For reasons I’m about to explain, I’m pretty sure about that. What I’m wondering is how Musk himself compares the two. He has declared publicly that he’s going after both goals and is sure of reaching them, though he’s talked considerably more about Mars than about the mind, but what does he think privately? I haven’t got the foggiest idea. But I do believe that if he had a more realistic understanding of what’s involved in direct brain-to-brain (B2B) thought transmission he would not be espousing it as the ultimate goal of Neuralink.
We have a very rich framework in which to think about manned missions to Mars. We’ve already landed men on the moon and returned them to earth. Astronauts have spent weeks and months, even a year, living in low-earth orbit in the International Space Station. We’ve landed robots on Mars and gotten useful information back. All of that experience is relevant to sending humans to Mars and – here’s the point – we’ve got frameworks in which we can evaluate that experience against the requirements of a manned mission to Mars. We have a rich understanding of the mechanical, kinematic, chemical, thermodynamic, electrical, and electronic principles involved in building the devices needed to perform the mission. We also know quite a bit about the biological and psychological requirements of supporting human life for such a mission.
Musk knows all that, certainly better than I do and perhaps as well as if not even better than any other single human currently alive. He’s trained in science and engineering and has experience in both arenas. While I have reservations about the business case for going to Mars (see Steve Rosenbaum’s remarks in the video below), the technical case seems reasonable to me.
B2B thought transmission
But he has little or no training in neuroscience (full disclosure, neither do I), though he has hired specialists for Neuralink. Of course, one doesn’t have to have formal training in an area in order to develop expertise in it. Just how much expertise Musk has developed, I don’t know.
I see two kinds of issues in developing technology for B2B thought transmission: 1) matters of principle, and 2) the technology itself. If I am right about the principle, then it doesn’t matter what kind of technology Musk, or anyone else, develops. It won’t work. But let’s set that aside for the moment.
The basic problem with developing technology is that, 1) the brain is relatively inaccessible beneath the skill, 2) neurons are very small, and 3) we don’t understand how neurons and the brain work. In contrast to, say, the physics and mechanics of rocket technology, our knowledge of basic principles is still poor.
I believe that there has been a fair amount of work on brain implants of one kind or another going back to the 1950s with the work of Jose Delgado. As far as know I we have yet to see the full-time routine implantation of a device in the brain that either controls motor activity or provides sensory input. There have been limited laboratory experiments with animals and medical experiments, but no permanent clinical use.
There are various problems. The brain is a hostile environment for anything we implant. Neurons are very small, so accurate targeting is extremely difficult. Moreover, interpreting neural impulses is difficult, as is generating artificial impulses to the muscles. And then there is the problem of numbers: The brain has roughly 86 billion neurons, each of then connected to 10,000 neurons on average. How many neurons are we going to have to tap for B2B thought transmission? 100 million? A billion? All of them? What kind of hardware would allow us to do this without shredding the brain? Neuralink’s current interface has 1000 electrodes, which is far from a million, let alone a billion.
That’s one problem. But let us assume we can link however many neurons are necessary for B2B communication without in any way harming the brain. It’s not at all clear to me that this would work. Why?
When the interface is activated, both brains will be receiving millions upon millions of impulses they had never before received. If thoughts are to be exchanged, then each brain must be able to tell which impulses are its own and which are coming from the other brain? How are the brains going to do that? If they can’t then how can they exchange thoughts? The idea doesn’t make any sense. As far as I can tell, the most likely result of such an interface would be confusion and perhaps, over time, the two individuals would learn how to function under these conditions, but this is by no means certain. I discuss this issue at greater length here, Why we'll never be able to build technology for Direct Brain-to-Brain Communication.
As far as I know, neither Musk, nor anyone else in this arena, such as Christof Koch or Rodolfo Llinás, has addressed this issue. It doesn’t seem to have occurred to them.
What does Elon believe?
Here then is my question: Does Musk think these two challenges, manned missions to Mars and direct B2B communication, are of roughly equivalent difficulty? It’s one thing to pursue both believing that one is merely of moon-shot difficulty while the other is out there beyond the twilight zone. That seems risky and foolish, but at least Musk knows it’s risky and foolish.
It’s quite something else to believe they are on roughly the same footing or that B2B communication is perhaps more difficult than going to Mars, but not THAT much more difficult. If THAT is what Musk believes, why? In one case, Mars, he can spell out the technical challenges in great detail and list possible solutions. In the other case, B2B thought transfer, there’s a whole lot of nothing that he’s overlooking. The list of potential problems is long and open-ended and the list of potential solutions is, at best, a work of fiction.