The Future of Humanity: Terraforming Mars, Interstellar Travel, Immortality, and Our Destiny Beyond Earth

by Michio Kaku

In addition to wormholes, the Alcubierre engine might offer a second way to break the light barrier.

In addition to wormholes, the Alcubierre engine might offer a second way to break the light barrier. I once interviewed the Mexican theoretical physicist Miguel Alcubierre. He was struck with a groundbreaking idea in relativistic physics while watching TV, perhaps the first time this has ever happened. During an episode of Star Trek, he marveled that the Starship Enterprise could travel faster than light. It could somehow compress the space in front of it so that the stars did not seem as distant. The Enterprise did not journey to the stars—the stars came to the Enterprise. Think of moving across a carpet to reach a table. The commonsense way is to walk along the carpet from one point to another. But there is another way. One could rope the table and drag it toward you, so that you are compressing the carpet. So instead of walking across the carpet to reach the table, the carpet folds up and the table comes to you. An interesting realization dawned on him. Usually, you start with a star or planet and then use Einstein’s equations to calculate the bending of space around it. But you can also go backward. You can identify a particular warping and use the same equations to determine the type of star or planet that would cause it. A rough analogy might be made to the way an auto mechanic builds a car. You could begin with the parts that are available—the engine, the tires, and whatnot—and assemble a car from them. Or you could select the design of your dreams and then figure out the parts necessary to create it.

Alcubierre turned Einstein’s math on its head, reversing the usual logic of theoretical physicists.

A starship equipped with Alcubierre drive would have to be surrounded by a warp bubble, a hollow bubble of matter and energy.

But negative matter and energy warp space-time in bizarre ways, creating an antigravitational force that can stabilize wormholes and prevent them from collapsing and propel warp bubbles to faster-than-light velocities by compressing space-time in front of them.)

Physicists then tried to calculate the amount of negative matter or energy necessary to propel a starship. The latest results indicate that the amount required is equivalent to the mass of the planet Jupiter.

Physicists then tried to calculate the amount of negative matter or energy necessary to propel a starship. The latest results indicate that the amount required is equivalent to the mass of the planet Jupiter. This means that only a very advanced civilization will be able to use negative matter or energy to propel their starships, if it is possible at all. (However, it is possible that the amount of negative matter or energy necessary to go faster than light could drop, because the calculations depend on the geometry and size of the warp bubble or wormhole.)

Star Trek gets around this inconvenient hurdle by postulating that a rare mineral called the dilithium crystal is the essential component of a warp drive engine. Now we know that “dilithium crystals” may be a fancy way of saying “negative matter or energy.”

Every few days, Giordano Bruno has his revenge. Bruno, Galileo’s predecessor, was burned alive at the stake for heresy in Rome in 1600. The stars in the heavens are so numerous, he observed, that our sun must be one of many. Surely these other stars, too, are orbited by a multitude of planets, some of which may even be inhabited by other beings.

Every few days, Giordano Bruno has his revenge. Bruno, Galileo’s predecessor, was burned alive at the stake for heresy in Rome in 1600. The stars in the heavens are so numerous, he observed, that our sun must be one of many. Surely these other stars, too, are orbited by a multitude of planets, some of which may even be inhabited by other beings. The church imprisoned him for seven years without trial, then stripped him naked, paraded him through the streets of Rome, tied his tongue with a leather strap, and lashed him to a wooden pillar. He was given one last chance to recant, but he refused to take back his ideas. To squelch his legacy, the church placed all his texts on the Index of Forbidden Books. Unlike Galileo’s works, Bruno’s were banned until 1966. Galileo merely claimed that the sun, not the Earth, was the center of the universe. Bruno suggested that the universe had no center at all. He was one of the first in history to posit that the universe might be infinite, in which case the Earth would be just another pebble in the sky. The church could no longer claim to be the center of the universe, because it had none. In 1584, Bruno summed up his philosophy, writing, “This space we declare to be infinite…in it are an infinity of worlds of the same kind as our own.” Now, more than four hundred years later, roughly four thousand extrasolar planets in the Milky Way have been documented, and the list grows almost daily. (In 2017, NASA listed 4,496 candidate planets, of which 2,330 have been confirmed, discovered by the Kepler spacecraft.)

