Tubes are present inside a conventional television set. In these tubes the images are broken down into small pixels with the help of a beam of electrically charged particles. The beam sends information about the colour and brightness of each pixel to a chemically luminescent layer on the rear of the screen. The electron beams light up the pixels on this layer depending upon the speed. They become blurred to form a picture for our eyes. Along with the fat-bellied tube televisions, there are also televisions with flat screens that have been improved very rapidly.
Category Communication
How did pictures ‘run’?
Pictures can ‘run’ only because our eyes cannot register more than 20 pictures per second. If we see more than 20 pictures, they look very similar but differ only in minor things; our brain perceives them as moving. Flip books or cartoon films work on this principle. The movements could not be recorded with cameras for a longtime because the exposure times were too long. The first serial photography succeeded in 1872. The British photographer Eadweard Muybridge captured a running horse with 30 cameras. He mounted the finished pictures on a disc, which was rotated in a device. Through a viewing hole you could see a running horse. Later individual photos were recorded with just one camera on a single film. This was the birth of the cinema.
When was the film invented?
The film as the storage option for images was invented at the beginning of the 19th century. The researchers at that time were experimenting with toxic chemicals to store light reflected from the objects on a long-term basis. The Frenchman, Louis Daguerre, finally succeeded in 1837 to fix the images on a light-sensitive material in a salt bath. This was the first film. However, the exposure times were very long. People had to sit for a long time while the photographer captured their image on a photographic plate. The path to the film roll was paved in 1889 by the American George Eastman – a thin layer of silver salts was applied on flexible plastic celluloid. Digital cameras do not need this because they store everything on a computer chip.
What is a camera obscura?
In a camera obscura, which is a Latin word meaning ‘dark chamber’, light enters a dark room or a closed box through a small hole. If the hole was small enough, a very faint inverted image would be seen on the opposite wall. At the end of the 13th century, astronomers made use of this to observe the sun. In this way they could study its hot surface, without having to look directly at it. Today, we buy a special pair of goggles to look at the sun.
Where is a simulation program used?
Simulation programs are used for training in areas where the possibility of something going wrong is very dangerous. For instance, a trainee pilot does not fly an aircraft just after training. Before that he practices at a simulator, which behaves like an aircraft, but is on the ground so it does not crash if le pilot makes a mistake. We can also simulate a fault in a power plant or a tsunami. Trainees must demonstrate that they can handle he crisis effectively.
How does a CD-ROM work?
A CD-ROM is a plastic disc with a thin aluminium layer from which music, texts, and other data can be retrieved. Like everything else in the world of computers, these files are also stored in the numeric sequence of 1 and 0. In this case, there are tiny grooves for 1 or none for 0. A laser beam in the reader scans these grooves, which reflect the laser beam in different ways. From these laser reflections, the chip in the computer or in the CD player deciphers the data present on the CD, which could be music, text, photos, or complete programs.