Lockyer, Norman

The focus of this section is the emission of ultraviolet and visible radiation following thermal or electrical excitation of atoms. Atomic emission spectroscopy has a long history. Qualitative applications based on the color of flames were used in the smelting of ores as early as 1550 and were more fully developed around 1830 with the observation of atomic spectra generated by flame emission and spark emission.Quantitative applications based on the atomic emission from electrical sparks were developed by Norman Lockyer (1836-1920) in the early 1870s, and quantitative applications based on flame emission were pioneered by IT. G. Lunde-gardh in 1930. Atomic emission based on emission from a plasma was introduced in 1964. 

Observed in the spectrum of sunlight by Pierre Jules Cesar Jansen (1824-1908) as well as by Norman Lockyer (1836-1920) and Edward Frankland (1825-1899). They believed the element to be a metal. 

Unfortunately, the Schrodinger equation for multi-electron atoms and, for that matter, all molecules cannot be solved exactly and does not lead to an analogous expression to Equation 4.5 for the quantised energy levels. Even for simple atoms such as sodium the number of interactions between the particles increases rapidly. Sodium contains 11 electrons and so the correct quantum mechanical description of the atom has to include 11 nucleus-electron interactions, 55 electron-electron repulsion interactions and the correct description of the kinetic energy of the nucleus and the electrons - a further 12 terms in the Hamiltonian. The analysis of many-electron atomic spectra is complicated and beyond the scope of this book, but it was one such analysis performed by Sir Norman Lockyer that led to the discovery of helium on the Sun before it was discovered on the Earth. 

Helium - the atomic number is 2 and the chemical symbol is He. The name derives from the Greek helios for sun . The element was discovered by spectroscopy during a solar eclipse in the sun s chromosphere by the French astronomer Pierre-Jules-Cesar Janssen in 1868. It was independently discovered and named helium by the English astronomer Joseph Norman Lockyer. It was thought to be only a solar constituent until it was later found to be identical to the helium in the uranium ore cleveite by the Scottish chemist William Ramsay in 1895. Ramsay originally called his gas krypton, until it was identified as helium. The Swedish chemists Per Theodore Cleve and Nils Abraham Langet independently found helium in cleveite at about the same time. 

Sir William Crookes will probably be longest remembered for his study of rarefied gases and for his discoveries in radioactivity and molecular physics. After Sir William Ramsay discovered helium in 1895, it was Crookes who established its identity with the helium that Sir Norman Lockyer had observed spectroscopically in the sun s atmosphere. Crookes also invented the radiometer and the spinthariscope. As early as 1886-88 he recognized the existence of atomic species of identical... 

French Medallion Cast in 1878 in honor of the French astronomer, Jules Janssen, and the English astronomer, Sir Norman Lockyer, for their method of analyzing the solar protuberances. 

Reproduced from Lockyer, T. Mary, and Winifred L. Lockyer, "The Life and Work of Sir Norman Lockyer, by permission of Macmillan and Co. 

Sir Joseph Norman Lockyer, 1836-1920. Director of the solar physics observatory of The Royal College of Science at South Kensington. Pioneer in the spectroscopy of the sun and stars. In 1868 Lockyer and Janssen independently discovered a spectroscopic method of observing the solar prominences in daylight. Such observations had previously been made only at the time of total eclipses of the sun. 

Sir Norman Lockyer s Story of helium, published in Nature on... 

February 6 and 13, 1896 and reprinted with additions in the biography by T. Mary Lockyer and Winifred L. Lockyer, is a masterpiece of clear, understandable scientific literature 22). In 1899 Sir Norman Lockyer detected helium in the water of the Harrogate springs 22). 

But no one had ever subdivided a hydrogen atom, nor had they convincingly transmuted one element into another. So why credit this untested idea In the 1870s, the astronomer Joseph Norman Lockyer suspected that it was simply a question of finding the right conditions. Lockyer proposed that to transmute elements you needed the fiery furnace of a star. 

Since this was the period when chemists like William Allen Miller and Edward Frankland were cooperating with astronomers like William Huggins and Norman Lockyer on spectroscopic surveys of the sun and stars, it was easy to speculate (as Brodie himself did) that some of his symbols that carried no earthly elementary meaning, snch as x, might represent elementary materials present in the sun, where dissociation constantly occnrred. 

J. Norman Lockyer, Solar Physics (London, 1874), 158, figures 47 and 48. 

Helium. Helium is present in very small quantities in the atmosphere. Its presence in the sun is shown by the occurrence of its sp>ectral lines in sunlight. These lines were observed in 1868, long before the element was discovered on earth, and the lines were ascribed to a new element, which was named helium by Sir Norman Lockyer (1836-1920). 

Pierre Janssen and Norman Lockyer discover helium in the spectrum of the sun. 

One of the earliest and most famous examples of the use of spectrometry to study the solar system occurred in 1868. While observing a solar eclipse in India, the French astronomer Pierre Janssen (1824-1907) found a new spectral line in sunlight very close to one found in the spectrum of sodium. Janssen was able to show, however, that the new yellow light was different from the sodium line. Indeed, it was a spectral line that had never before been observed on Earth. Janssen hypothesized that the presence of the line could be explained only if the Sun s atmosphere contained an element that had not yet been discovered on Earth. The British astronomer Sir Norman Lockyer (1836-1920) later suggested the name helium for the element, a name based on the Greek word for "sun," helios. It was almost 30 years later that Janssen s bold hypothesis was confirmed. In 1895, the British chemist and physicist Sir William Ramsay (1852-1916) first detected helium on Earth, during a series of experiments on an ore of uranium called clevite. 

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