Discovered: Twitter memes foreseen with 95 percent certainty; detecting light from extinguished stars; sea levels rising faster than previously thought; deepest supernova observed.
Predicting Twitter trends. Anyone who spends enough time on Twitter will be familiar with its cycles. Something funny happens, everyone laughs for awhile, until a few hours later when they're so over the meme. Someone says something stupid, a bunch of people get upset, then a bunch of other people get upset at all the people who got so upset in the first place. Twitter might be a great place to find up-to-the-minute news and snarky one-liners, but it's rather predictable. So predictable, in fact, that Massachusetts Institue of Technology researchers led by Prof. Devavrat Shah were able to create an algorithm that knows which subjects will become Trending Topics with a 95 percent certainty. They're able to make this prediction an hour and a half before Twitter promotes the topics to its Trending list. Shah says his model is entirely impersonal. "The problem with this is, I don’t know that things that trend have a step function. There are a thousand things that could happen," he says. So he'd rather "just let the data decide." [MIT]
Detecting dead star light. Much of the light we observe in the night sky emanated from stars that died long ago. They'll eventually disappear from the stellar canopy when their light finishes reaching us from millions of light years away. But even when that happens, astronomers will still be able to detect lingering evidence of dead stars, thanks to new research on old light. Bright galaxies that in the distant universe can actually amplify this dead light by capturing old photons and gamma rays. By studying these "stellar fingerprints," astronomers hope to better understand the early universe as it formed over 13 billion years ago. "Detecting these stars is very important but currently impossible," says Standford University astrophysicist Marco Ajello, a coauthor of the new study. "In this way, we are already able to set constraints on the amount and role of these stars in the early universe." [ScienceNews]
NASA, DOE, Fermi LAT Collaboration
Deep space supernova. Speaking of astronomical objects from long ago, in galaxies far, far away, scientists have just detected the furthest supernova yet known to Earthlings. Jeff Cooke from Australia's Swinburne University of Technology and colleagues have been studying images taken by the Canada-France-Hawaii Telescope atop Mauna Kea in Hawaii. They were able to locate ever-so-faint evidence of a supernova in the galaxy located in the Sextans constellation. They calculated the supernova's redshift at 3.90, placing it 12.1 billion light-years away from Earth. That means it only survived 1.6 billion years after the Big Bang—a short life for a star indeed. "This is a very, very promising sign for what we can expect in the coming years," says astronomer Volker Bromm of the University of Texas, Austin. [ScienceNow]
Sea levels rising faster than predicted. We know sea levels are rising, but we may have to revise our thoughts on how fast they're rising. University of Colorado geologist Bill Hay thinks previous climate change models haven't taken full account of factors like Arctic sea ice, the Greenland ice cap, soil moisture, and groundwater mining, all of which could play significant feedback roles in causing water to rise more. "You can lose most of the Greenland ice cap in a few hundred years, not thousands, just under natural conditions," says Hay. "There's no telling how fast it can go with this spike of carbon dioxide we are adding to the atmosphere." A 2007 IPCC report predicted 2100 ocean levels to rise between 0.2 and 0.5 meters. Hay thinks that figure should be doubled. [The Geological Society of America]