You can get MSP430 starter boards *very* cheap (~$20) from www.sparkfun.com. Then you can go to mspgcc.sf.net and build a GCC cross compiler, which is mildly painful, but not too bad. I was able to get the whole thing going and flash a program that blinks an LED onto the uC with about an hour of work.
Join their mailing list if you have trouble, it's quite active. There's also a very active Yahoo! group (ick) called MSP430.
There is a much, much better article with lots more detail on EETimes.com.
Re:Cost of Lifting Things
on
The Wrong Stuff
·
· Score: 5, Insightful
I'm starting to think we'll never see any real space development until a new, radical propulsion technology comes along. Until then, it just costs too much to heave things out of the gravity well. Incremental advances seem unlikely to do it - it requires an orders-of-magnitude shift in cost.
Weinberg's point is not that space flight is too expensive; his point is that manned space flight is too expensive and that the gains of sending a person along are marginal.
The figure that he cites it that it costs $3,000 per pound of payload for an unmanned rocket, and $10,000 per pound for the Space Shuttle.
Granted, the unmanned rocket is not cheap, but the manned flights cost more than three times as much.
There's a similar project at the University of Texas at Austin. It aims to image Mayan pyramids in Belize.
They have a fairly sparse website, but there's a quite good PDF of a slides from a talk that Roy Schwitters (former director of the Superconducting Supercollider) gave.
> Many locking mechanisms require power, and if the power fails, there are only two possibilities: either it will be locked shut and unopenable, or it will have a fail-safe mechanism to unlock automatically if the power fails.
From the article, "The first Optilocks have been designed for the automotive industry."
There are some automotive locks that already use power from the car's battery, so that's not a huge consideration.
I think it's very interesting that the artist, Richard Box, is an artist in residence with the Physics department at the University of Bristol.
It's cool to see art and science actively collaborating. From the article:
The Physics Department at the University of Bristol has played host to a number of artist residencies. In 2002 artist, Richard Box was awarded a Leverhulme Grant to become the department's third artist in residence. Whilst the starting point for other artists have varied, Richard's main interest was in the specialist glass blowing workshop that is integrated alongside the rest of the physics research activities. His interest in glass has always required him to have objects made by others, this residency offered him the chance to begin to learn how to develop his own glass blowing skills and so have greater authority over his own work.
Here's a similar chart from the American Institute of Physics (Fall 2003). They give a range of typical salaries for each degree type, which is an important fact - ChemE students earned 50-55k, while students with a Physics BS pulled in a much larger range, from about 32-52k.
Interesting to note that secondary school teachers seem to have the least opportunity salary-wise (as far as that chart shows); not only is their salary low, but they're locked in to the narrowest range, from about 27-32k.
There is a similar reasonably well-documented homebrew STM that was built by a guy named Jurgen Muller. His site is pretty interesting, and well worth the read.
Obviously there are a lot of articles on STMs in various academic journals. If you're at a university, you might start by searching in Reviews of Scientific Instruments and perhaps the Phys Rev journals.
I was involved with a STM project for a while, and our conclusion was that the 3D piezo setup is quite fragile, and extremely difficult to isolate from vibration, etc. It seemed that a better design was a so-called slip-stick walker, which uses a stage that slides on smooth rails. A tube of piezoelectric ceramic is attached and driven in such a way that it creates a series of small, sharp forces on the stage that momentarily break the static friction between the stage and base, causing it to move in small steps.
This stage is used to approach the sample to the STM tip, which is mounted on another piezo tube, and can be deflected laterally and vertically in order to do a raster scan of a small area of the surface.
The limitation to this method is that you can't scan a very large surface area. You can add a second "walker" unit underneath the first one so that you can move the sample from side to side in addition to moving it towards/away from the tip, so this would allow you to scan a stripe across the surface.
To get full 3D control, there are several designs called "beetles" (IIRC) that are described in the literature, which use a somewhat similar technique that allows more control.
