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Bang Diddley
03-11-2009, 12:19 PM
http://en.wikipedia.org/wiki/Technological_singularity

Ive just watched the second of these last night. So we are last generation who will see the world as it is. All change by 2035 when the TS comes and we are replaced by ever increasing intelligent machines who can design and make even more capable machines.

We will be able to live for hundreds of years and have nano stuff in us etc etc.

Is it the stuff of futorologists dreams or can it happen. Ive not seen parts 1 + 3 but is anyone familiar with stuff or have any thoughts ?

TechnoCalyps part 1: TransHuman
http://video.google.com/videoplay?docid=-7141762977713668208&hl=en

TechnoCalyps part 2: Preparing for the Singularity
http://video.google.com/videoplay?docid=2258529707984107504&hl=en

TechnoCalyps part 3: The Digital Messiah
http://video.google.com/videoplay?docid=8945702810854373085&hl=en

grizzleb
03-11-2009, 12:36 PM
It's a hippy dippy cliche. Nothing like this will happen, and Ray Kurzweil is a crackpot.

vimothy
03-11-2009, 12:52 PM
Nothing like what will happen? He may be a crackpot--I have no background in those disciplines--but it's not like we're far off some pretty out-there technology. We already have armies of droids, nanotech, quantumn computers...

swears
03-11-2009, 01:06 PM
Yeah, here's a good blog entry from Pharyngula on the subject: (http://scienceblogs.com/pharyngula/2009/02/singularly_silly_singularity.php)



Kurzweil tosses a bunch of things into a graph, shows a curve that goes upward, and gets all misty-eyed and spiritual over our Bold Future. Some places it's OK, when he's actually looking at something measurable, like processor speed over time. In other places, where he puts bacteria and monkeys on the Y-axis and pontificates about the future of evolution, it's absurd. I am completely baffled by Kurzweil's popularity, and in particular the respect he gets in some circles, since his claims simply do not hold up to even casually critical examination.


I suppose it's a bit like the space race, people saw a man on the moon and thought we'd be zipping off there on our holidays soon enough. You can't really predict what kind of changes are going to occur in technology in the long run with any accuracy.

nomadthethird
03-11-2009, 01:51 PM
Yeah, here's a good blog entry from Pharyngula on the subject: (http://scienceblogs.com/pharyngula/2009/02/singularly_silly_singularity.php)




I suppose it's a bit like the space race, people saw a man on the moon and thought we'd be zipping off there on our holidays soon enough. You can't really predict what kind of changes are going to occur in technology in the long run with any accuracy.

Zomg, Swears, OT, but did you see the Dinesh D'Souza post (http://scienceblogs.com/pharyngula/2009/11/dinesh_dsouza_promised_me_an_a.php) on Pharyngula last night? Hilarious comments.

vimothy
03-11-2009, 01:54 PM
Seems fair:


Now, it so happens that I didn't really need to read Kurzweil's book to learn this stuff, because I already think he's right. The basic hardware and software trends seem pretty indisputable to me, and the only serious arguments I've ever heard against the eventual development of genuinely intelligent machines all boil down to a thinly veiled belief that there just has to be something more to human intelligence than mere neurons and biochemistry. Well, no there doesn't. The pope's opinions notwithstanding, the evidence to date suggests that the brain really is just a biological computing device.

http://www.washingtonmonthly.com/archives/individual/2005_09/007172.php

[That's from your link BTW swears...]

nomadthethird
03-11-2009, 01:58 PM
Seems fair:



http://www.washingtonmonthly.com/archives/individual/2005_09/007172.php

[That's from your link BTW swears...]

Yeah, but we already have AI. That's not what the Singularity is, though. It's when we'll all become computers and have our memories stored in biological harddrives and be able to infinitely upload or download ourselves onto new hardware, so death becomes meaningless.

The ridiculous part of that whole shtick is that we're already biological computers. We're just ones that don't have infinite bandwidth. And we likely never will.

vimothy
03-11-2009, 01:59 PM
Have you read his book?

vimothy
03-11-2009, 02:01 PM
That's a rhetorical question, in case you were wondering; you don't actually need to answer it.

nomadthethird
03-11-2009, 02:15 PM
That's a rhetorical question, in case you were wondering; you don't actually need to answer it.

