The inventions that changed the world sbha 54 group

Refrigeration:

• Refrigerators cool things down by taking advantage of the way substances absorb and unload heat as their pressure points and phases of matter change (usually from gas to liquid and back). It's difficult to pinpoint a single inventor of the refrigerator, because the concept was widely known and gradually improved over the course of about 200 years. Some credit Oliver Evans' 1805 unproduced design of a vapor-compression unit, while others point to Carl von Linde's 1876 design as the actual precursor of the modern refrigerator in your kitchen. Dozens of inventors, including Albert Einstein, would refine or improve refrigerator designs over the decades.
• In the early 20th century, harvested natural ice was still common, but large industries such as breweries were beginning to use ice-making machines. Harvested ice for industrial use was rare by World War I. However, it wasn't until the development of safer refrigerant chemicals in the 1920s that home refrigerators became the norm.
• The ability to keep food cold for prolonged periods (and even during shipping, once refrigerated trucks were developed) drastically changed the food production industry and the eating habits of people around the world. Now, we have easy access to fresh meats and dairy products even in the hottest summer months, and we're no longer tied to the expense of harvesting and shipping natural ice -- which never could have kept pace with the world's growing population in any case.

Communications:

• Maybe it's cheating to lump the telegraph, telephone, radio and television into one 'invention,' but the development of communication technology has been a continuum of increased utility and flexibility since Samuel Morse invented the electric telegraph in 1836 (building on the prior work of others, of course). The telephone simply refined the idea by allowing actual voice communications to be sent over copper wires, instead of just beeps that spelled out the plain text in Morse code. These communication methods were point-to-point, and required an extensive infrastructure of wires to function.
• Transmitting signals wirelessly using electromagnetic waves was a concept worked on by many inventors around the world, but Guglielmo Marconi and Nikola Tesla popularized it in the early 20th century. Eventually, sound could be transmitted wirelessly, while engineers gradually perfected the transmission of images. Radio and television were new landmarks in communications because they allowed a single broadcaster to send messages to thousands or even millions of recipients as long as they were equipped with receivers.
• These developments in communications technology effectively shrank the world. In the span of about 120 years, we went from a world where it might take weeks to hear news from across the country to one where we can watch events occurring on the other side of the globe as they happen. The advent of mass communications put more information within our grasp and altered how we interact with each other.