14th Febrauary 1978

36 years ago on this day, Texas Instruments patented the first "micro on a chip".

It was actually the first speech synthesizer chip and was used in TI's famous Speak and Spell toy.

In 1976 TI began a feasibility study memory intensive applications for bubble memory then being developed. They soon focused on speech applications. This resulted in the development the TMC0280 one-chip Linear predictive coding (LPC) speech synthesizer which was the first time a single silicon chip had electronically replicated the human voice.

An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small plate ("chip") of semiconductor material, normally silicon.

Integrated circuits are used in virtually all electronic equipment today and have revolutionised the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the low cost of producing integrated circuits.
ICs can be made very compact, having up to several billion transistors and other electronic components in an area the size of a fingernail. The width of each conducting line in a circuit can be made smaller and smaller as the technology advances; in 2008 it dropped below 100 nanometres and in 2013 it is expected to be in the tens of nanometres.

 

ICs have consistently migrated to smaller feature sizes over the years, allowing more circuitry to be packed on each chip. This increased capacity per unit area can be used to decrease cost and/or increase functionality.

Chips are used in everything now from Kettles and toasters to mobile phones and TV's.  They are an incredible invention which continue to develop and evolve.

A word in your shell like.....

Ever put a sea shell to your ear and listened to the sea?  You've probably done it when you were young but have you ever wondered what it was you were listening to?

There are a number of ideas about what actually makes the 'wave' sound when you put a shell to your ear. One suggestion is that you're hearing the echo of your heart beating and the blood rushing around your body, in particular the blood vessels in your ear. But that's simply not true, because if you ran about a lot before putting the shell to your ear there would be a definite difference in the intensity of the 'waves' you hear. Why? Well, exercise of any sort increases you heart rate hence the waves would be louder, or more frequent, in time with the faster beating of your heart.

Another explanation is that the wave sound is created by air flowing through the shell, and this may have a little to do with it as the sound becomes louder when you lift the shell slightly away from your ear. However, if you put your ear to a shell in a soundproof room (where there is no ambient noise, but air is still cycling around the shell), the wave sound is noticeably missing. So, it must have something to do with outside noise.

When you hold up a shell to your ear, you block out direct noise to your ear. However, the shell captures any atmospheric noise, which then resonates inside the shell. This resonating chamber needs some noise to work with, but otherwise works regardless of whether your surroundings are noisy or not. However, it stands to reason that the louder the environment around you, the louder the sound inside the shell - as more sound waves are 'bouncing', for want of a better term, around the chamber. These frequencies are garbled by the walls of the chamber and become like radio static to us, as our ear is not finely tuned enough to distinguish every nuance. Thus you get that shhhhhh sound, like waves breaking on the sea shore.

The rushing sound that one hears is in fact the noise of the surrounding environment, resonating within the cavity of the shell. The same effect can be produced with any resonant cavity, such as an empty cup or even by simply cupping one's hand over one's ear. The similarity of the noise produced by the resonator to that of the oceans is due to the resemblance between ocean movements and airflow.

Noise from outside the shell also can change the intensity of the sound you hear inside the shell. You can look at the shell as a resonating chamber. When sound from outside enters the shell, it bounces around, thus creating an audible noise. So, the louder the environment you are in, the louder the ocean-like sound will be.

For more information visit:-
http://en.wikipedia.org/wiki/Seashell_resonance
http://h2g2.com/approved_entry/A46714665#conversations

How Boomerangs Work

Classic boomerangs have two arms or wings normally of equal length. They are joined at the elbow, at an angle of between 105° and 110°. The reason for this angle lies in the origins of boomerang manufacture; most boomerangs were made from the junction of a tree with its lateral (sideways) root. Each arm usually has a tapered tip, which is a carry-over from the ancestor of the boomerang - the killer stick.

All boomerangs are either right or left-handed - one is an exact mirror image of the other. This is to allow right and left-handed throwers to launch their boomerangs with relative ease because it's far more comfortable to throw away from, rather than across, the body. Having said this, it is possible to throw an opposite handed boomerang, with a few adjustments to your throwing action.

During the flight of the boomerang, the effect of many different aerodynamic principles can be seen. Bernoulli's theorem, Newton's laws of motion, gyroscopic stability, gyroscopic precession and many others all have a bearing on the action of the boomerang.

When the boomerang leaves the thrower's hand, it will be spinning very fast. As each arm of the boomerang has an aerofoil shape, similar in cross-section to that of an aircraft wing, air moving over the top of each wing has to travel further, and therefore faster, than air passing beneath the wings. Bernoulli's theorem states that 'air travelling at a higher speed creates less pressure than slower moving air'. As a result, the boomerang experiences a 'lift'¹ force.