Um...yes. But it depends on which one you're talking about.

Did you read the 15 page interview with Kurzweil in Rolling Stone a few months ago?

That's a rhetorical question. You don't actually need to answer it.

vimothy
03-11-2009, 02:21 PM
That's a rhetorical question. You don't actually need to answer it.

Clever.

nomadthethird
03-11-2009, 02:21 PM
That must be why you whipped it out, then, eh?

nomadthethird
03-11-2009, 02:23 PM
From the Pharyngula comments:


He was all giddy about nanotechnology and little molecu-bots dancing around in our bloodstream doing disease fighter detail a-la a Doom video game or some such nonsense. Has he never heard of the immune response?(dumbass!)

According to another Wired article last year sometime, he's now so hot and bothered about potentially missing the "singularity". Oh noes! So, he's gone off the deep end with the life extension cultists. It must be some sort of machine envy to think that we'd be so much better off without biological bodies.

Get over it people, there is no mind/body duality! This is the latest delusional faction of people who don't understand that basic fact. They're just as delusional as the god-strokers and new age woo mongers.


Exactly. We already have moleculebots dancing around in our bloodstream fighting disease! Ffs. Reinventing the wheel.

swears
03-11-2009, 02:42 PM
Zomg, Swears, OT, but did you see the Dinesh D'Souza post (http://scienceblogs.com/pharyngula/2009/11/dinesh_dsouza_promised_me_an_a.php) on Pharyngula last night? Hilarious comments.

Not a regular reader, but he is good. Yeah, it boggles the mind when people like D'Souza try to use rational arguments to explain supernatural beliefs: "Yeah, well quantum physics is like, really weird and counterintuitive... a bit like the love of our lord Jesus."

All this singularity stuff, I would have loved it when I was about 12, back when I could basically just choose to believe in stuff 'cuz it sounded cool. There night be some truth to it, I 'spose.

vimothy
03-11-2009, 02:53 PM
Kevin Drumm is basically correct, though, shirley. At some point, we should get self-improving AI. The rest is details.

padraig (u.s.)
03-11-2009, 03:05 PM
it sounds like the worse thing ever, and Kurzweil is just...I dunno, it all comes off like Ponce De Leon in the digital era, this bollocks about conquering death and bringing his dad back to life (as a clone or whatever), just...ugh. which may be only tangentially related to the self-improving AI, I guess. but it still sounds like the worst thing ever. count me 100% out, at least. (I mean, it does also sound a bit much like 3rd-rate William Gibson)

Vimothy, I'm curious tho, why exactly is self-improving AI so inevitable? is it one of those things where it's like "oh if you don't understand highly advanced math & whatever then you'll never get it"? or it there a relatively concise explanation for laypeople? I seem to remember that there's some debate over whether or not at the rate at which data storage capacity increases is actually beginning to level off.

you have to admit also that these Kevin Drumm types sound a wee bit self-important (I seem to remember a quote from a paper of his you linked along the lines of "getting to the Singularity is the single most important thing in the world"). which doesn't necessarily add to or detract from the substance of their arguments, I guess.

swears
03-11-2009, 03:13 PM
I have a pal who did Comp Sci at PHD level and wrote his thesis on AI. I've asked him before if all this way cool Neuromancer-type stuff could happen and he reckons it's possible, but even if we did have computers with has much processing power as the human brain, it would still be a tall order to program or teach them to think in the same way as humans. And that there might actually be physical, universal limits on how smart an artificial mind could be.

vimothy
03-11-2009, 03:29 PM
Barring disaster, or some limit we don't understand yet, at some point on a long enough timeline CPU power will equal the human brain. Don't think that's very controversial.

In the article I just linked to, Kevin Drumm was criticising Kurzweil and the Transhumanists because in general their programme is trivial and the specifics their programme are stupid. Pretty sure he's not written any papers on the singularity, but I could be wrong.

Mr. Tea
03-11-2009, 03:42 PM
At some point, we should get self-improving AI. The rest is details.

