Ok, I will disengage. I don’t think there is a plausible way for me to convince you that your model is unphysical.
I know that you disagree with what I am saying, but from my perspective, yours is a crackpot theory. I typically avoid arguing with crackpots, because the arguments always proceed basically how this one did. However, because of apparent interest from others, as well as the fact that nanoelectronics is literally my field of study, I engaged. In this case, it was a mistake.
Things got heated here.
I and many others are grateful for your effort to share your expertise.
Is there a way in which you would feel comfortable continuing to engage?
Remember that for the purposes of the prize pool there is no need to convince Cannell that you are right. In fact I will not judge veracity at all just contribution to the debate (on which metric you’re doing great!)
Dear Jake,
This is the second person in this thread that has explicitly signalled the need to disengage. I also realize this is charged topic and it’s easy for it to get heated when you’re just honestly trying to engage.
I would be happy to discuss the physics related to the topic with others. I don’t want to keep repeating the same argument endlessly, however.
Note that it appears that EY had a similar experience of repeatedly not having their point addressed:
I’m confused at how somebody ends up calculating that a brain—where each synaptic spike is transmitted by ~10,000 neurotransmitter molecules (according to a quick online check), which then get pumped back out of the membrane and taken back up by the synapse; and the impulse is then shepherded along cellular channels via thousands of ions flooding through a membrane to depolarize it and then getting pumped back out using ATP, all of which are thermodynamically irreversible operations individually—could possibly be within three orders of magnitude of max thermodynamic efficiency at 300 Kelvin. I have skimmed “Brain Efficiency” though not checked any numbers, and not seen anything inside it which seems to address this sanity check.
Then, after a reply:
This does not explain how thousands of neurotransmitter molecules impinging on a neuron and thousands of ions flooding into and out of cell membranes, all irreversible operations, in order to transmit one spike, could possibly be within one OOM of the thermodynamic limit on efficiency for a cognitive system (running at that temperature).
Then, after another reply:
Nothing about any of those claims explains why the 10,000-fold redundancy of neurotransmitter molecules and ions being pumped in and out of the system is necessary for doing the alleged complicated stuff.
Then, nothing more (that I saw, but I might have missed comments. this is a popular thread!).
If this is your field but also you don’t have the mood for pedagogy when someone from another field has strong opinions, which is emotionally understandable, I’m curious what learning material you’d recommend working through to find your claims obvious; is a whole degree needed? Are there individual textbooks or classes or even individual lectures?
For the theory of sending information across wires, I don’t think there is any better source than Shannon’s “A Mathematical Theory of Communication.”
I’m not aware of any self-contained sources that are enough to understand the physics of electronics. You need to have a very solid grasp of E&M, the basics of solid state, and at least a small amount of QM. These subjects can be pretty unintuitive. As an example of the nuance even in classical E&M, and an explanation of why I keep insisting that “signals do not propagate in wires by hopping from electron to electron,” see this youtube video.
You don’t actually need all of that in order to argue that the brain cannot be efficient from a thermodynamic perspective. EY does not understand the intricacies of nanoelectronics (probably), but he correctly stated that the final result from the original post cannot be correct, because obviously you can imagine a computation machine that is more thermodynamically efficient than pumping tens of thousands of ions across membranes and back. This intuition probably comes from some thermodynamics or statistical mechanics books.
What is the most insightful textbook about nanoelectronics you know of, regardless of how difficult it may be?
Or for another question trying to get at the same thing: if only one book about nanoelectronics were to be preserved (but standard physics books would all be fine still), which one would you want it to be? (I would be happy with a pair of books too, if that’s an easier question to answer.)
I come more from the physics side and less from the EE side, so for me it would be Datta’s “Electronic Transport in Mesoscopic Systems”, assuming the standard solid state books survive (Kittel, Ashcroft & Mermin, L&L stat mech, etc). For something closer to EE, I would say “Principles of Semiconductor Devices” by Zeghbroeck because it is what I have used and it was good, but I know less about that landscape.
I strongly disapprove of your attitude in this thread. You haven’t provided any convincing explanation of what’s wrong with Jacob’s model beyond saying “it’s unphysical”.
I agree that the model is very suspicious and in some sense doesn’t look like it should work, but at the same time, I think there’s obviously more to the agreement between his numbers and the numbers in the literature than you’re giving credit for. Your claim that there’s no fundamental bound on information transmission that relies on resistive materials of the form energy/bit/length (where the length scale could depend on the material in ways Jacob has already discussed) is unsupported and doesn’t seem like it rests on any serious analysis.
