Ralph Merkle and Tanya Jones answering questions from the audience at Transvision 2007
Ralph Merkle co-invented public key cryptography, for which he received the ACM Kanellakis Award, the IEEE Kobayashi Award, and the 2000 RSA Award in Mathematics. He is directly involved in the research of molecular manufacturing, also called nanotechnology or molecular nanotechnology. The central objective of which is the design, modeling, and manufacture of systems that can inexpensively fabricate most products that can be specified in molecular detail. Such systems are today theoretical, but should revolutionize 21st century manufacturing.
Dr. Merkle is a distinguished professor at the College of Computing at Georgia Institute of Technology and previous nanotechnology researcher and theorist at Xerox Palo Alto Research Center and Zyvex corporations. He has served for several years as an executive editor of the journal Nanotechnology, chaired both the Fourth and Fifth Foresight Conferences on Molecular Nanotechnology, and won the 1998 Feynman Prize in Nanotechnology for theory. At the 6th Alcor conference in Scottsdale, Arizona he delivered a talk entitled “Nanotechnology and Cryonics,” outlining the intersection between the two developing fields of science.
The following transcript of Ralph Merkle’s 2006 Alcor conference presentation has not been approved by the author. DVDs of the 6th Alcor conference are available for purchase at the Alcor website.
Nanotechnology and Cryonics
The first thing I thought I’d do is put in a plug for two things. One is my own cryonics website. The other site that I would really recommend to you is the Alcor website. It’s really worthwhile. I think there was a large impetus given a few years ago to improvements in the website when we had all of the legislative action going on, and we wanted to have the best information possible up on the website. And since then, it’s just been getting better.
So, I just thought I would put in that plug. Now what I would like to talk about, briefly, is nanotechnology. Nanotechnology will give us complete mastery of this new and amazing capability. It will let us manufacture products that are of remarkable precision, will get almost every atom in the right place, and we should be able to achieve manufacturing costs that are not a lot greater than the cost of raw materials and energy.
To give you a brief idea of what this means, it’s kind of like the economics of manufacturing are going to shift over to being largely like the economics of software. So, we are going to see a fundamental shift in our manufacturing paradigm, and a fundamental change in how we go about doing business in terms of manufacturing. And this has a big impact on all aspects of our physical world, and it is going to have a very big impact on medicine. Nanomedicine is going to be a complete change.
So, one of the key ideas that I would like to bring to the fore is that at our size we think nothing of holding parts and positioning them and assembling them. At the molecular scale, we don’t have that yet. We are just beginning to be able to hold and position molecular tools, and we’ve seen some remarkable advances in that capability. So bringing that ability to hold and position molecular tools down to the molecular level is going to have a huge and very favorable impact on technology in general and on medical technology, including cryonics, in particular.
Okay, so that’s a really brief introduction to nanotechnology. What’s the impact going to be? We are going to have very powerful computers. We will have computers the size of a sugar cube that have more computational power than all the computers in the world today. And I think I have to begin to be a bit cautious about that statement. I’ve been making that for many years and I think time is catching up. I may have to bump it into a few sugar cubes. Because all the computers in the world today are beginning to have a fair amount of computational power.
We will have more than 10^21 bits in the same volume. You know what a CD is, it has half a gigabyte of memory on it. Now imagine a football stadium filled up with CDs, crammed to the top. That is about 10^21 bits. And we’re going to be able to pack that into a sugar cube. We’re going to have really amazing memory technology, and be able to put almost a billion Pentiums in parallel. I’m not talking about Pentium 4′s, but old-fashioned Pentiums. We will have so much computational power that we will be able to run Windows 2015 and it will be zippy fast. Completely astonishing.
So let me then go into the scale of the kind of things we are talking about. In a sugar cube you can pack huge amounts of computational power and memory, but if you are talking about medical applications, you might want something that is fairly small, something that would be able to fit through your circulatory system, for example. And when you look at it, you can shrink things down to, say, 100 nanometers on a side. And a nanometer, again, is a billionth of a meter. It’s only a little bigger than an atom. So, a cube a hundred nanometers on a side is pretty small. And we will be able to fit a small CPU, probably an 8-bit processor, into that kind of volume. And we will also be able to have robotic arms, positional devices, that can reach out and position things at that size frame, and we will have a whole range of other capabilities, all at that size.
