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Archive for August, 2013

Fundamental Physics and Consumer Electronics: Back to School

Saturday, August 31st, 2013

We just wrapped up our first week of classes for the new semester here at Texas A&M. One of the two classes I’m taking this semester is classical mechanics.  It’s basically Newton’s three laws wrapped up in the much prettier package of Lagrangians.  At first I didn’t think this would offer much to write about physics-wise this semester, but I’m quickly finding out I was wrong.  Here are two examples.

The Wine Glass Resonator Gyroscope

After checking out John Blyler’s recent post on MEMS, I did a little research.  First off, I think it’s just flat out cool you can buy a gyroscope on a chip now.  I had no idea.  Things became even more interesting when I found out that one of the popular MEMS gyroscope designs is based on fundamental physics research done in 1890 by G.H. Bryan.  Bryan like many an ardent wine drinker had noticed that the tone of the sound made by a resonating crystal wine glass varied if it was moved, rotated, or spun.  He worked out some of the basic equations that described the change in tone and unknowingly set a research path in motion that would result in the MEMS wine glass resonator gyroscope a hundred years or so later.

GPS Without Satellites

One of the topics we’ll be discussing in classical mechanics this semester is the Coriolis force.  This force is what’s known as a fictitious force and is responsible for things like the circular motion of hurricanes.  It’s called fictitious because it’s not a result of one of the four basic forces like gravity or electromagnetism.  Instead, it results from the spinning motion of the earth.  In any event, it’s fairly basic and is covered rather extensively in undergraduate physics classes.

Here’s the kind of cool part they don’t tell you in undergraduate physics though.  In 1915, Arthur Compton, who would later go on to discover Compton scattering, built a global positioning system that allowed him to determine the position of his laboratory to within a few tenths of degree of latitude and longitude.  He was able to do this without taking any observations outside and well before satellites were available, much less satellite based positioning systems.  Compton’s system consisted only of a circular glass tube filled with water.  When the tube was rotated 180 degrees around its diameter the fluid inside began to rotate with respect to the tube due to the Coriolis force.  By measuring the rate of rotation of the fluid, Compton was able to work out the magnitude of the Coriolis force at his location, and hence the position of his location on the surface of the Earth.  You can read more about it in one of the original Scientific American articles on the apparatus.

 

 

Project Computers

Tuesday, August 27th, 2013

Arduinos are cool, but what about Raspberry Pis and BeagleBones? I recently came across the BeagleBone OMAP eval/hobbyist system from TI. With a 1 GHz ARM core, all the ports needed to hook it up quickly and get to work, and a price tag of $45, it’s looking like a pretty nice alternative to the Arduino for folks that already know how to program in a linux environment.

BeagleBone

It also looks like a very nice simple data acquisition system for laboratories and hobbyists.  The BeagleBone’s ADC has a sample rate of 125 ns which comes out to eight million samples per second. A digital sample rate that engineers at national labs in the ’90s would have killed for or at the very least, spent thousands of dollars for.  The Raspberry Pi is cheaper than the BeagleBone, but it doesn’t have a built-in ADC. There are, however, resources available for attaching an auxiliary ADC to the board.

On the hobbyist side of things, a simple somewhat low-bandwidth digital oscilloscope wouldn’t be too much of a stretch project with the board as is.  A project is already in the works to press the board into ham radio service as a software defined radio.  For excellent information on building a software defined radio from scratch check out this series of videos from Jerri Ellsworth.  While availability of an on-board hdmi output port makes the dream of a smart phone display slightly obsolescent, with both host and client USB capability, it should be easier to use a smart phone as a display with a Beagle Bone than it would be with an Arduino system.

The board computers look great for getting to work on a project if you have computing experience, but the Arduino still looks like the best choice for getting your hands dirty at the pin level.  Documentation for the board computers was rife with warnings about not exceeding I/O and ADC voltage levels.  While this is still a concern with the Arduino, error recovery is much simpler, at least on the plug-board based system I’ve been using.

The Original Crowd Sourcing: Government Funding

Friday, August 9th, 2013

If you’re looking for funding for your next entrepreneurial venture, amidst all the clamor for kickstarter and indiegogo, don’t forget one of the original crowd sourcing schemes, government funding. While doing research for an upcoming article on the internet of things, I came across a press release from ARM announcing they were turning their Cambridge campus into a demonstration vehicle for the internet of things by instrumenting it with over 600 sensors.  While the idea in and of itself was pretty cool, a few sentences into the press release ARM’s true genius became apparent.  Sure, they were building a living demonstration of the internet of things, one of their key revenue segments, even better, they were using this demonstration to highlight some of their customers uses of ARM processors, but best of all, they weren’t paying for it!  The project was funded by a  £800,000 grant from the UK government’s Technology Strategy Board.

Earlier in the week I came across this article describing the U. S. Air Force’s expenditure of $25,000 for a feasibility study of teleportation.  The study, authored by Eric Davis of Warp Drive Metrics, summarized the basic technological requirements for teleportation.  It detailed the requirements for teleportation via general relativistic wormholes as well as by quantum mechanical techniques.  In the end, it was determined that the technology currently available wasn’t up to the task.

These two examples highlight an often overlooked funding option, government grants.  The Air Force, Navy, Army, NASA and other government agencies routinely have rather open ended funding calls.  Some calls are targeted at small businesses through Small Business Research Initiatives while others are targeted at universities.  The university funding usually encourages collaboration with industry though, so it pays to network with the professors and students at your local institutions of higher learning.

To search for the latest government funding opportuinties check out
http://www.grants.gov/web/grants/search-grants.html?keywords=physics
and to sign up for automated updates on NASA funding go to
http://nspires.nasaprs.com/external/