Man has never liked the idea of getting old, nor has he ever liked knowing the fact that his life would end at around a predictable age. It is no wonder that there have always been stories about people who regained their youth or remained immortal. Poets in the Middle Ages wrote about a fountain of youth in which one could bathe in and become young. At around the same time, another group of men called alchemists took over the dream of eternal youth and made it one of their greatest projects next to transforming lead into gold. These alchemists, of course, failed.

As scientific knowledge grew, the old dream of eternal youth seemed less and less likely to be realized. However, the fascination of staying young and extending life has become this generation's worldwide obsession. Modern science has responded to this need to understand aging by creating a relatively new branch of research called gerontology. The name comes from the Greek word "geron" which means "old man". The aim of gerontology is to collect as much knowledge as possible about aging in man and animals. Researchers who work in this field are dedicated to finding out how and why aging happens and how we can hopefully slow it down.

There is still no clear-cut reason why men and animals lose their vitality with age. There seem to be three main possibilities. First, we age because our cells die off and can no longer be replaced. Animals that do not age are mostly of the kind that can replace all their cells. While man and other vertebrates have cells that they can renew all the time like blood cells and skin cells, the are unable to renew important cells like those in the brain. We keep using the same brain cells all of our lives, but they get fewer as we get older. Thus aging may simply be explained by a loss of cells or structures that we are not built to renew.

A second possibility that can explain aging has to do with cell formation. Perhaps the new cells formed by an old man are different from and not as good as, new cells formed by a baby. A third possibility is that aging is more complicated than any of these explanations. Aging may be the result of chemical changes and developments in our bodies that eventually damage us in some way and make us grow old.

These are only three of the theories that have been suggested to explain aging and no scientist knows for certain which, if any of them, is right. However, there have been important facts that have already been discovered along the way. It is interesting to note that changes in aging animals and the changes brought about by radiation are quite similar. This raises the possibility that if we could develop drugs to protect us against radiation, they could also protect us from aging. The other discovery is that aging can be slowed down. Many animals have shorter lives if they are fed heavily and are made to grow as fast as possible. These animals live longer if they eat less and grow more slowly.

Gerontologists are usually asked if they think it's a good idea to make people live longer. Obviously it would raise many population problems, but if we lived longer we could do more work in a lifetime and carry out bigger and better plans. The possibility of lengthening life does raise difficult questions. But at the moment we don't know for certain if we can ever hope to change or stop aging. It seemed reasonable to think that scientists might succeed someday, but as to how soon, we may never live to find out.