Quantum mechanics

The most advanced and toughest subject related to physics, especially mechanics is the quantum mechanics.it actually starts with the the famous scientist's works "Schrodinger's equation" and "Heisenberg picture". But the basics are derived from max planc's quantum theory. Let us see about it in detail.

Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of the wave–particle duality of matter and energy. The theory was developed in 1925 by Werner Heisenberg. Quantum mechanics describes the time evolution of physical systems via a mathematical structure called the wave function. The wave function encapsulates the probability that the system is to be found in a given state at a given time. Quantum mechanics also allows one to calculate the effect on the system of making measurements of properties of the system by defining the effect of those measurements on the wave function. This leads to the well-known uncertainty principle as well as the enduring debate over the role of the experimenter, epitomised in the Schrödinger's Cat thought experiment.

Quantum mechanics differs significantly from classical mechanics in its predictions when the scale of observations becomes comparable to the atomic and sub-atomic scale, the so-called quantum realm. However, many macroscopic properties of systems can only be fully understood and explained with the use of quantum mechanics. Phenomena such as superconductivity, the properties of materials such as semiconductors and nuclear and chemical reaction mechanisms observed as macroscopic behaviour, cannot be explained using classical mechanics.

The term was coined by Max Planck, and derives from the observation that some physical quantities can be changed only by discrete amounts, or quanta, as multiples of the Planck constant, rather than being capable of varying continuously or by any arbitrary amount. For example, the angular momentum, or more generally the action, of an electron bound into an atom or molecule is quantized. Although an unbound electron does not exhibit quantized energy levels, one which is bound in an atomic orbital has quantized values of angular momentum. In the context of quantum mechanics, the wave–particle duality of energy and matter and the uncertainty principle provide a unified view of the behavior of photons, electrons and other atomic-scale objects.

The mathematical formulations of quantum mechanics are abstract. Similarly, the implications are often counter-intuitive in terms of classical physics. The centerpiece of the mathematical formulation is the wavefunction (defined by Schrödinger's wave equation), which describes the probability amplitude of the position and momentum of a particle. Mathematical manipulations of the wavefunction usually involve the bra-ket notation, which requires an understanding of complex numbers and linear functionals. The wavefunction treats the object as a quantum harmonic oscillator and the mathematics is akin to that of acoustic resonance.

Prnanav mistry sixth sense device (with video)

                            Sixth sense and Its uses

Sixthsense is a wearable gestural interface device developed by Pranav Mistry, a PhD student in the Fluid Interfaces Group at the MIT Media Lab. It is similar to Telepointer, a neckworn projector/camera system developed by Media Lab student Steve Mann[1] (which Mann originally referred to as "Synthetic Synesthesia of the Sixth Sense").[2]

Construction and workings:- 

The SixthSense prototype comprises a pocket projector, a mirror and a camera contained in a pendant like, wearable device. Both the projector and the camera are connected to a mobile computing device in the user’s pocket. The projector projects visual information enabling surfaces, walls and physical objects around us to be used as interfaces; while the camera recognizes and tracks user's hand gestures and physical objects using computer-vision based techniques.[3] The software program processes the video stream data captured by the camera and tracks the locations of the colored markers (visual tracking fiducials) at the tips of the user’s fingers. The movements and arrangements of these fiducials are interpreted into gestures that act as interaction instructions for the projected 
application interfaces. SixthSense supports multi-touch and multi-user interaction.

Example applications:- 

The SixthSense prototype contains a number of demonstration applications.

The map application lets the user navigate a map displayed on a nearby surface using hand gestures to zoom and pan 

The drawing application lets the user draw on any surface by tracking the fingertip movements of the user’s index finger.

SixthSense also implements Augmented reality; projecting information onto objects the user interacts with.

 The system recognizes a user's freehand gestures as well as icons/symbols drawn in the air with the index finger, for example:

 A 'framing' gesture takes a picture of the scene. The user can stop by any surface or wall and flick through the photos he/she has taken.

Drawing a magnifying glass symbol takes the user to the map application while an ‘@’ symbol lets the user check his mail.

The gesture of drawing a circle on the user’s wrist projects an analog watch.

               Discovery of computers (Phase 1)

 Some important inventions led to discovery of computers are:-

2400 BC:-

The abacus- the first known calculator is invented in Babylonia.

500-300 BC:-Ancient Indian writer Pingala describes the first binary (two digit) numbering system.

1492 AD:- Italian Leonardo Davinci designs the first mechanical calculator and a humanoid robot.

1614 AD:-Scotsman John Napier invents a system of movable rods based on logarithms which could do sums.

1642 AD:-Frenchman Blaise Pascal invents the “PASCALINE”, the first serious calculating machine to help his father, a judge in a tax court.

1679 AD:German Gottfried Leibniz perfects the binary system.

1801 AD:-

Joseph Marie jacquard invents an automatic sewing machine controlled by punched cards. During its first demonstration in Lyon, France, the machine is destroyed an angry mob.

1834 AD:-

Charles Babbage designs the Analytical engine – the world’s first computer, with punch card input devices, an arithmetic processor and a memory to store numbers. He runs out of money before it is ever built.

  

iPhone (history)

                                             iPhone (history)

Development of the iPhone began with Apple CEO Steve Jobs' direction that Apple engineers investigate touchscreens. Apple created the device during a secretive and unprecedented collaboration with AT&T Mobility—Cingular Wireless at the time—at an estimated development cost of US$150 million over thirty months. Apple rejected the "design by committee" approach that had yielded the Motorola ROKR E1, a largely unsuccessful collaboration with Motorola. Instead, Cingular gave Apple the liberty to develop the iPhone's hardware and software in-house.

