From cave painters to Greek sculptors to post-modern filmmakers, humanity has always had its share of artists. Now, there's evidence that humans were decorating things thousands of years earlier than we thought.
Archaeologists have uncovered what they believe is a 100,000-year-old paint workshop in Blombos Cave, South Africa, about 186 miles east of Cape Town. The discovery, discussed in the journal Science, indicates that our early Homo sapien ancestors had a basic knowledge of chemistry and the ability to make long-term plans.
"This image of galaxy cluster MACS J1206.2-0847 (or MACS 1206 for short) is part of a broad survey with NASA's Hubble Space Telescope.
The distorted shapes in the cluster are distant galaxies from which the light is bent by the gravitational pull of an invisible material called dark matter within the cluster of galaxies. This cluster is an early target in a survey that will allow astronomers to construct the most detailed dark matter maps of more galaxy clusters than ever before.
These maps are being used to test previous, but surprising, results that suggest that dark matter is more densely packed inside clusters than some models predict. This might mean that galaxy cluster assembly began earlier than commonly thought.
The multi-wavelength survey, called the Cluster Lensing And Supernova survey with Hubble (CLASH), probes, with unparalleled precision, the distribution of dark matter in 25 massive clusters of galaxies. So far, the CLASH team has completed observations of six of the 25 clusters.
Dark matter makes up the bulk of the universe's mass, yet it can only be detected by measuring how its gravity tugs on visible matter and warps space like a fun-house mirror so that the light from distant objects is distorted.
Galaxy clusters like MACS 1206 are perfect laboratories for studying dark matter's gravitational effects because they are the most massive structures in the universe. Because of their heft, the clusters act like giant cosmic lenses, magnifying, distorting and bending any light that passes through them — an effect known as gravitational lensing.
MACS 1206 lies 4.5 billion light-years from Earth. Hubble's keen vision helped CLASH astronomers uncover 47 multiple images of 12 newly identified faraway galaxies. Finding so many multiple images in a cluster is a unique capability of Hubble, and the CLASH survey is optimized to find them. The new observations build on earlier work by Hubble and ground-based telescopes.
The era when the first clusters formed is not precisely known, but is estimated to be at least 9 billion years ago and possibly as far back as 12 billion years ago. If most of the clusters in the CLASH survey are found to have excessively high accumulations of dark matter in their central cores, then it may yield new clues to the early stages in the origin of structure in the universe."Source: NASA
As the rains raged on in 1340s Europe, most of the crops rotted, leading to food shortages in a colder environment. Amidst the malnourished population, rodents, fleas and perhaps even lice were spreading a disease that had most likely never before infected humankind, and would wipe out up to half of Europe within five years.
This is the vision of the Black Death that scientists put forth in a new study in the journal Nature. For the first time ever, they have reconstructed the genome of an ancient disease based on skeletal remains.
They found out that the medieval plague is not so genetically different from its modern descendant, a disease that exists today in certain parts of the world. They are both caused by variations of the bacteria strain Yersinia pestis but the kind they discovered in the medieval remains appears to no longer exist.