Space tortillas
on
Eating in Space
·
· Score: 4, Interesting
They wanted to (or did?) use MRI scans of tortilla dough to determine whether there were any changes on a molecular level that could be linked to tortillas taking on a bitter taste after being on the shelf for extended periods of time.
I wish I could get my own NMR spectrometer by saying that I want to study tortillas.
Does anyone have a page that lists the technical details of how DLP works? The picture of the slide wasn't very technically detailed. I'd like to see how these work.
There's a fair amount of info on DLP at dlp.com. They have a rather high level "Technical overview", but if you look in the right place, you can also find a small White Paper Library, which has a number of papers that are fairly technically detailed but (IMO) still quite understandable.
I've actually been working as an undergrad assistant in a lab at UT Austin that is very active in the MINOS consortium, so it's pretty cool to see the experiment getting some attention.
There are some neat photos of the detector; the steel scintillator modules weigh about 5,000 tons (!), and you can see one as it is lifted into place. The detector uses something like 2000 16 channel photomultiplier tubes (I don't remember the exact number of tubes) to detect the showers of particles that are created as neutrinos interact with the steel scintillator plates, and the data from those tubes is processed to reconstruct events. Did I mention that the whole thing is in a cavern about 1/2 mile underground to reduce background noise from cosmic rays?
The detector is supposed to come online and start collecting real data in 2004.
Another very interesting neutrino experiment is SNO, the Sudbury Neutrino Observatory, which is in an underground mine in Canada. SNO resolved the solar neutrino problem; people previously couldn't explain why we weren't seeing the right number of neutrinos coming from the sun - it turns out that they "oscillate" and change into other types of neutrinos, and SNO verified this. The neutrino oscillations also imply that they have a non-zero mass (explanation beyond the scope of this comment;)
The point of MINOS is to observe neutrinos from a controlled high-energy accelerator beam, rather than whatever we get from the sun, to very accurately measure the oscillations.
Feynman was flamboyant and made a great show of the O-ring problem in front of TV cameras, an unrehearsed and disruptive performance
I wouldn't call it flamboyant.You can watch a video of Feynman demonstrating the O-ring problem; he demonstrates the problem and describes it in a very matter-of-fact fashion. (Sorry for the link to a RealMedia file!)
Feynman's appendix to the Roger's Commission report on the Challenger disaster is a very interesting read. He makes the estimate that there is a 1 in 100 chance of a catastropic failure (pretty close, since the actual rate is now 2 in 107).
The appendix calls into question the management practices at NASA; I'm not sure how the agency has changed since then, but I am certain many of the points he makes are still highly relevant today.
Jamie Zawinski (former Lucid Emacs / Netscape hacker) looked into the option of Linux POS devices for his nightclub. You might want to read about his experiences.
A technician would pick the basket up off the rail and then use vacuum wands to move the wafers into the loading mechanism for the machine. Once processing was done, vacuum wand the wafers back into the basket and place it back on the track.
You must have been in one of the older fabs. There are two industry standard automated wafer carrier pods used these days: SMIF and FOUP. SMIF (Standard Mechanical InterFace) is used for 200mm wafers, and FOUP (Front Opening Unified Pod) is used for 300mm wafers. The pods are sealed from their environment and are not opened by fab technicians under normal circumstances. The overhead tracks run directly to each machine in the fab, and each fab tool loads the wafers directly from the pod without human intervention.
A major benefit of all this is that the wafers never enter the cleanroom air - they only encounter the air in the pod, and the air in whatever tools they enter. As a result, the air in the cleanroom doesn't have to meet such a high spec, which leads to big savings on air scrubbers.
Accidentilly forget which wafers have been processed already (many of the machines could only load 5 or 10 wafers, and a lot was 24 wafers)? Bad things happen when you double-dope or double-etch wafers.
