The quest for immortality has attracted, motivated, and moved humanity since the beginning. We have always wanted to escape the inevitable, discourage the undaunted, avoid the inevitable, and live forever. We have dreamed of eternal life, created eternal entities, books, poems, art - we, as a species, are obsessed. But is it really possible to live forever? How can we be immortal? Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay The first path usually taken when trying to answer this question is the biological route. What is immortality, from a biological point of view? Immortality is living forever, avoiding death. It follows then that if we want to be immortal we must first escape death itself. So, how can we avoid death? Why do we die? To answer this question it is useful to think of the body as a machine. As it performs its normal daily functions, it suffers from wear and tear, as any machine would. The body has mechanisms to deal with this damage, but over time they become less effective. As a result, our muscles weaken, our bones break, we get sick more often, and, eventually, our bodies can no longer keep going and we die. So the answer to living forever lies in somehow extending the life of these repair mechanisms and halting the effects of aging. There are many potential ways to slow aging. Senescent cells are zombie cells that form after a cell has divided and its chromosomes no longer have telomeres (to protect the genetic material). These cells don't die, they build up inside the body and have been linked to a number of diseases that accompany old age, such as diabetes and kidney failure. There are numerous studies looking for ways to kill these senescent cells, as this would theoretically extend the lives of humans, perhaps indefinitely. Studies involving older mice that had their senescent cells killed became much healthier; some even regrow their lost hair! There is a lot of research in this field and human trials are expected to begin soon. NAD+ is a coenzyme that tells our cells to take care of themselves. As we age, there are fewer and fewer of them in our body. Since in our country the coenzyme does not cross cell walls, there are currently many studies examining other enzymes that can enter cells and then be transformed into NAD+ within the cell itself. This would also slow down aging and allow us to live longer, perhaps even forever. Another field of research concerning the extension of lifespan is that of stem cells. Stem cells are cells with the potential to develop into any other cells found in some parts of the body. As we age, these cells become increasingly scarce. In mice, scientists observed that as they aged, stem cells declined and the mice began to develop diseases. The scientist then took stem cells from young mice and injected them directly into the hypothalamus of older mice. The new stem cells were found to reinvigorate the mice. After four months, their brains and muscles functioned better than those left untreated and they lived longer. What all of this tells us is that while there is no silver bullet to stop aging, we can potentially eliminate senescent cells, fill the space with fresh new stem cells, all by regulating the metabolism of these cells with NAD+..