If Light Can’t Escape Black Holes, How Do We Get Photos of Them… and More Questions From Our Readers
You asked, we answered
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Q: If the gravity of a black hole is so strong that nothing can escape from it, not even light, how has the Hubble Space Telescope recorded images of gas jets ejected from black holes?
— Joseph A. Leist | Hamilton, New Jersey
It’s true, no light can escape a black hole’s “event horizon,” or boundary, says Avi Loeb, a theorist at the Harvard-Smithsonian Center for Astrophysics. However, the Hubble images record light emitted by stars or gases in the vicinity of the black hole, not coming out of it. The Event Horizon Telescope, a project drawing on observatories around the world to simulate a telescope as big around as Earth, gathered radio data from around the black hole at the center of the Milky Way last April. Scientists hope that the data, which is still being processed, will yield the first silhouette of a black hole.
Q: In his autobiography, Charles Lindbergh wrote that when he finished his trans-Atlantic flight in Paris, someone stole his engine and navigation logs. Were they ever recovered?
— Robert Kittredge | Sedona, Arizona
No, says a rueful Bob van der Linden, curator in the aeronautics department at the National Air and Space Museum. When Lindbergh landed at Le Bourget airfield on May 21, 1927, he was greeted by 150,000 fans, many of whom rushed his plane to grab a souvenir. Some made off with scraps of fabric, items from the cockpit—and those two logs. Lindbergh used data from a third log for his book, giving his flight’s origin, duration and destination and the number of hours his engine ran. But the other two, which may contain more notes on his flight, remain lost to history.
Q: Many mammals give birth to multiple offspring at once. Do litters ever include identical twins?
— Christopher Hu | Shaker Heights, Ohio
Well, nine-banded armadillo females are famous (in some circles) for being polyembryonic; they bear litters of four genetically identical offspring from one fertilized egg. And an Irish wolfhound in South Africa made news in 2016, when researchers confirmed that she had born two genetically identical puppies. Beyond that, scientists don’t know much about mammalian identical-twin births, says Klaus-Peter Koepfli, a researcher at the Smithsonian Conservation Biology Institute, in part because the tests necessary to show identical genes go beyond the standard sex testing performed on animals, and haven’t been seen as necessary.
Q: How and when did “simon-pure” enter America’s political vocabulary?
— Ann Evett | Frenchglen, Oregon
The adjective comes from Simon Pure, a character in the English satirical play A Bold Stroke for a Wife, first performed in 1718. It meant “authentic” or “pure” when it entered our political vocabulary in the Civil War era, says Jon Grinspan, a curator at the National Museum of American History. Around the 1880s, however, as some voters began to stray from the political parties they’d been born into, candidates who hewed to their party line cast themselves as “simon-pure” Republicans or Democrats to court party loyalists, sharpening the meaning to “purely partisan.” That usage persisted at least into the 1980s.
It’s your turn to Ask Smithsonian.