50 Years ago

According to the present model, the solar corona consists of a gas of electrons and protons with a small mixture of heavy elements which is isothermal at a temperature of approximately a million degrees and which is in hydrostatic equilibrium in the gravitational field of the Sun. The alternative model which we propose is that the solar corona consists of trapped charged particles moving in the magnetic field of the Sun, very like the charged-particle cloud surrounding the Earth which has been recently discovered by Van Allen and his ollaborators.

In order to check the hypothesis suggested above, precise measurements of the polarization over a wide spectral range, as well as of the spectral composition of the light, will be important. We are now planning to carry out such measurements during the eclipse of October 2, 1959.

From Nature 9 May 1959

100 Years ago

Statements have been made in the medical and general Press that the electric waves used in wireless telegraphy are injurious to the operators and produce various diseases, such as conjunctivitis, corneal ulceration, and leukoma. Mr. Marconi writes to the Times to deny these suggestions, for which, he says, there is no evidence whatever. He adds: — “During the twelve years or so of our operations we have had to deal with no single case of compensation for any injury of this origin, nor, so far as I can ascertain, has any such injury been suffered. Speaking for myself, I may remark that my own good health has never been better than during the often extended periods when I have been exposed for many hours daily to the conditions now challenged, and in the constant neighbourhood of electrical discharges at our Transatlantic stations, which I believe are the most powerful in the world.”

From Nature 6 May 1909