image of extra dimensions

Big Mysteries: Extra Dimensions

August 17, 2017

Extra dimensions, which may well be an incorrect hypothesis, are one possible explanation for why gravity is so much weaker than the other forces.  In this video, Great Courses professor Dr. Don Lincoln explains it all with the help of a talking rabbit. […]


The Origin of Mass

August 3, 2017

Sophisticated consumers of science have heard that the Higgs boson is the origin of mass for ordinary matter. This is true, to a degree…  […]

Image of Roses

Will Flowering Plants Take Over the World?

July 17, 2017

Flowering plants arrived relatively late in geological time, between 290 to 145 million years ago. But once here, they evolved quickly and often displaced many other types of plants. In fact, in terms of species, flowering plants are the dominant plant form on Earth today with more than 300,000 types. Learn how their unique reproductive mechanisms led to this explosion of speciation in such a relatively short time.


Wave or Particle—What Is Light?

July 15, 2017

Light propagates through space as a continuous wave, but also exchanges energy in the form of discrete particles. So, wave or particle—what is light? […]

image of the eagle nebula by the hubble telescope

Hubble Images—Exploring the Birthplace of Stars

June 27, 2017

Among the incredible Hubble cloud images, none has been received with greater public acclaim than the detailed 1995 snapshot of newborn stars emerging from giant pillars of gas and dust inside the Eagle Nebula. This image looks like a fantasy landscape out of a dream or a children’s story. Get ready to explore this image in the context of galactic interstellar clouds, the process of star formation, and the impact of young stars on their interstellar environments. […]


Alternating Current vs. Direct Current—What’s The Difference?

June 21, 2017

Examine the nuances of alternating and direct currents, see how transformers use electromagnetic induction to transform voltage levels in AC circuits, and observe the role of diodes and capacitors in regulating current. See how the DC power supplies that charge our cell phones are constructed so that they convert alternating to direct current. […]

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