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Comment A few problems I have had with the Arduino boards (Score 2) 224

(a listing can be found at http://arduino.cc/en/Main/Hardware )

I have tried to use Arduino boards in the past, and while they're really cool for hobbyist stuff, they are very hard to integrate into battery-operated things:

1. The operating voltage is 5V (some may be 3.3V, I forget) and draw a lot of current. Batteries that supply this kind of voltage are HUGE. It would be really nice if they had a design that was optimized for low voltages and low currents, like for mobile sensing, so that I could use coin cells.

2. The devices are really memory-limited. The Uno, which is probably the most popular, has something like 2kB of ram. I used the board to interface with some sensors for tracking a flight trajectory on-board, and I could only record a few seconds of data before running out of room. Wireless transmission wasn't really an option because of power (= more batteries) limitations.

3. Connecting to USB resets the board, wiping the memory, unless you cut a trace on the board. This is supposed to help facilitate loading new programs, but becomes an annoyance if you wanted to use it to transfer sensor data stored on-board to a computer. When you cut the trace to disable the autoreset, it becomes difficult to time the reset button manually so that your program uploads.

Overall, as an EE, I was very impressed at how easy it was to use, but I think the issues I mentioned warrant some fixing if Arduino is going to be used for things like sensing.

Comment Recent science fair judge here (Score 2) 414

I have judged my city's (> 500,000 people, South) science fair for the last several years. It has been about 10 years since I graduated from high school, and I had participated every year in my county (~ 1 million people, not culturally Southern) science fair back then. I remember vividly, back then, having kids with amazing projects that were worthy of MS-level theses. One year, for example, someone found a new Group Theory result (with oversight by a college professor), for example. Many others did medical studies, had detailed demonstrations of traffic pattern simulations, and so on.

Fast forward to me judging the high school science fair here, and I'm appalled at what the "best" these kids could muster is. Most kids couldn't even design a simple experiment. For example, one girl was measuring the conductivity of a solution and varying the temperature, but her "data" consisted of her saying that the conductivity went down as the temperature went down. There was no actual data. The best projects were judged "best" by me by at least having some kind of quantitative data, using proper controls, and having some understanding of the implications of the work. Nothing blew me away, and I had to wonder where the mentor involvement was because it seemed like these kids did everything on their own.

Comment Re:Whoah (Score 3, Informative) 81

Advanced Silicon-Germanium transistors can hit 500GHz. You're correct that you need cryogenic temperatures for such operation because crystal lattice vibrations will slow electrons down at room temperature (this is a fundamentally different effect than what limits CPU's when you overclock them). IBM's 100GHz transistor was at room temperature, if I recall, which is probably the astounding part. The secret sauce there is simply very weak interactions between electrons and phonons (physics-y term for lattice vibrations).

Comment Method inferior to others (Score 1) 121

Nanopore sequencing has been around for at least a decade in the lab. They admit that their method of using tunnel junctions to detect the DNA cannot even distinguish between different base pairs.

For background, here's the basic idea of a classical nanopore sequencer:

1. Make a solution with ions in it with a very thin membrane separating two different compartments each containing an electrode. The membrane has a very tiny hole (nanopore)

2. Apply a voltage. This will either attract or repel the salt ions, thus you get a detectable current passing through the nanopore.

3. Put DNA in the solution. The hole is hopefully small enough that the DNA can only go through as if stranded like thread through a needle. As the different base pairs move through, they block up varying amounts of the hole, manifesting as small changes in resistance across the hole.

4. Profit

The only real limiter is how thin you can make the membrane. Recently, some researchers used graphene, which is thinner than your average base pair, and so you do not get a resistance that is the convolution of many base pairs blocking up the pore at any given time. For more, google "Dekker DNA translocation through graphene nanopores" to see that they can already detect single pairs - and do it thousands of times a second.

