Re:All disk galaxies rotate once every billion years: study
by semi-extrinsic on Wednesday March 14, 2018 @02:04PM
(#16586884)
This situation is trivially detectable though. Simply plot the inclination angle of disc galaxies as a function of azimuth and inclination, if it's like you say, there will be a very clear banded structure.
Re:All disk galaxies rotate once every billion years: study
by tossandturn on Wednesday March 14, 2018 @02:07PM
(#16586911)
That analogy does not hold up when the CD you are observing from is in the same plane as all the others.
Re:All disk galaxies rotate once every billion years: study
by jl6 on Wednesday March 14, 2018 @02:08PM
(#16586917)
I suspect that in your example you would observe a number of different apparent orientations, but that there would be some types of apparent orientation that could never occur.
Re:All disk galaxies rotate once every billion years: study
by sosuke on Wednesday March 14, 2018 @01:49PM
(#16586749)
That boggles my mind, do you have any sources I can read to start digging into on this?
Not sure why a question like this would be voted down but my own searches have only turned up articles about galaxies spinning in the same direction.
Someone else commented with some clarification. https://news.ycombinator.com/item?id=16586901
(Imagine standing in a room with a bunch of CDs suspended horizontally from the ceiling. From any vantage point you can see some CDs edge-on, some from the top, some from the bottom, etc. But they're all oriented in the same direction.)