by Alok Jha
This could be the case. The length of telomeres varies widely across species—in some birds it is up to a million base-pairs long, while in humans it is just over 10,000 base-pairs—and this might be indicative of Stindl’s “species clock.”
In the hypothesis, the erosion of the telomeres takes hundreds of thousands of years, which might explain the long, seemingly stagnant periods in evolution seen in the fossil record.
Is there a way to stop the decline?
If Stindl’s ideas are correct, how can we deal with the ticking clock in our DNA?
The body naturally produces an enzyme called telomerase reverse transcriptase, which can rebuild telomeres at the end of chromosomes after cells have divided. It might be possible to lengthen telomeres in embryos by somehow increasing the activity of this enzyme, thereby giving that person’s cells a longer lifespan. Unfortunately, adult humans produce little or none of it.
Scientists at the Dana-Farber Cancer Institute at Harvard Medical School have managed to rejuvenate mice by injecting them with telomerase. Without the enzyme the mice, which had been bred to mimic adult humans and not produce telomerase naturally, had been suffering from the effects of premature aging, including a poor sense of smell, shrinking brains, infertility and damaged intestines and spleens. When the mice were injected with telomerase for a month, the signs of aging were reversed. However, it is a proof of principle, and there would be problems translating that directly into humans—increased use of telomerase could lead to unchecked cell division, which is the start of cancer.
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Most species are not killed by asteroids or climate change; they just seem to whimper out.
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Telomeres can also lengthen in the normal course of things. After one of Stindl’s population crashes, small pockets of animals would have carried on, and Stindl reckons that inbreeding among the groups of survivors could reset the biological clock and lengthen the telomeres once again. There is some evidence from laboratory mice to support this idea of resetting—they have been intensively bred from a small starting population and have very much longer telomeres than their wild cousins.
Another solution might be to meditate. In the Shamatha Project, scientists from the University of California, San Francisco, have been investigating whether telomeres can be affected by psychological factors. Their early results are intriguing: at the end of a three-month retreat of meditation and relaxation, attendants of the Shambhala Mountain Center in Colorado had significantly raised telomerase activity. This is the first step to a reverse in cell aging and, eventually, a lengthening of the body’s telomeres.
It is unlikely that we will find a safe and robust way to lengthen our telomeres any time soon. But as the participants in the Shamatha Project might say, knowing the nature of the problem is the surest path to finding an answer.
It’s All a Dream
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You wake with a start, your sight blurred and your head feeling groggy. As the fog clears, you begin to remember. That life you led, the one on Earth—the Earth you have known, with its billions of people, its scientific achievements, art, culture, politics, problems, horrors and beauty—was nothing more than a dream. You imagined the whole thing. You have no idea what is real.
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Far-fetched or not, the idea that we are all in a dream has inspired philosophers and artists for thousands of years. It is a rich seam, from the ancient Chinese thinker Chuang Tsu, who wondered if he might be a butterfly dreaming he was a man, to multi-million-dollar Hollywood blockbusters such as The Matrix, in which a futuristic machine system imprisons all humans in a dream-like simulation of the modern world.
It is understandable. Dreams are the only immersive reality we experience apart from real life. When we dream, we do not know we are dreaming. However briefly, you really can believe that you are a Roman charioteer, a superhero capable of flying, or that you are having dinner with Albert Einstein. No one knows why we dream, but everyone has experienced a dream so vivid, they could not tell it was not real. It is, at the same time, the most natural, familiar and yet mystifying thing that billions of us do every day.
Artificial dreaming
If dreams happen naturally, is there any reason why we could not induce them artificially? Nick Bostrom, a philosopher and director of the Future of Humanity Institute at the University of Oxford, thinks it is just a matter of time. The basic idea behind his so-called “simulation argument” is that the vast amounts of computing power that may become available through technological advances in the future could be used, among other things, to run large numbers of fine-grained simulations of past human civilizations.
This raises the startling possibility that our minds are, right now, the products of computer simulations at some point far in the future. A bit like the people plugged into the Matrix, we think we are living in 2011, but in actual fact it is 2311 in the real world and our minds are being fed a simulated past. “If we are, we suffer the risk that the simulation may be shut down at any time,” says Bostrom. “Until a refutation appears of the argument ... it would be intellectually dishonest to neglect to mention simulation-shutdown as a potential extinction mode.”
Types of simulation
If you touch something hot, heat sensors in your fingers fire signals to your brain, which issues instructions telling you to pull your hand back via electrical signals to the muscles in your arm. The millions of inputs and outputs that characterize everyday actions are relegated to the subconscious, largely hidden from us as we go about our daily lives. Our thinking mind, the bit we are conscious of controlling, is aware of just a fraction of the inputs coming in from the senses, enough to keep us going without overloading us.