Comment Layman's summary (Score 4, Informative) 63

I guess since IAAP (Physicist), I can try to translate some of the physics-ese. Here is the basic argument of the letter:

1. One of the reasons Geim got the Nobel was that he "discovered" graphene. However, the paper the committee is using to establish the date he discovered it (2004) in fact has no reference to graphene but rather graphite, it's well-known cousin. This is an important distinction because a few other groups have graphene papers around the same time.

2. Geim uses a method for creating graphene that is not commercially viable, yet has been credited with a revolution in electronics technology.

3. One of Geim's collaborators goes almost completely uncited although his data is used in the document and appears credited to Geim.

Submission + - Nobel Prize committee criticized over inaccuracies (nature.com)

An anonymous reader writes: A leading researcher in the field of graphene has published a letter to the Nobel committee asking them to address significant problems with the factual accuracy of the supporting documents that laid the case for awarding Andrei Geim and Konstantin Novoselov the 2010 Nobel Prize in Physics. Nature talks with letter author Walt de Heer about his claims that, aside from factual inaccuracies, the document diminishes the role of other groups and 'reads like a nomination letter'. At least one change has already been made by the committee.

Submission + - Bruce Schneier Vs. The TSA (schneier.com)

An anonymous reader writes: Bruce Schneier has posted a huge recap of the TSA controversy, including more information about the lawsuit he joined to ban them. There's too much news to summarize, but it covers everything from Penn of Penn & Teller and Dave Barry's grope stories, other Israeli experts who say this isn't needed and hasn't ever stopped a bomb, the four-year-old girl who was traumatized by being groped and much, much more.

Comment Re:There is still long way to go (Score 2, Interesting) 410

When you take a flight all the televisions in airports run Windows.

Agree with what you said for the most part, but I just wanted to point out that I think Linux is used behind the scenes too. For example, on a long flight back to the U.S. while I was flying with a major European carrier, the entertainment system crashed and I saw the Linux penguin pop up on the screen. I agree though: especially in the states, most of the displays you see on walls in buildings are Windows.

Comment My view as someone in the field of graphene (Score 5, Interesting) 139

Geim's original paper on the subject ( http://arxiv.org/ftp/cond-mat/papers/0410/0410550.pdf ) was a real fascination because it was so simple and yet enabled many people to do real research. The original paper uses scotch tape to peel off monolayers of different bulk materials, but only graphene showed anything interesting (in particular, the so-called "field-effect" which is the principle behind CMOS transistors. To be sure, the quality of graphene produced from this method is complete crap compared to more advanced methods used by groups today (chemical vapor deposition of various organic molecules, carbon gettering from metals, epitaxial growth by silicon sublimation from SiC), but an impressive amount of exotic physical phenomena (e.g., quantum hall effect) was seen in what was essentially crap.

No doubt, Geim has probably indirectly gotten thousands of researchers perhaps a billion dollars in funding in less than a decade, but I don't think Geim's contribution was as much physics as it was successfully marketing his research (outsiders like to think of science as being purely meritocratic, but it scientists are still people, and people are susceptible to hype). In my opinion, there are many better physics researchers in the field than Geim himself, but none of them are nearly as good at communication and generating buzz.

In any case, congratulations to him for winning it so soon.

Comment I'm surprised at this... (Score 1, Flamebait) 764

... considering Apple does not even offer Macbooks with core i3's. You must get core i5 or i7 and pay out the wazoo (to the tune of $1700+) for it or else you're stuck with core 2 duo's, as far as I know. Then again, UVa is not a tech school and so I don't expect many of their incoming class to know or care. Meanwhile, my $500 dollar laptop from a local store 4 years ago still runs AutoCAD 2010 just fine with a $40 RAM upgrade.

Comment Caution about ArXiv (Score 4, Informative) 421

I have neither the capacity nor the will to vet the paper, but it should be noted that ArXiv is not peer reviewed. While experimentalists use it as a place to publish pre-prints of their papers and will typically only put them up after the papers have been accepted, but theorists use the medium as a substitute for publishing and so many wacky and untrue claims get put up there.

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