We learn about the world by slicing it up into smaller pieces. We study history, geography, math, art, music, science, and lots of other subjects. But to really understand our world, we must reconnect the pieces to see how they all work together.
This is a story about connections. This is a story about how events on the Sun 300 years ago may have affected some of the beautiful music we still hear today.
In the 17th century (1644 to 1737) lived a violin maker named Antonio Stradivari. His workshop was in Cremona, Italy. He made hundreds of violins, many of which are still played today. They are prized for their rich and beautiful sound, especially in the hands of master violinists.
A Stradivarius violin made in Italy about 300 years ago.
No one has since been able to make a violin that sounds quite like a Stradivarius (a violin made by Stradivari). Just how did Stradivari make such wonderful violins? No one knows for sure, but one new idea makes a lot of sense.
Violins are made from wood. The best violins are made from very hard, dense wood. The best wood comes from trees that have grown very slowly, laying down a thin ring of dense new growth each year. Long winters and cool summers make for slow tree growth.
Each year of this Douglas Fir tree's life, a new ring of growth was added. (Photo courtesy of H.D. Grissino-Mayer, web.utk.edu/~grissino/.)
During about 1560-1850, which included the time Stradivari made his violins, Europe (including Italy) experienced a "Little Ice Age." It was so cold that normally free-flowing rivers and canals froze over.
"Sports on a Frozen River," by Dutch painter van der Neer around 1660. Rivers in this area do not freeze now.
Stradivari used the hard, dense wood from the spruce trees growing during this time in a nearby forest to make his violins.
But why did Europe get so much colder than normal during these years? Only recently did scientists make the connection and figure out the most likely answer.
Astronomers have been studying the Sun for hundreds of years.
OF COURSE, THEY NEVER LOOKED AT THE SUN DIRECTLY AND NEITHER SHOULD YOU!
Using very special dark filters and lenses, they have studied the most obvious feature on the Sun: Sunspots.
Through special DARK filters, sunspots may look like the picture on the left. The sunspot groups are as big as the giant planet Jupiter! On the right is a closeup of some other sunspots. The larger sunspot on the right is bigger than Earth! (Images courtesy SOHO (NASA & ESA) and the Royal Swedish Academy of Sciences.)
Sunspots are areas of particularly strong magnetic forces on the Sun's surface. They appear darker than their surroundings because they are cooler. Even so, scientists have discovered that when there are lots of sunspots, the Sun is actually putting out MORE energy than when there are fewer sunspots. Sunspot activity occurs in cycles of about 11 years. But during about 1645 to 1715, hardly any sunspots were seen! From the time sunspot records were first kept until now, such a "solar rest period" has not been seen. It was during this period that Europe experienced the "Little Ice Age." It was during this time that Stradivari came along and made possibly the best violins ever from the slow-growing trees of his chilly era.
This picture is of made of three overlapping photos. It shows the rings in the spruce tree used to make the most famous Stradivarius violin, the "Messiah." The first row of numbers gives the width of each ring in millimeters (one mm is about the thickness of a fingernail). The bottom row gives the years in which each ring grew. (Photo courtesy of H.D. Grissino-Mayer, web.utk.edu/~grissino/.)
So, that is how the Sun of 300 years ago made beautiful music that we can still hear today!
A Solar Polar View
Scientists still have lots of questions about the Sun and its cycles of activity. One way they are studying it is with instruments on the Ulysses spacecraft. Ulysses was launched in October 1990. It is the first spacecraft to orbit the Sun's North and South poles. Most Sun-orbiting spacecraft swing around the Sun's equator in more or less the same plane as most of the planets. But Ulysses took a sharp turn early in its mission (thanks to a gravity boost from Jupiter) to study the Sun's magnetic field and the particles in the solar wind streaming from the Sun's poles.
Ulysses' orbit takes it over and under the ecliptic, the plane in which most of the planets orbit the Sun. This way, Ulysses can study the North and South Poles of the Sun.
Ulysses is a joint effort of NASA and the European Space Agency. Together, American and European scientists are discovering fascinating new things about the star whose every hiccup affects our lives.
Artist's idea of Ulysses passing over the Sun's north pole.