Jobs unveiled the iPhone to the public on January 9, 2007 at Macworld 2007. Apple was required to file for operating permits with the FCC, but since such filings are made available to the public, the announcement came months before the iPhone had received approval. The iPhone went on sale in the United States on June 29, 2007, at 6:00 pm local time, while hundreds of customers lined up outside the stores nationwide. The original iPhone was made available in the UK, France, and Germany in November 2007, and Ireland and Austria in the spring of 2008.

On July 11, 2008, Apple released the iPhone 3G in twenty-two countries, including the original six. Apple released the iPhone 3G in upwards of eighty countries and territories. Apple announced the iPhone 3GS on June 8, 2009, along with plans to release it later in June, July, and August, starting with the U.S., Canada and major European countries on June 19. Many would-be users objected to the iPhone's cost, and 40% of users have household incomes over US$100,000. In an attempt to gain a wider market, Apple retained the 8 GB iPhone 3G at a lower price point. When Apple introduced the iPhone 4, the 3GS became the less expensive model. Apple reduced the price several times since the iPhone's release in 2007, at which time an 8 GB iPhone sold for $599. An iPhone 3GS with the same capacity now costs $99. However, these numbers are misleading, since all iPhone units sold through AT&T require a two-year contract (costing several hundred dollars), and a SIM lock.

Apple sold 6.1 million original iPhone units over five quarters.The sales has been growing steadily thereafter, by the end of fiscal year 2010, a total of 73.5 million iPhones were sold. Sales in Q4 2008 surpassed temporarily those of RIM's BlackBerry sales of 5.2 million units, which made Apple briefly the third largest mobile phone manufacturer by revenue, after Nokia and Samsung. Approximately 6.4 million iPhones are active in the U.S. alone. While iPhone sales constitute a significant portion of Apple's revenue, some of this income is deferred.

The back of the original iPhone was made of aluminum with a black plastic accent. The iPhone 3G and 3GS feature a full plastic back to increase the strength of the GSM signal. The iPhone 3G was available in an 8 GB black model, or a black or white option for the 16 GB model. They both are now discontinued. The iPhone 3GS was available in both colors, regardless of storage capacity. The white model was discontinued in favor of a black 8 GB low-end model. The iPhone 4 has an aluminosilicate glass front and back with a stainless steel edge that serves as the antennae. It is available in black; a white version was announced, but has as of January 2011 not been released.

The iPhone has garnered positive reviews from critics like David Pogue and Walter Mossberg. The iPhone attracts users of all ages, and besides consumer use the iPhone has also been adopted for business purposes.

Hardware

Screen and input

The touchscreen is a 9 cm (3.5 in) liquid crystal display with scratch-resistant glass. The capacitive touchscreen is designed for a bare finger, or multiple fingers for multi-touch sensing. The screens on the first three generations of the iPhone have a resolution of 320 x 480 (HVGA) at 163 ppi, while the display on the iPhone 4 has a resolution of 640 x 960 at 326 ppi.

The touch and gesture features of the iPhone are based on technology originally developed by FingerWorks. Most gloves and styluses prevent the necessary electrical conductivity; however, capacitive styli can be used with iPhone's finger-touch screen. The iPhone 3GS also features a fingerprint-resistant oleophobic coating.

The iPhone has a minimal hardware user interface, featuring only four or five buttons, depending on whether the volume control is counted as one button or two. The only physical menu button is situated directly below the display, and is called the "Home button" because it closes the active app and navigates to the home screen of the interface. The home button is denoted not by a house, as on many other similar devices, but a rounded square, reminiscent of the shape of icons on the home screen. A multifunction sleep/wake button is located on the top of the device. It serves as the unit's power button, and also controls phone calls. When a call is received, pressing the sleep/wake button once silences the ringtone, and when pressed twice transfers the call to voicemail. Situated on the left spine are the volume adjustment controls. The iPhone 4 has two separate circular buttons to increase and decrease the volume; all earlier models house two switches under a single plastic panel, known as a rocker switch. Directly above the volume controls is a silence button that mutes all sound when engaged. All buttons except Home were made of plastic on the original iPhone and metal on all later models. The touchscreen furnishes the remainder of the user interface.

The display responds to three sensors. A proximity sensor deactivates the display and touchscreen when the device is brought near the face during a call. This is done to save battery power and to prevent inadvertent inputs from the user's face and ears. An ambient light sensor adjusts the display brightness which in turn saves battery power. A 3-axis accelerometer senses the orientation of the phone and changes the screen accordingly, allowing the user to easily switch between portrait and landscape mode. Photo browsing, web browsing, and music playing support both upright and left or right widescreen orientations. Unlike the iPad, the iPhone does not rotate the screen when turned upside-down, with the Home button above the screen. The 3.0 update added landscape support for still other applications, such as email, and introduced shaking the unit as a form of input. The accelerometer can also be used to control third party apps, notably games. The iPhone 4 also includes a gyroscopic sensor, enhancing its perception of how it is moved.

A software update in January 2008 allowed the first generation iPhone to use cell tower and Wi-Fi network locations trilateration, despite lacking GPS hardware. The iPhone 3G, 3GS and 4 employ A-GPS, and the iPhone 3GS and 4 also have a digital compass.

Some golden words

I can calculate the motion of heavenly bodies, but not the madness of people.

~ Isaac Newton

A man never tells you anything until you contradict him.

~ George Bernard Shaw


After climbing a great hill, one only finds that there are many more hills to climb.
~ Nelson Mandela