by Alok Jha
If this strangelet were to collide with a normal nucleus, the conversion of the latter into a strangelet would take a billionth of a second and release energy that would then be available for other nucleus conversions. One by one, every atomic nucleus in a collection of ordinary matter—the Earth, say—would be transformed into strangelets, leaving our planet a hot lump of strange matter.
One science-fiction writer who did think up something similar was the visionary Kurt Vonnegut. In Cat’s Cradle, he describes a fictional material called Ice Nine, which is supposed to be a more stable form of water that melts at 45.8°C instead of 0°C. When Ice Nine comes into contact with normal water, it acts as a catalyst to solidify the entire body of water. Inevitably, somebody uses this material to solidify all of the Earth’s oceans.
Do strangelets exist?
There is nothing to prove that vast clouds of strangelets are not floating undetected in deep space today. They might be produced naturally in cosmic collisions, and could be part of the explanation for the mysterious dark matter that scientists know makes up a quarter of the mass of the universe, but which we cannot see. If it is there, there is little we can do about it drifting into our solar system.
More worrying is the possibility of creating a strangelet on Earth. Whether we are at the mercy of death by strangelet has been considered seriously several times by physicists, usually while trying to calm public fears over the building of ever-larger particle accelerators that might accidentally produce strangelets in their high-energy collisions.
Before scientists fired up the Relativistic Heavy Ion Collider (RHIC) in 2000 in the United States, they carried out a study into the various catastrophic events that might occur by accident when particles are smashed at such high energies.
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One by one, every atomic nucleus in a collection of ordinary matter—the Earth, say—would be transformed into strangelets, leaving our planet a hot lump of strange matter.
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Describing the RHIC in 1999, Sheldon Glashow and Richard Wilson, physicists at Harvard University, said: “Beams of highly charged gold or lead atoms (the heavy ions) traveling at relativistic speeds (99.95% of light speed) will speed in opposite directions around circular racetracks before colliding. RHIC is truly an atom smasher: nucleus–nucleus impacts, taking place thousands of times per second, will each produce thousands of secondary particles. These incredibly complex ‘events’ will be recorded by sophisticated detectors and analyzed at supercomputers or farmed out to a world consortium of smaller computers. RHIC will study matter at densities and temperatures never seen in the laboratory. On a small scale, it will reproduce the extreme conditions that reigned in the early universe, conditions under which the constituents of ordinary matter are expected to be liberated as a quark–gluon plasma.”
The scientists go on to describe the conclusions of two safety studies. “Both groups include theorists who were among the first to speculate that lumps of strange matter called strangelets—which contain many strange quarks as well as the usual up and down quarks that make up atomic nuclei—might be more stable than ordinary matter. If strangelets exist (which is conceivable), and if they form reasonably stable lumps (which is unlikely), and if they are negatively charged (although the theory strongly favors positive charges), and if tiny strangelets can be created at RHIC (which is exceedingly unlikely), then there just might be a problem. A newborn strangelet could engulf atomic nuclei, growing relentlessly and ultimately consuming the Earth. The word ‘unlikely,’ however many times it is repeated, just isn’t enough to assuage our fears of this total disaster.”
Is it likely?
Glashow points to experiments in nature to allay fears that strangelets can be created easily. Cosmic rays (mostly very energetic protons in space) stream around the universe at speeds near to that of light; anything of appreciable size in the cosmos will be buffeted by these particles all the time. Glashow uses the Earth’s Moon as a good example of a natural experiment.
“Lacking a protective atmosphere, with a surface rich in mid-sized atoms such as iron, it is a plausible target on which incident cosmic rays of iron (or larger) nuclei with RHIC energies could produce strangelets,” he says. “Yet countless collisions over billions of years have left the Moon intact.”
Before you get too comfortable, though, here’s one more study to think about. The risk of a doomsday scenario in which high-energy physics experiments trigger the destruction of the Earth might have been estimated to be tiny, but this may give a false sense of security, according to Max Tegmark and Nick Bostrom, respectively a physicist at the Massachusetts Institute of Technology and a philosopher at the Future of Humanity Institute at the University of Oxford. “The fact that the Earth has survived for so long does not necessarily mean that such disasters are unlikely, because observers are, by definition, in places that have avoided destruction,” they pointed out in Nature in 2005.
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The fact that the Earth has survived for so long does not necessarily mean that such disasters are unlikely.
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Given that life on Earth has survived for nearly 4 billion years, it might be easy to assume that natural catastrophic events are extremely rare. Unfortunately, say the researchers, this argument is flawed, because it fails to take into account “an observation-selection effect, whereby observers are precluded from noting anything other than that their own species has survived up to the point when the observation is made. If it takes at least 4.6 [billion years] for intelligent observers to arise, then the mere observation that Earth has survived for this duration cannot even give us grounds for rejecting with 99% confidence the hypothesis that the average cosmic neighborhood is typically sterilized, say, every 1,000 years. The observation-selection effect guarantees that we would find ourselves in a lucky situation, no matter how frequent the sterilization events.”