If you go to Rome, you might want to visit the Campo de’ Fiori—the “Plain of Flowers”—where there is an imposing statue of Bruno on the very spot where he faced his death.

If you go to Rome, you might want to visit the Campo de’ Fiori—the “Plain of Flowers”—where there is an imposing statue of Bruno on the very spot where he faced his death. When I went, I found a bustling square full of shoppers, who may not all have been aware that the location had been an execution site for heretics. But Bruno’s statue itself gazes down upon a number of young rebels, artists, and street musicians who, unsurprisingly, congregate there. While taking in this peaceful scene, I wondered what kind of atmosphere could have existed back in Bruno’s day to inflame such a murderous mob. How could they be whipped up to torture and kill a vagabond philosopher?

Bruno’s ideas languished for centuries, because finding an extrasolar planet is exceedingly difficult and was once thought to be nearly impossible.

Bruno’s ideas languished for centuries, because finding an extrasolar planet is exceedingly difficult and was once thought to be nearly impossible. Planets do not give off light of their own. Even the reflected light of one is about a billion times dimmer than that of the mother star, the harsh glare of which can obscure the planet from view. But thanks to the giant telescopes and space-based detectors we have today, a flood of recent data has proven Bruno to be correct.

Gravitational lensing may be a promising alternate method, although it only works if there is perfect alignment between the Earth, the exoplanet, and the mother star.

Gravitational lensing may be a promising alternate method, although it only works if there is perfect alignment between the Earth, the exoplanet, and the mother star. We know from Einstein’s theory of gravity that light can bend as it moves near a celestial body, because a large mass can alter the fabric of space-time around it. Even if the object is not visible to us, it will change the trajectory of light, just as clear glass does. If a planet moves directly in front of a distant star, the light will be distorted into a ring. This particular pattern is called an Einstein Ring and signals the presence of a substantial mass between the observer and the star.

Some Jupiter-sized planets are in circular orbits, but they are so close to the mother star that if they were in our solar system, they would be within the orbit of Mercury.

We are at a loss to explain even the most common of these exoplanets. Many of the Jupiter-sized planets, which have been the easiest to find, are not moving in near-circular trajectories as expected but in highly elliptical orbits. Some Jupiter-sized planets are in circular orbits, but they are so close to the mother star that if they were in our solar system, they would be within the orbit of Mercury. These gas giants are called “hot Jupiters,” and the solar wind is constantly blowing their atmosphere into outer space. But astronomers once believed that Jupiter-sized planets originate in deep space, billions of miles from the mother star. If so, how did they get so close?

It has also been suggested that Proxima Centauri b may be tidally locked, so that, like our own moon, one side always faces the star.

Another unprecedented finding came in 2017. Astronomers located a solar system that violated all the theories of planetary evolution. It contained seven Earth-sized planets orbiting a mother star called TRAPPIST-1. Three of the planets are in the Goldilocks zone and may have oceans.

an analysis in 2017 showed that they are in resonance, meaning that their orbits are in phase with one another and no collisions will take place.

On Star Trek, whenever the Enterprise is about to encounter an Earth-like planet, Spock announces that they are approaching a “class M planet.” Actually, there’s no such thing in astronomy—yet. Now that thousands of different types of planets have made their debut, including a variety of Earth-like planets, it’s only a matter of time before a new nomenclature is introduced.

If a planetary twin of the Earth exists in space, it has eluded us so far.

But KOI 7711 is the exoplanet that is getting the most attention because, as of 2017, it is the one with the most Earth-like features.

But KOI 7711 is the exoplanet that is getting the most attention because, as of 2017, it is the one with the most Earth-like features. It is 30 percent larger than Earth, and its mother star is very much like our own. It is not at risk of being fried by solar flares. The length of one year on the planet is almost identical to a year on Earth. It is in the habitable zone of its star, but we do not yet have the technology to evaluate whether its atmosphere contains water vapor. All conditions seem right for it to host some form of life. However, at 1,700 light-years away, it is the farthest exoplanet of the three.

Astronomers have conjectured that rogue planets, too, might have radioactive cores that keep them relatively warm. This means a radioactive core could supply heat to hot springs and volcanic vents on the bottom of an ocean where the chemicals of life may be created. So if rogue planets are as numerous as some astronomers believe, then the most probable place to find life in the galaxy may not be within the habitable zone of a star but on the rogue planets and their moons.

