Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100

analyzed carefully. Any therapy using telomerase to rewind the biological clock must be checked to make sure it does not cause cancer.
    IMMORTALITY PLUS YOUTH
    The prospect of extending the human life span is a source of joy for some and a horror for others, as we contemplate a population explosion and a society of decrepit elderly who will bankrupt the country.
    A combination of biological, mechanical, and nanotechnological therapies may in fact not only increase our life span but also preserve our youth in the process. Robert A. Freitas Jr., who applies nanotechnology to medicine, has said, “ Such interventions may become commonplace a few decades from today. Using annual checkups and cleanouts, and some occasional major repairs, your biological age could be restored once a year to the more or less constant physiological age that you select. You might still eventually die of accidental causes, but you’ll live at least ten times longer than you do now.”
    In the future, extending the life span will not be a matter of drinking of the fabled Fountain of Youth. More likely, it will be a combination of several methods:
     
    1. growing new organs as they wear out or become diseased, via tissue engineering and stem cells
    2. ingesting a cocktail of proteins and enzymes that are designed to increase cell repair mechanisms, regulate metabolism, reset the biological clock, and reduce oxidation
    3.using gene therapy to alter genes that may slow down the aging process
    4. maintaining a healthy lifestyle (exercise and a good diet)
    5. using nanosensors to detect diseases like cancer years before they become a problem
    POPULATION, FOOD, AND POLLUTION
    But one nagging question is: If life expectancy can be increased, then will we suffer from overpopulation? No one knows.
    Delaying the aging process brings up a host of social implications. If we live longer, won’t we overpopulate the earth? But some point out that the bulk of life extension has already happened, with life expectancy exploding from forty-five to seventy to eighty in just one century. Instead of creating a population explosion, it has arguably done the reverse. As people are living longer, they are pursuing careers and delaying childbearing. In fact, the native European population is actually decreasing dramatically. So if people live longer and richer lives, they might space out their children accordingly, and have fewer of them. With many more decades to live, people will reset their time frames accordingly, and hence space out or delay their children.
    Others claim that people will reject this technology because it is unnatural and may violate their religious beliefs. Indeed, informal polls taken of the general population show that most people think that death is quite natural and helps to give life meaning. (However, most of the people interviewed in these polls are young to middle-aged. If you go to a nursing home, where people are wasting away, living with constant pain, and waiting to die and ask the same question, you might get an entirely different answer.)
    As UCLA’s Greg Stock says, “ Gradually, our agonizing about playing God and our worries about longer life spans would give way to a new chorus: ‘When can I get a pill?’ ”
    In 2002, with the best demographic data, scientists estimated that 6 percent of all humans who have ever walked the face of the earth are still alive today. This is because the human population hovered at around 1 million for most of human history. Foraging for meager supplies of food kept the human population down. Even during the height of the Roman Empire, its population was estimated to be only 55 million.
    But within the last 300 years, there has been a dramatic spike in world population coincident with the rise of modern medicine and the Industrial Revolution, which produced a bounty of food and supplies. And in the twentieth century, the world population soared to new heights, more than doubling from 1950 to 1992: from 2.5 billion to 5.5 billion. It now stands at 6.7 billion. Every year, 79 million people join the human race, which is more than the entire population of France.
    As a result, many predictions of doomsday have been made, yet so far humanity has been able to dodge the bullet. Back in 1798, Thomas Malthus warned us what would happen when the population exceeded the food supply. Famines, food riots, the collapse of governments, and mass starvation could ensue until a new equilibrium is found between