The Spectrum
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3

We can imagine the possibility of determining the shapes of stars, their distances, their sizes, and their movements; .whereas there is no means by which we will ever be able to examine their chemical composition, their mineralogical structure, or especially, the nature of organisms that live on their surfaces…Our positive knowledge with respect to the stars is necessarily limited to their observed geometrical and mechanical behavior.

—Auguste Comte (1864)

Remember this!

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However, the game was afoot

Alexander von Humbolt studies sunspots

42 years of observations revealed that sunspot activity varies on an 11-year cycle

Right: 1845 daguerreotype, perhaps the first photograph of the Sun

Note the sunspots

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Earth-Sun connection

Sir Edward Sabine in 1852 announces a remarkable coincidence between Earth’s magnetic fluctuations and the sunspot cycle

If the Sun could influence the Earth’s magnetic field, and hence navigational compasses, more intense solar studies were indicated

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Physics and Chemistry Unite

Robert Wilhelm Bunsen 1811-1899

Gustav Robert Kirchhoff 1824-1887

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In the 1850s Kirchhoff and Bunsen used a prism to examine the light produced when different elements, alone and in combination, are burned

“It is known that several substances have the property of producing certain bright lines when brought into the flame. A method of qualitative analysis can be based on these lines, whereby the field of chemical reactions is greatly widened and hitherto inaccessible problems are solved.”

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