Dear PC: R.I.P.

February 21, 2001 by Ray Kurzweil

Ray Kurzweil’s vision of the post-PC future includes nanobots and fully immersive virtual reality.

Originally published September 9, 2000 at Published on February 22, 2001.

Many long-range forecasts of technical feasibility dramatically underestimate the power of future technology because they are based on what I call the “intuitive linear” view of technological progress rather than the “historical exponential view.” It is not the case that we will experience 100 years of progress in the 21st century; rather we will witness on the order of 20,000 years of progress (at today’s rate of progress, that is).

Careful consideration of the pace of technology shows that the rate of progress is not constant, but it is human nature to simply adapt to the changing pace, so the intuitive view is that the pace will continue at the current rate. Even for those of us who have lived through a sufficiently long period of technological progress to experience how the pace increases over time, our unexamined intuition nonetheless provides the impression that progress changes at the rate that we have recently experienced. One reason for this is that an exponential curve approximates a straight line when viewed for a brief duration. So even though the rate of progress in the very recent past (i.e., this past year) is far greater than it was 10 years ago (let alone 100 or 1,000 years ago), our memories are nonetheless dominated by our very recent experience. It is typical, therefore, that even sophisticated commentators, when considering the future, extrapolate the current pace of change over the next 10 years or 100 years to determine their expectations. This is why I call this way of looking at the future the “intuitive linear” view.

But any serious consideration of the history of technology shows that technological change is at least exponential, not linear. There are a great many examples of this, of which the exponential growth of computing is just one. One can examine data on a wide variety of technologies, and on many different time scales, and see (at least) double exponential growth described by what I call the “law of accelerating returns.” This observation does not rely on an assumption of the continuation of Moore’s Law, but is based on a rich model of diverse technological processes. What it clearly shows is that technology advances (at least) exponentially and has been doing so since the advent of evolution on Earth. Most technology forecasts ignore altogether this “historical exponential view” of technological progress and assume instead the “intuitive linear view.” That is why people tend to overestimate what can be achieved in the short term (because we tend to leave out necessary details), but underestimate what can be achieved in the long term (because we ignore the fact of exponential growth).This observation also applies to paradigm shift rates, which are currently doubling (approximately) every decade. So, technological progress in the 21st century will be equivalent to what would require (at today’s rate of progress) on the order of 20,000 years. In terms of the growth of computing, the comparison is even more dramatic.

In considering applying the law of accelerating returns to the genesis of Moore’s Law, I put 49 famous computing devices over the past century on an exponential graph. From this exercise, it became apparent that the acceleration of computing power did not start with Moore’s Law at all, which is an insight regarding integrated circuits, but has continued through multiple paradigm shifts (electromechanical calculators, relays, vacuum tubes, transistors, and finally integrated circuits). Moore’s Law was not the first but the fifth paradigm to provide exponential growth in computing. The sixth paradigm, which will involve computing in three dimensions rather than the two manifested in today’s flat chips, will lead to computing at the molecular and, ultimately, the subatomic level. We can be confident that the acceleration of computing will survive the well-anticipated demise of Moore’s Law.

There are comparable exponential trends underlying a wide variety of other technologies. Communication speeds, both wired and wireless, are doubling every 12 months (this is, again, a double exponential trend because it was only doubling every 36 months two decades ago). Brain scanning speeds are doubling every 26 months and brain scanning resolution (per unit volume) is doubling every 12 months. Genetic scanning is doubling every 12 months with DNA sequencing costs having fallen from $12 per base pair to less than 1 cent in the past decade.

Miniaturization is another pervasive trend: We are currently shrinking technology (both electronic and mechanical) at a rate of 5.6 per linear dimension per decade. The mathematical models I’ve developed over the past couple of decades to describe these trends resulting from the law of accelerating returns have proven predictive of the developments we’ve seen during the 1990s. From these models, I believe we can be confident of continued exponential growth in these and other technologies for the foreseeable future.

 It is important to point out that these trends interact with one another in profound ways. We are currently seeing exponential trends in computation, communications, and miniaturization manifest themselves in the explosion of handheld wireless devices that access the Web. As an aside, it is ironic that Microsoft is being cited for a monopoly in “personal computing” operating systems just as the PC era is coming to a close: The predominant growth now in computing is in Webservers and handheld devices, neither of which is dominated by Windows.

 Because these devices are not large enough to provide a full keyboard, we will see a strong trend toward communicating with our machines through voice and language technologies. Talking is how we prefer to communicate with other people, and the broad trend in computing since its inception has been for machines to become more like people, rather than for people to become more like machines. Over the next several years, a legion of virtual assistants will emerge with sufficient intelligence to converse in natural language within limited task domains, such as conducting ecommerce transactions, making reservations, and finding information. When a display is available, even a small one, these virtual personalities will have a humanlike visual presence; without a display, they will work entirely using two-way voice dialogues.

