The Clock in the Sun: How We Came to Understand Our Nearest Star

The Clock in the Sun: How We Came to Understand Our Nearest Star by Pierre Sokolsky

In The Clock in the Sun: How We Came to Understand Our Nearest Star, Pierre Sokolsky does a nice job in covering the history of solar mechanics and exploration, concisely and clearly explaining things in his own language but also, in one of my favorite aspects of the book, offering up a number of lengthy passages from his source material, letting us hear those early thinkers in their own words.

The early sections on pre-Scientific Revolution observations are detailed and often fascinating, as he covers solar recordings of sunspots and eclipses from ancient China, Mesopotamia, and Russian, before delving into the contributions to astronomy/astrology from the Greeks, the Arabic world, and the western Medieval world. With the introduction of Galileo and his application of the telescope, we enter into the modern data collection time period. Here is one of those strong uses of original writings, when we get a liberally quoted back and forth in letters between Galileo and Christopher Scheiner as they tussle over sunspots, with Galileo more willing to break free from the traditional views and Scheiner (a meticulous observer despite his theoretical failings) was more conservative.

As we move forward in time, the book becomes less historical and more science based, as Sokolsky covers various inventions, discoveries and theories (some more successful than other), including but not limited to the solar wind, speculation over if the sun could be inhabited, possible links between solar activity and economic cycles (and even human behavior), the impact of the sun on our weather, mapping of the sun’s various aspects like the corona and photosphere, the effect of solar storms, how the sun is powered, cycles and variations in the sun’s energy output and sunspot activity, use of tree rings and ice cores.

While all the expected big names are here: Galileo, Herschel, Lowell, Sokolsky also brings in some far less familiar names, some of which you might recognize if you read a lot of popular astronomy books (I did and I do) and some of which will be new to you even if you have (they were and I have), including resurrecting the names of women scientists whose work all too often gets obscured or out and out erased. One of my favorites in the “lesser known” category was Henrich Schwabe, a full-time pharmacist and amateur astronomer who though (like many) he might be able to find a planet orbiting the Sun inside of Mercury’s orbit. This of course necessitated lots of solar observations and so, staring in 1826, after “seventeen years of observation and careful recordkeeping” he ended up discovering “an approximate ten-year periodicity to the sunspot number,” for which he was eventually award the gold medal of the Royal Astronomical Society (RAS). As Sokolsky notes, Schwabe “compared his experience to that of biblical Saul, who went out to search for his father’s asses and found another kingdom instead.” The president of the RAS said of Schwabe:

Pierre Sokolsky

Twelve years he spent to satisfy himself — six more years to satisfy and still thirteen more to convince mankind. For thirty years never has the Sun exhibited his disk above the horizon of Dessau withing being confronted by Schwabe’s imperturbable telescope . . . He has made 9000 observations … an instance of devoted persistence … unsurpassed in the annals of astronomy. The energy of one man has revealed a phenomenon that had eluded even the suspicion of astronomers for 200 years [He] has taught us that there are still mines rich in ore, though they lie deep buried.

As noted, for the most part the writing is clear and accessible, though we occasionally get lines like these: “Since these now have the opposite polarity to the Sun’s original poloidal field at the beginning of a cycle, the upward and downward-traveling magnetic flux tends to oppose the existing polar field.” But such moments are extremely rare and only show up at the very latter stages of the book. And even then, most of the harder language is more in insets or notes than the main portion of the text. The number of illustrations also are helpful in making the science accessible. Following the main text, we also get some appendices on electric and magnetic, electromagnetic waves, and some further technical details on the makeup and charge of atoms. These are followed by a number of quite interesting notes (recommended to not skip) and a useful “for further reading” section.

Recommended.