You are here
When most people think of a rocket launch, they think big. The Space Shuttle, Falcon 9, and Atlas V all stand well over 50 meters tall, and any of those would tower above the Statue of Liberty. They were made to lift heavy things, weighing anywhere from 10 tons to considerably larger, into orbit around Earth. But in recent years there has been a lot of noise in the small rocket industry, promising cheap, expendable boosters capable of carrying a few hundred kilograms into space.
As always in the aerospace industry, some of these efforts were overhyped or had wildly optimistic timelines. For example, the industry suffered a notable failure late last year when Firefly Space Systems declared bankruptcy. However, a number of other companies have made tangible progress this year, making it clear that this generation of small satellite launch vehicles is closing in on their first commercial flights.
It's an idea that could transform our understanding of how humans went from small bands of hunter-gatherers to farmers and urbanites. Until recently, anthropologists believed cities and farms emerged about 9,000 years ago in the Mediterranean and Middle East. But now a team of interdisciplinary researchers has gathered evidence showing how civilization as we know it may have emerged at the equator, in tropical forests. Not only that, but people started farming about 30,000 years earlier than we thought.
For centuries, archaeologists believed that ancient people couldn't live in tropical jungles. The environment was simply too harsh and challenging, they thought. As a result, scientists simply didn't look for clues of ancient civilizations in the tropics. Instead, they turned their attention to the Middle East, where we have ample evidence that hunter-gatherers settled down in farming villages 9,000 years ago during a period dubbed the "Neolithic revolution." Eventually, these farmers' offspring built the ziggurats of Mesopotamia and the great pyramids of Egypt. It seemed certain that city life came from these places and spread from there around the world.
But now that story seems increasingly uncertain. In an article published in Nature Plants, Max Planck Institute archaeologist Patrick Roberts and his colleagues explain that cities and farms are far older than we think. Using techniques ranging from genetic sampling of forest ecosystems, to soil analysis and lidar, the researchers have found ample evidence that people at the equator were actively changing the natural world to make it more human-centric. It all started about 45,000 years ago. People burned down vegetation to make room for crops and homes; they mixed specialized soils for growing plants; they drained swamps for agriculture; they domesticated animals like chickens; and they farmed yam, taro, sweet potato, chili pepper, black pepper, mango, and bananas.
Java and C continue to lead the Tiobe index of programming language popularity, but both dropped to all-time lows in the just-published August release of the index.
The longtime leaders have had to share the programming landscape with a growing number of language options attracting developers, which has caused their slippage in the index. Java’s rating this month was 12.961 percent, a drop of more than six percentage points since August 2016, while C’s rating was 6.477 percent, a year-over-year drop of nearly five points. Java’s rating last month was 13.774 percent while C was rated at 7.321 percent.
Neutrinos are noted for being extremely reluctant to interact with other matter. While it's possible to build hardware that will detect them, these detectors tend to be enormous in order to provide sufficient material for the neutrinos to interact with. Those interactions also take the form of energetic events that transform the identity of particles (for example, converting protons to neutrons).
Given the neutrino's low mass and tendency not to interact, the idea of detecting one simply bumping into another particle seems almost ludicrous. But that's what scientists from Oak Ridge National Lab are reporting today. They've seen brief flashes as atoms get nudged by a neutrino, which imparts a tiny bit of its tiny momentum to the atom's nucleus.
Oak Ridge National Lab is home to some hardware called the Spallation Neutron Source. This accelerates a beam of protons and smashes them into a tank of mercury. This creates debris that includes lots of neutrons, which are used for a variety of scientific purposes. But the debris also includes some neutrinos that are otherwise lost in the spray of particles that come flowing out of the collisions.