in acest caz participantii sunt migrenele, nu oamenii - adica are 110 "participanti" - insa numarul potrivit de subiecti pe studiu este dat de procedura statistica (care are parametri stricti, mai ales astea medicale) si rezultatele sale... si standardele jurnalului care publica dracovenia... pe mine, care n-am avut o migrena in viata mea, m-a convins
vezi ca sunt studii medicale (pe oameni, nu pe animalute care nu ti-au facut nimic) cu 15 participanti sau chiar mai putini
"Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma."
This last line implies that the drive may work by pushing against the ghostly cloud of particles and anti-particles that are constantly popping into being and disappearing again in empty space. But the Nasa team has avoided trying to explain its results in favour of simply reporting what it found: "This paper will not address the physics of the quantum vacuum plasma thruster, but instead will describe the test integration, test operations, and the results obtained from the test campaign."
However, it's fair to assume that the results will be picked over very closely indeed, like CERN's anomalous faster-than-light neutrinos. The neutrino issue was cleared up fairly quickly, but given that this appears to be at least the third independent propellant-less thruster to work in tests, the anomalous thrust may prove much harder to explain away.
A working microwave thruster would radically cut the cost of satellites and space stations and extend their working life, drive deep-space missions, and take astronauts to Mars in weeks rather than months.
A mere six months after civilian manufacturer 3D Systems debuted the world’s first 3D-printer that prints food at the Consumer Electronics Show in Las Vegas, the U.S. Army is making progress adapting food-printing technology for use by troops on deployment. Research teams at several Army installations, most notably the Natick Soldier Research, Development, and Engineering Center (NSRDEC) in Massachusetts, are working to develop 3D food printers that are customized for the rigors of areas of military operation.
It's not quite extraterrestrial life, but scientists have discovered sea plankton growing in space.
Russian space officials have confirmed traces of plankton and other micro-organisms were found living on the exterior of the International Space Station (ISS), and it appears they've been living there for years.
Space officials claimed the plankton were not carried there at launch, but are thought to have been blown over by air currents on Earth.
The particles, invisible to the naked eye, were able to survive in the vacuum of space, despite zero gravity, freezing temperatures, lack of oxygen, and cosmic radiation.
Although most of us worry about other things, climate scientists have become increasingly worried about the survival of civilization. For example, Lonnie Thompson, who received the U.S. National Medal of Science in 2010, said that virtually all climatologists "are now convinced that global warming poses a clear and present danger to civilization."
The burning of coal, oil, and natural gas has made the planet warmer than it had been since the rise of civilization 10,000 years ago. Civilization was made possible by the emergence about 12,000 years ago of the "Holocene" epoch, which turned out to be the Goldilocks zone - not too hot, not too cold. But now, says physicist Stefan Rahmstorf, "We are catapulting ourselves way out of the Holocene."
This catapult is dangerous, because we have no evidence civilization can long survive with significantly higher temperatures. And yet, the world is on a trajectory that would lead to an increase of 4C (7F) in this century. In the opinion of many scientists and the World Bank, this could happen as early as the 2060s.
What would "a 4C world" be like? According to Kevin Anderson of the Tyndall Centre for Climate Change Research (at the University of East Anglia), "during New York's summer heat waves the warmest days would be around 10-12C (18-21.6F) hotter [than today's]." Moreover, he has said, above an increase of 4C only about 10% of the human population will survive.
Masele de aer si curentii oceanici sunt sisteme haotice. Tipii sunt in stare sa faca o predictie rezonabila asupra evolutiei locale a vremii pe ~5 zile. Daca depasesc perioada asta erorile devin din ce in ce mai mari, si pe la ~10 zile deja au toate sansele sa rateze complet prognoza. De aceea, nu m-as hazarda chiar atat de tare pe chestia asta. Modelele alea care prezic evolutia temperaturii medii globale peste zeci/sute de ani pot sa fie niste tampenii totale.
Civilizatia e subminata de un pericol mult mai mare, anume prostia umana, iar eu unul nu sunt prea convins ca o eventuala evolutie nefavorabila a climei reprezinta una dintre fatetele ei. Ffs, perturbatiile gravitationale generate de celelalte planete din sistemul solar au zgaltait axa polara a planetei noastre si au provocat marile glaciatiuni. In comparatie cu asta, activitatea umana de la rasaritul epocii industriale incoace e un zbac insignifiant.
Desi sunt departe de a fi vreun specialist in vreun domeniu parca si eu am impresia ca vreun futai din asta colosal ce ar pune pe disparitie specia ar cam veni din exteriorul planetei. Pe mine ma fascineaza chestia aia cu http://en.wikipedia.org/wiki/Toba_catastrophe_theory, Toba catastrophe theory. Cand cica am ramas vreo 3-10 mii si am pus de un population bottleneck. Oare atunci am fost cel mai aproape de disparitie?
Waaagh! » 16 Jan 2015, 22:30 wrote: Modelele alea care prezic evolutia temperaturii medii globale peste zeci/sute de ani pot sa fie niste tampenii totale.
N-as prea crede, pentru ca in continuare se vor arde combustibili fosili iar concentratia de CO2 din atmosfera va creste. Deci cel mai probabil va creste si temperatura.
Somehow, most of the life on Earth perished in a brief moment of geologic time roughly 250 million years ago. Scientists call it the Permian-Triassic extinction or "the Great Dying" -- not to be confused with the better-known Cretaceous-Tertiary extinction that signaled the end of the dinosaurs 65 million years ago. Whatever happened during the Permian-Triassic period was much worse: No class of life was spared from the devastation. Trees, plants, lizards, proto-mammals, insects, fish, mollusks, and microbes -- all were nearly wiped out. Roughly 9 in 10 marine species and 7 in 10 land species vanished. Life on our planet almost came to an end.
