Everyone, once in the lifetime, must have used the camera, but does know how was it invented and it works?

So let us understand the invention and history of the Camera. To   understand the invention lets see how the camera works.

All cameras use the same basic design: light enters an enclosed box   through a converging or convex lens and an image is recorded on a   light-sensitive medium (known as a digital sensor, mainly a transition of   metal-halide). A shutter mechanism controls the length of time that   light can enter the camera. The forerunner to the photographic camera   was the camera obscura. Camera obscura is the natural optical   phenomenon that occurs when an image of a scene at the other side of a   screen is projected through a small hole in that screen and forms an   inverted image (left to right and upside down) on a surface opposite to   the opening. The oldest known record of this principle is a description by Han Chinese philosopher Mozi (c. 470 to c. 391 BC). Mozi correctly asserted that the camera obscura image is inverted because light travels in straight lines from its source. In the 11th century, Arab physicist Ibn al-Haytham (Alhazen) wrote very influential books about optics, including experiments with light through a small opening in a darkened room.

Before the development of the photographic camera, it had been known for hundreds of years that some substances, such as silver salts, darkened when exposed to sunlight. A German scientist Johann Heinrich Schulze demonstrated that the darkening of the salts was due to light alone, and not influenced by heat or exposure to air. The Swedish chemist Carl Wilhelm Scheele showed in 1777 that silver chloride was especially susceptible to darkening from light exposure and that once darkened, it becomes insoluble in an ammonia solution.

The first permanent photograph of a camera image was made in 1825 by Joseph Nicéphore Niépce using a sliding wooden box camera made by Charles and Vincent Chevalier in Paris. Niépce had been experimenting with ways to fix the images of a camera obscura since 1816. The photograph Niépce succeeded in creating shows the view from his window. It was made using an 8-hour exposure on pewter coated with bitumen. Niépce called his process "heliography".Niépce had experimented further with other chemicals, to improve contrast in his heliographs. In the 1830s, the English scientist William Henry Fox Talbot independently invented a process to capture camera images using silver salts. The first photographic camera developed for commercial manufacture was a daguerreotype camera, built by Alphonse Giroux in 1839. Giroux signed a contract with Daguerre and Isidore Niépce to produce the cameras in France with each device and accessories costing 400 francs. There was a constant devolvement in the camera.

The modern-day camera uses a digital sensor in place of chemicals. The architect and design of the camera were also improved. There are mainly two types of cameras commercially available - DSLRs and camera phones.

The invention of the automobile also known as cars is another very important   invention by mankind. Karl Benz is the inventor of the real automobile. Before   Karl's invention, there were many tries to make the automobile in the past. So   now let's know about the invention of the automobile.

The first model of an automobile was a Steam-powered car made by   Ferdinand Verbiest, a Flemish member of a Jesuit mission in China around   1672. It was a 65-centimeter (26 in)-long but was not able to carry a driver or   a passenger, thus making it a prototype of the automobile. Nicolas-Joseph   Cugnot is widely credited with building the first full-scale, self-propelled   mechanical vehicle steam-powered tricycle. He also made two steam tractors   for the French Army, one of which is preserved in the French National   Conservatory of Arts and Crafts. His inventions were, however, full of   problems with a water supply and maintaining steam pressure.

In 1807, Nicéphore Niépce and his brother Claude created what was probably the world's first internal combustion engine but they chose to install it in a boat on the river Saone in France. Coincidentally, in 1807 the Swiss inventor François Isaac de Rivaz designed his own 'de Rivaz internal combustion engine' and used it to develop the world's first vehicle to be powered by such an engine.

In November 1881, French inventor Gustave Trouvé demonstrated the first   working (three-wheeled) car powered by electricity at the International   Exposition of Electricity, Paris. From this, we can say that electric cars are not   a modern invention. In 1879, Benz was granted a patent for his first engine,   which had been designed in 1878. making him the inventor of the true   automobile. His first Motorwagen was built in 1885 in Mannheim, Germany. In   1896, Benz designed and patented the first internal combustion flat engine,   called boxermotor. During the last years of the nineteenth century, Benz was the largest car company in the world with 572 units produced. Karl's combustion engine consists of a fixed cylinder and a moving piston. The expanding combustion gases push the piston, which in turn rotates the crankshaft. After the piston compresses the fuel-air mixture, the spark ignites it, causing combustion. The   expansion of the combustion gases pushes the piston during the power stroke.

