What is a computation?
Intuitively some (say binary) states of the physical world are changed, voltage gates switched, rocks moved around (https://xkcd.com/505/), whatever. Now, in general if these physical changes were done with some intention like in my CPU or the guy moving the rocks in the xkcd comic, then I think of this as a computation, and consequentially I would care for example about if the computation I performed simulated a conscious entity.
However, surely my or my computer’s intention can’t be what makes the physical state changes count as a computation. But then how do we get around the slippery slope where everything is computing everything imaginable. There are billions of states I can interpret as 1′s and 0′s which get transformed in countless different ways every time I stir my coffee. Even worse, in quantum mechanics, the state of a point is given by a potentially infinitely wiggly function. What stops me from interpreting all of this as computation which under some encoding gives rise to countless Boltzmann brain type conscious entities and simulated worlds?
I think everything is a computation, and all computations happen… but somehow, some of those computations happen “more” and some of them happen “less”. (Similarly how in quantum mechanics any particle can be anywhere, but some combinations of particles “exist”more”, and some “exist less”, so in real life we don’t percieve literally everything, but some specific situations.)
Without understanding the nature of this “more” and “less” it will not make much sense… and I don’t really understand it.
If there are really infinite instances of conscious computations, then I don’t think it is unreasonable to believe that there exists no more/less measure and simply we have no reason at all to be surprised to be living in one type of simulation than another. I guess my interest with the question was if there is any way to not throw the baby out with the bathwater, by having a reasonable more restrictive notation of what a computation is.
I’m confused about your “interpretation”. Lets say I throw together a bunch of random transistors. They compute a totally random function. What “encoding” can you possibly use to interpret this is a conscious mind?
Lets just say we already know what consciousness is and what algorithm the human brain uses. Maybe it’s something like current neural networks. How would you find a computation of a neural network inside a random circuit?
I don’t think you could. You’d need to find groups of logic gates which just happen to compute multiplication of two numbers. And other groups which computes addition. And another group which saves the state. And all of these groups would have to be connected in just the right way.
I think conscious minds are a very specific kind of computation. That’s very unlikely to form by random chance.
Take the thermal noise generated in part of the circuit. By setting a threshold we can interpret it as a sequence 110101011 etc. Now if this list sequence was enormous we would eventually have a pixel by pixel description of any picture, letter by letter description of every book, state after state description of the tape on any Turing machine etc (basically a Library of Babel situation). Now of course we would need a crazy long sequence for this, but there is similar noise associated with the motion of every atom in the circuit, likewise the noise is far more complex if we don’t truncate it to 0′s and 1′s, and finally there are many many many encodings of our resulting strings (does 110 represent the letter A, 0101 a blue pixel and so on).
If I chose ahead of time the procedure of how the thermal noise fluctuates and I seed in two instances of noise I think of as representing 2 and 3, and after a while it outputs a thermal noise I think of as 5 then I am ok calling that a computation. But why should my naming of the noise and dictating how the system develops be required for computation to occur?
Random sequences aren’t really interesting. Even the digits of pi are believed to contain every possible sequence of integers. The hard part is finding where each sequence is located. The index is likely to be longer than the sequence itself!
And a sequence of digits isn’t computation. A recording of your neural activity isn’t conscious. It’s just a static object.
If I chose ahead of time the procedure of how the thermal noise fluctuates and I seed in two instances of noise I think of as representing 2 and 3, and after a while it outputs a thermal noise I think of as 5 then I am ok calling that a computation.
But there is no computation happening there. It’s just random noise. It’s just as likely to output 5 as 6 or 3. There is no causal link between you inputting “2+3” and the output.
I agree with your sentiment. I am hoping though that one can define formally what a computation is given a physical system. Perhaps you are on to something with the causal requirement, but I think this is hard to pin down precisely. The noise is still being caused by the previous state of the system, so how can we sensibly talk about cause in a physical system. It seems like we would be more interested in ‘causes’ associated to more agent-like objects like an engine than formless things like the previous state of a cloud of gas. Actually I think Caspar’s article was trying to formalize something like this but I don’t understand it that well: http://lesswrong.com/r/discussion/lw/msg/publication_on_formalizing_preference/
I think causality is the only requirement for “computation”. Step A causes step B. A computation has happened. If A and B are independent, then there is no computation happening..