Haven't we had this, in the form of neural nets, for years already? Or is this a more specialised informatic usage of "self-improving"? (Like it learns a language in its spare time or volunteers at a cat shelter?)

vimothy
03-11-2009, 03:49 PM
Transhumanist people mean AI that is effectively intelligent enough enough build AI better than humans. Computers that can build better computers than humans. That's one of Kurzweil's possible singularities. Eliezer Yudkwosky as well. Probably lots of others.

vimothy
03-11-2009, 03:51 PM
Doubtless most of these people will be wrong. Prediction is hard, especially about the future and all that. Still, it promises to be pretty weird.

Mr. Tea
03-11-2009, 04:14 PM
Computers that can build better computers than humans.

Again, aren't we doing this already? Surely ICs have been designed using computer algorithms for decades? I can't imagine there are huge rooms full of engineers painstakingly deciding where each and every transistor in a Pentium Dual Core has to go.

And I don't see that this whole concept is really, at base, all that groundbreaking. It's obvious that you can make a better axe if you have some elementary metalworking and woodworking tools lying around than if you're using your bare hands to manipulate a lump of flint, a stick and some twine. An axe is a tool for chopping stuff up and a computer is a tool for performing calculations very quickly.

Sorry if this is sounding at all facetious, it's really not meant that way!

grizzleb
03-11-2009, 04:16 PM
"Yeah, well quantum physics is like, really weird and counterintuitive... a bit like the love of our lord Jesus."hahaha

massrock
03-11-2009, 04:19 PM
I don't think the concept is supposed to groundbreaking as such, it's attempting to be a prediction, to say this is where it looks like things are going. And part of that is based on extrapolating from observations of where we are now, like you above saying that computers are already being used to design computers.

massrock
03-11-2009, 04:21 PM
the only serious arguments I've ever heard against the eventual development of genuinely intelligent machines all boil down to a thinly veiled belief that there just has to be something more to human intelligence than mere neurons and biochemistry
Even this question doesn't necessarily matter so much. No absolute reason why AIs should be based on human intelligence.

Maybe the issue for AI coming up is one of Initiative (or Will). ?

grizzleb
03-11-2009, 04:21 PM
Does anyone think that the hard problem of AI is one that we'll ever get over - i.e do you think we'll ever build robots that can actually think rather than respond as if they can? http://en.wikipedia.org/wiki/Chinese_room

Bang Diddley
03-11-2009, 04:35 PM
Thanks for all the info here. I wish I could comment more but im still finding out stuff on all of this. Will read the thread in detail and links more fully later.

vimothy
03-11-2009, 04:39 PM
Sorry if this is sounding at all facetious, it's really not meant that way!

Of course it's true that humans use technology to design and build more technology. But I tihnk that the transhumanists would make a distinction between that and...

turtles
04-11-2009, 06:45 AM
The singularity for AI is not about making an AI that can learn, it's about making an AI that can write an AI smarter than itself (which then makes an AI smarter than itself, etc etc). Neural nets learn, but they haven't, as yet, learned how to make something better at learning than a neural net.

The main problem with this idea as applied to the singularity is that there's no proof that intelligence increases in any sort of continuous fashion (there could be large, discontinuous jumps in between levels) and that there isn't an upper maximum to intelligence. It's some weak induction plus wishful thinking.

Would be cool though. I'd upload my brain no problem.

Bang Diddley
04-11-2009, 08:46 AM
AI and NN have been around a while, I think Genetic Algorithms may hold the key in that they generate loads of solutions and then access if they are fit for purpose, keeping the nearest fits and basing new better solutions on the previous sets of logic. Kinda like they self analyse. I dont think they will replicate human intelligence and intuition im not even sure that that would be a requirement in machine intel. I think some of what these TS guys talk about could happen but perhaps not in the time frames they talk about ie by 2035 . . . Still feeling my way around this . . .

nomadthethird
04-11-2009, 02:22 PM
AI already exists, it will likely get more streamlined and advanced. So? There are already programs that write programs, so it's not a huge leap to think there will be AI machines that create AI machines.

We are AI machines. This is what people don't seem to get. There's not any difference between our brains and the brain of an AI machine, except arguably a few layers of emergence/complexity. We're similarly "programmed" with all sorts of biological information, we're limited by our biochemical hardware, and our brains function exactly the same way a computer does, by turning a bunch of inputs into output.

