Actually the Scanning Tunneling Microscope does not demand a single-atom tip (in the sense considered here). Rather, a reasonably sharp apex will have one atom which is slightly closer to the surface than its neighbors from which most of the electron tunneling takes place. A tip with a radius of curvature less than, say, 100 nanometers is generally sufficient for most STM usage. Problems can arise when the tip has multiple protrusions which are a roughly equal distance from the surface, especially when scanning larger surface features such as carbon nanotubes (as compared to an atomically flat surface).
That said, better tips mean better images, especially with larger surface features, and also lower field emission voltages, which means applications in electron microscopy and even flat-panel display technology.
That said, I've make single-atom tips (of the sort discussed in this article) in the lab on a regular basis over the past several years with an ion sputtering-based process, a technique that is not limited to tungsten (tungsten is hard, but oxidizes, meaning the tip will not withstand removal from an ultra-high vacuum environment). This is a very interesting technique, but claiming it to be the sharpest object ever made is certainly overstating the achievement.
As a fellow Illini I understand the feeling, and I have an especially strong feeling on this particular issue. As it happens, after reading about the Moore's law article on Slashdot I popped into the library on one of my regular trips, actually found the book and read through it (though I didn't walk off with it!). Part of me wanted to take it down to the desk and suggest that it be kept under lock and key for a few weeks, but for some reason I didn't act on that instinct, and boy do I feel dumb. The next day it walked away =(
Perhaps I am misunderstanding the situation, but I thought that patents existed exactly for individuals and companies who created new and different (revolutionary) technology. If Nintendo invented a new technological innovation for incorporation into their next-generation system, I would have expected them to have filed for a patent on the invention long ago, thus preventing their competition from "stealing" the idea.. or is it not revolutionary enough to be original? Thoughts, explanations?
I am sure that an interface for a specific suite of codes could be more complex, but the GUI I am talking about it basically nothing more than a namelist editor. All of the codes that I'm refering to use namelist input, and a configuration file is written for each code, specifying variables, their type, max, min, default, and a description of the variable. The namelist editor (NLEdit) simply uses this configuration file to create a list of variables, including descriptions, along with other useful features. It tests the limits specified in the config file, has an array editor, and some basic plotting capabilities.
Well, I can't speak for other agencies, but here at NASA Glenn Fortran is very much alive. A huge amount of the thermodynamic cycle/turbomachinery analysis that gets done around here is done using legacy Fortran code. Though they are no longer developing new codes in Fortran (at least in my office), it still lives. Rather than rewriting Fortran code, the effort (mine anyways) currently goes into writing generic GUIs for Windows to interface with those programs.
Individuals with computers that do not support the fiber gigabit cards (for example, many mac computers, which do oftentimes have GB ethernet cards for UTP rather than fiber) are getting somewhat shafted in the switch, and are being issued 100MB tranceivers to convert the signal from fiber to copper for their computers. Thus, they aren't seeing the same kind of improvement. I am not certain if the same applies for laptops, but I imagine that it does.
As a current CWRU student who is currently living in the dorms over the summer and currently has his computer hooked up to the network I can try to clear up any confusion on this =)
The network does, indeed, feature fiber running to every desktop. As several individuals have stated previously, the University ran fiber optic cable to every dorm room and office several years back (longer back than I remember). That same fiber is now being used to provide gigabit connections to every room. Every student was (or will be) provided a Netgear GA621 gigabit fiber optic network card for their personal computer, which does, indeed, equate to "fiber to the desktop" =)
Slashdot Mirror
Actually the Scanning Tunneling Microscope does not demand a single-atom tip (in the sense considered here). Rather, a reasonably sharp apex will have one atom which is slightly closer to the surface than its neighbors from which most of the electron tunneling takes place. A tip with a radius of curvature less than, say, 100 nanometers is generally sufficient for most STM usage. Problems can arise when the tip has multiple protrusions which are a roughly equal distance from the surface, especially when scanning larger surface features such as carbon nanotubes (as compared to an atomically flat surface).
That said, better tips mean better images, especially with larger surface features, and also lower field emission voltages, which means applications in electron microscopy and even flat-panel display technology.
That said, I've make single-atom tips (of the sort discussed in this article) in the lab on a regular basis over the past several years with an ion sputtering-based process, a technique that is not limited to tungsten (tungsten is hard, but oxidizes, meaning the tip will not withstand removal from an ultra-high vacuum environment). This is a very interesting technique, but claiming it to be the sharpest object ever made is certainly overstating the achievement.
It engaged me. I am better for having read it. Thank you.
As a fellow Illini I understand the feeling, and I have an especially strong feeling on this particular issue. As it happens, after reading about the Moore's law article on Slashdot I popped into the library on one of my regular trips, actually found the book and read through it (though I didn't walk off with it!). Part of me wanted to take it down to the desk and suggest that it be kept under lock and key for a few weeks, but for some reason I didn't act on that instinct, and boy do I feel dumb. The next day it walked away =(
Perhaps I am misunderstanding the situation, but I thought that patents existed exactly for individuals and companies who created new and different (revolutionary) technology. If Nintendo invented a new technological innovation for incorporation into their next-generation system, I would have expected them to have filed for a patent on the invention long ago, thus preventing their competition from "stealing" the idea.. or is it not revolutionary enough to be original? Thoughts, explanations?
I am sure that an interface for a specific suite of codes could be more complex, but the GUI I am talking about it basically nothing more than a namelist editor. All of the codes that I'm refering to use namelist input, and a configuration file is written for each code, specifying variables, their type, max, min, default, and a description of the variable. The namelist editor (NLEdit) simply uses this configuration file to create a list of variables, including descriptions, along with other useful features. It tests the limits specified in the config file, has an array editor, and some basic plotting capabilities.
Well, I can't speak for other agencies, but here at NASA Glenn Fortran is very much alive. A huge amount of the thermodynamic cycle/turbomachinery analysis that gets done around here is done using legacy Fortran code. Though they are no longer developing new codes in Fortran (at least in my office), it still lives. Rather than rewriting Fortran code, the effort (mine anyways) currently goes into writing generic GUIs for Windows to interface with those programs.
Individuals with computers that do not support the fiber gigabit cards (for example, many mac computers, which do oftentimes have GB ethernet cards for UTP rather than fiber) are getting somewhat shafted in the switch, and are being issued 100MB tranceivers to convert the signal from fiber to copper for their computers. Thus, they aren't seeing the same kind of improvement. I am not certain if the same applies for laptops, but I imagine that it does.
As a current CWRU student who is currently living in the dorms over the summer and currently has his computer hooked up to the network I can try to clear up any confusion on this =) The network does, indeed, feature fiber running to every desktop. As several individuals have stated previously, the University ran fiber optic cable to every dorm room and office several years back (longer back than I remember). That same fiber is now being used to provide gigabit connections to every room. Every student was (or will be) provided a Netgear GA621 gigabit fiber optic network card for their personal computer, which does, indeed, equate to "fiber to the desktop" =)