Problem: Antenna (radio):

The net quality of a ground reflection depends on the topography of the surface. When the irregularities of the surface are much smaller than the wavelength, we are in the regime of specular reflection, and the receiver sees both the real antenna and an image of the antenna under the ground due to reflection. But if the ground has irregularities not small compared to the wavelength, reflections will not be coherent but shifted by random phases. With shorter wavelengths (higher frequencies), this is generally the case.

When will reflections not be coherent?
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A: ground has irregularities

Problem: Friedrich Hayek:

On his mother's side, Hayek was second cousin to the philosopher Ludwig Wittgenstein. His mother often played with Wittgenstein's sisters, and had known Ludwig well. As a result of their family relationship, Hayek became one of the first to read Wittgenstein's Tractatus Logico-Philosophicus when the book was published in its original German edition in 1921. Although Hayek met Wittgenstein on only a few occasions, Hayek said that Wittgenstein's philosophy and methods of analysis had a profound influence on his own life and thought. In his later years, Hayek recalled a discussion of philosophy with Wittgenstein, when both were officers during World War I. After Wittgenstein's death, Hayek had intended to write a biography of Wittgenstein and worked on collecting family materials; and he later assisted biographers of Wittgenstein.

How often times did Hayek and Wittgenstein meet?
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A: on only a few occasions

Problem: Biodiversity:

The control of associated biodiversity is one of the great agricultural challenges that farmers face. On monoculture farms, the approach is generally to eradicate associated diversity using a suite of biologically destructive pesticides, mechanized tools and transgenic engineering techniques, then to rotate crops. Although some polyculture farmers use the same techniques, they also employ integrated pest management strategies as well as strategies that are more labor-intensive, but generally less dependent on capital, biotechnology and energy.

What is one of the great polyculture challenges that farmers face?
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A: unanswerable

Problem: Steven Spielberg:

In 2002, Spielberg was one of eight flagbearers who carried the Olympic Flag into Rice-Eccles Stadium at the Opening Ceremonies of the 2002 Winter Olympic Games in Salt Lake City. In 2006, Premiere listed him as the most powerful and influential figure in the motion picture industry. Time listed him as one of the 100 Most Important People of the Century. At the end of the 20th century, Life named him the most influential person of his generation. In 2009, Boston University presented him an honorary Doctor of Humane Letters degree.

Where is Rice-Eccles Stadium?
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A:
unanswerable