Natural Astronomy – Solstice

Natural Astronomy – Solstice

Music; Ambience: dawn chorus, amherst

JM: Long before the advent of calendars, almanacs and clocks, humans marked the movement of the sun as it traveled across our sky, noting the corresponding change of seasons throughout the year. I’m Jim Metzner and this is the Pulse of the Planet, presented by the American Museum of Natural History. For those of us in the Northern Hemisphere, this week is the winter solstice, the time of year when the northernmost point on the Earth’s axis leans at its greatest angle away from the sun and we experience the shortest days in the year. Judy Young is a Professor of Physics and Astronomy at the University of Massachusetts in Amherst.

JY: “So, the way we know the Earth is spinning is we watch the stars go by. And we watch the sun rise and set every day. But where does it rise and set? That tells us the day, the month and the season. And on the solstices, the sun changes very little in its rising and setting from day to day.”

JM: This fact wasn’t lost on ancient astronomers who, with the help of structures like Stonehenge, tracked the location of the rising sun throughout the year. They noticed that, for several days days around both June 21st and December 21st, the sun’s rising place seemed fixed at either its northernmost or southernmost point on the horizon.

JY: “The sun changes its rising and setting position every day, but not at the same rate. It moves very fast around the equinoxes, and slows down and stops at a solstice, that’s what solstice means, stand still.”

JM: Throughout history, both the summer and winter solstices have been crucial days in the calendars of traditional cultures around the world. Not only does the position of the rising sun seem to stand still for several days, but people come to a pause in their activities to celebrate. Pulse of the Planet is presented by the American Museum of Natural History. Additional funding for this series has been provided by the National Science Foundation. I’m Jim Metzner.

Natural Astronomy - Solstice

This week is the winter solstice. But without a calendar, would you be able to tell?
Air Date:12/21/2012
Scientist:
Transcript:

Natural Astronomy - Solstice

Music; Ambience: dawn chorus, amherst

JM: Long before the advent of calendars, almanacs and clocks, humans marked the movement of the sun as it traveled across our sky, noting the corresponding change of seasons throughout the year. I'm Jim Metzner and this is the Pulse of the Planet, presented by the American Museum of Natural History. For those of us in the Northern Hemisphere, this week is the winter solstice, the time of year when the northernmost point on the Earth's axis leans at its greatest angle away from the sun and we experience the shortest days in the year. Judy Young is a Professor of Physics and Astronomy at the University of Massachusetts in Amherst.

JY: "So, the way we know the Earth is spinning is we watch the stars go by. And we watch the sun rise and set every day. But where does it rise and set? That tells us the day, the month and the season. And on the solstices, the sun changes very little in its rising and setting from day to day."

JM: This fact wasn't lost on ancient astronomers who, with the help of structures like Stonehenge, tracked the location of the rising sun throughout the year. They noticed that, for several days days around both June 21st and December 21st, the sun's rising place seemed fixed at either its northernmost or southernmost point on the horizon.

JY: "The sun changes its rising and setting position every day, but not at the same rate. It moves very fast around the equinoxes, and slows down and stops at a solstice, that's what solstice means, stand still."

JM: Throughout history, both the summer and winter solstices have been crucial days in the calendars of traditional cultures around the world. Not only does the position of the rising sun seem to stand still for several days, but people come to a pause in their activities to celebrate. Pulse of the Planet is presented by the American Museum of Natural History. Additional funding for this series has been provided by the National Science Foundation. I'm Jim Metzner.