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

tenth of a millimeter.
    Already, scientists are envisioning an MRI-type machine with a resolution down to the size of a cell, and even smaller, one that can scan down to the individual molecules and atoms.
    In summary, a replicator does not violate the laws of physics, but it would be difficult to create using self-assembly. By late in this century, when the techniques of self-assembly are finally mastered, we can think about commercial applications of replicators.
    GRAY GOO?
    Some people, including Bill Joy, a founder of Sun Microsystems, have expressed reservations about nanotechnology, writing that it’s only a matter of time before the technology runs wild, devours all the minerals of the earth, and spits out useless “gray goo” instead. Even Prince Charles of En gland has spoken out against nanotechnology and the gray-goo scenario.
    The danger lies in the key property of these nanobots: they can reproduce themselves. Like a virus, they cannot be recalled once they are let loose into the environment. Eventually, they could proliferate wildly, taking over the environment and destroying the earth.
    My own belief is that there are many decades to centuries before this technology is mature enough to create a replicator, so concerns about the gray goo are premature. As the decades pass, there will be plenty of time to design safeguards against nanobots that run amok. For example, one can design a fail-safe system so that, by pressing a panic button, all the nanobots are rendered useless. Or one could design “killer bots,” specifically designed to seek out and destroy nanobots that have run out of control.
    Another way to deal with this is to study Mother Nature, who has had billions of years of experience with this problem. Our world is full of self-replicating molecular life-forms, called viruses and bacteria, that can proliferate out of control and mutate as well. However, our body has also created “nanobots” of its own, antibodies and white blood cells in our immune system that seek out and destroy alien life-forms. The system is certainly not perfect, but it provides a model for dealing with this out-of-control-nanobot problem.
    SOCIAL IMPACT OF REPLICATORS
    For a BBC/Discovery Channel special I once hosted, Joel Garreau, author of
Radical Evolution,
said, “ If a self-assembler ever does become possible, that’s going to be one of history’s great ‘holy s—!’ moments. Then you are really talking about changing the world into something we’ve never recognized before.”
    There is an old saying, Be careful what you wish for, because it may come true. The holy grail of nanotechnology is to create the molecularassembler, or replicator, but once it is invented, it could alter the very foundation of society itself. All philosophies and social systems are ultimately based on scarcity and poverty. Throughout human history, this has been the dominant theme running through society, shaping our culture, philosophy, and religion. In some religions, prosperity is viewed as a divine reward and poverty as just punishment. Buddhism, by contrast, is based on the universal nature of suffering and how we cope with it. In Christianity, the New Testament reads: “It is easier for a camel to go through the eye of a needle than for a rich man to enter into the kingdom of God.”
    The distribution of wealth also defines the society itself. Feudalism is based on preserving the wealth of a handful of aristocrats against the poverty of the peasants. Capitalism is based on the idea that energetic, productive people are rewarded for their labors by starting companies and getting rich. But if lazy, nonproductive individuals can get as much as they want almost for free by pushing a button, then capitalism no longer works. A replicator upsets the entire apple cart, turning human relations upside down. The distinctions between the haves and have-nots may disappear, and along with it the notion of status and political power.
    This conundrum was explored in an episode in
Star Trek: The Next Generation,
in which a capsule from the twentieth century is found floating in outer space. Inside the capsule are the frozen bodies of people who suffered from incurable diseases of that primitive time period, hoping to be revived in the future. The doctors of the starship
Enterprise
quickly cure these individuals of their diseases and revive them. These fortunate individuals are surprised that their gamble paid off, but one of them is a