This is the reason behind the wireless control system. Old fabs use paper-based flow logging, meaning that each wafer lot has a paper attached to show where it has been and where it has to go. Did I mention that this is special (read: expensive) cleanroom paper, because regular paper flakes off lots of particles that are a no-no in the cleanroom environment? In modern fabs, the SMIF and FOUP pods have electronic tags that carry all the information needed to process the wafer lot - the recipe for which machines it has to go to, what to do when it gets to the machine, notes by technicians, etc etc.
Um, just millimeter? You'd think where chips have components measured in nanometers, that you'd need just a bit more than millimeter precision. Oops, that transistor's off a bit again! i wonder why?:P
They're referring to the system that shuttles containers of wafers around the fab, moving them from machine to machine. Robots run around on rails, dropping down to pick up a sealed container of wafers and whisk it away to the next stage in the manufacturing process.
Once a wafer is loaded into a stepper for printing, rest assured that it is aligned very precisely.
Interesting... I was at UNT from 1999-2001, and one day I was outside McConnell Hall with a few friends. We looked up and said "Holy shit, it's a stealth bomber! And look at how low it is!"
So, black triangular thing that we assumed was a stealth bomber, flying VERY low over denton at moderate speeds.
For you poor saps running Windows with no viewer for Postscript, there is a great online viewer that converts ps, pdf, and word docs to gif images, suitable for viewing in your favorite web browser.
Interesting tidbit, CodeCon was hosted at the DNA Lounge, the nightclub in San Francisco that was recently bought, remodeled, and reopened by JWZ (also known as Jamie Zawinski), the "retired" programmer of Netscape fame.
"Every time I think I've discovered something interesting, I look on the internet and find that somebody else has done it too" -- Knuth
I'm sure that at times, most everyone in a technical field feels like everything has been done before. It's nice to know that someone as badass as Knuth has the same problem:)
This would be very easy to do. Write a script to grab the page with the filter on and off for the same search query (you probably want to set it to return 100 results), and just diff the two pages.
Slashdot Mirror
You can get MSP430 starter boards *very* cheap (~$20) from www.sparkfun.com. Then you can go to mspgcc.sf.net and build a GCC cross compiler, which is mildly painful, but not too bad. I was able to get the whole thing going and flash a program that blinks an LED onto the uC with about an hour of work.
Join their mailing list if you have trouble, it's quite active. There's also a very active Yahoo! group (ick) called MSP430.
See also: This post on diveintomark.com called How To Install Windows XP In 5 Hours Or Less.
There's another article on the subject in this month's issue of Physics Today: DOE Warms to Cold Fusion
There is a much, much better article with lots more detail on EETimes.com.
I'm starting to think we'll never see any real space development until a new, radical propulsion technology comes along. Until then, it just costs too much to heave things out of the gravity well. Incremental advances seem unlikely to do it - it requires an orders-of-magnitude shift in cost.
Weinberg's point is not that space flight is too expensive; his point is that manned space flight is too expensive and that the gains of sending a person along are marginal.
The figure that he cites it that it costs $3,000 per pound of payload for an unmanned rocket, and $10,000 per pound for the Space Shuttle.
Granted, the unmanned rocket is not cheap, but the manned flights cost more than three times as much.
If you're using Windows, you should probably be using all of these programs (if you need them). Most of them are pretty stable and mature.
Audacity - Sound editing (so this post is on-topic!)
Mozilla FireFox - Web browsing.
The Gimp - graphics/photo editing
Sodipodi - Vector graphics (SVG) editing. It's no Illustrator, but the basics are there, and they're pretty nice.
OpenOffice - Not quite ready to replace Word/Excel/PPT, but it's great if you (or your employer/university) haven't already shelled out for Office.
FileZilla - FTP client
Gaim - AOL Instant Messenger client
PuTTY - ssh client
There's a bit more elaboration and links on my blog.
There's a similar project at the University of Texas at Austin. It aims to image Mayan pyramids in Belize.