Using information on planet-formation rates, the distribution of birth dates for intelligent species, they add, can be calculated under different assumptions about the rate of cosmic sterilization. “Combining this with information about our own temporal location enables us to conclude that the cosmic sterilization rate for a habitable planet is, at most, of the order of 1 per 1.1 [billion years] at 99.9% confidence.”
So no need to get too concerned yet.
Genetic Superhumans
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With the first draft sequence of the human genome in 2000, scientists finally gathered the tools that guided the biochemistry of life. Their first task has been to understand and manipulate that biochemistry to banish disease. But what about using that knowledge to make humans even better, faster, stronger, more intelligent?
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If genetic technology could be used to stop disease, why not select genes to improve a person’s physical or mental ability? If someone has the money and the inclination, might they program their children to be superachievers? If the technology is available, why leave human evolution to the slow and random process of natural selection, when instead you can ramp up the benefits and the speed with active design of a genome?
Successive generations of enhanced children might even start to separate into a new species, different from the run-of-the-mill humans we see today, with their ragbag mixture of advantages and flaws. These enhanced people will be all-perfect, and ultimately, might even outcompete their unenhanced cousins into extinction. Thanks to genetic technology, we could create a new species of humans, and perhaps bring an end to Homo sapiens.
What is possible with genetic modification?
In 1953, Francis Crick and James Watson sent molecular biology into a spin by detailing the molecular structure of DNA, the molecule that encodes the instructions to make a living organism. This double-helix molecule, they said, was made of four nucleotide molecules (adenine, thymine, guanine and cytosine) in a specific sequence. They were bound in pairs along the length of the DNA—adenine with thymine, guanine with cytosine—and held in place by
a backbone of phosphate and sugar molecules.
Almost 50 years later, President Bill Clinton and UK Prime Minister Tony Blair held a joint press conference to announce that scientists had finished sequencing the 3 billion nucleotide letters contained in a human genome.
It was a huge moment. Understanding the DNA contained in a person is the key to understanding most, if not all, human diseases, including cancers and untreatable neurodegenerative conditions such as Alzheimer’s. DNA is also an important factor in the range of normal physical characteristics such as height, cognitive ability, muscle mass and rate of metabolism. The Human Genome Project revealed the basic letters and vocabulary with which nature writes its grand narratives of life. For the past ten years scientists have been trying to work out the stories that our genes are telling us. Curing disease is at one end of the applications possible with this genetic knowledge. Enhancing healthy people is at the other.
How easy is genetic modification?
The idea that you might be able to reprogramme your child’s genome to make sure it has the best possible traits has been the cornerstone of popular hopes for genetic technology. “When will it possible to remove harmful genetic mutations from my future baby?” you might ask. And while you’re doing that, why not give him blue eyes and an increased number of fast-twitch muscle fibers so that he can grow up to be a star sprinter?
For now, genetic reprogramming is hard work and the results are not guaranteed. There are many technical reasons: selecting a gene means that one or other of the parents has to have that gene to start with. And if you want a baby with a specific gene, you would need to create several dozen embryos at once and somehow select those with the most suitable genes. This technique, called pre-implantation genetic diagnosis (PGD), is used in combination with in-vitro fertilization (IVF).
If you want to program a whole genome with specific genes, however, PGD is very clunky. Altering a lot of specific genes at once would require the creation of scores (perhaps hundreds) of embryos, and then sorting through them to find a perfect match. Think of the number of eggs that would be wasted if you wanted to pick lots of different genes for your baby; and bear in mind that even if you found a perfect set, the chances of an embryo growing to full term in an IVF cycle are not guaranteed.
In addition, our understanding of genes is nowhere near sophisticated enough to be so prescriptive about the kinds of results a genetic programmer might demand. Diseases caused by a single gene defect are rare—a classic example is cystic fibrosis, a hereditary condition that can cause the airways in the lungs to become clogged with sticky mucus. Scientists have pinpointed that it is caused when both copies of the CFTR gene do not work properly. Most diseases have hundreds of genes involved at varying levels. And for physical characteristics, genes are only part of the picture, with the rest down to environmental factors. Having the genes for sprinting muscles is only useful if you train sufficiently to make them work.
Another way of reprogramming a genome is to alter the germ-line cell (the egg or sperm) of a parent. Scientists can already stop the action of particular genes in animals for the purposes of research, and this is done by modifying germ-line cells. The technique is full of dangers, though. Around 15 percent of such experiments tried out on mice have proved lethal, and an even higher number produce disabilities in the animals. Many genes have multiple uses in humans—the same gene is associated with a boost in IQ, for example, but also a muscle condition that can leave sufferers in a wheelchair.
