Forbush Decreases

19 Sep 2014

At www.spaceweather.com September 18th .... on the 12th a CME hit Earth's magnetic field igniting an intense geomagnetic storm - and providing England with a week of summer temperatures. Students launched a helium Balloon into the stratosphere, expecting to measure lots more radiation than normal. Instead, them measured less - a lot less. Why?

Well, it seems that when the CME swept past the Earth it gathered up a lot of cosmic rays that normally occupy the upper atmosphere - sweeping them away. This process was first discovered in the 20th century by Scott Forbush.

Meanwhile, there are some lovely images of aurora produced by the CME. Not sure about copyright so you will have to visit the site (above). One of them is spectacular - an aurora (greenish blue) above an Icelandic volcano (a reddish tinge).

At http://phys.org/print330140352.html ... consensus theory has thought in terms of galaxy mergers largely resulting in elliptical galaxies. Now, radio telescopes have found evidence of merging galaxies from disc galaxies - and this is, apparently, quite common. Disc galaxies include spiral galaxies such as the Milky Way. They are defined by pancake shaped regions of dust and gas - why is food so often ued to describe astronomical features?

Needless to say it was a computer simulation that predicted mergers would result in elliptical galaxies - a fact that clashes with observational evidence that over 70 per cent of galaxies are in fact disc galaxies. See www.arxiv.org/abs/1407.6873