Our awareness of the world and our place in it is a result of electrical impulses that circulate around our brain cells. We interpret some of these electrical circuits as memories, others as feelings of pressure, yet more as elements of vision or sound. We exist in the world as flesh, blood and bone. But we only know it because of the electricity flowing around these brain circuits.
What if you could artificially induce these flows of electricity? Using implants, perhaps, what if a computer program could electrically stimulate your brain cells in precisely the right way at the right time to make your brain think your body was actually in a field surrounded by flowers, rather than strapped to a computer?
This is called the “brain in a vat” scenario. The philosopher David J. Chalmers describes it thus: a “disembodied brain is floating in a vat, inside a scientist’s laboratory. The scientist has arranged that the brain will be stimulated with the same sort of inputs that a normal embodied brain receives. To do this, the brain is connected to a giant computer simulation of a world. The simulation determines which inputs the brain receives. When the brain produces outputs, these are fed back into the simulation. The internal state of the brain is just like that of a normal brain, despite the fact that it lacks a body. From the brain’s point of view, things seem very much as they seem to you and me.”
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The point of a simulation is that you cannot tell that you are in it.
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The brain is clearly deluded by the simulation. It thinks it has a body, when none actually exists. It believes it is walking outside in a sunny park in London, when it is in fact in a dark lab in San Francisco. The reality experienced by the brain is clearly false, at least compared to “real” reality. Nonetheless, the brain (and the person in that brain) experiences its world with as much visceral clarity as you or I do ours.
How do we know what is real?
“When the possibility of a matrix is raised, a question immediately follows. How do I know that I am not in a matrix? After all, there could be a brain in a vat structured exactly like my brain, hooked up to a matrix, with experiences indistinguishable from those I am having now,” says Chalmers. “From the inside, there is no way to tell for sure that I am not in the situation of the brain in a vat. So it
seems that there is no way to know for sure that I am not in a matrix.”
The point of a simulation is that you cannot tell that you are in it. If the designer of the simulation was benevolent and wanted us to know, however, he or she could make it abundantly clear what was happening. “For example, the simulators could make a ‘window’ pop up in front of you with the text ‘YOU ARE LIVING IN A COMPUTER SIMULATION. CLICK HERE FOR MORE INFORMATION.’ Or they could uplift you into their level of reality,” says Bostrom. Or we could find strong indirect evidence one day, perhaps by creating our own perfect simulation.
But what if our computer simulators were not feeling so benevolent? In that case, we had better hope that their simulation is not so perfect.
Perhaps the computing power needed to create a perfect simulated universe that behaves like ours at the smallest scales is too great, even for futuristic civilizations. But a simulation does not have to be anywhere near comprehensive in order to fool our brains. Your simulated hands do not need to have the structure of real hands, unless you are going to train a microscope on them, in which case the simulation could easily be added to for that particular moment. In other words, details only emerge if someone pays attention.
“The idea is that some of our experimental findings could be ‘faked’ by the simulators, if they wanted to conceal the fact that we are in a simulation and if such faking was the most efficient way to conceal it,” says Bostrom. “Consider the fact that while you are dreaming, your own brain often succeeds in making you unaware of the fact that you are dreaming. If your own humble brain can do this, then presumably it would be quite feasible for some technologically super-advanced builders of ancestor-simulations to achieve the same delusion.”
A more promising method of working out whether we are in a simulation is to look for glitches and bugs in the program. These might manifest themselves as miracles or paranormal activity in the world around us. Perhaps as things that defy the known laws of physics. Again, this strategy is fraught with problems: seeing something odd is not conclusive, and a motivated simulator could simply erase the mind of anyone in the simulation who was hell-bent on looking for errors.
Does it matter if we are dreaming?
We might be brains floating in jars somewhere in a dark room, but our beliefs are still always real, says Chalmers. Perhaps, he adds, we are disembodied minds outside space–time, made of ectoplasm. “When I think ‘I am outside in the sun,’ an angel might look at my ectoplasmic mind and note that in fact it is not exposed to any sun at all. Does it follow that my thought is incorrect? Presumably not: I can be outside in the sun, even if my ectoplasmic mind is not. The angel would be wrong to infer that I have an incorrect belief. Likewise, we should not infer that an envatted being has an incorrect belief.”
The moral, he says, is that the immediate surroundings of our minds may well be irrelevant to the truth of most of our beliefs. What matters is the processes our minds are connected to, those sensory and motor inputs that create the illusion of reality in our brains. Everything else is extraneous anyway.
Information Extinction
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Many tens of thousands of years ago, groups of early humans would make marks on the walls and ceilings of caves. They scratched and painted images of bison and elephants and the people who hunted them. Some of them left behind abstract symbols on the rock, others made clear handprints. Thousands of years on, we can still see the marks they made.
