Monday, July 19, 2010

The Worlds Tiniest Guitar....

Imagine playing the world's smallest guitar, with a laser for your guitar pick. Some nanotechnologists are strumming tiny strings this way – but there's no jamming going on. As this ScienCentral News video reports, they're trying to make much smaller, cheaper electronics that could use less energy.
Playing with Light
The next time a friend is pouring out his sob story to you, you can tell him that the world's tiniest guitar is playing for him. Physicists at Cornell University have created a nanoscale "guitar" about as wide as a single red-blood cell.
This device isn't really a guitar, but since the researchers are building very tiny objects to study vibration and resonance, it's obvious why they're thinking musically. "There tends to be sort of a natural assignment of names that have musical association," saysHarold Craighead, professor of applied and engineering physics and co-director of the Nanobiotechnology Center at Cornell University. "We have little discs that vibrate; sometimes we refer to those as the drums. We've made sets of rods, and when you put those side by side, they tend to look something like a harp, or a xylophone, and so we often refer to these devices as the harp device, or the xylophone device. Even simple shapes often end up having a shape that sort of suggests a musical instrument, and they also vibrate. So when we talk about the vibrations, that, of course is analogous to what goes on in an instrument that has a string or something else that shakes."

The nano "guitar" and its strings are made of silicon, with techniques adapted from those used to make electronic integrated circuits. The team "plays" their guitar in a vacuum chamber, using a laser in place of a guitar pick. When a laser hits a string, the heat makes it vibrate at extremely high frequencies, about 130,000 times—or 17 octaves—higher than a normal guitar. "The so-called strings are free to move, clamped at both ends," says Craighead. "That clamping allows us to shine light on that string, change the temperature, and generate stresses that cause the string to move. The different motions of a single string or different strings moving allow us to do something analogous to playing the guitar." The nano "guitar"'s frequencies are much too high for the human ear to pick up. But the Cornell team can detect the vibrations and electronically scale them down to audible tones. "When we move the light beam around, we can make tones that every once in a while sound sort of appealing," says Craighead.

nano xylophone
A nano "xylophone"
image: Lidija Sekaric
The goal of the nano "guitar" and other tiny "instruments" isn't to make music, but rather to use very small devices that vibrate at very high frequencies to find ways to create cheaper electronics that save energy. "One of our major advances has been to learn how to use light beams to cause things to vibrate," says Craighead. "This is an alternative to using lots and lots of little wires to interact with things. We can use light beams that scan over the surface and start things in motion and detect what goes on. We're trying to figure out what sort of new possibilities are allowed by this optical method of interacting with mechanical devices."

As a start, the Cornell team, that includes the research groups of Craighead andJeevak Parpia, professor of physics, uses the laser light to measure the motion it creates. All the "instruments," Craighead explains, have some parts that can move and some that are clamped down to a surface. "We need the light to bounce off the underlying surface and the moveable part simultaneously in order to make things move," he says. "The exact ways in which parts are clamped to the surface are critical for the motion."
Nano-objects that can vibrate at a higher frequency than the guitar—radio frequencies up to hundreds of megahertz—could substitute for other components in electronic circuits. Tiny vibrating nanorods could replace the oscillating quartz crystals used in cell phones and other wireless devices, taking up little space and drawing only tiny amounts of power.
The tiny instruments also could sense very small forces in machinery, to detect or even predict problems. But more research needs to be done. "When things get small, their mechanical properties may change," says Craighead. "They could get either stronger or weaker or stiffer or softer. So we have to figure out how the materials work before we can figure out how we can design things. Then we may be able to design things for completely different uses."
This research was presented in November, 2003 at the American Vacuum Society. It is part of the Cornell Center for Materials Research Nanomechanics research activity supported by the National Science Foundation.


Feature

Some Known Brands Of Guitars

Nestled amongst the crowded acoustic guitar racks of any respectable music or guitar shop you will find a few manufacturers names which really stand out from the ordinary. These aren't just guitars, they are hand crafted works which embody years of guitar technology and craftsman's manufacturing history to bring an unmistakable sound and comfortable playing experience. Quality components are used, such as maple, rosewood and mahogany and the construction is always light delivering a high degree of resonance without distortion or fuzzy sound.                                                                                          


One of the most famous guitar manufacturers is the Martin Guitar Company which was founded in 1833. Their guitars are renowned for their sound and exquisite manufacturing and their designs have been copied by numerous other manufacturers. I've had the good fortune to play one or two Martin guitars and you'll find it difficult to get owners of the guitars to let you play them, such is the prestige and frequently, expense of the instrument. I've always wanted to own one, simply because of the ease and comfort of playing the instrument and their delightful tone and resonance. Since the instruments are hand crafted, you'll find that various pieces of wood within the guitar are tuned, which means no two instruments will sound exactly the same and the quality of the sound is infinitely superior to most other guitars within a similar price range. There is always a crisp clear sound which is mellowed by a strong tone which holds its' presence for just the desired length, something which isn't present in cheaper guitars. The action of most Martin's is nearly always perfect from the word go and you won't have to spend excessive time adjusting the neck to get the guitar right.
Japanese manufacturer, Ibanez Guitars, began building their own guitars in the late 1930's and got their name from the Spanish guitar manufacturer Salvador Ibanez whose workshop was destroyed during the Spanish Civil War. The Hoshino Gakki company had been importing the Ibanez guitars, but bought the rights to the Ibanez brand name since demand for the high quality instruments was still high. The brand became more popular in American markets in the late 1950's and is currently endorsed by the likes of Steve Vai. They continue to produce exceptional guitars in a range of affordable guises. I was fortunate to inherit an Ibanez AW series from my father in 2001 when he bought himself a Takamine. The sound on my Ibanez is quite exquisite and many guitar playing friends.
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Saturday, July 10, 2010

Harmonics

       First harmonic - the string open      Second harmonic - caused by harmonics at the 12th fret - node at the 12th fret     (divides string into 2 equal sections)      Third harmonic - caused by harmonics at the 7th fret - nodes at the 7th, and 19th fret      Fourth harmonic - caused by harmonics at the 5th fret - nodes at the 5th, 12th, and      over the neck pu (or close to it)      Fifth harmonic - caused by harmonics at the 9th fret - nodes: 4th, 9th, 16th, and      between the neck and middle pu's on a strat

Sunday, July 4, 2010

Tips For Playing Acoustic Guitars:

Tip 1 - It is important that you take time and practice every lesson relating to playing guitar chords as much as possible. Spending time at the beginning making sure that the hand positions are correct will further help to ensure that you play the chords you are learning on an acoustic guitar properly.

Tip 2 - If you intend to use online lessons to help you play guitar chords properly then carry out plenty of research before you hand over money. Some will charge you lots of money for their lessons but will not be able to cater your own particular way of learning to play this instrument.

Purchasing a Chord Book in the beginning of Learning how to play an Acoustic Guitar would be very beneficial.