They have a fairly sparse website, but there's a quite good PDF of a slides from a talk that Roy Schwitters (former director of the Superconducting Supercollider) gave.
From the article, "The first Optilocks have been designed for the automotive industry."
There are some automotive locks that already use power from the car's battery, so that's not a huge consideration.
It's cool to see art and science actively collaborating. From the article:
Here's a similar chart from the American Institute of Physics (Fall 2003). They give a range of typical salaries for each degree type, which is an important fact - ChemE students earned 50-55k, while students with a Physics BS pulled in a much larger range, from about 32-52k.
Interesting to note that secondary school teachers seem to have the least opportunity salary-wise (as far as that chart shows); not only is their salary low, but they're locked in to the narrowest range, from about 27-32k.
There is a similar reasonably well-documented homebrew STM that was built by a guy named Jurgen Muller. His site is pretty interesting, and well worth the read.
Obviously there are a lot of articles on STMs in various academic journals. If you're at a university, you might start by searching in Reviews of Scientific Instruments and perhaps the Phys Rev journals.
I was involved with a STM project for a while, and our conclusion was that the 3D piezo setup is quite fragile, and extremely difficult to isolate from vibration, etc. It seemed that a better design was a so-called slip-stick walker, which uses a stage that slides on smooth rails. A tube of piezoelectric ceramic is attached and driven in such a way that it creates a series of small, sharp forces on the stage that momentarily break the static friction between the stage and base, causing it to move in small steps.
This stage is used to approach the sample to the STM tip, which is mounted on another piezo tube, and can be deflected laterally and vertically in order to do a raster scan of a small area of the surface.
The limitation to this method is that you can't scan a very large surface area. You can add a second "walker" unit underneath the first one so that you can move the sample from side to side in addition to moving it towards/away from the tip, so this would allow you to scan a stripe across the surface.
To get full 3D control, there are several designs called "beetles" (IIRC) that are described in the literature, which use a somewhat similar technique that allows more control.
That explains this $136,216.20 proposal to NASA to study Development of Extended Shelf-Life for Tortillas for Long-Duration Space Missions".
They wanted to (or did?) use MRI scans of tortilla dough to determine whether there were any changes on a molecular level that could be linked to tortillas taking on a bitter taste after being on the shelf for extended periods of time.
I wish I could get my own NMR spectrometer by saying that I want to study tortillas.
Does anyone else find this to be hilarious?
Have a look at the paper Keeping Secrets in Hardware: the Microsoft XBox Case Study by Andrew "bunnie" Huang, XBox hacker extraordinaire.
Also have a look at his xbox hacking page for lots of other goodies.
Does anyone have a page that lists the technical details of how DLP works? The picture of the slide wasn't very technically detailed. I'd like to see how these work.
There's a fair amount of info on DLP at dlp.com. They have a rather high level "Technical overview", but if you look in the right place, you can also find a small White Paper Library, which has a number of papers that are fairly technically detailed but (IMO) still quite understandable.
I've actually been working as an undergrad assistant in a lab at UT Austin that is very active in the MINOS consortium, so it's pretty cool to see the experiment getting some attention.
;)
There are some neat photos of the detector; the steel scintillator modules weigh about 5,000 tons (!), and you can see one as it is lifted into place. The detector uses something like 2000 16 channel photomultiplier tubes (I don't remember the exact number of tubes) to detect the showers of particles that are created as neutrinos interact with the steel scintillator plates, and the data from those tubes is processed to reconstruct events. Did I mention that the whole thing is in a cavern about 1/2 mile underground to reduce background noise from cosmic rays?
The detector is supposed to come online and start collecting real data in 2004.
Another very interesting neutrino experiment is SNO, the Sudbury Neutrino Observatory, which is in an underground mine in Canada. SNO resolved the solar neutrino problem; people previously couldn't explain why we weren't seeing the right number of neutrinos coming from the sun - it turns out that they "oscillate" and change into other types of neutrinos, and SNO verified this. The neutrino oscillations also imply that they have a non-zero mass (explanation beyond the scope of this comment
The point of MINOS is to observe neutrinos from a controlled high-energy accelerator beam, rather than whatever we get from the sun, to very accurately measure the oscillations.
