An anonymous reader quotes a report from the BBC: A healthy baby girl has been born using a womb transplanted from a dead person. The 10-hour transplant operation -- and later fertility treatment -- took place in Sao Paulo, Brazil, in 2016. The mother, 32, was born without a womb. There have been 39 womb transplants using a live donor, including mothers donating their womb to their daughter, resulting in 11 babies. But the 10 previous transplants from a dead donor have failed or resulted in miscarriage. In this case, reported in The Lancet, the womb donor was a mother of three in her mid-40s who died from bleeding on the brain. The recipient reportedly had Mayer-Rokitansky-Kuster-Hauser syndrome, which affects about one in every 4,500 women and results in the vagina and uterus (womb) failing to form properly.

The baby girl was delivered by Caesarean section on December 15, 2017, weighing 6 pounds (2.5kg).

On Wednesday, SpaceX successfully sent a Dragon spacecraft to the International Space Station to deliver supplies, but unfortunately it wasn't able to recover the Falcon 9 rocket that launched with it. "The first stage of the Falcon 9 launch vehicle appeared to lose control as it approached Landing Zone 1 at Cape Canaveral," reports CNET. "The live feed from the rocket cut away on the SpaceX webcast, but video from people in the media area at the cape showed the Falcon 9 appearing to regain control before making an unplanned landing in the water rather than ashore at the landing area." From the report: Musk tweeted shortly afterward that cutting the live feed "was a mistake" and shared the full clip of the water landing from the rocket's perspective. The rocket took off from Kennedy Space Center in Florida at 1:16 p.m. local time, a little more than 48 hours after SpaceX sent another Falcon 9 to space from the West Coast on Monday. Dragon's flight to low-Earth orbit was supposed to happen Tuesday, but the mission was pushed back a day to replace some food being sent to the space station for experimental mice living there.

SpaceX had planned to land the first stage of the brand-new Block 5 Falcon 9 rocket at a landing zone ashore at Cape Canaveral, but as the rocket descended toward the cape, the live feed from the booster's onboard cameras appeared to show the craft going into some sort of uncontrolled spin. Musk tweeted that the problem was that a "grid fin hydraulic pump stalled, so Falcon landed just out to sea." Musk also tweeted that the pump that failed didn't have a backup because "landing is considered ground safety critical, but not mission critical. Given this event, we will likely add a backup pump & lines."

One of the most galling mysteries in physics is that of the dark matter and dark energy. Scientists believe that together, these could account for up to 95 percent of the total mass in the universe. Now, a researcher at the University of Oxford says a new theory could explain all that "dark phenomena." From a report: The two mysterious dark substances can only be inferred from gravitational effects. Dark matter may be an invisible material, but it exerts a gravitational force on surrounding matter that we can measure. Dark energy is a repulsive force that makes the universe expand at an accelerating rate. The two have always been treated as separate phenomena. But my new study, published in Astronomy and Astrophysics, suggests they may both be part of the same strange concept -- a single, unified "dark fluid" of negative masses.

Negative masses are a hypothetical form of matter that would have a type of negative gravity -- repelling all other material around them. Unlike familiar positive mass matter, if a negative mass was pushed, it would accelerate towards you rather than away from you. Negative masses are not a new idea in cosmology. Just like normal matter, negative mass particles would become more spread out as the universe expands -- meaning that their repulsive force would become weaker over time. However, studies have shown that the force driving the accelerating expansion of the universe is relentlessly constant. This inconsistency has previously led researchers to abandon this idea. If a dark fluid exists, it should not thin out over time.

In the new study, I propose a modification to Einstein's theory of general relativity to allow negative masses to not only exist, but to be created continuously. "Matter creation" was already included in an early alternative theory to the Big Bang, known as the Steady State model. The main assumption was that (positive mass) matter was continuously created to replenish material as the universe expands. We now know from observational evidence that this is incorrect. However, that doesn't mean that negative mass matter can't be continuously created. I show that this assumed dark fluid is never spread too thinly. Instead it behaves exactly like dark energy.