Scientists have shown how gravitational waves—invisible ripples in the fabric of space and time that propagate through the universe—might be “seen” by looking at the stars. The new model, developed in part by researchers at the Museum, proposes that a star that oscillates at the same frequency as a gravitational wave will absorb energy from that wave and brighten, an overlooked prediction of Einstein’s 1916 theory of general relativity. The study, which was published today in the Monthly Notices of the Royal Astronomical Society: Letters, contradicts previous assumptions about the behavior of gravitational waves.
This year, autumn arrives in the northern hemisphere at 10:29 pm ET the evening of Monday, September 22.
With summer’s official conclusion in the northern hemisphere, cooler temperatures and less hazy skies gradually will allow clearer nighttime sky watching. Although solar system objects such as the Moon, Venus, and Jupiter are easily seen even from Manhattan, fainter planets and stars are certainly best viewed from darker sites.
Madagascar’s rainy season is relentless. Unpaved roads turn to mud. Rivers flood. Feet start to blister from constant dampness. Humidity permeates everything, soaking maps, seeping into GPS units, attacking cameras and other electronic equipment. So why did herpetologists Christopher Raxworthyand Sara Ruane schedule their latest expedition to the island for January and February, at the height of the wet season?
“When I first came to Madagascar in 1985, there was very little practical knowledge about reptiles and amphibians anywhere, and most people were coming out in October or September,” says Raxworthy, who is associate curator in the Division of Vertebrate Zoology. “I remember talking to one of the really good local guides, and I asked him—when do you think is the best time to come out and look for chameleons, frogs, and snakes? He said, the middle of the rainy season. Since then, I’ve gone to Madagascar during the peak rainy season, and that’s made all the difference.”
More than 20,000 species of plants and animals around the world are currently under threat of extinction, and hundreds vanish each year. We don’t always know the exact time of extinction, but for the Pinta Island giant tortoise, the date was June 24, 2012.
Over the last two years, Wildlife Preservations taxidermy experts have worked closely with Museum scientists to preserve Lonesome George as he appeared in life—down to a missing toenail on his left front foot.
Happy #FossilFriday! Meet the phytosaur Machaeroprosopus gregorii, or “knife-face.”
Some phytosaurs reached gigantic size, and this specimen was probably over 40 feet long! Phytosaurs were clearly carnivorous: in a few specimens, bones of other reptiles have been found as stomach contents. Machaeroprosopus lived 210 million years ago, and was collected near Cameron, Arizona in 1936.
Lonesome George, the last Pinta Island giant tortoise, was unveiled at the Museum this afternoon. He will be on public view for just over 3 months, through January 4, 2015. Museum scientists worked closely with taxidermy experts to preserve Lonesome George as he appeared in life.
The Hall of North American Mammals looked a little different in 1907.
This photograph of the Wapiti Elk Group was taken by J. Otis Wheelock in 1907, before the scene was recreated as one of the Museum’s iconic dioramas. You can compare this image with the modern Wapiti diorama here.
Jack Tseng and Camille Grohé, postdoctoral fellows in the Division of Paleontology at the American Museum of Natural History, have been blogging from the field during an expedition to Inner Mongolia. Now that they are back in New York City, they’ve been going over the fruits of their labor from the two and a half weeks in the Gobi.
Dr. Brian Smith will be answering questions today from 3 pm-4 pm. You can ask Brian about his job, what it’s like to head into the field, his favorite bird, or anything else! Just tweet @amnh today with #AskACurator.
Dr. Brian Smith, an assistant curator of ornithology in the Division of Vertebrate Zoology at the American Museum of Natural History, will be answering your queries on September 17 from 3 to 4 pm EDT. Just tweet your questions to @amnh using the hashtag #AskaCurator.
His research focuses on the evolution of birds, and particularly on the avian tree of life. Just last week, his research about the speciation of birds in the Neotropics was published in the journal Nature.
Spiders of the genus Latrodectus are found worldwide, and in North America, black widows are among the few species harmful to people. Still, they’re web builders that stay in their retreats day and night. If you see one outside its web, it’s likely a male in search of a female. That trip can end badly. As their name suggests, female black widows sometimes eat males after mating.
Check me out: If I have a red hourglass on my underside, I’m a widow spider.
Species Range: From Canada to the warmer regions of the western U.S. and south to Mexico
Habitat: Terrestrial; crevices, including those in and around houses
Should you worry? Yes. I’m shy and my fangs are small, but my venom is potent. Black widow venom contains powerful chemicals called neurotoxins, including one specific to vertebrates like us. Once injected, the venom may flood nerve endings with chemical signals, causing paralysis.
Unlikely to Bite: Black widows are shy and tend not to bite humans unless disturbed. Most bites involve such a small amount of venom that the victim survives.
As the global climate changes, wild animals are shifting where they live—even beyond the protected areas that are crucial to their survival. This visualization highlights predictions and solutions for range shifts by an iconic species of North American wilderness, the wolverine.
Bighorn Sheep - September Morning, Alberta, Canada
Stalwart symbols of mountain wilderness, a “bachelor band” of bighorn sheep stands before Mount Athabasca in the Canadian Rockies. Male sheep older than two years leave their mothers to follow a leading ram. Horn and body size determine rank, so the leader of this band is certainly the ram on the right.
Equally sized males may duel to secure their rank. Rivals will repeatedly face off, charge and then crash horns until one loses balance and concedes. During the mating season, when rams fight for ewes, battles are even more violent. The collisions will echo across the ravines of the Rockies, and some contenders will even be pushed off the edge.