This is very small. It’s much smaller than the subcellular organelles. An “ordinary” cell is perhaps 20 microns in size. So, we are looking at a huge difference in size. Abandon the idea that cells are these very, very teeny things. From the point of view of molecular machines, cells are these gigantic empty spaces, and you can pack literally hundreds of thousands of molecular machines into a single typical cell. This is going to lead to a fundamental change in medicine. Right now, the key issue in medicine is to keep the tissue functioning. If tissue is not functioning, it cannot repair itself. We have no ability to repair tissue that is damaged beyond its own self-repair capability. We can provide support to the cells, but basically the cells are repairing themselves. As a consequence, cellular function must be preserved because if cellular function is lost, the cell is set on a downward spiral that we today are helpless to stop.
In the future, with cell repair systems, we will be abe to repair passive structures. So, structures that are beyond our present medical capability, structures that are no longer functioning but are largely intact, will be repairable by using molecular machines that are small, precise, and will be able to deal with the kind of damage at the molecular and cellular levels that we see in those tissues. I cannot overemphasize the importance of this distinction. If you lose function, that happens relatively easily. Losing structure is difficult, and, in fact, there is every reason to believe that the kind of structural preservation we can provide today will be enough for future repair technologies to reverse the damage.
Dr. Merkle during his presentation at the 6th Alcor Conference on cryonics
This brings us to cryonics. Cryonics, as you all know, is the process of cooling tissue using the best currently available technology down to the temperature of liquid nitrogen. And then, when we develop this future technology, of warming the tissue back up. If you take a purely scientific view of what is cryonics or whether it works, the first thing you would do is say, “Let’s conduct clinical trials.” Clinical trials are very simple in medicine. If someone wants to know whether a procedure or treatment is helpful, then the answer is you try it out and see if it works. This is what we would want to do with cryonics. Now, the correct experimental process for testing this to see if cryonics works is to select some subjects, vitrify and cool them down to the temperature of liquid nitrogen, then wait a hundred years to see if the medical technology of 2100 can indeed revive them.
Now, we have a problem, which is that we do not have the results of that experiment today. The correct answer to the question “Does cryonics work?” is that from the point of view of clinical trials, come back in a hundred years. The experiment is ongoing. And the question that we have to ask ourselves today is, Do you want to be in the experimental group or the control group? We have a high degree of confidence about what happens to the control group. We do not have a high degree of confidence about what happens to the experimental group, and, in fact, I think the odds for the experimental group are pretty good.
And, in fact, this leads to a payoff matrix. There are one of two possibilities. Either cryonics works or it does not. And either you sign up or you don’t. If you do not sign up, or cryonics does not work, then the outcome is the familiar one, and it’s uninteresting. But if cryonics works, and you sign up, then you will be welcomed into a future of very advanced technology. We know that it will be very advanced because we have to have the advanced technology to revive people. And you will be awakened into a future where the basic value of human life has been preserved, because if human life has been lost as a value, you won’t wake up. So, we have pretty much as a guarantee that if you wake up it will probably be a pretty good future.
A critical point is that cryonics is not about freezing people who are dead. Death, a permanent cessation of all vital functions, is exactly what I expect not to happen with cryonics. We expect a temporary suspension, followed by waking up and again being healthy. And if you meet someone on the street and you say, “Hello, how are you?” A nd they say, “I’m fine.” And you say, “But I thought you were dead.” And their response likely is, “Well, no. The rumors of my demise have been greatly exaggerated. I am, in fact, alive, as you can see. Oh, I did spend some time, while I was legally dead, (and we know law and reality go their separate ways,) I’m over that now and I’m all better.”
So, basically, our distinction is that we dispute the diagnosis of death. We want a second opinion from a future position. This idea, that it’s hard to tell when someone is dead, actually goes back to ancient times. Democritus in around 400 BC asserted that there are in reality no characteristics of death sufficiently certain for physicians to rely upon. And he was being quoted by Aulus Cornelius Celsus, who wrote De Medicina, which is a text dating back to about the first century AD. So we’ve had this concern, about how you tell when someone is dead, for a long time. In fact, there have been problems with the diagnosis of death.
In the 19th century, people were alarmed by the prevalence of premature burial. And as a consequence, they often requested as part of the last offices that wounds or mutilations be made to ensure that they would not awaken. Embalming recieved a considerable impetus from the fear of premature burial. Compared with today’s statistics, you would often find that people were in fact buried alive, because the diagnostic criteria were rather rough and were not always accurate.