Newton's second law of motion states that 'the rate of change of momentum of an object is equal to the force applied to that object'. For an object with constant mass, this reduces to the well-known formula Force applied = Mass x Acceleration. The force here is a combination of friction and other resistive forces. To reduce the acceleration (or deceleration, since the force is negative), the mass needs to be large, but not so large that the boomerang falls quickly to the ground.

The length of the boomerang's arms, and the angle at which they are joined, allow the boomerang to spin in a stable plane as a result of the spin imparted on launching. This is known as gyroscopic stability. If this were not the case, the motion of the boomerang would at best be unpredictable. At worst, the boomerang would lose its spin rapidly, and be unable to sustain flight.

We now have a stable, rapidly spinning boomerang, moving forward from the force of the throw. We now need to take a slightly closer look at the effect of Bernoulli's theorem. As each wing rotates forward, into the direction of travel, it creates more lift than the other wing because the relative air speed is higher. If you imagine the spinning boomerang as a clock face, sideways on, this leads to the maximum force being created near the 12 o'clock position.

Due to the gyroscopic stability of the spinning boomerang, the effect of this force manifests itself at 90° further round the cycle of spin - at the 9 o'clock position of our clock face. The action of this force is to change the direction of flight - to the left for a right-handed boomerang and vice versa. Compare this with a 'no hands' bicycle turn - the only difference being the magnitude of the force. A small force over most of the duration of the flight produces a large, smooth turn for the boomerang, while a sudden strong force produces an abrupt bicycle turn.

As the boomerang travels, it loses velocity². Eventually, gyroscopic precession becomes the dominant force. Coupled with the initial 'off-vertical' tilt, the effect is to push the boomerang over on its side, so that it spins in a horizontal plane.

The effect of each of these principles varies with the way in which the boomerang is thrown. The basic flight path of a boomerang is circular, although advanced throwers can produce a virtually triangular flight path.

¹This is slightly misleading - the boomerang is thrown in a near vertical position, so the resulting 'lift' actually acts sideways.

²As it is rare to get absolutely dead-calm conditions, the wind starts to have an effect. This means that it is necessary to launch the boomerang 50° off the wind - the flight path should curl across the wind, and end with the boomerang being almost 'blown back' to the thrower.

 

Origins

 

The origin of the term is uncertain, and many researchers have different theories on how the word entered the English vocabulary. One source asserts that the term entered the language in 1827, adapted from an extinct Aboriginal language of New South Wales, Australia, but mentions a variant, wo-mur-rang, which it dates from 1798. The boomerang was first encountered by western people at Farm Cove (Port Jackson), Australia, in December 1804 where its use as a weapon was witnessed during a tribal skirmish.

 

http://www.h2g2.com/approved_entry/A407521

http://en.wikipedia.org/wiki/Boomerang

 

 

The Mobius Strip!

The Mobius Strip

The Mobius strip is a topological device with many amazing properties. You can make one from a simple strip of paper.

To make your very own Mobius strip simply take a paper strip, giving it a half twist and then joining the ends together to form a loop.

No matter how you twist or bend a Mobius strip (short of tearing it in two and glueing it back together again) you'll never be able to get rid of that twist and turn it into just a normal loop.

 

The Mystery of the Mobius

But what's so special about this strip? Try colouring one side of your strip green and the other side yellow. You'll find that you just end up colouring the whole thing a dull blue. Why is that? Because the most amazing thing about the Mobius strip is that it only has one side. A line drawn starting from the seam down the middle will meet back at the seam but at the "other side". If continued the line will meet the starting point and will be double the length of the original strip. This single continuous curve demonstrates that the Möbius strip has only one boundary.

This is where the symbol for infinity comes from. The sideways figure 8 you see, meaning infinity, is actually supposed to represent a Mobius strip, since the Mobius strip goes on forever.

More Fun With Your Mobius

Try to cut it in half to make two of them. Draw completely around the centreline of your strip. Remember that you won't need to lift the pen to do both sides. Then get a sharp knife or a pair of scissors and cut along the line. When you get back to the start of your cut after cutting all the way around the strip.

You'll find that you can't cut your Mobius strip in two at all. You've still just got one long loop with a couple of extra twists thrown in for good measure.

Try cutting it in two again. Do it the same way - all the way around the strip, and this time you really do get two strips. But the Mobius strip still has another trick up its topological sleeve. The two strips you now have are linked together!

What use is it?

There have been several technical applications for the Mobius strip. Giant Mobius strips have been used as conveyor belts that last longer because the entire surface area of the belt gets the same amount of wear, and as continuous-loop recording tapes (to double the playing time). Mobius strips are common in the manufacture of fabric computer printer and typewriter ribbons, as they allow the ribbon to be twice as wide as the print head while using both halves evenly.

A Mobius Scarf

For more information or to read up further on this visit:-

http://www.h2g2.com/approved_entry/A337592

http://en.wikipedia.org/wiki/M%C3%B6bius_strip