What is QR Code?

Short for quick response code, a QR code is a type of two-dimensional (2D) barcode that can be read using a QR barcode reader or camera-enabled smartphone with QR reader software. A QR code is able to carry information in both the vertical and the horizontal direction, which is why it is called a 2D barcode. The QR Code is a registered trademark of Denso Wave Inc. in Japan and other countries.

QR Codes are popular with mobile phone users as the barcode can be used to store addresses and URLs. With a camera-enabled smartphone, users can scan the QR Code which has been coded to do things like display text, provide contact data or even open a webpage in the browser on the smartphone. The QR Code specification outlines data types, or services for this information. By using the standards it ensures QR Code software can correctly read the barcode. Some examples include:

• URL: (HTTP) encode the text of URL in the barcode
• Email address: (MAILTO) encode an e-mail address using the mailto URI
• Telephone numbers: (TEL) encode a telephone number with digits understood as a telephone number
• SMS: (SMS) encode an SMS shortcode or number by creating an SMS URI.

QR Codes can be printed and displayed anywhere a mobile phone user might scan the code such as in a magazine or displayed at a cash register. They can also be displayed online.
There are a number of online services that will generate a QR Code based on the information you specify when mapping the QR code.

What is Quantum computing?

First proposed in the 1970s, quantum computing relies on quantum physics by taking advantage of certain quantum physics properties of atoms or nuclei that allow them to work together as quantum bits, or qubits, to be the computer's processor and memory. By interacting with each other while being isolated from the external environment, qubits can perform certain calculations exponentially faster than conventional computers.

Qubits do not rely on the traditional binary nature of computing. While traditional computers encode information into bits using binary numbers, either a 0 or 1, and can only do calculations on one set of numbers at once, quantum computers encode information as a series of quantum-mechanical states such as spin directions of electrons or polarization orientations of a photon that might represent a 1 or a 0, might represent a combination of the two or might represent a number expressing that the state of the qubit is somewhere between 1 and 0, or a superposition of many different numbers at once. A quantum computer can do an arbitrary reversible classical computation on all the numbers simultaneously, which a binary system cannot do, and also has some ability to produce interference between various different numbers. By doing a computation on many different numbers at once, then interfering the results to get a single answer, a quantum computer has the potential to be much more powerful than a classical computer of the same size. In using only a single processing unit, a quantum computer can naturally perform myriad operations in parallel.

Quantum computing is not well suited for tasks such as word processing and email, but it is ideal for tasks such as cryptography and modeling and indexing very large databases.

Read more »