By 2009, computers will disappear. Visual information will be written directly onto our retinas by devices in our eyeglasses and contact lenses. In addition to high resolution virtual monitors appearing to hover in space, these intimate displays will provide full-immersion visual virtual reality. We will have ubiquitous very high bandwidth wireless connection to the Internet at all times. “Going to a Website” will mean entering a virtual reality environment–at least for the visual and auditory senses–where we will meet other real people. There will be simulated people as well, but these virtual personalities will not be up to human standards, at least not by 2009. The minuscule electronics powering these developments will be invisibly embedded in our glasses and clothing. Thus we won’t be searching for our misplaced mobile phones, Palms, notebooks, and other gadgets. And we won’t have to deal with the mess of wires that now entangle our lives. We will be plugged in all the time, and able to have any type of interaction with anyone regardless of physical proximity.

 Any sort of communication, that is, except for touching. Tactile virtual reality devices are already emerging, but will remain cumbersome until virtual reality enters our bodies and brains. By 2029, as a result of continuing exponential trends in miniaturization, computation, communication, and neural scanning, we will have billions of nanobots–intelligent robots the size of blood cells or smaller–traveling through the capillaries of our brain communicating directly with our biological neurons.

 Nanobot technology will provide fully immersive, totally convincing virtual reality in the following way. The nanobots take up positions close to every interneuronal connection coming from all of our biological sensory receptors (e.g., eyes, ears, skin). We already have technology for electronic devices to communicate with neurons in both directions that requires no direct physical contact with the neurons. For example, scientists at the Max Planck Institute in Heidelberg, Germany, have developed “neuron transistors” that can detect the firing of a nearby neuron, or alternatively, can cause a nearby neuron to fire or suppress it from firing. This amounts to two-way communication between neurons and the electronic-based neuron transistors. The institute’s scientists demonstrated their invention by controlling the movement of a living leech from their computer.

 When we want to experience nonvirtual reality, the nanobots will just stay still (in the capillaries) and do nothing. If we want to enter virtual reality, they will suppress all input coming from the real senses, and replace them with the signals that would be appropriate for the virtual environment. You (i.e., your brain) could decide to cause your muscles and limbs to move as you normally would, but the nanobots again intercept these interneuronal signals, suppress your real limbs from moving, and instead cause your virtual limbs to move and provide the appropriate movement and reorientation in the virtual environment. Of course, your virtual body will not need to have the same appearance and other characteristics that it has in real reality–we could have different bodies for different partners and situations.

The Web will provide a panoply of virtual environments to explore. Some will be recreations of real places, others will be fanciful environments that have no “real” counterpart. Some would be impossible in the physical world (perhaps, because they violate the laws of physics). We will be able to “go” to these virtual environments by ourselves or we will meet others there, both real people and simulations. Of course, ultimately, there won’t be a clear distinction between the two.

Just as Webcams showing people’s intimate lives are popular today, during the fourth decade of this century, people will “Web beam” their lives, and you will be able to share the full sensory experience and even emotional response of others through the Web, similar to the plot concept of the movie Being John Malkovich, except that these experiences can include emotional levels beyond just the five senses. Particularly interesting experiences will be archived and can be relived at any time.

 Nanobot technology will be able to expand our minds in almost any imaginable way. Our brains today are relatively fixed in design. Although we do add patterns of interneuronal connections and neurotransmitter concentrations as a normal part of the learning process, the current overall capacity of the human brain is highly constrained, restricted to a mere 100 trillion connections. Brain implants based on massively distributed intelligent nanobots will vastly expand our memories and otherwise improve all of our sensory, pattern recognition, and cognitive abilities. Since the nanobots are communicating with one another over a wireless local area network, they can create any set of new neural connections, can break existing connections (by suppressing neural firing), and can create new hybrid biological-nonbiological networks, as well as adding vast new nonbiological networks.

 Using nanobots as brain extenders is a significant improvement over the idea of surgically installed neural implants, which are beginning to be used today (for people with disabilities and medical conditions such as deafness and Parkinson’s disease). Nanobots will be introduced without surgery; they will be injected or swallowed. People will have the power to direct them to leave, so the process will be easily reversible. The bots would be programmable, in that they could provide virtual reality one minute, and a variety of brain extensions the next. They could change their configuration, and alter their software. Perhaps most importantly, unlike surgically introduced neural implants that can only be placed in one or at most a few locations, these nanobot-based implants will be massively distributed and therefore can take up billions or trillions of positions throughout the body.

 Oh, and one more thing: We’ll live a long time. The expanding human life span is another one of those exponential trends. In the 18th century, we added a few days every year to human longevity; in the 19th we added a couple of weeks each year; and now we’re adding almost a half a year every year. With the revolutions in rational drug design, genomics, therapeutic cloning of our own organs and tissues, and related developments in bio-information sciences, we will add more than a year every year within 10 years. So take care of yourself the old-fashioned way for just a little while longer, and you may actually get to experience the remarkable century ahead.

Reproduced with permission. Copyright (C) 2000 Business 2.0