Wanna be invisible Read on

There is a legend of a magic cap which renders the wearer invisible. In his ‘Ruslan and Ludmila' celebrated Russian poet Alexander Pushkin provides a classical description of the miraculous properties of this Cap

Man has done things which were thought to be impossible but today we can drill mountains, trap lightening and travel by flying carpets; But invisibility? Is it possible? Let's see... In his book ‘the invisible man' HG. Wells makes us believe that it is quite possible to render ourselves invisible. The hero in this novel discovers how to make all the tissues of the organism and even its pigments transparent. He applied his invention to his own body obtaining the spectacular result of total invisibility. But let me tell you its not that easy... Read on.....

Well, Wells demonstrates his logic that an invisible man thus acquires almost unlimited power. He is able to enter any place unnoticed and steal anything with impunity. So, at the outset, the invisible man triumphs.

So the question which arises in your mind is, Are the physical truths on which this science fiction novel is based right?

To our surprise the answer is yes. In a transparent medium every transparent object becomes invisible when the difference between refractive index is less than 0.05.

The transparent preparations method evolved by Prof. Spalteholtz in 1911 are as follows:

After treatment (bleaching and washing) the prepared specimen is soaked in methyl salicynate, a colourless liquid with large refractive index. Specimens of rats, fishes and human organs were prepared; however, full transparency was not gained. We can achieve full transparency if necessary though. But this is far from Well's dream of a living man so transparent so as to be absolutely invisible. Firstly, because we must know how to treat living tissue with this transparency liquid without Nolatiy organic function, Secondly because Prof. Spalteholtz's preparations were transparent, not invisible.

Now, you are beginning to think that an invisible man is a possibility, don't you? But let me tell you a crushing truth "an invisible man must be..., blind". Because if every part of his body is transparent then even his eyes are rendered invisible and possess a refractive index identical to that of the air.

For the moment let me teach you some biology and recall the function of the eye. Its crystalline lens, virtuous humour and other elements refract light so as to produce a retinal image of the surroundings, but when refractivity of eye and air become equal the sole purpose of refractivity is removed. Passing from one medium to another of same refractivity, light will not change direction and consequently its rays will not be able to concentrate at one point. Therefore an absolutely transparent eye will naturally be unable to check radiation otherwise it wouldn't be transparent.

All creatures drawing upon transparency for protection have eyes that are not completely transparent provided they have eyes.

The well known oceanographer Murray writes, "Immediately below the surface most animals are transparent and colourless. When taken from the tow nets they are often distinguishable only by their little black eyes. Their blood is devoid of haemoglobin and the entire body perfectly transparent and consequently it will fail to produce any mental image!!

In other words, if we desire the cap of invisibility it would be futile for us to copy Wells. Even a successful result would be a sorry one.

So, do you still want to be invisible?

Your Comments please ....