Dark Matter's Really Big Mystery

by Roger Bourke White Jr., copyright July 2012


This essay was inspired by an article I read in the 16 Jun 12 Science News, At Home in the Universe: Astronomers lay bare the Milky Way’s biggest secrets by Alexandra Witze, which updated my information on the Milky Way, and then lead me to a mind-boggling insight: the dark matter that is controlling galaxy gravity has some really, really weird features to it.

The weirdness centers around the bar in bar galaxies, which, this article states, the Milky Way is. (This was news to me, what I'd learned in high school was the Milky Way was pure spiral.)

The weirdness is the stars in the bar part rotate cylindrically, as if they are rotating around the bar, not as if they are rotating around the center of the galaxy the way all the other stars do. From the article:

"Rich’s survey uncovered a curious feature of how the bar rotates: cylindrically, like a toilet roll holder, even as it spins with the pinwheel of the rest of the galaxy. This cylindrical rotation has been seen in other galaxies and could be common throughout the universe, the team wrote in March in the Astronomical Journal."

The more I thought about this, the stranger and stranger the implications became. This has become mind boggling.

Strange in many ways

The first strangeness of this is that it means there is a dark matter "bar" of some nature and it's hefty. It has so much mass that it influences the orbits of those stars in the bar much more than the rest of the galactic mass does.

The second strangeness is this is the only example I can think of of planetary or stellar bodies not orbiting around a point. Every other instance of orbiting is characterized by having an orbit around masses creating one or more centers of gravity that act like points. This bar is acting like a line, not a point. ...very strange.

The third strangeness is what's holding this bar in a bar shape? This dark matter bar has huge gravity and it's spanning 8,000 lightyears. Compare this to how much difficulty we have on earth just making buildings a mile high, and how we will be pushing the limits of the material strength that can be produced by atoms when we construct a "space elevator" a few thousand miles in length, and that rocky planetary bodies always get spherical when they get bigger than 500 miles across. This galactic bar is 8,000 lightyears in length and it's keeping a bar shape.

How does dark matter do this! How does it make a seemingly rigid structure of this weight and length? And one with a super massive black hole sitting dead center in the middle of it? Why doesn't that suck it in? This is truly freaky and mind boggling.

Conclusion: there are still some big mysteries to be solved in our universe.


--The End--