Sonntag, 17. September 2017

2017


Transformation Power Of The Seed

divers





Roman Ruins Discovered Underwater in Tunisia



Archaeologists recently discovered more than 50 acres (20 hectares) of Roman ruins submerged off the coast of northeastern Tunisia, believing they may have finally found convincing evidence that the city of Neapolis existed. Tunisian National Heritage Institute and the University of Sassari
Archaeologists recently discovered more than 50 acres (20 hectares) of Roman ruins submerged off the coast of northeastern Tunisia, believing they may have finally found convincing evidence that the city of Neapolis existed. Tunisian National Heritage Institute and the University of Sassari
Historians have long speculated about an epic disaster that leveled a city and killed thousands. But there's been little evidence to support that theory — until now.
Archaeologists recently discovered more than 50 acres (20 hectares) of Roman ruins off the coast of northeastern Tunisia, a small country on the northern tip of Africa and situated on the Mediterranean Sea. The discovery has researchers believing they may have finally found some convincing evidence that the city of Neapolis (not to be confused with the Italian city by the same name) was wiped out by a natural disaster about 1,650 years ago. In addition to streets and monuments, researchers found about 100 tanks that would have been used to produce a garum, a fish-based fermented condiment commonly consumed in ancient Rome.
"This discovery is important because it lends support to the theory that Tunisian Neapolis was submerged by a tsunami in the 4th century A.D. — a useful reminder that environmental catastrophe is not only a phenomenon of the modern world," Carlos F. Noreña, associate professor of history at the University of California, Berkeley, says in an email.
Scientists wrote in a 2013 study in the journal Nature that a tsunami was caused by an earthquake that occurred in 365 C.E. in Crete. There's no surefire way to know the extent of the quake since measuring tools didn't exist at the time, but scientists believe two separate tremors happened in succession and the larger one had a magnitude of 8.0 on the Richter scale. The resulting tsunami destroyed about 50,000 homes and killed approximately 5,000 people in the city of Alexandria, Egypt. And because the geological fault at the center of the earthquake was located off the coast of Crete, that Greek island was actually lifted up in certain areas by as much as 33 feet (10 meters).
Historian Ammianus Marcellinus recorded the event, and the newly found ruins reveal that there's much more to the story. "The discovery also illuminates the economy of Roman North Africa, and provides further evidence for the popularity of garum in the Roman diet," Noreña says. The detail is significant; garum was a big deal throughout the Roman Empire, and as Italian archaeologist Claudio Giardino told NPR, it played a major role in the society's economy.
"According [to] the Roman writers, a good bottle of garum could cost something like $500 today," he said. "But you can also have garum for slaves that is extremely cheap. So it is exactly like wine."
The underwater findings of Neapolis and its abundant manufacturing materials indicate that the city was a major historical hub. "This discovery has allowed us to establish with certainty that Neapolis was a major centre for the manufacture of garum and salt fish, probably the largest centre in the Roman world," head researcher Mounir Fantar, told AFP.
Neapolis — which means "new city" in Greek — was originally founded in the fifth century B.C.E., and various warring territories claimed ownership of it throughout its history. Experts believe that because the city failed to pledge allegiance to the Romans, there are very few written records documenting the details of life there. That means the new discovery is that much more important to understanding the full history of the era.
"Our picture of the Roman Empire tends to be dominated by Rome and the other major cities," Noreña says. "But it was in the smaller provincial centers such as Neapolis that the rhythms of everyday life in antiquity are to be found."





