8. “Crookes radiometer,” Wikipedia, http://en.wikipedia.org/wiki/Crookes_radiometer.
9. Note that some of the momentum of the photons is transferred to the air molecules in the bulb (since it is not a perfect vacuum) and then transferred from the heated air molecules to the vane.
10. Albert Einstein, “Does the Inertia of a Body Depend Upon Its Energy Content?” (1905). This paper established Einstein’s famous formula E = mc2.
11. “Albert Einstein’s Letters to President Franklin Delano Roosevelt,” http://hypertextbook.com/eworld/einstein.shtml.
Chapter 3: A Model of the Neocortex: The Pattern Recognition Theory of Mind
1. Some nonmammals, such as crows, parrots, and octopi, are reported to be capable of some level of reasoning; however, this is limited and has not been sufficient to create tools that have their own evolutionary course of development. These animals may have adapted other brain regions to perform a small number of levels of hierarchical thinking, but a neocortex is required for the relatively unrestricted hierarchical thinking that humans can perform.
2. V. B. Mountcastle, “An Organizing Principle for Cerebral Function: The Unit Model and the Distributed System” (1978), in Gerald M. Edelman and Vernon B. Mountcastle, The Mindful Brain: Cortical Organization and the Group-Selective Theory of Higher Brain Function (Cambridge, MA: MIT Press, 1982).
3. Herbert A. Simon, “The Organization of Complex Systems,” in Howard H. Pattee, ed., Hierarchy Theory: The Challenge of Complex Systems (New York: George Braziller, Inc., 1973), http://blog.santafe.edu/wp-content/uploads/2009/03/simon 1973.pdf.
4. Marc D. Hauser, Noam Chomsky, and W. Tecumseh Fitch, “The Faculty of Language: What Is It, Who Has It, and How Did It Evolve?” Science 298 (November 2002): 1569–79, http://www.sciencemag.org/content/298/5598/1569.short.
5. The following passage from the book Transcend: Nine Steps to Living Well Forever, by Ray Kurzweil and Terry Grossman (New York: Rodale, 2009), describes this lucid dreaming technique in more detaiclass="underline"
I’ve developed a method of solving problems while I sleep. I’ve perfected it for myself over several decades and have learned the subtle means by which this is likely to work better.
I start out by assigning myself a problem when I get into bed. This can be any kind of problem. It could be a math problem, an issue with one of my inventions, a business strategy question, or even an interpersonal problem.
I’ll think about the problem for a few minutes, but I try not to solve it. That would just cut off the creative problem solving to come. I do try to think about it. What do I know about this? What form could a solution take? And then I go to sleep. Doing this primes my subconscious mind to work on the problem.
Terry: Sigmund Freud pointed out that when we dream, many of the censors in our brain are relaxed, so that we might dream about things that are socially, culturally, or even sexually taboo. We can dream about weird things that we wouldn’t allow ourselves to think about during the day. That’s at least one reason why dreams are strange.
Ray: There are also professional blinders that prevent people from thinking creatively, many of which come from our professional training, mental blocks such as “you can’t solve a signal processing problem that way” or “linguistics is not supposed to use those rules.” These mental assumptions are also relaxed in our dream state, so I’ll dream about new ways of solving problems without being burdened by these daytime constraints.
Terry: There’s another part of our brain also not working when we dream, our rational faculties to evaluate whether an idea is reasonable. So that’s another reason that weird or fantastic things happen in our dreams. When the elephant walks through the wall, we aren’t shocked as to how the elephant could do this. We just say to our dream selves, “Okay, an elephant walked through the wall, no big deal.” Indeed, if I wake up in the middle of the night, I often find that I’ve been dreaming in strange and oblique ways about the problem that I assigned myself.
Ray: The next step occurs in the morning in the halfway state between dreaming and being awake, which is often called lucid dreaming. In this state, I still have the feelings and imagery from my dreams, but now I do have my rational faculties. I realize, for example, that I am in a bed. And I could formulate the rational thought that I have a lot to do so I had better get out of bed. But that would be a mistake. Whenever I can, I will stay in bed and continue in this lucid dream state because that is key to this creative problem-solving method. By the way, this doesn’t work if the alarm rings.
Reader: Sounds like the best of both worlds.
Ray: Exactly. I still have access to the dream thoughts about the problem I assigned myself the night before. But now I’m sufficiently conscious and rational to evaluate the new creative ideas that came to me during the night. I can determine which ones make sense. After perhaps 20 minutes of this, I invariably will have keen new insights into the problem.
I’ve come up with inventions this way (and spent the rest of the day writing a patent application), figured out how to organize material for a book such as this, and come up with useful ideas for a diverse set of problems. If I have a key decision to make, I will always go through this process, after which I am likely to have real confidence in my decision.
The key to the process is to let your mind go, to be nonjudgmental, and not to worry about how well the method is working. It is the opposite of a mental discipline. Think about the problem, but then let ideas wash over you as you fall asleep. Then in the morning, let your mind go again as you review the strange ideas that your dreams generated. I have found this to be an invaluable method for harnessing the natural creativity of my dreams.
Reader: Well, for the workaholics among us, we can now work in our dreams. Not sure my spouse is going to appreciate this.
Ray: Actually, you can think of it as getting your dreams to do your work for you.
Chapter 4: The Biological Neocortex
1. Steven Pinker, How the Mind Works (New York: Norton, 1997), 152–53.
2. D. O. Hebb, The Organization of Behavior (New York: John Wiley & Sons, 1949).
3. Henry Markram and Rodrigo Perrin, “Innate Neural Assemblies for Lego Memory,” Frontiers in Neural Circuits 5, no. 6 (2011).
4. E-mail communication from Henry Markram, February 19, 2012.
5. Van J. Wedeen et al., “The Geometric Structure of the Brain Fiber Pathways,” Science 335, no. 6076 (March 30, 2012).
6. Tai Sing Lee, “Computations in the Early Visual Cortex,” Journal of Physiology—Paris 97 (2003): 121–39.
7. A list of papers can be found at http://cbcl.mit.edu/people/poggio/tpcv_short_pubs.pdf.
8. Daniel J. Felleman and David C. Van Essen, “Distributed Hierarchical Processing in the Primate Cerebral Cortex,” Cerebral Cortex 1, no. 1 (January/February 1991): 1–47. A compelling analysis of the Bayesian mathematics of the top-down and bottom-up communication in the neocortex is provided by Tai Sing Lee in “Hierarchical Bayesian Inference in the Visual Cortex,” Journal of the Optical Society of America 20, no. 7 (July 2003): 1434–48.