Letters from the man who can’t be seen! – Tavleen Singh

Dear world,

Let me tell you a story.
When I was ten, it was the perfect trick to play during hide and seek. Till date no one has any idea why I could never be found.
When I was fifteen, it became my wingman, helping me sneak into girls rooms and understand the unexplicable creatures.
When I was eighteen, it made me survive those horrible curfews at hostel.
But it was when I started studying calcite in my chemistry class, that it became the boon of my very existance. The driving force.
They started calling me insane, but I knew if I worked hard enough, I’d know from where it emerged. I could explain it and recreate it.
And so I began my work, joining two crystals of calcite in such a way that it would be able to refract light around an object present between the crystals.You see, calcite is an optically anisotropic material since its refractive index depends upon the polarization and direction of propogation of light. Because of multiple refractions, From outside the system the object is not visible for at least 3 orders of magnitude larger than the wavelength of light in all three dimensions, I assure you.
It has taken me a very long time to reach the exact calculations and configuration of each and every piece in my project, I have been waiting for the day I finally get to disclose that I have found Harry Potter’s Invisibility Cloak.
But you, dear muggles, will never know. You have called me the demented scientist, but I have seen through your facade.
You will use science to propagate your wars, to fulfill your selfish needs and I don’t want to live to see that day. For this would replace all your drones, all your spy systems.
No place would be safe. The people rich enough would intrude on any sense of privacy the others have left.
Robbers and theives would spread like a disease.
You’d literally trip ‘over nothing’.
I think about the uses I put to my toy and I realize no productive use was ever given to it.
There’s a reason why there exists only one Invisibility Cloak even in the Wizarding World.
So I shall take this secret with me to my grave.

Yours,
Loony man who shouts Eureka for no reason.

Lines and squares

We have seen it n number of times, actually on everything we purchase from a packet of chips to everything one can possibly purchase. Sometimes in form of black vertical lines and sometimes in form of squares- The Barcode.

What is this barcode all about?

Barcode is representation of data of the concerned object which are machine readable(scanners). Few years back there were special barcode readers but today one can use their handy smartphones to decode them. Barcodes comes in various shapes and sizes. Typically, they are categorized as one dimensional code and two dimensional code.

One dimensional code consists of black bars with spaces between them. One can see them on every product purchased from a grocery store. UPC  is a type of one dimensional code, UPC-A has two parts a machine readable barcode and a human readable 12 digit number.

Upc code-

Qr code-

he first small digit called the number system character, the next five digits represent manufacturer code digits, the next five digits represents the product code and the last digit is the check digit. The first and last digits are placed outside the symbol to indicate quiet zones that are necessary for barcode scanners to work properly.

The 2-dimensional code also called matrix code reads in two direction vertically and horizontally. QR code looks as above.

It contains a finder pattern which consists of squares which determines the size of code also the direction it s facing and even at what angle the code.is being scanned. An alignment pattern to determine whether the code is distorted or not. Margins for error present,if the code is smudged then also the code can be scanned.

The first barcode scanned was the UPCcode on a pack of chewing gum of Wrigley company in june 1974.

There are number of free barcode generator available online, one can even add a barcode to one`s residential address.