Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100 (31 page)

But in the long term, there is a price to pay. Every year, it becomes easier and easier to manipulate the genes of living organisms. Costs keep plummeting, and the information is widely available on the Internet.

Within a few decades, some scientists believe that it will be possible to create a machine that will allow you to create any gene simply by typing the desired components. By typing in the A-T-C-G symbols making up a gene, the machine will then automatically splice and dice DNA to create that gene. If so, then it means that perhaps even high school students may one day do advanced manipulations of life-forms.

One nightmare scenario is airborne AIDS. Cold viruses, for example, possess a few genes that allow them to survive in droplets of aerosols, so that sneezing can infect others. At present, the AIDS virus is quite vulnerable when it is exposed to the environment. But if the cold virus genes are implanted into the AIDS virus, then it is conceivable that they might make it able to survive outside the human body. This could then cause the AIDS virus to spread like the common cold, thereby infecting a large portion of the human race. It is also known that viruses and bacteria do exchange genes, so there is also the possibility that the AIDS and common cold viruses can exchange genes naturally, although this is less likely.

In the future, a terrorist group or nation-state may be able to weaponize AIDS. The only thing preventing them from unleashing it would be the fact that they, too, would also perish if the virus were to be dispersed into the environment.

This threat became real right after the tragedy of 9/11. An unknown person mailed packets of a white powder containing anthrax spores to well-known politicians around the country. A careful, microscopic analysis of the white powder showed that the anthrax spores had been weaponized for maximum death and destruction. Suddenly, the entire country was gripped with fear that a terrorist group had access to advanced biological weapons. Although anthrax is found in the soil and throughout our environment, only a person with advanced training and maniacal intentions could have purified and weaponized the anthrax and pulled off this feat.

Even after one of the largest manhunts in U.S. history, the culprit was never found, even to this day (although a leading suspect recently committed suicide). The point here is that even a single individual with some advanced biological training can terrorize an entire nation.

One restraining factor that has kept germ warfare in check is simple self-interest. During World War I, the efficacy of poison gas on the battlefield was mixed. The wind conditions were often unpredictable, so the gas could blow back onto your own troops. Its military value was largely in terrorizing the enemy, rather than defeating him. Not a single decisive battle was won using poison gas. And even at the height of the Cold War, both sides knew that poison gas and biological weapons could have unpredictable effects on the battlefield, and could easily escalate to a nuclear confrontation.

All the arguments mentioned in this chapter, as we have seen, involved the manipulation of genes, proteins, and molecules. Then the next question naturally arises: How far can we manipulate individual atoms?

The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom.
—RICHARD FEYNMAN, NOBEL LAUREATE

Nanotechnology has given us the tools to play with the ultimate toy box of nature—atoms and molecules. Everything is made from these, and the possibilities to create new things appear limitless.
—HORST STORMER, NOBEL LAUREATE

The role of the infinitely small is infinitely large.
—LOUIS PASTEUR

The mastery of tools is a crowning achievement that distinguishes humanity from the animals. According to Greek and Roman mythology, this process began when Prometheus, taking pity on the plight of humans, stole the precious gift of fire from Vulcan’s furnace. But this act of thievery enraged the gods. To punish humanity, Zeus devised a clever trick. He asked Vulcan to forge a box and a beautiful woman out of metal. Vulcan created this statue, called Pandora, and then magically brought her to life, and told her never to open the box. Out of curiosity, one day she did, and unleashed all the winds of chaos, misery, and suffering in the world, leaving only hope in the box.

So from Vulcan’s divine furnace emerged both the dreams and the suffering of the human race. Today, we are designing revolutionary new machines that are the ultimate tools, forged from individual atoms. But will they unleash the fire of enlightenment and knowledge or the winds of chaos?

Throughout human history, the mastery of tools has determined our fate. When the bow and arrow were perfected thousands of years ago, it meant that we could fire projectiles much farther than our hands could throw them, increasing the efficiency of our hunting and increasing our food supply. When metallurgy was invented around 7,000 years ago, it meant that we could replace huts of mud and straw and eventually create great buildings that soared above the earth. Soon, empires began to rise from the forest and the desert, built by the tools forged from metals.

And now we are on the brink of mastering yet another type of tool, much more powerful than anything we have seen before. This time, we will be able to master the atoms themselves out of which everything is created. Within this century, we may possess the most important tool ever imagined—nanotechnology that will allow us to manipulate individual atoms. This could begin a second industrial revolution, as molecular manufacturing creates new materials we can only dream about today, which are superstrong, superlight, with amazing electrical and magnetic properties.

Nobel laureate Richard Smalley has said, “The grandest dream of nanotechnology is to be able to construct with the atom as the building block.” Philip Kuekes of Hewlett-Packard said, “Eventually, the goal is not just to make computers the size of dust particles. The idea would be to make simple computers the size of bacteria. Then you could get something as powerful as what’s now on your desktop into a dust particle.”

This is not just the hope of starry-eyed visionaries. The U.S. government takes it seriously. In 2009, because of nanotechnology’s immense potential for medical, industrial, aeronautical, and commercial applications, the National Nanotechnology Initiative allocated $1.5 billion for research. The government’s National Science Foundation Nanotechnology Report states, “Nanotechnology has the potential to enhance human performance, to bring sustainable development for materials, water, energy, and foods, to protect against unknown bacteria and viruses ….”

