The Once and Future Sun

Talan Memmott’s Lexia to Perplexia is an online fictional hyper­text project that interleaves conventional writing with program­ming code for Html and Javascript to explore the ways human culture has been shaped by emerging digital communication tech­nologies. Memmott writes: “The Earth’s own active crust we are, building, building—up and out—antennae, towers to tele*.”55 Memmott evokes an interesting concept. Humans have produced an electronic crust, or an information and technology layer, over Earth’s surface and extending into orbit. This layer of electron­ics is comprised of technologies ranging from radio and televi­sion relay stations perched on mountain tops to fiber-optic lines in homes and businesses, from cell towers dotting the high ground to transoceanic cables in the ocean depths. This data-rich envelope extends from backyard satellite dishes to powerful astronomical radio telescopes lined across the desert in Socorro, New Mexico, to billions of dollars in satellite hardware in low Earth orbit.

This infrastructure transmits information to cell phones, radios, televisions, computers, global positioning devices, emergency ser­vice centers, hospitals, and weather reporting stations, etc. Mem – mott writes, “I spread out—pan—s end out signals, smoke and otherwise, waiting for Echo.”56 The point is that since the ancient past, humans have extended their communication capabilities over larger and larger distances, through technologies that today trans­mit information around the globe at the speed of light. But this diaphanous “skin” is sensitive to the conditions of the space envi­ronment just as our skin is sensitive to the Sun. Never before have we been so dependent upon an understanding of the inner work­ings of the Sun and its impact on the electronics that sustain our information-based culture. As we continue to expand and rely on

this electronic, information layer encasing the Earth, we’re increas­ingly impacted by the Sun’s powerful magnetic reach.

Evolutionarily, we’ve adapted to living with our star. As John Freeman points out, humans, like other mammals, insects, and plants, have evolved “sense organs that can make use of the Sun’s outward flood of electromagnetic radiation. It’s not an accident that our eyes are sensitive to the same portion of the electromag­netic spectrum where solar radiation is most intense.”57 Similarly, our skin is well adapted to sunlight in a number of ways, one being that in about fifteen minutes of exposure our skin absorbs the daily recommended amount of vitamin D. Our lives are intimately bound up with the Sun, and not just because of our need for its light and warmth. The iron in our blood was forged inside massive stars over 4.5 billion years ago and then surfed the blast waves of supernovae into interstellar space. Stars like the Sun spewed heavier elements into space that eventually coalesced into our Sun and Solar System. Harlow Shapley popularized this concept in the early 1900s by claiming that we are made of “star stuff.” The human body, as all life on Earth, is comprised of carbon, calcium, oxygen, and other heavy elements forged in the cores of stars that exploded long before our Sun was born. Given how much more there is to it than meets the eye, it’s fitting that one of NASA’s ini­tial Braille books for the blind focused on the Sun.58

The Solar Dynamics Observatory, launched in early 2010, is carrying on SOHO’s work with even greater accuracy in exam­ining the Sun’s interior and interpreting the sound waves travel­ing inside and across its surface. Part of NASA’s “Living with a Star” program, SDO is tracking magnetic fields within the Sun in hopes of discovering the mechanism that drives the Sun’s eleven – year cycle. SDO is sending data to Earth at a rate a thousand times faster than SOHO, equivalent to downloading 300,000 songs a day. The satellite is 50 percent heavier than SOHO and views the Sun in high definition, or nearly IMAX quality, taking a picture in eight different colors every ten seconds.59 It’s serving as a first alert against magnetic storms sweeping over our fragile home in space.

We’ve learned from SOHO and other missions that the rock­steady light from the Sun, varying by less than a percent from year to year or decade to decade, is not the whole story. In invisible forms of radiation, the Sun is epic and Byzantine in its behavior, and scientists have not fully understood this apparently simple, middle-aged and middle-weight star. Scattered through the Milky Way galaxy, there are an estimated hundred million habitable Earth-l ike worlds orbiting Sun-l ike stars, and each will have its own complex relationship with its parent star.60 Our Sun and the space weather it produces will determine the future of our species as well as that of all life on Earth, even the planet itself. Having sustained our world for billions of years, the Sun is still a devoted protector and guardian. It reaches out across a hundred million miles to cradle, caress, stroke, and occasionally, scold us.