Today, if you look at modern definitions of death, and you go to the philosophers who are talking about it, and I’m quoting particularly from Robert Veatch, basically there continues to be this same uncertainty about what it is to be dead. And people bemoan the fact that our current medical criteria are inelegant and don’t seem to have any theoretical underpinnings, and are justified merely by an empirical result, which is that people who are declared dead don’t very often wake up in the morgue. And seriously, this is exactly what the definition of death is for. The definition of death is a pragmatic decision made by physicians today when a patient has reached the point where none of the procedures available today are capable of reviving them.
That’s what death is all about. It’s a statement that our current medical technologies are not able to revive the patient. There is no statement whatsoever about whether future technologies will or will not be able to revive the patient. And this raises an obvious and interesting question. Is there a criterion for death which is in fact solidly founded and which would be applicable regardless of future advances in technology. And the answer is yes. It’s been called information theoretical death. If the structures in the brain that encode memory and personality have been so disrupted that it is no longer possible in principle to restore them to an appropriate functional state, then the person is dead. In other words, if we can restore you in principle, if within the framework of the known laws of physics it is possible to restore you to a healthy, functional state you’re not dead.
So, with that thought in mind, we can now begin to look at our current environment. We have legal death on the one hand, which we require before we can be cryopreserved. And we have information theoretical death on the other hand. So, you can look at a lot of tissues that have been successfully cryopreserved, and there is a whole long list of tissues that have been cooled down to low temperatures and been warmed up successfully, which implies that the level of damage that takes place must be pretty small, because a lot of tissues can survive the process. You find things like control studies on protein stability in postmortem rat cerebella show that the spectrum of abundant proteins is also unchanged after up to 16 hours at room temperature.
So if someone says, “Gee, when you die, your proteins fall apart.” No, that is not true. There have been studies. The proteins are still there 16 hours later. That sounds like a good thing. You also find that in studies lysosomes did not rupture for approximately four hours, and in fact did not release fluorescent dye until after reaching the postmortem necrotic phase of injury. I don’t know what the necrotic phase is, but it sounds bad. But, whatever it is, it’s obviously taking place after four hours. You find statements from a number of sources that say damage under the light microscope is not seen until 24 hours postmortem. And you also find that this claim that the brain dies after five or six minutes is incorrect. To quote from Hossman, “It turned out in fact that appropriate treatment of post-ischemic recirculation disturbances led to recovery of energy metabolism and
neuronal excitability after complete cerebro-circulatory arrest of as long as one hour at normal body temperature.”
So there seems to be evidence of recovery of function after an hour under optimal conditions, not the conditions one normally finds in cryonic suspensions. But it does indicate that structure and function are preserved longer than one would anticipate. You then start asking fundamental questions like, “What is it we are trying to preserve?” And the answer that comes back is, well, memory. Structures that encode your personality. A lot of that information is stored in synapses. It appears that synaptic changes are the hallmark of long-term memory. And we see that synapses are preserved, actually, quite effectively by cryopreservation. We also find that once you’ve been cooled to the temperature of liquid nitroge, you are going to be preserved for a long time, very effectively.
So, the next question is, “Is information theoretical survival enough?” In principle, it is. And in practice, I think it will be enough once we approach what is feasible in principle. Now, we will be able to engage in complete structural analysis and repair, down to the level of molecules and atoms. A major technology for doing this would be scanning probe microscopy, or future descendants of scanning probe microscopes, which would basically be able to scan over a surface and analyze it, gradually moving through the tissue, removing molecules and laying bare what lies underneath, analyzing that in turn. For this to be practical with the volume of the human brain, you would literally have to have billions and billions of repair devices. If we had 3 x 10^15, that’s about three million billion, so that’s a lot.
If you had that many repair devices, you could go through the repair process in tissue preserved at low temperature in about three years. And that seemed like a reasonable set of assumptions on which to proceed. So, if you want to, it was actually published in Medical Hypotheses. I discuss the various repair scenarios that would occur, and conclude that there are a number that would work quite nicely.
Cryonics is not for everyone. Not everyone would decide cryonics was a good idea, even if you provided 100% assurance. To give you an example, Shirley MacLaine has said, “Everyone who has died and told me about it said it was terrific!” So, I think that she would decline the invitation, even given absolute assurances that technically it would work like a charm.
So, if I could close out with a quote from Bones McCoy of the Starship Enterprise, “Don’t leave him in the hands of 20th century medicine.”
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