The DNA double helix encodes for life. The “rungs” of the ladder-shaped molecule contain a 3-billion-long sequence of the chemical bases A, C, G and T and this is read by cellular machinery to make the proteins required by life.
A more promising way of altering gene expression is a technique that does not involve germ-line cells or programming fetuses. Instead it uses the body’s natural mechanism for deciding which genes are active in which cells and to what degree. This method, called epigenetics, is defined as the changes in gene expression that have nothing to do with the sequence of DNA. Epigenetics can change a huge range of things in an organism, from the shape of flowers to the color of a fruit fly’s eyes.
One procedure involves attaching molecules, called methyl groups, on to a specific part of a gene. In effect, the methyl group silences the action of the gene. The methyl group can be a temporary addition, and can even be introduced via local environmental factors, including chemicals or food.
The problem with unchecked modification
One day, we will overcome the technology hurdles. Imagine a future where you are able to choose what your kids look like (based, of course, on your own looks), whether they are tall or short, how good their eyesight is, whether they will be sprinters or marathon runners, how clever they will be and whether they will tend toward kindness or being selfish. Of course you will already have excluded any genes that might cause disease.
If these technologies become available, it is hard to imagine that people will not make use of them. The world is a competitive place; any advantage you can give your child has to be worth it, right? “This has been a focus for many opponents of germ-line genetic engineering who worry that it will widen the gap between haves and have-nots,” says Nick Bostrom, philosopher at the University of Oxford and director of its Future of Humanity Institute. “Today, children from wealthy homes enjoy many environmental privileges, including access to better schools and social networks. Arguably, this constitutes an inequity against children from poor homes. We can imagine scenarios where such inequities grow much larger thanks to genetic interventions that only the rich can afford, adding genetic advantages to the environmental advantages already benefiting privileged children. We could even speculate about the members of the privileged stratum of society eventually enhancing themselves and their offspring to a point where the human species, for many practical purposes, splits into two or more species that have little in common except a shared evolutionary history.”
These genetically privileged people, says Bostrom, might become ageless, healthy supergeniuses of flawless physical beauty, who are graced with a sparkling wit and a disarmingly self-deprecating sense of humor, radiating warmth, empathetic charm and relaxed confidence. “Everyone else would remain as people are today but perhaps deprived of some of their self-respect and suffering occasional bouts of envy. The mobility between the lower and the upper classes might disappear, and a child born to poor parents, lacking genetic enhancements, might find it impossible to successfully compete against the super-children of the rich. Even if no discrimination or exploitation of the lower class occurred, there is still something disturbing about the prospect of a society with such extreme inequalities.”
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The Human Genome Project provided the basic letters and vocabulary with which nature writes its grand narratives.
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Might there be a scenario in which there is so much tension between the enhanced and the unenhanced that they eventually go to war? Would the enhanced humans, with their superior strength and intellect, simply enslave their normal-human cousins? As far as modern humans go, it would spell the end.
Is it likely?
Our understanding of genes will continue to get better, and scientists will improve their ability to genetically modify humans. You could argue about how much will be possible, but there is little use in betting against what is essentially a technology issue. The question about its impacts, and the potential doomsday consequences for the modern human race, comes down to how the technology is made available, implemented and regulated.
One way of preventing potential problems is to ban everything. This might work among the law-abiding, but if the fruits of genetic enhancement were potentially big, a black market would soon develop and the two-tier society would still evolve. Bostrom suggests the opposite as a way to stem the problems. To counteract some of the inequality-increasing tendencies of enhancement technology, governments could widen access to the technology b
y subsidizing it or providing it for free to children of poor parents. “In cases where the enhancement has considerable positive externalities, such a policy may actually benefit everybody, not just the recipients of the subsidy,” he says. “In other cases, we could support the policy on the basis of social justice and solidarity.”
Which might sound like an overly rosy view of the world. But for anyone more cynical, Bostrom has another example of why genetic enhancements might not be the danger that pessimists imagine, in particular why a war between the enhanced and unenhanced is highly unlikely. Right now, the tallest 90 percent of the population could, in principle, band together and kill or enslave the remaining, shorter 10 percent of the human race, he says. “That this does not happen suggests that a well-organized society can hold together even if it contains many possible coalitions of people sharing some attribute such that, if they unified under one banner, would make them capable of exterminating the rest.”
It might be possible to use genetic technology to design a new human species and eventually destroy the original, unmodified humans. The only way to prevent that happening is to hope that humanity itself is not designed out in our quest for perfection.
Dysgenics
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Is our modern lifestyle interfering with natural selection? With better medicine and healthcare, are we allowing the spread of “undesirable” DNA, the stuff that would once have been weeded out of the human gene pool by evolution? Could this lead to big problems for our species?