Later on, the first design for an American car with a gasoline internal   combustion engine was made in 1877 by George Selden of Rochester, New   York. Selden applied for a patent for a car in 1879. In 1892, German engineer   Rudolf Diesel was granted a patent for a "New Rational Combustion Engine".   In 1897, he built the first diesel engine.

Nowadays only internal combustion engines are used in vehicles but in the   future, their place will be exchanged by eco-friendly electric cars.

Many inventions happened in the world but some of them were a world   changer.

  The steam engine was a great invention by James Watt in the year 1776   and was used to power train for a very long time. James Watt was a   Scottish inventor, mechanical engineer and chemist. Initially, Watt was   educated at home by his mother, later going on to attend Greenock   Grammar School. There he showed great interest in mathematics, while   Latin and Greek failed to interest him. It was said that he suffered from   an illness called prolonged bouts of ill-health in which the person   infected gets headache frequently all his life.

  There is a very popular story that James Watt got the inspiration of   creating a steam engine from a boiling kettle, the steam was lifting the lid of the kettle after a time. This made James Watt understand the power of steam.

Steam engine work like this it performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force is transformed, by a connecting rod into rotational force for work. It was not easy to make a steam engine as they were prone to blast and steam used to condense in the pump only. Watt began to experiment with steam in the year 1759, though he had never seen an operating steam engine.

He tried constructing a model; it failed to work, but he continued his experiments and began to study everything he could about the subject. Understanding of the steam engine science of thermodynamics would not be formalized for nearly another 100 years. But he didn't lose hope he continued doing experiments for 17 years. In the year 1776, it was used in mine to take water out from mines. for the next 5 years, watt was busy installing machines. Watt continued to do improvement in the engine. He also made a two-cylinder engine for more power in 1784.

   William Murdoch, a Scottish inventor, built a model steam rail   locomotive, An early working model of a steam rail locomotive was   designed and constructed by John Fitch in the United States probably   during the 1780s or 1790s. The first functional railway steam   locomotive was built by Richard Trevithick in the United Kingdom and,   on 21 February 1804, the world's first railway journey took place. The   steam locomotive was so famous as it made transportation way easy   and faster many improvements were done in the steam locomotive. The   steam locomotive was made till the late 20th century. Usage of steam   engine declined as they were weaker than the modern fuel combustion   engine.

When we think about great invention, we cannot exclude the light bulb   from the list. Let's talk about the Light bulb today. The light bulb was   made by Thomas Alva Edison in January 1879. When Edison was a child,   he had a great interest in chemistry and electronics. Edison's mother   Nancy would teach him at their home as she was a teacher. Edison   developed hearing problems at the age of 12. He was deaf from one ear   and another one he could barely hear. Edison believed his hearing loss   allowed him to avoid distraction and concentrate more easily on his   work. Modern-day historians and medical professionals have suggested   he may have had ADHD. In his early career, he enrolled in a chemistry   course at The Cooper Union for the Advancement of Science and Art. In   the year 1878, Edison began working on electrical illumination. Which   he wanted to compete with gas and oil-based lamp. In the starting Edison faced the problem of creating a long-lasting incandescent lamp. The light bulb work like this first we put a filament in a flask then electricity runs through the filament and make it glow. The filament used in the light bulb should be able to resist the force of the electricity to glow for a longer period of time and use less energy to glow. These early bulbs all had flaws such as an extremely short life and requiring a high electric current to operate which made them difficult to apply. Edison tried filament of every element to make the light bulb glow longer. After many failures, Edison found that a carbon filament or strip coiled and connected to platinum contact wires makes the bulb stand longer. He then filed the patent for his invention but after several months he found that carbonized   bamboo could make it last longer for 1200 hr. ( 50 days).In 1878. Edison   formed his own company named Edison Electric Light Company in New   York City with several financiers. Edison made the first public   demonstration of his light bulb on December 31, 1879, in Menlo Park. In   the demonstration, he said, "We will make electricity so cheap that only   the rich will burn candles." Since that day the light bulb gained so much   attention that made many people join Edison’s team to make the light   bulb more efficient and better. Some later modifications in the light   bulbs-for example tungsten was used as a filament and air was   evacuated from the bulb because oxygen in the air oxidises the metal   filament to form an oxide and therefore its life was very short. Now with   the modification of vacuum bulbs, the life of the light bulbs have   enhanced considerably included filling the bulbs with inert gases like Argon. we all use the light bulb and now you know how it was made.