The 13th century Venetians glass blowers are known to have produced reading stones made of solid glass that was put into hand-held, single lens-type frames made of horn or wood. These reading stones were similar to hand-held magnifying lenses of today.
The stronger the magnetic field, the larger the magnetosphere. Some 20,000 times stronger than Earth's magnetic field, Jupiter's magnetic field creates a magnetosphere so large it begins to avert the solar wind almost 3 million kilometers before it reaches Jupiter. The magnetosphere extends so far past Jupiter it sweeps the solar wind as far as the orbit of Saturn.
Yes. It has a modest magnetic field that is approximately aligned with the planet's axis of rotation. The field is a planetary dipole, and it is though to be generated in a manner similar to the way the earth is though to generate its magnetic field-dynamo action at or around the core.he discovery of a magnetic field around Mercury led some scientists to believe that the planet's outer core, like Earth's, consists of liquid iron.. - NASA The magnetic field is so weak that the solar wind impinges on the surface and is absorbed.