5 ms·

How interesting. You have given me quite a lot to think about it. I am still unable to get past the following, but I will continue to consider everything you

How interesting. You have given me quite a lot to think about it. I am still unable to get past the following, but I will continue to consider everything you have said in our discussion very carefully. Issue: I carried out theoretical physics energy calculations on the work done by cells as a result of cell self-replication in the human nervous system (recall the nervous system primarily functions to send signals at ~the speed of light from one part of the body to another) The thing I am unable to get past for arguments of the type you made, e.g. when you stated: > "There are fewer than 10 billion people in the world. That's a finite number. Even a quadratic problem remains quadratic if there is a bounded number of compute resources" The issue is: the human body does not completely fall apart, it all works fine and there are no issues like this, there is some kind of bound from being a physical object in the real world, but physically and quite practically for all purposes the human nervous system is capable of expending an exponential amount of energy Question: Since the human body does not fall apart despite the fact that its doing cell self-replication, given how theoretical physics shows there truly is an exponential level of energy expended during cell-replication, how are these types of issues that you raise, quite legitimately from a pure-math/theoretical comp-sci perspective, not also a major issue for the human nervous system? Thanks again! This discussion has been enlightening

eesmith 7y ago
The nervous system does not work at the speed of light. https://en.wikipedia.org/wiki/Nerve_conduction_velocity https://en.wikipedia.org/wiki/Nerve_conduction_velocity says: > Nerve impulses are extremely slow compared to the speed of electricity, ... however, it is very fast compared to the speed of blood flow, with some myelinated neurons conducting at speeds up to 120 m/s (432 km/h or 275 mph). > the human nervous system is capable of expending an exponential amount of energy I don't know what that means. Exponent in what dimension? Time? What's the exponent? Do you have any demonstrable evidence? At some point the human nervous system will be limited by the amount of food needed. The Tour de Frace cyclists consume some 7000 food calories per day. Another limit is the need to keep cool, because that consumed power must go somewhere. > given how theoretical physics shows there truly is an exponential level of energy expended during cell-replication Here again you'll need to explain what you mean. 1.0 is an exponent, so in some since you are trivially correct. But I strongly suspect that's not what you meant. I think you mean that at the beginning there is 1 cell, the zygote, then 2, then 4, etc. But this exponential growth phase is short. It must be, otherwise it would quickly consume all available energy in its environment. > not also a major issue for the human nervous system? Again, I don't follow. I am not aware of humans being able to solve NP-hard problems in polynomial time. We certainly can solve some NP-hard problems when N is small, but how do you know it scales polynomially?
- calhoun137 7y ago
  > The nervous system does not work at the speed of light I think it's ok to call a limiting maximum velocity for the transmission of signals by definition "the speed of light in the human body". Your point is well taken about the actual speed of light and how fast the nervous system works > I don't know what that means. Exponent in what dimension? Time? What's the exponent? Do you have any demonstrable evidence? I meant exponential in time, and yes I have evidence. It's theoretical physics energy calculations I did on the work done according to the principles of theoretical physics as a result of cell self-replication. (Consider a single particle to have kinetic energy 1/2mv^2, and then allow for self replicating particles) What I did was read a lot of biology text books and look at the experimental evidence of how the human body actually works. Hopefully I didn't make any major mistakes in these calculations, but to me its quite clear that all of the experimental evidence has tended to show that the human nervous system is capable of expending an exponential amount of energy in time > Again, I don't follow. > I am not aware of humans being able to solve NP-hard problems in polynomial time I understand the nature of your objection to involve arguments about the nature of this being unrealistic. I have tried to show why I believe this is quite realistic, and explain why I feel so strongly this is a practical question for a computer program I am writing so I can figure out the best way to design the software. When I said "not also a major issue for the human nervous system?" what I meant was this: Make an analogy where the human brain is a master CPU, and it has an object oriented programming language where each cell is an Object, and self replication is the new operator. I felt like your objections about "not being realistic" could be objected to on the basis that these ideas come from physics and have real world applications in engineering for a new type of self-replicating 3d printer. In my view, it would be rather useful to further develop the theory of these types of systems I believe you have made an extremely strong point about the speed of light and the nature of the reasons this kind of approach needs to be bounded in a strong form or else will clearly not work Hope that clears it up!
  - eesmith 7y ago
    > I think it's ok to call a limiting maximum It's the rather trivial limit. I mean, it's pretty clear the limiting maximum for my walking speed is also the speed of light. Yet it's not useful to consider that detail when figuring out how long it will take me to walk to the store. > Consider a single particle to have kinetic energy 1/2mv^2, and then allow for self replicating particles That short summary appears to violate the conservation of energy. How does a self-replicating particle get the mass and energy to replicate a new particle, much less one with the same kinetic energy? > its quite clear that all of the experimental evidence has tended to show that the human nervous system is capable of expending an exponential amount of energy in time Can you point to any of the evidence? Especially evidence which shows it's unbounded? How can a human body produce 1 MW of power? (A simple estimate using the Stefan–Boltzmann law shows the body temperature would be over 1,000 degrees C.) > Make an analogy ... Your analogy doesn't support the ability to add new CPUs, only new objects. Your theory requires the ability to self-replicate the master CPU, which the human body does not have. I have a graduate degree in physics. There's no need to use an argument by an analogy with me if you can present the theoretical physics energy calculations.

