Immortality

Man is the longest living mammal on earth
In the Book of Genesis Chapter 6 verse 3 we read "And God said: My spirit shall not always dwell in man, since he is of flesh; yet the number of his days shall be one hundred and twenty years"
Gerontologists who are scientists that study the causes and effects of aging and the means of controlling this biological process, accept the theologian's estimate of 120 for the maximum life span. One significant difference between the 2 groups relates to achieving immortality.
For theologians with their cathedrals, pyramids, mosques, synagogues, temples or other places of worship the solution is simple. They just convince their followers with the compromise that you must first die in order to achieve "afterlife everlasting" or immortality
To some gerontologists, the requirement of death on earth is too high a price to pay. Some have even become skeptical of this theological guarantee. So in their houses of worship called laboratories rather than preach they feel the solution lies in experiments designed to extend maximum life span. There is
another group out there called longevists who experiment on themselves by taking dubious potions, like free radical scavengers and other nutritional supplements, or by becoming involved in life extension programs like calorie restriction, body temperature lowering devices, and in some cases even yielding to the most Draconian measure of suspended animation by having their entire bodies preserved in liquid nitrogen a process called cryogenics-a procedure which must be done while you are still alive. I am told that some commercial cyrogenic labs offer specials for those who only want to preserve their heads- a bargain which might appeal to the Nobel laureate's and other geniuses especially if their bodies were crippled with arthritis, diabetes, heart disease or other chronic diseases. Such individuals feel that in the future we will have developed procedures to thaw such frozen bodies and bring them back to life- like we now do with human sperm, ova and more recently with early human embryos.
At the present time the closest procedure man has developed for achieving immortality on earth is by procreation- some family trees going back for many centuries. For procreation you don't need theological guarantees from preachers and their elaborate institutions, gerontologists with their sophisticated laboratories, shiny equipment, and shelves of anti-aging drugs and nutrients. All you need is just doing "what comes naturally "