Merging beliefs requires the plausibility of the sources of the information to be merged. They are typically assumed equally reliable in lack of hints indicating otherwise; yet, a recent line of research spun from the idea of deriving this information from the revision process itself. In particular, the history of previous revisions and previous merging examples provide information for performing subsequent mergings. Yet, no examples or previous revisions may be available. In spite of the apparent lack of information, something can still be inferred by a try-and-check approach: a relative reliability ordering is assumed, the merging process is performed based on it, and the result is compared with the original information. The outcome of this check may be incoherent with the initial assumption, like when a completely reliable source is rejected some of the information it provided. In such cases, the reliability ordering assumed in the first place can be excluded from consideration. The first theorem of this article proves that such a scenario is indeed possible. Other results are obtained under various definition of reliability and merging.

SpaceX has successfully landed a rocket on a floating platform in the Atlantic Ocean, for the second month in a row, following a Japanese satellite mission. The unmanned SpaceX rocket blasted off from Florida early this morning to put the communications satellite into orbit, with the launch vehicle's main-stage booster completing a quick return landing on the floating platform. Due to the high altitude of the mission, SpaceX did not expect a successful landing, but the Falcon 9 rocket touched down on the drone platform - nicknamed Of Course I Still Love You - just over eight minutes after launching. SpaceX has successfully landed a rocket on a floating platform in the Atlantic Ocean after a delivering a Japanese satellite into orbit early this morning, and is the second rocket to successfully land in the space of a month. A company webcast showed the 23-story-tall rocketsoaring off a seaside launch pad at Cape Canaveral Air ForceStation at 1:21 am EDT (06:21 BST).

Robot Wars will soon back on TV in the UK, and a very similar battle is heading for the country's seas. The British Royal Navy will be holding a demonstration of unmanned technology off the coast of Scotland this autumn. And during the event, one company will be trialling the world's first unmanned aerial vehicle (UAV) capable of landing autonomously on a moving ship. The British Royal Navy will be holding a demonstration of unmanned technology off the coast of Scotland this autumn. One company, Roke, will be trialling the world's first unmanned aerial vehicle (UAV) capable of landing autonomously on a moving ship (test phases pictured) The machines will compete in their very own version of'robot wars' to demonstrate they could be part of the Navy's future.

Second stage continuing to carry JCSAT-14 to a Geosynchronous Transfer Orbit. This is the second successful touchdown in a row on a floating platform, after the last one in April. There were previously four failed attempts. SpaceX also made a successful landing on a ground-based pad in December. About two and a half minutes after the launch, the rocket's first stage was scheduled to shut down and separate, leaving the second stage to deliver the satellite into its intended orbit more than 25,000 miles (40,000 km) above the Earth.

One month after landing its first-stage rocket booster on a drone ship, SpaceX repeated the feat and launched a commercial communications satellite late Thursday night. SpaceX's Falcon 9 rocket was launched at 10:21 p.m. PST from Cape Canaveral Air Force Station in Florida, and video of the event was streamed live. Weather conditions pushed the launch from Wednesday to Thursday. The Falcon 9 rocket carried the JCSAT-14 satellite into a geosynchronous transfer orbit. The satellite, operated by the Japanese communications company SKY Perfect JSAT Corp., will replace another of the firm's satellites and provide coverage to Asia, Oceania, Russia and the Pacific Islands.

On Friday, Space Exploration Technologies Corp. founder Elon Musk will try to repeat a successful attempt to pitch a SpaceX rocket from the Florida coastline to a robotic platform floating 200 miles away in the Atlantic Ocean. This time, however, the company's Falcon 9 rocket will be moving much faster than the one that deftly kissed the floating landing platform last month when SpaceX made aerospace history. The April 8 landing, part of the CRS-8 Dragon mission that delivered a payload to the International Space Station, proved Musk's idea that first-stage rockets can be recovered and reused instead of dropped into the ocean like very expensive garbage. But this idea is still in its experimental stage and would require repeated successes to become part of normal operating procedures. If the process is repeatable using the same first-stage rocket, it promises to significantly lower the cost of sending satellites, astronauts and other payloads into orbit.

SpaceX founder Elon Musk plans to send a capsule to Mars in 2018. The company is going to send one of its Dragon capsules - in this case known as the Red Dragon - to the planet. It won't carry any astronauts with it, but represents Mr Musk's first step towards his ultimate plan of colonising Mars. For now, the Dragon is too small to carry astronauts further than the Moon, he said, since it is about the size of a large family car. "Wouldn't be fun for longer journeys," Mr Musk explained in a tweet.

Nimble-fingered robots that exactly mimic the movements of a human hand could soon be used to help decommission nuclear power stations. Remote-controlled robots with hand-like manipulators are used in many situations that are difficult or dangerous for humans, such as bomb disposal. However, their movements are typically controlled by human operators via joysticks, which limits their dexterity. To address this, Miika Perä and Hamid Reza Zaheri at London firm Cambrian Intelligence have built a system that lets robotic arms and hands emulate hand movements exactly. To guide the robot, a human carries out the desired actions either in front of a video camera or while wearing a glove that captures movement.

A robot assistant lifeguard called EMILY is making waves by helping migrants cross the Mediterranean Sea safely. In the wake of unrest, over 500 refugees have drowned attempting to cross the Mediterranean from Turkey to Greece. Members from the Texas A&M Engineering Experiment Station's (TEES) Center for Robot-Assisted Search and Rescue (CRASAR) and Roboticists Without Borders gathered at the Greek island of Lesvos to assist the local Coast Guard and lifeguard organizations to prevent this from happening in the future. Dr. Robin Murphy, Raytheon Professor in the Department of Computer Science and Engineering at Texas A&M University, aided authorities in Lesvos alongside CRASAR, of which she is an active member. She is working with students to continually improve the lifesaving device, which can carry up to eight people at once.

Nasa has announced that it has found evidence of flowing water on Mars. Scientists have long speculated that Recurring Slope Lineae -- or dark patches -- on Mars were made up of briny water but the new findings prove that those patches are caused by liquid water, which it has established by finding hydrated salts. Several hundred camped outside the London store in Covent Garden. The 6s will have new features like a vastly improved camera and a pressure-sensitive "3D Touch" display