This has been done. Damian Conway implemented it as a Perl module, Acme::Bleach, quite some time ago.
Hit your nearest CPAN mirror and 'use Acme::Bleach' for great justice.
Feynman was flamboyant and made a great show of the O-ring problem in front of TV cameras, an unrehearsed and disruptive performance
I wouldn't call it flamboyant.You can watch a video of Feynman demonstrating the O-ring problem; he demonstrates the problem and describes it in a very matter-of-fact fashion. (Sorry for the link to a RealMedia file!)
Feynman's appendix to the Roger's Commission report on the Challenger disaster is a very interesting read. He makes the estimate that there is a 1 in 100 chance of a catastropic failure (pretty close, since the actual rate is now 2 in 107).
The appendix calls into question the management practices at NASA; I'm not sure how the agency has changed since then, but I am certain many of the points he makes are still highly relevant today.
Jamie Zawinski (former Lucid Emacs / Netscape hacker) looked into the option of Linux POS devices for his nightclub. You might want to read about his experiences.
A technician would pick the basket up off the rail and then use vacuum wands to move the wafers into the loading mechanism for the machine. Once processing was done, vacuum wand the wafers back into the basket and place it back on the track.
You must have been in one of the older fabs. There are two industry standard automated wafer carrier pods used these days: SMIF and FOUP. SMIF (Standard Mechanical InterFace) is used for 200mm wafers, and FOUP (Front Opening Unified Pod) is used for 300mm wafers. The pods are sealed from their environment and are not opened by fab technicians under normal circumstances. The overhead tracks run directly to each machine in the fab, and each fab tool loads the wafers directly from the pod without human intervention.
A major benefit of all this is that the wafers never enter the cleanroom air - they only encounter the air in the pod, and the air in whatever tools they enter. As a result, the air in the cleanroom doesn't have to meet such a high spec, which leads to big savings on air scrubbers.
Accidentilly forget which wafers have been processed already (many of the machines could only load 5 or 10 wafers, and a lot was 24 wafers)? Bad things happen when you double-dope or double-etch wafers.
This is the reason behind the wireless control system. Old fabs use paper-based flow logging, meaning that each wafer lot has a paper attached to show where it has been and where it has to go. Did I mention that this is special (read: expensive) cleanroom paper, because regular paper flakes off lots of particles that are a no-no in the cleanroom environment? In modern fabs, the SMIF and FOUP pods have electronic tags that carry all the information needed to process the wafer lot - the recipe for which machines it has to go to, what to do when it gets to the machine, notes by technicians, etc etc.
Um, just millimeter? You'd think where chips have components measured in nanometers, that you'd need just a bit more than millimeter precision. Oops, that transistor's off a bit again! i wonder why? :P
They're referring to the system that shuttles containers of wafers around the fab, moving them from machine to machine. Robots run around on rails, dropping down to pick up a sealed container of wafers and whisk it away to the next stage in the manufacturing process.
Once a wafer is loaded into a stepper for printing, rest assured that it is aligned very precisely.
Interesting... I was at UNT from 1999-2001, and one day I was outside McConnell Hall with a few friends. We looked up and said "Holy shit, it's a stealth bomber! And look at how low it is!"
So, black triangular thing that we assumed was a stealth bomber, flying VERY low over denton at moderate speeds.
Cached version of the Knuth document is here.
Pics from the con are also available on the club's website.
I'm sure that at times, most everyone in a technical field feels like everything has been done before. It's nice to know that someone as badass as Knuth has the same problem
This would be very easy to do. Write a script to grab the page with the filter on and off for the same search query (you probably want to set it to return 100 results), and just diff the two pages.
*scurries off to write pr0n-search.pl*