Tag: botany

Winter is Coming: Why Leaves Fall

The physiology of deciduous trees (start time: 11:09) For many people living in places with four distinct seasons, such as here in Colorado, a favorite pastime at this midpoint in autumn is watching the faded leaves fall from their branches, and listening to the crackling sound while raking up the dried leaves. In this week’s How On Earth show, we explore questions like, Why do the leaves of aspen, ash and other deciduous trees “change” color in the fall?  (Spoiler alert: They actually reveal their true colors.) Why do they shed their leaves every fall? And what happens to the naked trees in the winter? Host Susan Moran interviews Dr. Stephanie Mayer, a senior instructor emerita in the Department of Ecology and Evolutionary Biology at the University of Colorado Boulder.
-Resources for winter watering:
Colorado State University Extension
Denver Botanic Garden
-Resources for citizen science opportunities:
The National Phenology Network

Host/ Show Producer: Susan Moran
Cohost/Engineer: Joel Parker
Executive Producer: Beth Bennett
Headline Contributors: Lorraine Healy, Max Hebebrand, Shelley Schlender

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Plants in Space // Relativity

Former undergraduate researcher Elizabeth Lombardi talks with Professor Barbara Demmig-Adams in the greenhouse on the roof of the Ramaley building at the University of Colorado Boulder. (Photo by Casey A. Cass/University of Colorado)

Plants in Space (start time 04:36) What would you miss if you were to spend an extended time in space—driving a car? Going to the movies? Hiking? Playing with your dog? Gravity, maybe? Or maybe something as simple as eating good, nutritious vegetables. How On Earth’s Beth Bartel speaks with University of Colorado undergraduate researcher Lizzy Lombardi about harvesting healthier veggies for our astronauts. Or, as we like to think about it, plants in space.

What Is Relativity? An Intuitive Introduction to Einstein’s Ideas, and Why They Matter by Jeffrey Bennett Relativity (start time 13:30) Albert Einstein published his special theory of relativity in 1905 and his general theory in 1915. Special relativity revealed bizarre and powerful ideas, including the famous equation E=mc2, but the basic theory hinges on a single realization: all observers, no matter how fast they are moving, always measure the same speed of light in space. A decade later, general relativity, the result of Einstein’s “happiest thought” that “the gravitation field has only a relative existence” unseated Newton’s law of gravitation. General relativity has passed every observation trial—so far. Relativity is important in everyday experience, for example enabling the incredible accuracy of the Global Positioning System, but the theory, especially the general form, can be a tough mathematical challenge. Boulder astrophysicist Dr. Jeffrey Bennett’s just-published book, What Is Relativity? An Intuitive Introduction to Einstein’s Ideas, and Why They Matter, gently straightens the curved spacetime. Join Jeff and host Jim Pullen live in the studio to learn why ‘black holes don’t suck’!

 

Hosts: Beth Bartel and Jim Pullen
Producer: Beth Bartel
Engineer: Jim Pullen
Executive Producer: Jim Pullen
Additional contributions: Jane Palmer

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Podcast: Play in new window | Download (Duration: 24:08 — 33.1MB)

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