eesmith 7y ago

The nervous system does not work at the speed of light. https://en.wikipedia.org/wiki/Nerve_conduction_velocity https://en.wikipedia.org/wiki/Nerve_conduction_velocity says: > Nerve impulses are extremely slow compared to the speed of electricity, ... however, it is very fast compared to the speed of blood flow, with some myelinated neurons conducting at speeds up to 120 m/s (432 km/h or 275 mph). > the human nervous system is capable of expending an exponential amount of energy I don't know what that means. Exponent in what dimension? Time? What's the exponent? Do you have any demonstrable evidence? At some point the human nervous system will be limited by the amount of food needed. The Tour de Frace cyclists consume some 7000 food calories per day. Another limit is the need to keep cool, because that consumed power must go somewhere. > given how theoretical physics shows there truly is an exponential level of energy expended during cell-replication Here again you'll need to explain what you mean. 1.0 is an exponent, so in some since you are trivially correct. But I strongly suspect that's not what you meant. I think you mean that at the beginning there is 1 cell, the zygote, then 2, then 4, etc. But this exponential growth phase is short. It must be, otherwise it would quickly consume all available energy in its environment. > not also a major issue for the human nervous system? Again, I don't follow. I am not aware of humans being able to solve NP-hard problems in polynomial time. We certainly can solve some NP-hard problems when N is small, but how do you know it scales polynomially?

calhoun137 7y ago
> The nervous system does not work at the speed of light I think it's ok to call a limiting maximum velocity for the transmission of signals by definition "the speed of light in the human body". Your point is well taken about the actual speed of light and how fast the nervous system works > I don't know what that means. Exponent in what dimension? Time? What's the exponent? Do you have any demonstrable evidence? I meant exponential in time, and yes I have evidence. It's theoretical physics energy calculations I did on the work done according to the principles of theoretical physics as a result of cell self-replication. (Consider a single particle to have kinetic energy 1/2mv^2, and then allow for self replicating particles) What I did was read a lot of biology text books and look at the experimental evidence of how the human body actually works. Hopefully I didn't make any major mistakes in these calculations, but to me its quite clear that all of the experimental evidence has tended to show that the human nervous system is capable of expending an exponential amount of energy in time > Again, I don't follow. > I am not aware of humans being able to solve NP-hard problems in polynomial time I understand the nature of your objection to involve arguments about the nature of this being unrealistic. I have tried to show why I believe this is quite realistic, and explain why I feel so strongly this is a practical question for a computer program I am writing so I can figure out the best way to design the software. When I said "not also a major issue for the human nervous system?" what I meant was this: Make an analogy where the human brain is a master CPU, and it has an object oriented programming language where each cell is an Object, and self replication is the new operator. I felt like your objections about "not being realistic" could be objected to on the basis that these ideas come from physics and have real world applications in engineering for a new type of self-replicating 3d printer. In my view, it would be rather useful to further develop the theory of these types of systems I believe you have made an extremely strong point about the speed of light and the nature of the reasons this kind of approach needs to be bounded in a strong form or else will clearly not work Hope that clears it up!
- eesmith 7y ago
  > I think it's ok to call a limiting maximum It's the rather trivial limit. I mean, it's pretty clear the limiting maximum for my walking speed is also the speed of light. Yet it's not useful to consider that detail when figuring out how long it will take me to walk to the store. > Consider a single particle to have kinetic energy 1/2mv^2, and then allow for self replicating particles That short summary appears to violate the conservation of energy. How does a self-replicating particle get the mass and energy to replicate a new particle, much less one with the same kinetic energy? > its quite clear that all of the experimental evidence has tended to show that the human nervous system is capable of expending an exponential amount of energy in time Can you point to any of the evidence? Especially evidence which shows it's unbounded? How can a human body produce 1 MW of power? (A simple estimate using the Stefan–Boltzmann law shows the body temperature would be over 1,000 degrees C.) > Make an analogy ... Your analogy doesn't support the ability to add new CPUs, only new objects. Your theory requires the ability to self-replicate the master CPU, which the human body does not have. I have a graduate degree in physics. There's no need to use an argument by an analogy with me if you can present the theoretical physics energy calculations.