Ultimately, the world economy and fate of nations may depend on this. Around 2020 or soon afterward, Moore’s law will begin to falter and perhaps eventually collapse. The world economy could be thrown into disarray unless physicists can find a suitable replacement for silicon transistors to power our computers. The solution to the problem may come from nanotechnology.

Nanotechnology might also, perhaps by the end of this century, create a machine that only the gods can wield, a machine that can create anything out of almost nothing.

The first to call attention to this new realm of physics was Nobel laureate Richard Feynman, who asked a deceptively simple question: How small can you make a machine? This was not an academic question. Computers were gradually becoming smaller, changing the face of industry, so it was becoming apparent that the answer to this question could have an enormous impact on society and the economy.

In his prophetic talk given in 1959 to the American Physical Society titled “There’s Plenty of Room at the Bottom,” Feynman said, “It is interesting that it would be, in principle, possible (I think) for a physicist to synthesize any chemical substance that the chemist writes down. Give the orders and the physicist synthesizes it. How? Put the atoms down where the chemist says, and so you make the substance.” Feynman concluded that machines made out of individual atoms were possible, but that new laws of physics would make them difficult, but not impossible, to create.

So ultimately, the world economy and the fate of nations may depend on the bizarre and counterintuitive principles of the quantum theory. Normally, we think that the laws of physics remain the same if you go down to smaller scales. But this is not true. In movies like Disney’s
Honey, I Shrunk the Kids
and
The Incredible Shrinking Man,
we get the mistaken impression that miniature people would experience the laws of physics the same way we do. For example, in one scene in the Disney movie, our shrunken heroes ride on an ant during a rainstorm. Raindrops fall onto the ground and make tiny puddles, just as in our world. But in reality, raindrops can be larger than ants. So when an ant encounters a raindrop, it would see a huge hemisphere of water. The hemisphere of water does not collapse because surface tension acts like a net that holds the droplet together. In our world, surface tension of water is quite small, so we don’t notice it. But on the scale of an ant, surface tension is proportionately huge, so rain beads up into droplets.

(Furthermore, if you tried to scale up the ant so that it was the size of a house, you have another problem: its legs would break. As you increase the size of the ant, its weight grows much faster than the strength of its legs. If you increase the size of an ant by a factor of 10, its volume and hence its weight is 10 × 10 × 10 = 1,000 times heavier. But its strength is related to the thickness of its muscles, which is only 10 × 10 = 100 times stronger. Hence, the giant ant is 10 times weaker, relatively speaking, than an ordinary ant. This also means that King Kong, instead of terrorizing New York City, would crumble if he tried to climb the Empire State Building.)

Feynman noted that other forces also dominate at the atomic scale, such as hydrogen bonding and the van der Waals force, caused by tiny electrical forces that exist between atoms and molecules. Many of the physical properties of substances are determined by these forces.

(To visualize this, consider the simple problem of why the Northeast has so many potholes in its highways. Every winter, water seeps into tiny cracks in the asphalt; the water expands as it freezes, causing the asphalt to crumble and gouging out a pothole. But it violates common sense to think that water expands when it freezes. Water does expand because of hydrogen bonding. The water molecule is shaped like a V, with the oxygen atom at the base. The water molecule has a slight negative charge at the bottom and a positive charge at the top. Hence, when you freeze water and stack water molecules, they expand, forming a regular lattice of ice with plenty of spaces between the molecules. The water molecules are arranged like hexagons. So water expands as it freezes since there is more space between the atoms in a hexagon. This is also the reason snowflakes have six sides, and explains why ice floats on water, when by rights it should sink.)

In addition to surface tension, hydrogen bonding, and van der Waals forces, there are also bizarre quantum effects at the atomic scale. Normally, we don’t see quantum forces at work in everyday life. But quantum forces are everywhere. For example, by rights, since atoms are largely empty, we should be able to walk through walls. Between the nucleus at the center of the atom and the electron shells, there is only a vacuum. If the atom were the size of a football stadium, then the stadium would be empty, since the nucleus would be roughly the size of a grain of sand.

(We sometimes amaze our students with a simple demonstration. We take a Geiger counter, place it in front of a student, and put a harmless radioactive pellet in back. The student is startled that some particles pass right through his body and trigger the Geiger counter, as if he is largely empty, which he is.)

But if we are largely empty, then why can’t we walk through walls? In the movie
Ghost,
Patrick Swayze’s character is killed by a rival and turns into a ghost. He is frustrated every time he tries to touch his former fiancée, played by Demi Moore. His hands pass through ordinary matter; he finds that he has no material substance and simply floats through solid objects. In one scene, he sticks his head into a moving subway car. The train races by with his head sticking inside, yet he doesn’t feel a thing. (The movie does not explain why gravity does not pull him through the floor so he falls to the center of the earth. Ghosts, apparently, can pass through anything except floors.)

So why can’t we pass through solid objects like ghosts? The answer resides in a curious quantum phenomenon. The Pauli exclusion principle states that no two electrons can exist in the same quantum state. Hence when two nearly identical electrons get too close, they repel each other. This is the reason objects appear to be solid, which is an illusion. The reality is that matter is basically empty.

When we sit in a chair, we think we are touching it. Actually, we are hovering above the chair, floating less than a nanometer above it, repelled by the chair’s electrical and quantum forces. This means that whenever we “touch” something, we are not making direct contact at all but are separated by these tiny atomic forces. (This also means that if we could somehow neutralize the exclusion principle, then we might be able to pass through walls. However, no one knows how to do this.)