The external enemy that proved to be the greatest continuing threat ever to the Byzantine empire during the 15th century would be known as the Turks.
Answer: was held on 26 April 1920 at the Smithsonian Museum of Natural History, between the astronomers Harlow Shapley and Heber Curtis. It concerned the nature of so-called spiral nebulae and the size of the universe; Shapley believed that distant nebulae were relatively small and lay within the outskirts of Earth's home galaxy, while Curtis held that they were in fact independent galaxies, implying that they were exceedingly large and distant.
The two scientists first presented independent technical papers about "The Scale of the Universe" during the day and then took part in a joint discussion that evening. Much of the lore of the Great Debate grew out of two papers published by Shapley and by Curtis in the May 1921 issue of the Bulletin of the National Research Council. The published papers each included counter arguments to the position advocated by the other scientist at the 1920 meeting.
In the aftermath of the public debate, scientists have been able to verify individual pieces of evidence from both astronomers, but on the main point of the existence of other galaxies, Curtis has been proven correct.
Roosevelt essentially took the opposite approach as Hoover in taking on the Great Depression. Herbert Hoover thought that America and its economy could naturally recover from the Depression in due course, so he adamantly restrained the federal government from intervening on behalf of the people affected. On the other hand, Roosevelt dramatically increased employment by expanding the federal government and establishing agencies that would aid in relieving some of the country's worst problems.
<span>Joan Of Arc is the answer to your question.
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