You can’t blame Jacob for not engaging with your arguments because you haven’t made any arguments. You’ve just said that his model is unphysical, which I agree with and presumably he would also agree with to some extent. However, by itself, that’s not enough to show that there is no bound on information transmission which roughly has the form Jacob is talking about, and perhaps for reasons that are not too dissimilar from the ones he’s conjectured.
Ok, I will disengage. I don’t think there is a plausible way for me to convince you that your model is unphysical.
I know that you disagree with what I am saying, but from my perspective, yours is a crackpot theory. I typically avoid arguing with crackpots, because the arguments always proceed basically how this one did. However, because of apparent interest from others, as well as the fact that nanoelectronics is literally my field of study, I engaged. In this case, it was a mistake.
Sorry for wasting our time.
Dear spxtr,
Things got heated here. I and many others are grateful for your effort to share your expertise. Is there a way in which you would feel comfortable continuing to engage?
Remember that for the purposes of the prize pool there is no need to convince Cannell that you are right. In fact I will not judge veracity at all just contribution to the debate (on which metric you’re doing great!)
Dear Jake,
This is the second person in this thread that has explicitly signalled the need to disengage. I also realize this is charged topic and it’s easy for it to get heated when you’re just honestly trying to engage.
Best, Alexander
Hi Alexander,
I would be happy to discuss the physics related to the topic with others. I don’t want to keep repeating the same argument endlessly, however.
Note that it appears that EY had a similar experience of repeatedly not having their point addressed:
Then, after a reply:
Then, after another reply:
Then, nothing more (that I saw, but I might have missed comments. this is a popular thread!).
:), spxtr
If this is your field but also you don’t have the mood for pedagogy when someone from another field has strong opinions, which is emotionally understandable, I’m curious what learning material you’d recommend working through to find your claims obvious; is a whole degree needed? Are there individual textbooks or classes or even individual lectures?
It depends on your background in physics.
For the theory of sending information across wires, I don’t think there is any better source than Shannon’s “A Mathematical Theory of Communication.”
I’m not aware of any self-contained sources that are enough to understand the physics of electronics. You need to have a very solid grasp of E&M, the basics of solid state, and at least a small amount of QM. These subjects can be pretty unintuitive. As an example of the nuance even in classical E&M, and an explanation of why I keep insisting that “signals do not propagate in wires by hopping from electron to electron,” see this youtube video.
You don’t actually need all of that in order to argue that the brain cannot be efficient from a thermodynamic perspective. EY does not understand the intricacies of nanoelectronics (probably), but he correctly stated that the final result from the original post cannot be correct, because obviously you can imagine a computation machine that is more thermodynamically efficient than pumping tens of thousands of ions across membranes and back. This intuition probably comes from some thermodynamics or statistical mechanics books.
What is the most insightful textbook about nanoelectronics you know of, regardless of how difficult it may be?
Or for another question trying to get at the same thing: if only one book about nanoelectronics were to be preserved (but standard physics books would all be fine still), which one would you want it to be? (I would be happy with a pair of books too, if that’s an easier question to answer.)
I come more from the physics side and less from the EE side, so for me it would be Datta’s “Electronic Transport in Mesoscopic Systems”, assuming the standard solid state books survive (Kittel, Ashcroft & Mermin, L&L stat mech, etc). For something closer to EE, I would say “Principles of Semiconductor Devices” by Zeghbroeck because it is what I have used and it was good, but I know less about that landscape.
I strongly disapprove of your attitude in this thread. You haven’t provided any convincing explanation of what’s wrong with Jacob’s model beyond saying “it’s unphysical”.
I agree that the model is very suspicious and in some sense doesn’t look like it should work, but at the same time, I think there’s obviously more to the agreement between his numbers and the numbers in the literature than you’re giving credit for. Your claim that there’s no fundamental bound on information transmission that relies on resistive materials of the form energy/bit/length (where the length scale could depend on the material in ways Jacob has already discussed) is unsupported and doesn’t seem like it rests on any serious analysis.
You can’t blame Jacob for not engaging with your arguments because you haven’t made any arguments. You’ve just said that his model is unphysical, which I agree with and presumably he would also agree with to some extent. However, by itself, that’s not enough to show that there is no bound on information transmission which roughly has the form Jacob is talking about, and perhaps for reasons that are not too dissimilar from the ones he’s conjectured.