A few milligrams of all the scientific news of the week
Posted at 8:00 a.m.
Sunscreen and corals
Sunscreen was known to damage corals. Now we know why: because coral cells transform oxybenzone, an ingredient found in many sunscreens, into a phototoxin, which makes corals more sensitive to UV rays from the sun. In Australia, creams are banned from some beaches near the Great Barrier Reef. The results of this study, conducted by Stanford University, were published in the journal Science at the beginning of May.
Quiz
What effect does the absence of predators have on the chameleon?
Its colors are getting brighter, according to a new US-Australian study. Biologists from the Australian National University and the University of the Pacific in Hawaii have compared the liveliness of the skin of chameleons from Kenya (in their original habitat) and this US state (where they were accidentally introduced in the 1970s ). Big difference: chameleons have no predators in Hawaii. The researchers also compared the liveliness of adornments of other similar species of chameleons, birds and snakes in the two ecosystems. They also did field experiments in Hawaii with snakes and birds that are the Kenya chameleon’s predator. They found that even a brief encounter with the enemy alters the liveliness of his skin.
The number
16
This is the number of new pieces of space debris from the explosion in mid-April of a Russian rocket engine in elliptical orbit around the Earth, according to an analysis by the US Army Space Force released in early May. This engine, called SOZ, is used to finalize the position of the satellites. It is particularly prone to explosions because it contains a reserve of fuel, according to a Harvard University astrophysicist quoted by space.com. There are currently 64 SOZ engines in orbit, and 54 of them have already exploded. The one that exploded on April 15 was launched in 2007.
Detect earthquakes faster
Earthquakes larger than magnitude 8 on the Richter scale could be detected more quickly by satellites thanks to elastogravity, a wave traveling at the speed of light created by sudden changes in Earth’s gravity, according to researchers. CNRS researchers in France. French seismologists, who describe their results in mid-May in the journal Naturetested their strategy with data from the March 2011 Japanese earthquake. They conclude that the magnitude of an earthquake could be apparent in seconds rather than minutes, which is particularly important for tsunamis.
Good and bad news for breeders
Best Cattle Breeding Techniques Meet Greenhouse Gas Emissions Reduction Targets Consistent with Warming Limited to 1.5℃ by 2030, But Not by 2050, New Institute Study Says International Livestock Research in Kenya. These techniques, adopted almost mainly by rich countries, make it possible to reduce methane emissions by 12% per kilogram of milk or meat. But the expected increase in demand for dairy and beef products in emerging countries means that these techniques will not suffice in the long term, according to the study published in mid-May in the journal PNAS.