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Comment by mistercow | Hacker News Reader

> We don’t even have micromachines. Mechanical objects on microscales do not exist.

Huh? Aren’t micromirror devices made of millions of microscale mechanical objects?

The first DMD page that came up for me is a TI DLP4500, which has about an 11mm diagonal and is about 1000 mirrors wide, putting the individual mirrors, and their tiny hinges at around 10 microns. What definition of “microscale” is the author using?

Edit: I didn’t realize that this article is 12 years old, but it doesn’t matter. DMDs had been in use in consumer products for almost a decade when this was written.

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Yes, this is a weird argument and unnecessary for the main target of the article. There were plenty of successful microactuators, sensors, full microrobots, etc even when this article was written (2010).

Yeah, I agree that it’s tangential to the main point. Still, it makes me question the author’s credibility on the subject. If you’re claiming something won’t exist, and you’re overlooking a large amount of technology that does exist, I can’t help but think that you might have overlooked something in your assessment of the state of the art.

It is obvious that the author is referring to the sort of technology that Drexler and company were positing - a technology explicitly claimed to be so unlike anything then- (and now) realized that it would be radically transformative. At the time of writing, nothing even approaching a proof-of-concept existed (DMD devices certainly are not that), and this has not changed in the decade+ since.

You can, of course, suppose that the author has overlooked something, but there are others who have equally - and perhaps more carefully, by your standard - made the same points, such as Richard Smalley, who is quoted here.

When he says "even" he presumably means micro in contrast to nano machines.

Look at the sentence in context. It is obvious that the author is referring to microscale machines, not nanoscale. And the statement he makes there is simply false.

My point is that the case against Drexler’s concept does not collapse because of this one mistake.

Right, which I already acknowledged.

Well, you did indeed nominally acknowledge that this is only one detail, but then you continued by using this one technical error to cast doubt on the article as a whole! What were we supposed to make of that? There are cases where one apparently small issue is devastating (“who shaves the barber?”) but this is not one of them.

MEMS [1] is, I believe, the name you're looking for. Lots of cool detail on the Wiki page.

[1] https://en.m.wikipedia.org/wiki/Microelectromechanical_syste...

Ah yes. DMDs were just the example that immediately popped into my mind, probably because they were one of the first that I read about in any depth.

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