Still plenty of room at the bottom?

Following up on Plenty of Room at the Bottom - how did Feynman do?

As I pointed out in an earlier post, Feynman's quintessential article imagines what accomplishments of which very, very tiny technologies and machines might be capable.

To summarize the contents of the article, Feynman:

• Appeals to visual logic by calculating how little space printed materials really need to take up (he shows that one could write the entire contents of all the volumes of the Encyclopedia Britanica on the head of a pin)
• Imagines a way, based on technologies available in 1960, to write and copy "written" information at such a small scale
• Describes how, by taking advantage of all three spatial dimensions, all print copies of every written medium in 1960 could fit on a spec of dust.
• Points out a need for the development of a better electron microscope to take this information processing strategy from being a possibility to becoming a reality; he also talks about several earth-shattering consequences of an electron microscope able to map and manipulate individual atoms
• Discusses possibilities and advantages of miniaturizing the computer
• Imagines miniaturizing machines, such as cars and robotic hands, and thinks through the logistical limits of scale, such as the volume needed in the engine blocks for combustion to occur, or the limits of human dexterity.
• Calls for high-school contests which use such "miniaturization technology"

So how did Feynman do? Nearly 50 years later, what has become reality and what is still a beckoning call to the modern physicist? 

• Computers are VERY much miniaturized compared with what they were in 1959. The logic gates used in modern computers are, in fact, reaching the limits of size, going down to about the scale Feynman calls out as the size limit (100s of atoms). New strategies are emerging which will allow for further increases in computational power once the limits of conventional electronics are reached (more on that in an upcoming blog post)! 
• Information is stored in very tiny capsules. Just think, the computer or smart phone you're using to read this has the ability to store about as much information as five average sized libraries! All in the palm of your hand.
• Modern electron microscopes have aided in the understanding of biological processes, and was instrumental in DNA sequencing, essential in mapping the human genome
• There are communities supporting high school students who regularly use scanning electron microscopes to take images such as this (a moth's eye):

photo credit: http://remf.dartmouth.edu/images/insectPart3SEM/image/22noctuidae120.jpg

For all the remarkable predictions Feynman made, some of his dreams have yet to become reality. These include: 

• a high numeric aperture electron microscope, capable of repeatably and reliably manipulating individual atoms
• miniature robotic hands capable of manipulating at the nanoscale (although there are tools which can be used to physically scribe things at that scale, such as the atomic force microscope)

One of the most important aspects of the continued development of the field of nanotechnology is understanding how physics is different at that scale, and what effects that are imperceptible to us at the scales we deal with in our day-to-day lives affect the nanoscale miniatures we're making every day. Several of the upcoming blog posts will deal with some of these weird effects and how we can explain them.