Gliese 1214 b, the first of six known potentially water-covered exoplanets to be identified, was found in 2009.

Gliese 1214 b, the first of six known potentially water-covered exoplanets to be identified, was found in 2009. It is forty-two light-years away and six times larger than the Earth. It lies outside the habitable zone, orbiting seventy times closer to its mother sun than the Earth does. It may get as hot as 280 degrees Celsius, so life as we know it probably cannot exist. But by using various filters to analyze light scattered through the planet’s atmosphere as it transits the mother star, significant amounts of water have been confirmed. The water may not be in familiar liquid form due to the planet’s temperature and pressure. Instead, Gliese 1214 b might be a steam planet.

The aeons involved in traversing the galaxy are not daunting to immortal beings. —SIR MARTIN REES, ASTRONOMER ROYAL OF ENGLAND

The movie The Age of Adaline is the tale of a woman born in 1908 who is caught in a snowstorm and freezes to death. Fortunately, she is hit by a freak lightning bolt, which revives her. This peculiar event changes her DNA, and she mysteriously stops aging.

The movie The Age of Adaline is the tale of a woman born in 1908 who is caught in a snowstorm and freezes to death. Fortunately, she is hit by a freak lightning bolt, which revives her. This peculiar event changes her DNA, and she mysteriously stops aging. As a result, she remains young while her friends and lovers grow old. Inevitably, suspicions and rumors start, and she is forced to leave town. Instead of rejoicing in her limitless youth, she withdraws from society and rarely speaks to anyone. Immortality, instead of being a gift, is a curse to her. Finally, she is hit by a car and dies in the accident. In the ambulance, the electric shock from the defibrillator not only revives her, it reverses the genetic effects of the lightning bolt, and she becomes mortal. Instead of weeping at her loss of immortality, she rejoices when she finds her first gray hair.

While Adaline eventually rejects the promise of immortality, science is actually moving in the other direction, making enormous strides in understanding aging.

While Adaline eventually rejects the promise of immortality, science is actually moving in the other direction, making enormous strides in understanding aging. Scientists concerned with deep space exploration are keenly interested in this research, because the distance between stars is so great that it may take centuries for a ship to complete its voyage. Thus, the process of building a starship, surviving the voyage to the stars, and settling on distant planets might require several lifetimes. In order to survive the journey we would have to build multigenerational ships, put our astronauts and pioneers in suspended animation, or extend their life spans.

So can modern science now unlock the secrets of the aging process, slowing down or even stopping the clock, increasing life expectancy to an almost limitless degree?

Recently, scientists have revealed some of the deepest secrets of the aging process. After centuries of false starts, there are now a few reliable, testable theories that seem promising. These involve caloric restriction, telomerase, and age genes.

On average, animals that eat 30 percent fewer calories live 30 percent longer.

Resveratrol, found in red wine, helps to activate the sirtuin molecule, which has been shown to slow down the oxidation process, a principle component in aging, and therefore it may help protect the body from age-related molecular damage.

Another clue to the cause of aging might be telomerase, which helps to regulate our biological clock.

Another clue to the cause of aging might be telomerase, which helps to regulate our biological clock. Every time a cell divides, the tips of the chromosomes, called telomeres, get a bit shorter. Eventually, after approximately fifty to sixty divisions, the telomeres become so short that they disappear and the chromosome begins to fall apart, so the cell enters a state of senescence and no longer functions correctly. Thus there is a limit to how many times a cell can divide, called the Hayflick limit. (I once interviewed Dr. Leonard Hayflick, who laughed when asked if the Hayflick limit can somehow be reversed to give us the cure for death. He was extremely skeptical. He realized that this biological limit was fundamental to the aging process, but its consequences are still being studied, and because aging is a complex biochemical process involving many different pathways, we are a long way from being able to alter that limit in humans.) Nobel laureate Elizabeth Blackburn is more optimistic and says, “Every sign, including genetics, says there’s some causality [between telomeres] and the nasty things that happen with aging.” She notes that there is a direct link between shortened telomeres and certain diseases. For example, if you have shortened telomeres—if your telomeres are in the bottom third of the population in terms of length—then your risk of cardiovascular disease is 40 percent greater. “Telomere shortening,” she concludes, “seems to underlie the risks for the diseases that kill you…heart disease, diabetes, cancer, even Alzheimer’s.” Recently, scientists have been experimenting with telomerase, the enzyme discovered by Blackburn and her colleagues that prevents the telomeres from shortening. It can, in some sense, “stop the clock.” When bathed in telomerase, skin cells can divide indefinitely, far beyond the Hayflick limit. I once interviewed Dr. Michael D. West, then of the Geron Corporation, who experiments with telomerase and claims that he can “immortalize” a skin cell in the lab so that it lives indefinitely. (This has added a new verb to the English language: “to immortalize.”) The skin cells in his lab can divide hundreds of times, not just fifty or sixty. But it should be pointed out that telomerase has to be regulated very carefully, because cancer cells are also immortal and they use telomerase to attain that immortality. In fact, one of the things that separates cancer cells from normal ones is that they live forever and reproduce without limit, eventually creating the tumors that can kill you. So cancer may be an unwanted byproduct of using telomerase.