sat internet





Constellations of Internet Satellites Will Beam Broadband Everywhere



Satellites like this may enable people living far off the grid to receive some of the fastest internet service available in the next few years. SES Networks
Satellites like this may enable people living far off the grid to receive some of the fastest internet service available in the next few years. SES Networks
Almost all of the world's internet data zips from place to place through underground and undersea cables. Now, several companies are looking to the heavens to expand the web's capacity and bring broadband coverage to everyone in the world, including the billions of people worldwide who lack it.
SpaceX, OneWeb and LeoSat are in the early stages of launching hundreds, even thousands, of satellites to create an orbiting internet network. One company is already up there. SES Networks, headquartered in Betzdorf, Luxembourg, has 12 satellites circling the globe with four more due to launch in 2018 and another four on order. Its fleet is delivering high-throughput data services to diverse places, many of which are remote or impoverished and could not afford to install the infrastructure necessary to support cable fiber. Think the Cook Islands, East Timor, Papua New Guinea, Chad, Madagascar, Democratic Republic of Congo, South Sudan, the Caribbean and many others.
"In the rapid development of the company, we've been able to very quickly deliver high volume data to remote parts of the world and to enable them to connect to the internet, Facebook, Google, remote medical support, humanitarian aid, and more," says Stewart Sanders, executive vice president of technology for SES Networks.
"It's difficult to overestimate the social and economic benefits this has enabled for our customers," he says.

Internet From the Sky

The fleet of satellites have their origin in a company called O3b Networks, which SES acquired in 2016. Entrepreneur Greg Wyler founded O3b in 2007. Wyler spent the early 2000s setting up telecommunications in rural parts of Africa. While working with the post-war government of Rwanda to bring mobile phone service online, the entrepreneur began thinking about a better way to deliver to high bandwidth to the other 3 billion — hence "O3b" — people in the world who lacked access to the internet.
Because fiber was too expensive and vulnerable to breaks or power outages common in developing nations, Wyler considered using satellites. He wasn't interested in the kind already providing internet through companies like Dish Network and DirecTV. These companies have satellites flying about 22,000 miles (35,700 kilometers) above the equator in geosynchronous Earth orbit (GEO) — an orbit that has traditionally been used for telecommunications. At that height, the satellites beam signals that can cover huge swaths of the planet, nearly 2,000 miles (3,000 kilometers) wide at a time. But the distance creates a delay, or latency.
"People always talk about home usage and ask, 'What's my throughput? How much data am I pulling down?'" Sanders says. "But a key factor that affects performance and the user experience is latency."
Signals from geostationary satellites can take about 500 milliseconds (0.5 seconds) to travel down to Earth and back up again. This amount of latency isn't ideal for providing internet services.
Wyler settled on satellites that could fly at medium-Earth orbit (MEO), roughly 5,000 miles (8,000 kilometers) up, significantly lower than the geostationary orbit. At that lower height, latency is less than 150 milliseconds (0.15 seconds). The O3b fleet is now a part of SES Networks, which also flies more than 50 satellites in GEO.
Each MEO satellite has 12 beams, two of which are directed at gateways on the ground. Of the remaining 10 beams, five connect to one gateway beam and five to the other. These 10 beams are called user beams, and each one can provide a customer with up to 2 gigabits per second (Gbps) throughput. SES Networks has nine gateways installed around the world directly supporting the O3b MEO Fleet, and Sanders says that at any given time, a satellite in medium-Earth orbit can see multiple gateways.

Launch Party

In 2012, Wyler left O3b Networks to start up OneWeb, which in addition to SpaceX, wants to launch satellites into low-Earth orbit — 111 to 1,242 miles or 180 to 2,000 kilometers — where the lower orbit could enable even lower latency. It also reduces the time a satellite can "see" a gateway, so the number of satellites required for global coverage is significantly higher, and that increases the system's complexity.
In November 2016, SpaceX filed a proposal to launch 4,425 satellites into low-Earth orbit at 700 miles (1,110 kilometers) and higher above the planet.
Getting that many satellites into orbit will take time and money, says Sanders. "The launch costs alone will be a significant portion of the investment, and the technical challenges with the overall implementation will be significant," he says.
But SpaceX, as well as the rocket company Blue Origin, owned by Amazon's Jeff Bezos, are developing reusable rockets, which could bring that cost way down. SpaceX told Congress it intends to start its ambitious satellite launch campaign in 2019.
OneWeb intends to launch 720 LEO satellites into space, with plans to send up its first 10 craft in 2018. By 2019, the company aims to start providing low latency broadband in 2019.
As these space-based systems begin to come online, so too will the fifth generation of wireless service, known as 5G. This means that people now living in the most remote regions of the planet as well those living far off the grid may soon be receiving some of the fastest internet service available.
"I've been in this industry well over 30 years, and there's been more activity in the last five or so years, than probably in the previous 20," Sanders says. "It's incredible."