The first intriguing findings have been released from the Dark Energy Survey, a project that's studying the sky to find clues about the mysterious force that seems to be accelerating the expansion of the universe. And among the data is the discovery of 11 new stellar streams, the remains of smaller galaxies that our own Milky Way has torn to shreds.In the late 1990s, it was discovered that the expansion of the universe is accelerating. That goes against the previous prevailing ideas of Einstein's theory of General Relativity, which stated that expansion should be slowing down thanks to gravity. Physicists coined the term "dark energy" to refer to the unknown force that seems to be driving the acceleration, and apparently contributes more than 68 percent of the total energy in the universe. While there is some argument that dark energy doesn't exist, it is currently the most accepted idea to explain these observations.The Dark Energy Survey (DES) was launched in 2013 to try to learn more about the strange phenomenon, and the results from the first three years of that project were released to the public at the American Astronomical Society meeting last week. That data dump includes hundreds of terabytes of images snapped by the 570-megapixel Dark Energy Camera that cover an eighth of the entire sky through about 40,000 photos, as well as catalogs describing hundreds of millions of stars and galaxies."There are all kinds of discoveries waiting to be found in the data," says Brian Yanny, a data management project scientist on DES. "While DES scientists are focused on using it to learn about dark energy, we wanted to enable astronomers to explore these images in new ways, to improve our understanding of the universe."

 

In today's concrete jungle, pavement takes up a lot of space, so we might as well cram some smarts in there. Previously we've seen ground coverings that light up, absorb solar energy, generate electricity from the footsteps of pedestrians, and even emit Wi-Fi signals. Now NASA is combining a little of all of those in a high-tech new path due to greet visitors to the Kennedy Space Center.

The US$2 million installation is made up of about 1,000 tiles spread across 40,000 square feet (3,700 sq m). These tiles form mosaic images of Earth, Mars, the Moon and the International Space Station, but it's what's inside that counts.

Each tile contains circuit boards, six small solar panels, a battery, LEDs, a Bluetooth and a Wi-Fi transmitter, micro controllers and a piezoelectric element. All of this is encased in cavities in thin, high-performance concrete and topped off with a strong glass tile. Piezoelectric systems generate energy from mechanical stress, and in this case that means footsteps.

 

"No one has made anything like this — an outdoor tile system using a piezoelectric element to trigger customized and off-the-shelf electronics and coupling them for human interactions," says Ilan Stern, senior research scientist at Georgia Tech, which is collaborating with NASA on the project. "When you step on the load-bearing glass tile, it compresses the piezoelectric element, creating an electrical charge that lights up the cavity's 125 LEDs."

Along with lighting up in a variety of colors, the tiles can also beam a wireless signal to the phones of passersby to deliver nuggets of wisdom on NASA's space missions, the mechanics of piezoelectric technology, and other things.