100 Amazing Inventions
26. How have personal stereos changed the world of music?
PERSONAL STEREO:
A Personal stereo is a portable audio player. When talking of personal stereos, the first name that comes to mind is Sony Walkman. In July 1979, the Sony Corporation launched Sony Walkman, a silver and blue coloured portable player with flashy buttons and leather case but it was a little bulky.
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| A Personal Stereo |
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| A Personal Stereo( Music Player ) |
One day, Sony's co-founder , Masaru Ibuka while travelling for business, asked his executive deputy president to design a model that could be used with light compact headphones. This high quality, slimmer device for music lovers captured the market, and took the world by storm. It brought about a revolution in the music world by allowing people to carry their favourite music while they were on the move.
27. What is an X-ray telescope?
X-RAY TELESCOPE:
Earth based telescopes suffer from the limitations caused by light pollution, atmospheric turbulence, and weather systems.
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| X-Ray Telescope |
Added to this, the Earth's atmosphere absorbs electromagnetic radiations of the shorter wavelengths such as X-rays, which are emitted by objects in the Universe. An X-ray telescope is an instrument designed to detect and resolve X-rays from sources outside Earth's atmosphere.
X-rays do not reflect off mirrors the same way that visible light does. This means that X-ray telescopes must be very different from optical telescopes. The mirrors have to be precisely shaped, and aligned nearly parallel to incoming X-rays.
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| X-Ray Telescope |
Thus, they look more like barrels than the familiar dish shape of optical telescopes. Because of atmosphere absorption, X-ray telescopes must be carried to high altitudes or placed in orbit outside the atmosphere. X-ray telescopes are used to study the Sun, stars and supernovas.
28. What is an air car?
AIR CAR:
Can a car run on air? If it could, all our worries about the world's diminishing supply of oil and petrol would end.
It would be the ideal solution because air never runs out, air is non-polluting, and best of all, air is free. Unfortunately, air alone can't be used as a fuel. First, energy has to be stored in it by squeezing the air tightly, using a mechanical air compressor. Once the compressed air is released, it expands. This expanding air can be used, for example, to drive the pistons that power an engine.
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| Air Car |
The idea of using compressed air to power a vehicle isn't new. In 1979, Terry Miller invented a car that runs on compressed air, and applied for a patent in 1983. In the 1980s, inventions Claud Mead, Des Hill, Ricardo Perez-Pomar, and George Miller said that they had invented an air car.
In 2012, Tata Motors presented their concept for the air car, and said that it would go to production as one of the cheapest and simplest cars on the road. However, this has not happened so far.
29. Why is Maglev an important invention?
MAGLEV TRAIN:
Maglev is short for magnetic levitation. It is a method of transport in which high speed vehicles are lifted by magnetic repulsion, and propelled along an elevated guideway, by powerful magnets attached to the vehicle.
If you've ever played with magnets, you know that opposite poles attract and like poles repel each other. This is the basic principle behind electromagnetic propulsion. Electromagnets are similar to other magnets in that they attract metal objects, but the magnetic pull is temporary.
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| Maglev Train |
Today, many countries have started using powerful electro-magnets to propel high speed trains called maglev trains. These trains will float over a guideway, using the basic principles of magnets to replace the old steel wheel and track trains.
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| Maglev Train Illustration |
The trains do not physically touch the guideway, do not need engines, and do not burn fuel. Instead, they are magnetically propelled by electric power fed to coils located on the guideway.
Maglev is cheaper, faster, non-polluting, and safer than normal modes of transport. Many countries already have maglev trains. The world's first commercial high speed magnetically levitated train was implemented in Shangai, China, in 2004. It travels at a speed of 430km per hour.
30. What is interesting about the invention of Post-it notes?
POST IT NOTES:
A Post-it note is a small piece of paper with a re-usable strip of glue on its back. It can be stuck on documents, or in any prominent spot with messages that act as reminders, and peeled off easily after use.
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| Post-it notes on a wall |
Interestingly, two accidents led to the invention of the Post-it note. The first was by Spencer Silver, who accidentally created a weak adhesive agent. It has two interesting features. Firstly, when stuck to a surface, it could be peeled away. Secondly, the adhesive was re-usable.
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| A Bundle of Post-it notes |
Four years later, the second accident occurred. Arthur Fry was singing in the church's choir, and the markers he used to note his place in the hymn book kept falling out. Fry used some of the Silver's adhesive to keep the markers in place. The weak adhesive kept the markers in place. He lifted off the markers easily without damaging the pages, and this marked the beginning of the Post-it notes.