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For the past 75 years, the vast majority of televisions have been built around the same technology: the cathode ray tube (CRT). In a CRT television, a gun fires a beam of electrons (negatively-charged particles) inside a large glass tube. The electrons excite phosphor atoms along the wide end of the tube (the screen), which causes the phosphor atoms to light up. The television image is produced by lighting up different areas of the phosphor coating with different colors at different intensities
Cathode ray tubes produce crisp, vibrant images, but they do have a serious drawback: They are bulky. In order to increase the screen width in a CRT set, you also have to increase the length of the tube (to give the scanning electron gun room to reach all parts of the screen). Consequently, any big-screen CRT television is going to weigh a ton and take up a sizable chunk of a room.
Recently, a new alternative has popped up on store shelves: the plasma flat panel display. These televisions have wide screens, comparable to the largest CRT sets, but they are only about 6 inches (15 cm) thick. Based on the information in a video signal, the television lights up thousands of tiny dots (called pixels) with a high-energy beam of electrons. In most systems, there are three pixel colors -- red, green and blue -- which are evenly distributed on the screen. By combining these colors in different proportions, the television can produce the entire color spectrum.
The basic idea of a plasma display is to illuminate tiny colored fluorescent lights to form an image. Each pixel is made up of three fluorescent lights -- a red light, a green light and a blue light. Just like a CRT television, the plasma display varies the intensities of the different lights to produce a full range of colors.
The central element in a fluorescent light is a plasma, a gas made up of free-flowing ions (electrically charged atoms) and electrons (negatively charged particles). Under normal conditions, a gas is mainly made up of uncharged particles. That is, the individual gas atoms include equal numbers of protons (positively charged particles in the atom's nucleus) and electrons. The negatively charged electrons perfectly balance the positively charged protons, so the atom has a net charge of zero.
If you introduce many free electrons into the gas by establishing an electrical voltage across it, the situation changes very quickly. The free electrons collide with the atoms, knocking loose other electrons. With a missing electron, an atom loses its balance. It has a net positive charge, making it an ion.
In a plasma with an electrical current running through it, negatively charged particles are rushing toward the positively charged area of the plasma, and positively charged particles are rushing toward the negatively charged area.

TECHNOLOGY

Are you a victim of the ‘wire web’? Is your home an entangled web of wires, plugs, multi-plugs, extension cords and adaptors? Does the space behind the TV or PC look like a high-tech tangle? And we’re not even talking of personal gadgets like iPods and cellphones!Recent technological research reveals that a three-bedroom house now needs an average of 40 plug sockets; you’re lucky if you get 15. But before you race off to tear up your walls, here are options to make your life a tad more bearable. And wait, wireless electricity will be in your homes soon enough.For personal devices (not laptops though), you may want to get yourself this new thing called a Chargepod. Recently launched by Callpod, the device can charge as many as six devices simultaneously—without extension cords or wires. Hurray!Now, India also has smart multiple sockets, with power-saving options. If you switch off your PC, attendant machines like printers and scanners will switch off automatically. Or you can install a programmed switch at the main door, so that when you leave home, all appliances except essentials like refrigerators, will be switched off.Then there will be WiTricity. A team of MIT researchers has developed wireless power; they can light up a 60 W bulb from a distance of 2 m. The implications are phenomenal. It’s akin to the feeling of weightlessness you experienced in moving from broadband to Wi-Fi. Except this can expand to your entire house. When used commercially, WiTricity could be adapted to charge devices like laptops from several meters away. It’s the last-mile tether that the mobile techie needs to sever. That too is just around the corner.