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Using available data, he obtains a velocity of 310 740 000 m/s and states "This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according ...
The history of electromagnetic theory begins with ancient measures to understand atmospheric electricity, in particular lightning. [1] People then had little understanding of electricity, and were unable to explain the phenomena. [ 2 ]
The Italian Guglielmo Marconi transmits wireless telegraph messages by electromagnetic waves over a distance of five kilometers. 1898 The Danish physicist Valdemar Poulsen creates the world's first magnetic recording and reproduction, using a 1 mm thick steel wire as a magnetizable carrier.
Africa has the world's oldest record of human technological achievement: the oldest surviving stone tools in the world have been found in eastern Africa, and later evidence for tool production by humans' hominin ancestors has been found across West, Central, Eastern and Southern Africa. [1] The history of science and technology in Africa since ...
This timeline lists significant discoveries in physics and the laws of nature, including experimental discoveries, theoretical proposals that were confirmed experimentally, and theories that have significantly influenced current thinking in modern physics. Such discoveries are often a multi-step, multi-person process.
Saharan trade routes c. 1400, with modern Niger highlighted A map of North Africa as it was known to Europeans in 1482, created by German cartographer Lienhart Holl and based on Ptolemey's fourth map of Africa. In 1297, King Denis of Portugal took a personal interest in exports.
These timelines of world history detail recorded events since the creation of writing roughly 5000 years ago to the present day. For events from c. 3200 BC – c. 500 see: Timeline of ancient history; For events from c. 500 – c. 1499, see: Timeline of post-classical history; For events from c. 1500, see: Timelines of modern history
There were many kingdoms and empires in all regions of the continent of Africa throughout history. A kingdom is a state with a king or queen as its head. [1] An empire is a political unit made up of several territories, military outposts, and peoples, "usually created by conquest, and divided between a dominant centre and subordinate peripheries".