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1st century AD – Pliny in his Natural History records the story of a shepherd Magnes who discovered the magnetic properties of some iron stones, "it is said, made this discovery, when, upon taking his herds to pasture, he found that the nails of his shoes and the iron ferrel of his staff adhered to the ground". [6]
For example, in 1820 Hans Christian Ørsted of Copenhagen discovered the deflecting effect of an electric current traversing a wire upon a suspended magnetic needle. [11] This discovery gave a clue to the subsequently proved intimate relationship between electricity and magnetism which was promptly followed up by Ampère who some months later ...
In its first year, Canva had more than 750,000 users. [12] In April 2014, Guy Kawasaki joined the company as its chief evangelist. [13] In 2015, Canva for Work was launched, focusing on marketing materials. [14] During the 2016–17 financial year, Canva's revenue increased from A$6.8 million to A$23.5 million, with a loss of A$3.3 million. In ...
The machine illustrated here uses eight disks and nine rows of magnets: 72 magnets in all. The rotors first used were wound as sixteen axial bobbins, one per pole. Compared to the bipolar dynamo, this did have the advantage of more poles giving a smoother output per rotation, [ note 2 ] which was an advantage when driving arc lamps.
'Magnet' is derived from the legend of Magnes, or from the territory of Magnesia. Pliny states that Magnes, the shepherd, discovered it, and the legend told of him is that while carrying a message over Mount Ida he felt his feet clinging to the earth, to the iron ore which lay thickly upon the hill. Hence the name of the Magnet.
Archaeomagnetic dating is the study and interpretation of the signatures of the Earth's magnetic field at past times recorded in archaeological materials. These paleomagnetic signatures are fixed when ferromagnetic materials such as magnetite cool below the Curie point, freezing the magnetic moment of the material in the direction of the local magnetic field at that time.
In the late 1920s, Gregory Breit and Merle Tuve at the Bureau of Terrestrial Magnetism constructed a working device that used varying magnetic fields to accelerate electrons. Their device placed two solenoidal magnets next to one another and fired electrons from a gun at the outer edge of the magnetic field. As the field was increased, the ...
The Magnetes (Greek: Μάγνητες) were an ancient Greek tribe. In book 2 of the Iliad, Homer includes them in the Greek Army that is besieging Troy, and identifies their homeland in Thessaly, in a part that is still known as Magnesia. [1]