The mechanism of aging is slowly being revealed, and many scientists are cautiously optimistic that it might be controllable sometime in the coming decades.

In 1956, Clive M. McCay of Cornell University sewed the blood vessels of two rats together, one old and decrepit and the other young and vigorous. He was astonished to find that the old mouse started to look younger, while the reverse happened to the young mouse.

In 2017, a major study on more than eight hundred subjects by the University of Haifa in Israel found evidence of the opposite effect, that HGH might actually decrease a person’s life expectancy.

Another controversy involves the human growth hormone (HGH), which has created an enormous fad, but its effectiveness in preventing aging is based on very few reliable studies. In 2017, a major study on more than eight hundred subjects by the University of Haifa in Israel found evidence of the opposite effect, that HGH might actually decrease a person’s life expectancy. Furthermore, another study indicates that a genetic mutation that results in a reduced HGH level may lengthen the human life span, so the effect of HGH may backfire.

Like Adaline, people might realize that the gift of immortality was actually a curse.

advances in slowing down or stopping the aging process could have a profound effect on space travel.

In addition to biological immortality, there is a second type, called digital immortality, which raises some interesting philosophical questions. In the long run, digital immortality may be the most efficient way to explore the stars. If our fragile biological bodies cannot stand the strain of interstellar travel, there is the possibility of sending our consciousness to the stars instead.

One day, we might have a Library of Souls. Instead of reading a book on Winston Churchill, we might have a conversation with him.

One day, we might have a Library of Souls. Instead of reading a book on Winston Churchill, we might have a conversation with him. We would talk to a projection with his facial gestures, body movements, and voice inflections. The digital record would have access to his biographical data, his writings, and his opinions on political, religious, and personal matters. In all ways it would feel like talking to the man himself. I would personally enjoy having a conversation with Albert Einstein to discuss the theory of relativity. One day your great-great-great-grandchildren may have a conversation with you. This is one form of digital immortality.

The next level of digital immortality beyond the Library of Souls is the Human Connectome Project, an ambitious effort to digitize the entire human brain.

But what happens when we are able to reproduce your brain, neuron for neuron, so that all your memories and feelings are recorded? The next level of digital immortality beyond the Library of Souls is the Human Connectome Project, an ambitious effort to digitize the entire human brain. As Daniel Hillis, cofounder of Thinking Machines, once said, “I’m as fond of my body as anyone, but if I can be 200 with a body of silicon, I’ll take it.”

As Daniel Hillis, cofounder of Thinking Machines, once said, “I’m as fond of my body as anyone, but if I can be 200 with a body of silicon, I’ll take it.”

This approach is called the BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies). Its goal is to unravel the neural structure of the brain itself, cell by cell, and ultimately to map the pathways of every neuron in the brain.

If we die and our connectome lives on, then are we in some sense immortal?

Although living inside a computer may sound unappealing to some, there is no reason you couldn’t have all the sensation of a living, breathing human being.

At the 2014 World Cup in São Paolo, Brazil, a man kicked a soccer ball to start the games, an event witnessed by a billion people. This by itself was not remarkable. What was remarkable was that this man was paralyzed. Professor Miguel Nicolelis of Duke University had inserted a chip into the man’s brain. The chip was connected to a portable computer that controlled his exoskeleton. By simply thinking, this paralyzed individual was able to walk and kick the ball.

