cells to deteriorate over time.
The cell cannot last forever. Bacterial costs do not have these costs. their DNA is organized like a ring, and a ring is a structure that does not wear out in any way, it works the same all the time, more or less.
Our DNA is very large, due to the fact that we are complex, our cells are much more complex than bacterial ones, and the metabolism is rather cumbersome. There are a lot of proteins, there are a lot of genes for them.
DNA is, as it were, laid down with a ruler, well, it is wound around proteins many times, compactly packed, but in principle it is a linear molecule. She has ends. And these ends make cells critically vulnerable, they are called telomeres. With each cell division, they are slightly shortened.
If about a bacterial cell, when it shared, it is impossible to say which was the first and which was the second, they are two the same, they both appeared at 15:45, they are two simultaneous cells, then about the cells of our body you can always say: this is the mother's cell , but this is a daughter one.
The daughter is younger, her telomeres are longer.
And there is such a Hayflick Limit, the so-called - how many times one cell can share at all. We have body cells that do not divide, for example, nerve cells, because they need to store memory.
But many cells in our body are able to divide. These are epithelial cells, cells of connective tissues, they are renewed.
But for them there are certain limits, they cannot do this forever. They have 50 - 54 divisions. It is not very much in fact, within the framework of our body, in which there are billions of cells. Trillions of red blood cells alone, 87 billion neurons, that is, everything is very cumbersome. And all this, I want to note, is a one-off construction, albeit a very complex one, in order to transfer your genes further, in order for the germ cells to become a new person.
Sounds pretty irrational, bacteria. In this sense, they look much more ergonomic - in the sense of the most efficient transfer of genes further.
About what types of death are in living organisms
In living nature, we rarely meet natural death, that is, for an animal or plant to survive until it.
In this sense, death is a kind of human achievement, it is that we sometimes live to the point of natural death.
True, there is death from cancer. By the way, it can still be considered natural, albeit with some stretch, because you can poke your finger into a tumor and say: "Here is a killer!"
Plants have a very long lifespan. There are sequoias that live for several thousand years. And in principle, again, they are affected by either some kind of disease, or something happens to the soil, the water supply becomes worse, or something else, and the tree may dry out. That is, the tree is gigantic and it has nothing to eat and it stands dead.
But in plants, everything is generally quite ridiculously arranged, they have never been determined whether they are alive or dead. They have tissues, both living and dead, and they are fine. Actually, the wood that we touch has a lot of dead cells in it. And the plant feels good, although at the same time it has half of its body - or even more is dead. In general, this is not a problem for them.
And the plants die with pleasure for a while. Until a certain moment, a seed is a dead structure.
Recently, from some Egyptian pyramid, seeds were taken out, which are four thousand years old. They were dead, they lay in a vessel for four thousand years. They were planted and they sprouted! And soon we will have dates the same as the ancient Egyptian pharaohs ate.
That is, the plants have not yet decided whether they are alive or dead. Everything varies with them.
In animals, everything is simpler, everything is clear there, when the animal is dead, it does not "roll back". You are alive while you can and dead when you can no longer pull.
About transhumanism and life outside the body
If you abandon the idea of the body - because “I am my body”, and come to the conclusion that “I am my brain”, my memories, experiences, plans, dreams, achievements and so on, then really: for the brain already there are different options.
Already now there are different neurointerfaces, when the brain is sewn to a mechanical arm and a person uses it quite effectively.
And in this sense, I agree that the forecast that over time it will be possible to put the brain in a robot, to sew a huge number of connections to it, is correct. But the question is, how will a person feel at the same time?
We are not aware of this, but we have a huge number of receptors and we constantly receive a huge amount of information from the world.
All the time we collect the visual picture with our eyes, we hear the crying of a child or some other sounds, we feel our position. That is, the nervous system is not just brains. Nerve endings that reach different receptors are also an important part of the nervous system, and this is what allows us to focus on the external environment.
Whether the robot will have the ability to sense the outside world is unclear. Rather, the brain will feel quite isolated.
That is, of course, the brain will still be alive and it still contains the memory of its past, this is so, but how it will feel is incomprehensible.
It is quite possible that it will look like some kind of torture, for whom - you have consciousness and is working, but no impulses come. Therefore, I'm not sure it will be very optimistic right away. Just like the brains in the jar. Generally speaking, an animated head is an unlikely scenario, unlike a robot in my opinion.
“Brains in a jar” will remember the whole body, they will remember that there are arms, legs, and so on below the head. That is, most likely, it will be associated with very severe phantom pain. Even the loss of a finger is painful for a very long time, and what can I say about the whole body. What will such a head be capable of, except for this terrible phantom pain from the fact that it does not feel what it should "reach" for?
But the concept that we are our brains is not very close to me. The concept that we are generally a body is close to me. Because the accumulated experience, of course, is almost entirely in the nervous system, but many of the motor skills that I have, like karate or cycling and snowboarding, are body skills too. They are remembered, of course, by the brain, but the muscles are trained for this, they have the experience of this performance.
The entire program featuring Yelena Sudarikova can be viewed here.