Comments on: Quantum Brains

By: Test Post « metadatta

Test Post « metadatta — Sun, 01 Apr 2007 14:44:50 +0000

[...] something Roger Penrose has discussed in a good deal of depth. (Matt Leifer has a similar post, asking the question: “if quantum computers are more efficient than classical ones then why [...]

By: Philosophia Naturalis #8 « {metadatta}

Philosophia Naturalis #8 « {metadatta} — Fri, 30 Mar 2007 20:17:23 +0000

By: assman

assman — Wed, 14 Mar 2007 04:09:03 +0000

I argue that in nature robustness is very important. The reason nature never evolved wheels is because wheels are not guaranteed to work in all possible conditions: in snow, in water, up mountains, in forests etc. My view is that evolution is capable of pretty much anything we have done but much of what we have done is very nonrobust so evolution does not tend to favor it. The brain is extremely robust. You can cut in in half, remove parts of it, bang on it, change temperature etc and it still keeps functioning. Most of our technology is not capable of that. Robustness is important because evolution is trying to create survival machines and the environment is constantly changing.

By: serafino

serafino — Tue, 20 Feb 2007 23:13:31 +0000

Anonymous, there is a paper by Albert about ‘quantum automata’ and their behaviour. But also this amazing quote …
“Once, at the afternoon tea, in the Institute [Copenhagen] E.Teller tried to explain to Bohr
why he thought Bohr was wrong in thinking that the historical set-up of classical concepts would forever dominate our way of expressing our sense experience. Bohr listened with closed eyes and finally only said: “Oh, I understand. You might as well say that we are not sitting here, drinking tea, but that we are just dreaming all that.”
-’The Copenhagen Interpretation’, by C.F.von Weizsaecker, in ‘Quantum Theory and Beyond’, Ted Bastin ed., Cambridge U.P., 1971.

By: Anonymous

Anonymous — Mon, 19 Feb 2007 16:07:02 +0000

So what would the classical world look like to a quantum observer?

By: rb

rb — Wed, 14 Feb 2007 10:45:05 +0000

Jan: Your arguments were actually nicely addressed in the original blog post (specifically, explanation 1).

By: rb

rb — Wed, 14 Feb 2007 10:42:42 +0000

> In order for an adaptation to evolve, it has to be reachable by a path, and every step along that path has to be an improvement locally.

Not necessarily, there can be some non-immediately-improving steps which are still kept in the genome and later harnessed together with some improvement.

By: scerir

scerir — Mon, 12 Feb 2007 17:34:23 +0000

It is the ‘Algernon law’, named after Algernon, the mouse from the novel ‘Flowers for Algernon’, written by Daniel Keyes Moran. Any simple major enhancement to human intelligence is a net evolutionary _disadvantage_. Human intelligence is (supposed to be) at its optimal level. Not maximal, but optimal for our _survival_.

By: Matthew Leifer

Matthew Leifer — Sat, 10 Feb 2007 18:30:38 +0000

“Does this option not exist on your blog, or is my browser missing it?”

It’s probably something to do with the settings, so I’ll look into it. This being a Quantum Foundations blog, I’m worried about the crank contingent taking over the comments, so I’ve got just about every filtering option set as high as possible. You’re doing well if you managed to get a comment to appear at all!

By: Torbjörn Larsson

Torbjörn Larsson — Fri, 09 Feb 2007 21:23:53 +0000

“evolution does not seem to have selected that strongly even for classical computing ability”

But the methods of the brain doesn’t have a direct bearing on math ability. In fact, our representation of the environment is incredibly sparse, which probably explain why we have problems with this new task.

Evolution is an ongoing process, so if you wait a couple of thousand years, who knows what we can do?

Robin:

“an umlaut”

Thanks. Technically it is a diaeresis in Swedish, it is a genuine letter. (It can be done with HTML: “& # 246 ;” remove quotation marks and spaces. Testing: Torbjörn.)

“As far as I know, while flagella do make use of rotational motion, it is indirect — akin to a baseball player’s or stone slinger’s rotational motion, which is induced by coordinated linear muscle action.”

I don’t know about those, but it could be – apparently there are a huge number of variants. But this has been discussed a lot because creationists use them as examples of cellular machines. (Though they mistake it for an outboard engine, when in fact it is an inboard engine.)

Here is a post that links to a really nifty youtube animation of bacterial flagella evolution and workings: http://www.pandasthumb.org/archives/2006/12/ode_to_the_flag.html . It shows the bearings and the rotor engine, driven by ATP. Note: It isn’t entirely accurate.

And here is the (accurate) source material for the animation, including drawings of different flagella and TEM pictures: http://www.talkdesign.org/faqs/flagellum.html . It discusses some of the variants like you mention, starting from the archetypical membrane secretion system, over sticking, pushing, and wiggling flagella to rotational. I believe the article developes an evolutionary model over this sequence, btw.