But Dr. Nicolelis wants to go much farther with this technology. He told me that all these breakthroughs in neurology will eventually give rise to the “brain net,” which is the next stage in the evolution of the internet. Instead of transmitting bits of information, brain net will transmit entire emotions, feelings, sensations, and memories. This could help to break down barriers between people. Often, it is hard to understand other people’s point of view, their suffering and anguish. But with brain net, we would be able to experience firsthand the anxieties and fears that trouble others.

So astronauts of the future may be able to use brain net in important ways. They will be able to mentally communicate with other settlers, instantly exchange vital information, and amuse themselves with an entirely new form of entertainment. Also, since space exploration is potentially dangerous, they will be able to sense a person’s mental condition much more accurately than before. When embarking on a new space mission to explore dangerous terrain, having brain net will help astronauts bond and also reveal mental problems, such as depression or anxiety.

The Nazi jet pack used hydrogen peroxide as fuel, which quickly ignites in contact with a catalyst (such as silver) to release energy and water as waste products.

So jet packs and ray guns will not become real until we create miniature power packs, perhaps in the form of a nanobattery that can store energy at the molecular level.

On a planet with a thin atmosphere and rugged terrain like Mars, perhaps the most convenient way to travel is the jet pack, a staple of science fiction cartoons and movies. It appeared in the very first Buck Rogers strip back in 1929, when Buck meets his future girlfriend while she is soaring through the air using a jet pack. In reality, the jet pack was deployed during World War II when the Nazis needed a quick way to transport troops across a river whose bridge had been destroyed. The Nazi jet pack used hydrogen peroxide as fuel, which quickly ignites in contact with a catalyst (such as silver) to release energy and water as waste products. However, there are several problems with jet packs. The main one is that the fuel supply lasts for only thirty seconds to a minute. (In old news clips, you sometimes see daredevils using jet packs to float in the air, such as at the 1984 Olympics. However, these tapes are carefully edited since people float for only thirty seconds to a minute before they fall to the ground.) The solution to this problem is to develop a portable power pack with enough energy to power longer periods of flight. Unfortunately, no such power supply is available at the present time. This is also the reason why we don’t have ray guns. A laser can work like a ray gun but only if you have a nuclear power plant generating the energy. However, it’s impractical to have a nuclear power plant on your shoulders. So jet packs and ray guns will not become real until we create miniature power packs, perhaps in the form of a nanobattery that can store energy at the molecular level.

Bioethicists, worried about the possible misuses of this technology, have organized conferences to discuss this new science because the side effects and complications are not known, and they made a series of recommendations to try to cool down the furious pace of CRISPR research. In particular, they raised concerns that this technology may lead to germ-line gene therapy.

Bioethicists, worried about the possible misuses of this technology, have organized conferences to discuss this new science because the side effects and complications are not known, and they made a series of recommendations to try to cool down the furious pace of CRISPR research. In particular, they raised concerns that this technology may lead to germ-line gene therapy. (There are two types of gene therapy, somatic cell gene therapy, where non-sex cells are modified, so that the mutations do not spread to the next generation, and germ-line gene therapy, where your sex cells are altered so that all your descendants can inherit the modified gene.) Germ-line gene therapy could, if unchecked, alter the genetic heritage of the human race. It means that once we venture among the stars, new genetic branches of the human race might emerge. Usually, this would take tens of thousands of years, but bioengineering may reduce that to a single generation if germ-line gene therapy becomes a reality.

Rather than being repulsed by technology or fighting its influence, the transhumanists believe that we should embrace it.

Rather than being repulsed by technology or fighting its influence, the transhumanists believe that we should embrace it. They relish the idea that we can perfect humanity. To them, the human race was a byproduct of evolution, so our bodies are a consequence of random, haphazard mutations. Why not use technology to systematically improve on these quirks? Their ultimate goal is to create the “posthuman,” a new species that can transcend humanity.

If we ever encounter extraterrestrial intelligence, I believe it is overwhelmingly likely to be post-biological in nature, a conclusion that has obvious and far-reaching ramifications for SETI [the search for extraterrestrial intelligence].”

Our basic personality has not changed much since we first emerged as modern humans two hundred thousand years ago.

after our basic needs are met, we place a high value on the opinions of our peers.

Even superheroes have to obey the caveman principle.