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Domain: scitation.org
Stories and comments across the archive that link to scitation.org.
Stories · 2
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Mercury -- Not Venus -- is the Closest Planet To Earth on Average, New Research Finds (gizmodo.com)
That's the finding presented by a team of scientists who have published their results this week in an article in the magazine Physics Today. From a report: They explain that our methods of calculating which planet is "the closest" oversimplifies the matter. But that's not all. "Further, Mercury is the closest neighbor, on average, to each of the other seven planets in the solar system," they write. Wait -- what?
Our misconceptions about how close the planets are to one another comes from the way we usually estimate the distances to other planets. Normally, we calculate the average distance from the planet to the Sun. The Earth's average distance is 1 astronomical unit (AU), while Venus' is around 0.72 AU. If you subtract one from the other, you calculate the average distance from Earth to Venus as 0.28 AU, the smallest distance for any pair of planets. But a trio of researchers realized that this isn't an accurate way to calculate the distances to planets. After all, Earth spends just as much time on the opposite side of its orbit from Venus, placing it 1.72 AU away.
One must instead average the distance between every point along one planet's orbit and every point along the other planet's orbit. The researchers ran a simulation based on two assumptions: that the planets' orbits were approximately circular, and that their orbits weren't at an angle relative to one another. -
Scientists Accidentally Blow Up Their Lab With Strongest Indoor Magnetic Field Ever (vice.com)
An anonymous reader quotes a report from Motherboard: Earlier this year, researchers at the University of Tokyo accidentally created the strongest controllable magnetic field in history and blew the doors of their lab in the process. As detailed in a paper recently published in the Review of Scientific Instruments, the researchers produced the magnetic field to test the material properties of a new generator system. They were expecting to reach peak magnetic field intensities of around 700 Teslas, but the machine instead produced a peak of 1,200 Teslas. (For the sake of comparison, a refrigerator magnet has about 0.01 Tesla)
In both the Japanese and Russian experiments, the magnetic fields were generated using a technique called electromagnetic flux-compression. This technique causes a brief spike in the strength of the magnetic field by rapidly "squeezing" it to a smaller size. [...] Instead of using TNT to generate their magnetic field, the Japanese researchers dumped a massive amount of energy -- 3.2 megajoules -- into the generator to cause a weak magnetic field produced by a small coil to rapidly compress at a speed of about 20,000 miles per hour. This involves feeding 4 million amps of current through the generator, which is several thousand times more than a lightning bolt. When this coil is compressed as small as it will go, it bounces back. This produces a powerful shockwave that destroyed the coil and much of the generator. To protect themselves from the shockwave, the Japanese researchers built an iron cage for the generator. However they only built it to withstand about 700 Teslas, so the shockwave from the 1,200 Teslas ended up blowing out the door to the enclosure. While this is the strongest magnetic filed ever generated in a controlled, indoor environment, the strongest magnetic field produced in history belongs to some Russian researchers who created a 2,800 Tesla magnetic field in 2001.