According to the scientific knowledge we have today, humans cannot live forever. Aging is a natural process in all multicellular organisms, and humans are no exception. As we get older, our cells gradually deteriorate and lose their ability to function properly. This process eventually leads to death.

There are several theories that attempt to explain why we age. One popular theory is the "free radical theory" which states that aging is caused by the damage to cells caused by free radicals, which are unstable molecules that can damage DNA, proteins, and other molecules in the body. Another theory is the "telomere theory" which states that aging is caused by the shortening of telomeres, which are protective caps at the ends of chromosomes. As we get older, our telomeres get shorter, and eventually the cells can no longer divide and die.

While there is currently no way to stop or reverse the aging process, there are many things we can do to promote healthy aging and extend our lifespans. These include eating a healthy diet, exercising regularly, getting enough sleep, and avoiding stress.