Dimitar Sasselov: How we found hundreds of potential Earth-like planets. New-planet Boom Faces a Budget Bust. When the mission was planned, astronomers assumed that natural variations in the light detected by Kepler would be much as variations in our sun’s light. But Kepler taught them something new. On average, starlight appeared to vary twice as much as sunlight. “Kepler is rewriting the textbooks,” Gilliland says. That was an important scientific finding but an ominous turn for the mission. Last June Gilliland reported at an American Astronomical Society meeting in Boston that the unanticipated variation in starlight means Kepler has to make more observations to complete the survey of its little patch of sky. It can still do what it is supposed to do, but it needs more time.
The Kepler team estimates that the telescope will now need about eight years to complete what was originally planned to be a 3.5-year mission. The annual cost to salvage the mission would be relatively small—$17 to $20 million, about what NASA spent on a new toilet for the International Space Station. . — Andrew Grant. Rare Earth: Why Complex Life is Uncommon in the Universe / Peter D. Ward and Donald Brownlee. It is said that one of the most important skills a physicist needs is the ability to quickly make “back-of-the-envelope” calculations. For example, Jan Wolitzky (in Jon Bently's Programming Pearls) tells about Enrico Fermi, Robert Oppenheimer, and the other Manhattan Project brass who were behind a low blast wall awaiting the detonation of the first nuclear device from a few thousand yards away.
Fermi was tearing up sheets of paper into little pieces, which he tossed into the air when he saw the flash. After the shock wave passed, he paced off the distance traveled by the paper shreds, performed a quick “back-of-the-envelope” calculation, and arrived at a figure for the explosive yield of the bomb, which was confirmed much later by expensive monitoring equipment. But expensive monitoring equipment which can confirm the calculation does not always exist, and hence in some fields, our entire knowledge is based on back-of-the-envelope calculations and rough estimates. 'Earth-like' Planets May Be Nothing Like Earth. This past year there have been hundreds of news reports about the discovery of so-called “Earth-like” planets. Only a month ago, a team of researchers announced that a super-Earth class planet called GJ667C is close enough to its orange dwarf star to have surface oceans. Two months earlier, Kepler-22b was widely reported as the smallest planet yet found to orbit in the middle of the habitable zone of a sun-like star.
The planet is about 2.4 times the radius of Earth making it a big ball of rock (presumably). PHOTOS: Exquisite Exoplanetary Art The ultimate goal of NASA’s Kepler mission it to give us a statistical estimate for the abundance of Earth-sized planets in stellar habitable zones across our galaxy. Now let me toss out another huge qualifier: Not all rocky planets are made from exactly the same recipe. In a recent Astrophysical Journal Letter Jade C. Other stars have proportionally different abundances of elements. ANALYSIS: Big Question for 2012: Will We Find Earth 2.0? Brian Greene: Is our universe the only universe? George Smoot on the design of the universe. The Mediocre Universe. Tufts University is understandably a little ambivalent about its Antigravity Rock.
On the plus side, it’s not an unattractive boulder, as boulders go; it has a catchy name and bears a handsome inscription; and it came with a modest research grant. Unfortunately, it doesn’t float, the inscription on its plaque posits an unlikely relationship between antigravity and safe airplane flight, and the money is available only for research on antigravity. Alexander Vilenkin is one Tufts faculty member who believes the pros outweigh the cons. In fact, he rarely fails to offer visitors the opportunity to stroll across campus to check the boulder out. Many accept, the alternative being to stay in Vilenkin’s modest, slightly cheesy office and sit in his Metastable Chair, a rickety piece of furniture that affords a fair chance of experiencing the rush of gravity firsthand.
Vilenkin seems to enjoy the air of wry surrealism that these gravity-related attractions lend his existence. Then there’s Tufts.