What is a computation? Intuitively some (say binary) states of the physical world are changed, voltage gates switched, rocks moved around (https://xkcd.com/505/), whatever.
Now, in general if these physical changes were done with some intention like in my CPU or the guy moving the rocks in the xkcd comic, then I think of this as a computation, and consequentially I would care for example about if the computation I performed simulated a conscious entity.
However, surely my or my computer’s intention can’t be what makes the physical state changes count as a computation. But then how do we get around the slippery slope where everything is computing everything imaginable. There are billions of states I can interpret as 1′s and 0′s which get transformed in countless different ways every time I stir my coffee. Even worse, in quantum mechanics, the state of a point is given by a potentially infinitely wiggly function. What stops me from interpreting all of this as computation which under some encoding gives rise to countless Boltzmann brain type conscious entities and simulated worlds?
I think everything is a computation, and all computations happen… but somehow, some of those computations happen “more” and some of them happen “less”. (Similarly how in quantum mechanics any particle can be anywhere, but some combinations of particles “exist”more”, and some “exist less”, so in real life we don’t percieve literally everything, but some specific situations.)
Without understanding the nature of this “more” and “less” it will not make much sense… and I don’t really understand it.
If there are really infinite instances of conscious computations, then I don’t think it is unreasonable to believe that there exists no more/less measure and simply we have no reason at all to be surprised to be living in one type of simulation than another. I guess my interest with the question was if there is any way to not throw the baby out with the bathwater, by having a reasonable more restrictive notation of what a computation is.
I think having a measure is exactly the way to not throw the baby out with the bathwater. But I am not really an expert on this.
I’m confused about your “interpretation”. Lets say I throw together a bunch of random transistors. They compute a totally random function. What “encoding” can you possibly use to interpret this is a conscious mind?
Lets just say we already know what consciousness is and what algorithm the human brain uses. Maybe it’s something like current neural networks. How would you find a computation of a neural network inside a random circuit?
I don’t think you could. You’d need to find groups of logic gates which just happen to compute multiplication of two numbers. And other groups which computes addition. And another group which saves the state. And all of these groups would have to be connected in just the right way.
I think conscious minds are a very specific kind of computation. That’s very unlikely to form by random chance.
Take the thermal noise generated in part of the circuit. By setting a threshold we can interpret it as a sequence 110101011 etc. Now if this list sequence was enormous we would eventually have a pixel by pixel description of any picture, letter by letter description of every book, state after state description of the tape on any Turing machine etc (basically a Library of Babel situation). Now of course we would need a crazy long sequence for this, but there is similar noise associated with the motion of every atom in the circuit, likewise the noise is far more complex if we don’t truncate it to 0′s and 1′s, and finally there are many many many encodings of our resulting strings (does 110 represent the letter A, 0101 a blue pixel and so on).
If I chose ahead of time the procedure of how the thermal noise fluctuates and I seed in two instances of noise I think of as representing 2 and 3, and after a while it outputs a thermal noise I think of as 5 then I am ok calling that a computation. But why should my naming of the noise and dictating how the system develops be required for computation to occur?
Random sequences aren’t really interesting. Even the digits of pi are believed to contain every possible sequence of integers. The hard part is finding where each sequence is located. The index is likely to be longer than the sequence itself!
And a sequence of digits isn’t computation. A recording of your neural activity isn’t conscious. It’s just a static object.
But there is no computation happening there. It’s just random noise. It’s just as likely to output 5 as 6 or 3. There is no causal link between you inputting “2+3” and the output.
I agree with your sentiment. I am hoping though that one can define formally what a computation is given a physical system. Perhaps you are on to something with the causal requirement, but I think this is hard to pin down precisely. The noise is still being caused by the previous state of the system, so how can we sensibly talk about cause in a physical system. It seems like we would be more interested in ‘causes’ associated to more agent-like objects like an engine than formless things like the previous state of a cloud of gas. Actually I think Caspar’s article was trying to formalize something like this but I don’t understand it that well: http://lesswrong.com/r/discussion/lw/msg/publication_on_formalizing_preference/
Read Causal Universes first if you haven’t.
I think causality is the only requirement for “computation”. Step A causes step B. A computation has happened. If A and B are independent, then there is no computation happening..