Friday, July 14, 2006

From biomimetic: Nanowires from bacteria.

Biomimetic has posted the following, asking for a thread to be started. I'd like to start a topic about Uncommon Descent and the dishonest way they try to wow their readers with BS.

The latest example is a post about bacteria that excrete metal nanowires. This is cool, but it's really not that special.

The fact that microorganisms excrete metals is far from new. A friend of mine would feed certain bacteria metal ions and they'd crap out reduced metal, usually in the form of nanoparticles or nanocrystals. The nanocrystals would even have neato shapes, like tertrahedra and cubes, but that is due to the crystal structure of the metal and slow crystal growth, not to some magic that was front-loaded into the bacteria. These metal nanowires are just anopther case of that. This time, though, the crystal grew along one crystallographic axis for a really long time, yielding a nanowire. Nothing magic, just chemistry and biology at work.

5 comments:

Alan Fox said...

Link to UD thread.

jujuquisp said...
This comment has been removed by a blog administrator.
jujuquisp said...

What would you expect from people who don't understand science?

biomimetic said...

Sorry, I don't check these things that often and I forgot for a while that I came here.

But UD's latest lightning thread is stupid too.

The function (purpose, not the same thing, but...) is to balance charge between the ground and the air.

I tried posting a comment at UD, but I guess it never made it out of moderation.

Heat from the sun drives the hydrological cycle. Clouds build up static charge, etc etc. Then it discharges when there is a good low-resistance path for the electrons.

I think this misunderstanding from Dembski and the whole crowd over there is perfectly illustrative of their entire endeavor. Just because something has a function doesn't mean it has a "purpose" the way we define it. What "use" is it?

Thunder is a side product of lightning, but it also has its own functions. It serves as a warning to animals that wish to seek shelter from the oncoming rainstorm among other things. Another function of lightning is to start fires that clear out old and dead plants making way for new ones.

I think this sort of thinking from them is why they can see the nanowire formation as something "magical" or something that must have some unknown "purpose." The function of the nanowires is to be waste. The bacteria excrete the toxic metals in a reduced metallic state. Just because these wires may have a side benefit to us humans has nothing to do with an underlying "purpose" to the nanowires, especially with respect to the bacteria. They only want to get the metal out of their system. After that the wires are of no "use" to them.

Everything works like this. It's energy being built up, or pumped up, and then released along a low-resistance pathway. The pathway has some side products (like thunder or nanowires formation) which may go one to perform other functions, and so on. Only when you try to cram the world into some "purposeful" (teleological) framework, do misunderstandings like this crop up, and they subsequently make forming further testable hypotheses much more difficult. IMO, equating "function" with "purpose" tends toward science stoppage.

I think maybe, for the sake of internet discussion with creationists, we should not use the word "function,: since they almost invariably hear "purpose." Maybe we could replace these words when talking to them with, "result," "product," or "consequence." Maybe that would clear up some confusion on their parts or at least make them stop conflating "function" and "purpose."

JohnADavison said...

I take it thenthat biomimetic believes there was no purposein evolution producing as its terminal product Homo sapiens, that we are mere accidents and,as Stephen J. Gould put it,"Intelligence was an evolutionary accident?"

Am I safe in drawing that conclusion?