I came across a fascinating article in Scientific American the other day. It was "The Dark Side of the Milky Way" written by Leo Blitz, a professor at the University of California, Berkeley and a former director of the Radio Astronomy Laboratory. The article appears in the October 2011 issue on pages 36 to 45.
The article describes how the Milky Way disc is warped, not flat, and that that this warped condition is unstable meaning that the galaxy is undergoing a ringing effect as if it were some kind of gong. This is tied by the author into issues of dark matter and satellite galaxies.
Of course, I suggest you find and read the article itself rather than my trying to explain things here.
The oscillation that causes the apparent warp is said to consist of three frequencies, the lowest of which is 64 octaves below middle C.
Really?? Just how slow is that I started to wonder so taking sixty seconds to each minute, sixty minutes to each hour, twenty-four hours to each day and three-hundred and sixty-five days to each year, the answer comes out like this:
The period of galactic oscillation is somewhat more than two billion years.
Sometimes, a "gee whiz" just isn't enough.
Fascinating. I'm curious to find the article and find out how they made these exquisitely fine measurements and what the relationship among the 3 frequencies is. Thanks for the post John.
Posted by: Jack Lubowsky | November 19, 2015 at 07:18 PM