What bothers me about this Singularity business is the notion that lurks in the background, which is that "intelligence" progresses in lifeforms in a sort of steep line of reflection up the x-y-- pretty silly. The idea that you can abstract the "intelligence" of a person (as if it's some kind of essence) from the body itself and then simply inject it into other bodies is pretty ridiculous in its own right. The mind IS part of the body. If we can use computer chips or something to make our minds work more efficiently or better, we should do it. But for goodness sake, it won't be such a huge deal. We've already got microchips in there. Amino acids, proteins, nucleic acids, lipids.

massrock
04-11-2009, 02:44 PM
But aren't most of the Singularity proponents talking about what if we or something subsequent to us can overcome the limitations of out biological hardware and the limitations of having to make our environments with solid matter? What if human like or human level or better intellects can operate on super efficient hardware and inhabit practically infinitely designable software environments? Then taking the possibilities afforded by that scenario and projecting to the next iteration, and the next etc.

grizzleb
04-11-2009, 02:50 PM
Well I like the idea of protein machines, you could get all sorts of crazee designs on the go that were still 'biological' in nature. Sensory upgrades et al. I don't really think that machines can be conscious, at least not until these neural nets complexity reaches such a vast degree. Even then? Maybe if we make machines that can talk to us without ever being taught how to do so. Or what talking is, like babies have to. I can't see that happening though.

sufi
04-11-2009, 03:26 PM
i find this all a bit previous actually,
far as i'm concerned technological singularity is upon us and has been for a while, we have a typically human brain-fuzz preventing us from recognising how far it's gone;
given the wooly definitions of what is intelligence anyway, havent we already massively augmented human thought (both on an individual and species level) using simple technologies like writing and having technological capacity to store and share information, so it's not really about cyborgs or any wicked scifi shit like that
& furthermore
this is not just restricted to primitive mind/body distinctions. by technologically augmenting our communications in this way (not to mention other essentials such as accommodation, food, transport, medicine etc etc) the species and the individual achieve huge benefits, almost to the point that within a few generations we have come to rely utterly on machines, and now it's a struggle to imagine survival without them. Increasingly they actually have the upper hand, and humans without access to tech, or to the 'machine' are more and more disadvantaged and excluded

roll on astronomical singularity :cool:

massrock
04-11-2009, 03:45 PM
far as i'm concerned technological singularity is upon us and has been for a while, we have a typically human brain-fuzz preventing us from recognising how far it's gone;
I don't know if it is though, upon us that is, at least not by any definition that fans of the Singularity concept would recognise. The idea is that technological advancements proceed at an exponential rate eventually hitting an effectively infinite rate of innovation / change / improvement. That's the Omega Point or whatever. I'm not necessarily saying I believe that's how it will go down but that's what they say, and I can see reasons for thinking something like this might happen.

But yeah, of course the process of technological development has been under way for some time, that's the basis of the idea anyway isn't it?

Mr. Tea
04-11-2009, 04:36 PM
I don't know if it is though, upon us that is, at least not by any definition that fans of the Singularity concept would recognise. The idea is that technological advancements proceed at an exponential rate eventually hitting an effectively infinite rate of innovation / change / improvement. That's the Omega Point or whatever. I'm not necessarily saying I believe that's how it will go down but that's what they say, and I can see reasons for thinking something like this might happen.

But yeah, of course the process of technological development has been under way for some time, that's the basis of the idea anyway isn't it?

Thing is, exponential increase just keeps getting gradually steeper and steeper, there's no sudden cut-off moment where everything goes "WHOOSH!" all in one go. I think the idea of the Singularity is that some breakthrough is made which enables not merely a quantitative change in the pace of technological innovation, which after all is happening all the time (Moore's law) , but a qualitative shift so that a graph of processor power or whatever vs. time effectively looks like a vertical wall.