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Throughout time, humans have used many ways to record their knowledge and tell the stories of their lives. Only a few thousand years ago, Babylonians made records of the movements of heavenly bodies on clay tablets. And all of that information is intact. It may take time for us to understand what they are telling us, but we can see the symbols and work out something of the lives of our ancestors.
Thousands and tens of thousands of years from now, what will our descendants know about us? We have more knowledge today than any of our ancient ancestors, and we probably create more knowledge in a year than our predecessors might have done in centuries. We record all of it in myriad ways—on paper, in painting, but mostly on electronic hard disks.
What if the Earth were to succumb to some cataclysm in which the computers that store our knowledge were all compromised? Perhaps the power grids would go down for good, or most of the world’s population would be wiped out by a virus, leaving no one left to maintain the machines. If, in tens of thousands of years, we wanted to tell the story of the 21st century, what would our descendants be able to retrieve?
If they forgot all about us, it might not be the end of the world in physical terms, but it would be the end of our world.
Our modern memories
We live in an unparalleled age in human history, driven by information and kept functioning through an intricate network of computers, switches and data connections. It is the latest step in the human ability to transfer complex knowledge from one person to another, from one place to another, from one generation to another, an ability that has defined our path to becoming the most dominant species on the planet.
To get to where we are, we needed a collective memory, something that all of humanity could add to and access. First there were stone tablets distributed among the few, then came paper and writing, after that books, and today, we have hard disks. Whereas in the past the systematic records in existence were bureaucratic, legal or ecclesiastical documents, nowadays we record much more and more often.
“The digital revolution is transforming the nature of personal archiving: from curation techniques to the kinds of lives being preserved for posterity—not just the rich and famous, but now everyone participating in the digital age,” says Jeremy Leighton John, curator of eMANUSCRIPTS at the British Library. With the emergence of personal computing in the 1970s, says John, more and more people are passing on details of their lives to future generations as digital files. The electronic hard disk is the substrate for our collective memory, and there are several in each modern home, hundreds in each scientific laboratory, billions around the world.
On those disks are all of our ideas—histories, photographs, diaries, data, novels, bank records, films, scientific theorems—whole or in fragments. And most of them are personal: the International Data Corporation estimated that by the end of the first decade of the 21st century, around 70 percent of the world’s digital information will be created by individuals rather than organizations.
The problem is that hard disks have never been intended for very long-term storage and no one really knows if they will survive with their precious cargo intact. Every year, as technology advances, hard disks become smaller, thinner and more dense with information. This is good if you want a smaller computer or to put memory in places where it has never been before (a fridge, say, or a phone). But there are problems, too—the smaller a disk is, the more information is kept on it per square centimeter and the more of that information you lose if the disk gets damaged.
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If, in tens of thousands of years, we wanted to tell the story of the 21st century, what would our descendants be able to retrieve?
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Important information on hard disks is often backed up on magnetic tapes or optical discs such as CDs or DVDs. But these formats are no more trustworthy than hard disks. In tests, the best discs have been shown to survive for perhaps a century. The cheapest CDs will last between five and ten years before dropping information and starting to become unreliable.
Prehistoric rock paintings found at Tassili N’Ajjer in Algeria. It has survived thousands of years to pass its messages on to modern humans. Will our storage devices do the same?
And the tide of new information goes on. “Future generations may well have comprehensive video and [GPS] recordings of their lives, along with records of neurological and physiological parameters such as heart rate, not to mention personal DNA sequences,” says John. “Bionic devices that partially restore, enhance or extend an indiv
idual’s physical or sensory capabilities will be digitally tuned for each individual, just as digital hearing aids are today. Personal fabricators will allow individuals to create for themselves useful and ornamental physical artifacts. People already interact online through virtual versions of themselves in online gaming environments, and in future this will be advanced with immersive visualization, complemented by touch, taste and scent. What will happen to these digital representations in the long run?”
How much of a loss would it be if this information was irretrievable in the future? The details of your daily life via Twitter, Facebook or Flickr probably will not matter much to the humans living 20,000 years from now. It is the same with the surviving ancient manuscripts and stone tablets—these are important for their historic rather than their informational value.
But what about all that genome-sequencing data that we have been patiently collecting for the past few decades? How about the raw information from the Large Hadron Collider, which can be mined for years to come to understand and explain the laws of physics? How about the blueprints to make aircraft, computer circuits and radio transmitters? What about our great novels and the histories of what happened while we were alive?
Sending messages to the future
Another problem presents itself to anyone thinking about how to make sure knowledge persists: language. Would we be able to understand the humans living 10,000 years ago? Probably not. So who is to say that anyone in the future will speak our language? It is a problem facing scientists who want to bury the waste from nuclear power stations, material that will remain radioactive for hundreds of thousands of years. They need to place signs outside the facilities that will communicate the danger of what lies within, and there is no reason to expect that humans 500 generations from now will understand our language or customs. The nuclear scientists have to guess what might be meaningful to people in the distant future.