For the full story, visit: http://news.berkeley.edu/2016/05/11/star-has-four-mini-neptunes-orbiting-in-lock-step/ A four-planet system observed several years ago by the Kepler spacecraft is actually a rarity: Its planets, all miniature Neptunes nestled close to the star, are orbiting in a unique resonance that has been locked in for billions of years. For every three orbits of the outermost planet, the second orbits four times, the third six times and the innermost eight times. Such orbital resonances are not uncommon – our own dwarf planet Pluto orbits the sun twice during the same period that Neptune completes three orbits – but a four-planet resonance is. Astronomers from the University of Chicago and University of California, Berkeley, who are reporting the discovery online May 11 in Nature, are particularly interested in this stellar system because our system’s four giant planets – Jupiter, Saturn, Neptune and Uranus – are thought to have once been in resonant orbits that were disrupted sometime during their 4.5-billion-year history. According to co-author Howard Isaacson, a UC Berkeley research astronomer, the Kepler-223 star system can help us understand how our solar system and other stellar systems discovered in the past few decades formed. In particular, it could help resolve the question of whether planets stay in the same place they formed, or whether they move closer to or farther from their star over the eons. ...

Physics 111 Advanced Laboratory. Professor Sumner Davis Modern condensed matter physics began in 1912 when Laue, Friedrich, and Knipping presented a paper on the diffraction of x-rays by crystals. They proved that crystals are periodic lattices of atoms, and ever since then this periodicity has been invaluable to studies of condensed matter. In the experiment you observe first hand the diffraction of x-rays, and will learn about crystallography. The equipment is a commercial instrument all in one package. http://advancedlab.org