One possible catalyst people have mentioned already could be computers that are better at designing things than we are - genetic algorithms and the like. Another could be quantum computers, which (once some fairly substantial practical difficulties are solved) offer effectively limitless computing power. I think some theorists think they may even be able to solve problems that are even in principle insoluble to classical Turing machines (eg. common-or-garden computers as they exist today). Then there's work people have been doing with pieces of DNA, using base pairs as digits to perform immensely complex calculations...some people think DNA/RNA can unzip and re-zip much more quickly than it 'should' be able to according to semi-classical molecular dynamics, which means the nucleotides may be existing in quantum superposition before actually binding to the phosphate backbone to complete the reaction.

I dunno if it counts as a fully-fledged subdiscipline yet, but people are already writing papers on 'quantum biology'. :D And some of them have a bit more of a basis in experimental reality than Penrose's magic tubules, too.

massrock
04-11-2009, 04:54 PM
Thing is, exponential increase just keeps getting gradually steeper and steeper, there's no sudden cut-off moment where everything goes "WHOOSH!" all in one go. I think the idea of the Singularity is that some breakthrough is made which enables not merely a quantitative change in the pace of technological innovation, which after all is happening all the time (Moore's law) , but a qualitative shift so that a graph of processor power or whatever vs. time effectively looks like a vertical wall.
"Effectively infinite". I don't think it's precise, I don't think that you can necessarily measure "technological developments" as proceeding at an "exponential rate", this is obviously an approximation to aid visualisation. Moore's law isn't a law either as such, but it's proved to be pretty close to the truth.

I don't know if it's necessary that a specific technological breakthrough be made, though several of significance may be made along the way - Teilard De Chardin's original Omega Point thing had to do with a certain threshold level of complexity of organisation being reached in the Universe.

nomadthethird
05-11-2009, 04:43 AM
Well I like the idea of protein machines

I do, too! I am one. A protein machine where each protein is ultimately made out of only 20 amino acids. Which are in turn just amine groups with carboxyl group side chains. Which are ultimately just hydrogen and carbon and oxygen bonded in various combinations.


Then there's work people have been doing with pieces of DNA, using base pairs as digits to perform immensely complex calculations...some people think DNA/RNA can unzip and re-zip much more quickly than it 'should' be able to according to semi-classical molecular dynamics, which means the nucleotides may be existing in quantum superposition before actually binding to the phosphate backbone to complete the reaction.

I dunno if it counts as a fully-fledged subdiscipline yet, but people are already writing papers on 'quantum biology'. :D And some of them have a bit more of a basis in experimental reality than Penrose's magic tubules, too.

This shit is the bomb. There are people who can fucking swap codons around to see what happens. I just heard a seminar by a lady who does it, something about "codon wobble" in tRNA and arg pairs (I was sleeping with my eyes open). Those are small! O the patience her lackies must have...

3 Body No Problem
06-11-2009, 04:29 PM
Another could be quantum computers, which (once some fairly substantial practical difficulties are solved) offer effectively limitless computing power. I think some theorists think they may even be able to solve problems that are even in principle insoluble to classical Turing machines (eg. common-or-garden computers as they exist today).

There is no reason to believe quantum computers can do that. QC can speed up some computations like the factoring of integers (which would be problematic for the kind of cryptography used today to secure the internet.


I dunno if it counts as a fully-fledged subdiscipline yet, but people are already writing papers on 'quantum biology'.

Others discuss (http://www.neuroquantology.com/repository/index2.php?option=com_sobi2&sobi2Task=dd_download&fid=6&format=html) if there's substance behind quantum biology.

nomadthethird
06-11-2009, 05:12 PM
Others discuss (http://www.neuroquantology.com/repository/index2.php?option=com_sobi2&sobi2Task=dd_download&fid=6&format=html) if there's substance behind quantum biology.

When this is at the beginning:


Disclaimer: The views expressed by all the participants were for the purpose of
lively debate and do not necessarily express their actual views.

I don't know how seriously to take what the people are saying.

Mr. Tea
06-11-2009, 06:19 PM
There is no reason to believe quantum computers can do that. QC can speed up some computations like the factoring of integers (which would be problematic for the kind of cryptography used today to secure the internet.


Is that so? Shame, I was probably getting confused with Penrose's quantum tubules again. Which can supposedly decide non-computational problems because they're quantum-gravitational tubules. Naturally!

