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The phonautograph, patented by Léon Scott in 1857, used a vibrating diaphragm and stylus to graphically record sound waves as tracings on sheets of paper, purely for visual analysis and without any intent of playing them back. In the 2000s, these tracings were first scanned by audio engineers and digitally converted into audible sound. Phonautograms of singing and speech made by Scott in 1860 were played back as sound for the first time in 2008. Along with a tuning fork tone and unintelligible snippets recorded as early as 1857, these are the earliest known recordings of sound.

In what year was phonautograms patented?
Answer: 1857
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In July 2012, Ancestry.com reported on historic and DNA research by its staff that discovered that Obama is likely a descendant through his mother of John Punch, considered by some historians to be the first African slave in the Virginia colony. An indentured servant, he was "bound for life" in 1640 after trying to escape. The story of him and his descendants is that of multi-racial America since it appeared he and his sons married or had unions with white women, likely indentured servants and working-class like them. Their multi-racial children were free because they were born to free English women. Over time, Obama's line of the Bunch family (as they became known) were property owners and continued to "marry white"; they became part of white society, likely by the early to mid-18th century.

When was Punch indentured?
Answer: 1640
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A new style of wafers composed of gallium-nitride-on-silicon (GaN-on-Si) is being used to produce white LEDs using 200-mm silicon wafers. This avoids the typical costly sapphire substrate in relatively small 100- or 150-mm wafer sizes. The sapphire apparatus must be coupled with a mirror-like collector to reflect light that would otherwise be wasted. It is predicted that by 2020, 40% of all GaN LEDs will be made with GaN-on-Si. Manufacturing large sapphire material is difficult, while large silicon material is cheaper and more abundant. LED companies shifting from using sapphire to silicon should be a minimal investment.

What size are the wafers used to create white LEDs?
Answer:
200-mm