Rocks Cooled the Whole Planet 15 Million Years Ago

New indications as to what initiated a long phase of cooling in Earth’s climate and kept it going may debunk a long-held theory about the pre-ice-age cooling.

Fifteen million years ago, the Earth’s climate entered into a period of slow, continuous cooling, and simultaneously the Antarctic ice sheet grew steadily larger. Finally, around 2.5 million years ago, ice covered Greenland, thrusting the Earth into its current bipolar ice age.

Geoscientists have been debating what brought about this global cooling for many years. Some argue that major mountain ranges such as the Andes, the Himalayas, and the Alps started to form 15 million years ago, and that they accelerated erosion and the weathering of rocks. This theory posits that the formation of mountains drew more carbon dioxide (CO2) from the atmosphere than processes such as volcanic eruptions were giving off, causing temperatures to continuously decrease.

Researchers have now demonstrated that this hypothesis is not accurate enough. Read more.

Radiocarbon helps date ancient objects — but it’s not perfect

For nearly 70 years, archaeologists have been measuring carbon-14 levels to date sites and artifacts.

Nothing good can last — and in the case of carbon-14, a radioactive isotope found in Earth’s atmosphere, that’s great news for archaeologists.

Over time, carbon-14 decays in predictable ways. And with the help of radiocarbon dating, researchers can use that decay as a kind of clock that allows them to peer into the past and determine absolute dates for everything from wood to food, pollen, poop, and even dead animals and humans. Read more.

New Method Developed for Tracking Water Pollution Sources

The International Atomic Energy Agency and the University of Massachusetts have developed a new method for tracing the origin of nitrogen pollution in lakes, seas, and rivers. Their nuclear-derived analytical tool provides a cheaper, safer, faster way to determine whether excessive nitrogen compounds in water stem from agriculture, sewage systems, or industry, which will aid prevention and remediation efforts. Read more.

How prostate cancer cells mimic bone when they metastasize

Understanding this process could lead to innovative and improved therapies

Prostate cancer often becomes lethal as it spreads to the bones, and the process behind this deadly feature could potentially be turned against it as a target for bone-targeting radiation and potential new therapies. Read more.