Speaking of biological intelligence, I think it's pretty cool that a slime mould can solve a maze (http://www.abc.net.au/science/news/stories/s189608.htm):

http://www.abc.net.au/science/news/img/slime.jpg

Never mind a lack of nerve cells, slime moulds don't even have separate cells - they're just a naked mass of protoplasm with nuclei strewn throughout. Lovecraft-tastic!

Edit:



Others discuss (http://www.neuroquantology.com/repository/index2.php?option=com_sobi2&sobi2Task=dd_download&fid=6&format=html) if there's substance behind quantum biology.


The subconscious is to consciousness as the quantum world is to the classical world.

Like, duuude, whoaah...

nomadthethird
06-11-2009, 07:28 PM
There is no reason to believe quantum computers can do that. QC can speed up some computations like the factoring of integers (which would be problematic for the kind of cryptography used today to secure the internet.



Others discuss (http://www.neuroquantology.com/repository/index2.php?option=com_sobi2&sobi2Task=dd_download&fid=6&format=html) if there's substance behind quantum biology.

Ok, I just waded through that, and that's not actually what they're discussing. They're discussing whether the effects of quantum physics are trivial in biological systems, which is a different claim.

Quantum biology would be a superimposition of principles from quantum physics over biological processes, but not necessarily over biological systems as wholes, would it not?

3 Body No Problem
07-11-2009, 01:32 PM
Is that so? Shame, I was probably getting confused with Penrose's quantum tubules again. Which can supposedly decide non-computational problems because they're quantum-gravitational tubules. Naturally!

There are only very few known quantum algoritms (see this list (http://www.its.caltech.edu/~sjordan/zoo.html)), most are fairly artificial. The big one that put (the idea of) quantum computing on the map is Shor's algorithm (http://en.wikipedia.org/wiki/Shor%27s_algorithm) for factoring integers. All known conventional (i.e. non-quantum) algorithms for factoring integers run in time exponential in the length of the number, which means they are very slow for large numbers. Essentially all cryptography that you use (whether you are aware of this or not) when you use the internet is based on (the hope) that no fast factoring algorithms exist.

It is not known if Shor's algorithm can be implemented on classical computers.

It is also not known if quantum computers can be built.


Speaking of biological intelligence, I think it's pretty cool that a slime mould can solve a maze (http://www.abc.net.au/science/news/stories/s189608.htm):

http://www.abc.net.au/science/news/img/slime.jpg

Never mind a lack of nerve cells, slime moulds don't even have separate cells - they're just a naked mass of protoplasm with nuclei strewn throughout. Lovecraft-tastic!


That's brilliant. How do they do it?

3 Body No Problem
07-11-2009, 01:57 PM
Ok, I just waded through that, and that's not actually what they're discussing. They're discussing whether the effects of quantum physics are trivial in biological systems, which is a different claim.

No, it's the same, just more politely expressed.

The question is: do we to go down to the level of QM to explain biological phenomena, i.e. how the proteins work in cells, or can all of this be explained classically?

The people who are argue for quantum biology all say: in the future we will find biological effects that can only be explained with reference to quantum phenomena. Their detractors say: there is currently no example where we know that it cannot be explained classically, please quantum biology guys & girls show us one.

A strong form of detractors says: biological entities (like macro molecules) are too large to exhibit quantum effects due to decoherence..

I'm not a physicist, please correct me if I'm wrong, but I think the strong detractor's claim touches on an interesting open problem on physics (which is also key to the question whether we can build real quantum computers): can large systems exhibit quantum effects, or not. Nothing in quantum mechanics as we understand it today says there cannot be macroscopic quantum effects, but there seem to be serious obstacles to scaling quantum effects to macroscopic systems. They may just be engineering problems that will eventually be overcome, but it is also possible that there is a fundamental scale limitation to quantum effects which we don't understand.


Quantum biology would be a superimposition of principles from quantum physics over biological processes, but not necessarily over biological systems as wholes, would it not?

Biology is based on chemistry, and chemisty is based on quantum mechanics. However, for large systems, quantum mechanics (as far as we know) collapses to classical mechanics, and consequently we work with classical physics in biology. The claim of quantum biologists is that there are biological phenomena that cannot be explained classically.

Mr. Tea
07-11-2009, 02:52 PM
A strong form of detractors says: biological entities (like macro molecules) are too large to exhibit quantum effects due to decoherence..

