Another installment in the Sixty Symbols series. I love the chaos inherent in this system and the simple underlying explanation.
In the matter of Walter Lewin, MIT goes medieval
13 hours ago in The Curious Wavefunction
One of the biggest questions about this financial crisis gripping our economy: How did it happen? Wasn't someone supposed to watching things? Making sure people were acting prudently? Stopping, say, the largest insurance company in the world from making a 185 billion dollar bet that it couldn't make good on? This week, we hear the stories of the people who were supposed to be overseeing things.
In an isolated sector of our solar system suspended in orbit from the sixth planet from our sun lies a distant outpost. A technologically perfect world where mistakes are impossible because the impossible is unthinkable. It is called Saturn 3...
The theory of planet formation has evolved significantly with the detection of more than 300 planets orbiting nearby stars. However, half of stars similar to the Sun are members of binary or multiple star systems. A function of the binary star separation, evolution from the planetesimal to planet embryo stage faces some significant dynamical challenges and is not expected to occur for binary stars with close separations. Contradicting standard theory, a few planets have now been discovered even in close binary systems and provides an impetus to reconsider mechanisms for planet formation in these challenging environments.The problem observers often face is finding a suitable target to invest intensive observing resources towards (and of course the other problem is having too many targets). There are clues from where past planets have been found, as mentioned above, and from theories of planet formation as the article explains
No one yet knows for certain precisely how planets form, but the process seems to be a complex chain reaction that is highly dependent upon initial conditions. It begins with the creation of a star, which forms from a gravitationally collapsing cloud of gas and dust. The leftovers flatten out, due to the conservation of angular momentum, forming a spinning disk of material. To create a rocky world like Earth, dust must condense in the disk to form grains, grains must settle to form pebbles and rocks, and rocks must collide to form planetesimals, kilometer-sized objects that can gravitationally attract each other. These planetesimals must collide to form embryos, Moon-sized objects that collide in turn to finally form a planet.Fischer and many others (a team including Greg Laughlin who runs a blog on exoplanets, Systemic) have realized that the Alpha Centauri system's proximity make it a serendipitously excellent target for observing. There remain doubts as to whether a suitable planet can form in this particular binary system, but regardless the observing has begun. The team will be looking for doppler shifts in the motion of the two stars to determine if other massive bodies (a planet) are perturbing the orbit of the stars. It will be a cosmic starring contest lasting several years.