Historians do not know for sure just how fire was discovered, but most believe that humans first saw fire after lightning struck a tree during the Lower Paleolithic age. Soon, humans discovered that it was possible to not only use the flame for heat and light, but also to cook food.Know More
Many historians believe that the very first evidence of controlled fire being used by humans was seen during the Lower Paleolithic age at a site known as Gesher Benot Ya'aqov, located in Israel. It was here that researchers found wood and seeds that had been charred. Later it was found that this site was over 790,000 years old.
Not all scientists believe that the Gesher Benot Ya'qov site was the first example of controlled fire. Others believe that the first sign of controlled fire was at Zhoukoudian, which is a Lower Paleolithic site in China dated close to 400,000 years ago. Others believe that the first sign of controlled fire is at Qesem Cave in Israel, which dates back between 200,000 and 400,000 years.
It was not until the Middle Paleolithic age that a hearth was used. A hearth is a simple fireplace that is made from a circle of stones or by simply reusing the same area many times to build a fire. Some hearths are believed to be over 125,000 years old.Learn more in Chemistry
To make a fire, lay four split logs on the floor of the fireplace, cover them with kindling, add rolled newspaper, and light the paper on fire. This 20-minute process requires a fireplace, split logs, kindling, newspaper and a lighter.Full Answer >
Controlling fire is largely about preventing its spread and chiefly involves keeping flammable objects at an appropriate distance. Knowing how material responds to fire is also important, and having the right fuel is essential for keeping a fire burning well.Full Answer >
The only way to know for sure whether or not a dog has a kidney infection is through a veterinary examination. According to the Merck Manual for Pet Health, symptoms that may indicate a kidney infection include pain in the sides, fever and a general sense that the dog is not well. Vomiting, reduced appetite, increased urination or thirst are other symptoms of a possible kidney infection.Full Answer >
Oxygen was discovered in 1772 by Carl Wilhelm Scheele, who wrote a paper with his findings in 1775, which was published in 1777. In 1774, Joseph Priestley independently discovered oxygen and published his findings in 1775.Full Answer >