But macromolecules are made up of micromolecules, aren't they? And micromolecules are made up of atoms. I mean, genetic nucleotides are pretty small, and molecules bigger than that (Buckyballs, for example) have been shown to exhibit explicitly quantum-mechanical behavior, viz. diffracting when you pass a beam of them through a narrow slit.

Then in the brain you've got nitrous oxide acting as a neurotransmitter, and that's only got three atoms - not to mention the individual potassium/sodium ions involved in the transmission of nerve impluses. Decoherence time is, AFAIR, inversely proportional to the size* of the system under consideration, so it's much longer for a single atom or a monocyclic molecule than for, say, a whole protein or something.


*not sure if this means mass or length scale, but doesn't substantially change the argument

nomadthethird
07-11-2009, 05:56 PM
No, it's the same, just more politely expressed.

The question is: do we to go down to the level of QM to explain biological phenomena, i.e. how the proteins work in cells, or can all of this be explained classically?

The people who are argue for quantum biology all say: in the future we will find biological effects that can only be explained with reference to quantum phenomena. Their detractors say: there is currently no example where we know that it cannot be explained classically, please quantum biology guys & girls show us one.

A strong form of detractors says: biological entities (like macro molecules) are too large to exhibit quantum effects due to decoherence..

I'm not a physicist, please correct me if I'm wrong, but I think the strong detractor's claim touches on an interesting open problem on physics (which is also key to the question whether we can build real quantum computers): can large systems exhibit quantum effects, or not. Nothing in quantum mechanics as we understand it today says there cannot be macroscopic quantum effects, but there seem to be serious obstacles to scaling quantum effects to macroscopic systems. They may just be engineering problems that will eventually be overcome, but it is also possible that there is a fundamental scale limitation to quantum effects which we don't understand.



Biology is based on chemistry, and chemisty is based on quantum mechanics. However, for large systems, quantum mechanics (as far as we know) collapses to classical mechanics, and consequently we work with classical physics in biology. The claim of quantum biologists is that there are biological phenomena that cannot be explained classically.


Ahhhhh...now a couple of things from the debate make more sense.

I don't know, I think I'm with the "Yes" team on this. There are plenty of things that we just can't explain yet with reference to classical explanations (biomechanical ones), viz., for example, how spindle fibers/microtubules move down a cell during mitosis. In fact, there are plenty of microbiological processes that work and we just can't figure out how the cells parts know to move this way or that way--what is attracting them?? This doesn't mean that we will never discover a way to explain them with reference to classical physics, but I wouldn't be shocked if somebody comes up with a wacky and awesome quantum explanation. There does seem to be a gaping whole at the center of microbiology just waiting to be filled by somebody.

Why not think big? (Or small...whatever...)

nomadthethird
07-11-2009, 06:01 PM
But macromolecules are made up of micromolecules, aren't they? And micromolecules are made up of atoms. I mean, genetic nucleotides are pretty small, and molecules bigger than that (Buckyballs, for example) have been shown to exhibit explicitly quantum-mechanical behavior, viz. diffracting when you pass a beam of them through a narrow slit.

Then in the brain you've got nitrous oxide acting as a neurotransmitter, and that's only got three atoms - not to mention the individual potassium/sodium ions involved in the transmission of nerve impluses. Decoherence time is, AFAIR, inversely proportional to the size* of the system under consideration, so it's much longer for a single atom or a monocyclic molecule than for, say, a whole protein or something.


*not sure if this means mass or length scale, but doesn't substantially change the argument

Oh yes there are some amazingly simple and elegant neurotransmitters, including all kinds of ions. Ca 2+ is a fav of mine.

Are you saying here that the quantum tendencies of a system cohere longer in a more complex system? Or can't this be expressed this way?

Mr. Tea
08-11-2009, 05:34 PM
Are you saying here that the quantum tendencies of a system cohere longer in a more complex system? Or can't this be expressed this way?

I don't think complexity is the main thing, it's more to do with size. Bigger systems decohere faster, meaning there's less time for quantum interference between different states, not more. Though it seems reasonable to assume bigger systems are generally more complex than smaller ones.