Celebrating the History of Science
and the Science behind History
During the Renaissance, French kings and queens built many palaces, in an area known as the Loire Valley. The royal family would travel from palace to palace to get away from Paris, the way you might head to a lake house. The Loire Valley is not very close to Paris. It’s about 110 miles from Paris to the palace of Chambord, for instance. I wondered how long it took sixteenth century travelers to make this journey—and why there were so many palaces.
First, the distance. Under the best of conditions (good roads, decent weather, level ground), humans can walk four miles per hour over long distances. Horses can’t do much better–maybe five mph—but a lot less if they’re pulling something or if roads are in awful condition. A horse can canter at 20 mph, but it can only do that for six to eight miles at a time, after which it will slow down and walk, or stop completely. So it would have taken a long time to get from place to place. Under the best conditions, a journey from Paris to Chambord would have taken three weeks.
But in fact, it took a lot longer than that. Because in the sixteenth century, the royal court didn’t just hop on a horse and head to their country home. They took everything and everyone with them, loading all the stuff onto the backs of horses and mules.
When Catherine de Medici was queen of France, she traveled with her ladies and gentlemen, foreign ambassadors, pet bears, servants, retainers, attendants, apothecaries, astrologists, tutors, musicians, cooking pots, food, clothing, portable triumphal arches, wall hangings, and furniture.
And the reason there were so many palaces is simply that the court in Renaissance times –thousands of people–had to move around from estate to estate so as to find new hunting grounds. Once they’d exhausted the food supply in the area, they moved on to the next estate. Also, the sanitation was dreadful. After thousands of people had taken up residence in and around a great estate for a few weeks, filth piled up, and with it, stench and disease.
The royal procession could be miles long. When Catherine de Medici’s court packed up and left for a new palace, the beginning of the royal caravan sometimes entered a town before those traveling at the back of it had left the last one.
Sara Albee's recent book is Why'd They Wear That?, published by National Geographic in 2015. Get ready to chuckle your way through centuries of fashion dos and don'ts! In this humorous and approachable narrative, you will learn about outrageous, politically-perilous, funky, disgusting, regrettable, and life-threatening creations people have worn throughout the course of human history, all the way up to the present day. For more information, click here.
MLA 8 Citation
Albee, Sarah. "Renaissance Road Trips." Nonfiction Minute, iNK Think Tank, www.nonfictionminute.org/the-nonfiction-minute/renaissance-road-trips.
by David M. Schwartz
the amazing, engaging, math exponent
A light year is not a year that has gone on a diet. It is not a year that’s been trimmed to 300 days. It’s not a year spent under high-wattage lamps. A light year isn’t any kind of year.
A light year is a distance. It is a vast distance; the distance light travels in a year. To appreciate a light year, you have to understand how fast light travels.
The speed of light is truly mind-boggling: 186,000 miles per . . . second. That’s “per second,” not “per hour.” In one tick-tock second, light travels a distance of 186,000 miles. If it could go in circles, it could travel around the earth more than seven times in just one second! But light travels in straight lines, not in circles. Imagine something traveling that fast in a straight line—not for a second, not for a minute, not for an hour, not for a day, but for an entire year. The distance it goes in that year is called a light year.
A light year is a convenient unit of measure when distances are enormous. You could talk about the same distances in miles. It's about 5,878,499,810,000 (5 trillion, 878 billion, 499 million, 810 thousand ) of them. But these measurements are so large that they are unwieldy. It's much easier to just name that enormous distance with two simple words: a "light year."
The star closest to our solar system is Proxima Centauri. Some of the light that leaves Proxima Centauri goes to Earth, cruising along at 186,000 miles per second. At that speed, light takes about 4.2 years to get to Earth from Proxima Centauri So how far away is Proxima Centauri? It is 4.2 light years away.
To give you an idea of how far that is, imagine going to Proxima Centauri in a spaceship traveling at the speed of the space shuttle — about ten miles per second. (That’s much faster than airplanes can fly.) You would get there in about 70,000 years.
Our Sun is much closer than Proxima Centauri. It is 93 million miles away. There is another way to refer to the distance from the earth to the Sun. Light leaving the Sun takes about eight minutes to get to Earth, so we say the Sun is eight “light minutes” away. If you traveled at the speed of light, you could get there in eight minutes. Have a nice trip!
© David M. Schwartz, 2014
David Schwartz has been fascinated by big numbers and big distances ever since he was a little boy riding his bicycle, wondering “How long would it take for me to ride to Proxima Centauri, 4.2 light years away?” He wrote about light years in his math alphabet book G Is for Googol.
David is a member of iNK’s Authors on Call. He can visit in your classroom via interactive video conferencing. Learn more here.
MLA 8 Citation
Schwartz, David M. "What Is a Light Year?" Nonfiction Minute, iNK Think Tank, 14 Sept. 2017, www.nonfictionminute.org/the-nonfiction-minute/what-is-a-light-year.
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