3 ms·
That’s the argument I think. Per that Wikipedia link: > Randall hypothesizes a plane of dark matter exists roughly on the plane of the Milky Way galaxy. As the
by ckcheng 3y ago
That’s the argument I think. Per that Wikipedia link:
> Randall hypothesizes a plane of dark matter exists roughly on the plane of the Milky Way galaxy. As the Sun oscillates in its orbit around the center of the galaxy, it passes through the dark matter.
- exe34 3y agoAh that's probably where I learnt it from then!
- jagged-chisel 3y agoWhat would cause the oscillation?
- roywiggins 3y agoIf you're not smack bang in the middle of the galactic plane, you're going to be accelerated towards it by gravity, so you'll tend to bob up and down, like a pendulum.
- cwillu 3y agoI'm not sure I buy that the oscillation around the plane can have a period other than the orbital period.
- partitioned 3y agodo you think motion in X is always dependent on motion in Y?
- tejtm 3y agoThe oscillations are not "around" the plane, they are through the plane. That is; the plane itself has a local gravitational attraction which is orthogonal to the galaxy core gravitational attraction. If a mass is above or below the plane, the "local" gravity will pull towards the plane. since nothing stops it at the mid line of the plane it passes through to the opposite side; rinse and repeat. This bouncing above and below center line of the disk is more or less independent of our solar system completing galactic orbits.
- jagged-chisel 3y agoThis is the best explanation IMO.
- cwillu 3y agoFair; the descriptions I've seen seem to focus on the galactic orbit more than the local neighbourhood as the cause of the oscillation; this makes more sense.
- shagie 3y agoThe Radcliffe wave is oscillating through the plane of the galaxy. https://en.wikipedia.org/wiki/Radcliffe_wave https://en.wikipedia.org/wiki/Radcliffe_wave And a recent paper on its oscillation - https://www.sci.news/astronomy/oscillating-radcliffe-wave-12719.html https://www.sci.news/astronomy/oscillating-radcliffe-wave-12...
- mattsan 3y agoI haven't done the math but I would think it's possible due to interactions from other solar systems. Similar to how satellites oscillate around Lagrange points
- exe34 3y agoThe up down oscillation is completely decoupled from the orbit itself, assuming the orbital potential is uniform. It's like the galaxy wasn't rotating at all. You put something above the disk, and it gets accelerated downwards, but doesn't stop at the disk, it keeps going, until it gets dragged back up. Think of it like a pendulum.
- truculent 3y agoWould we expect the oscillation to get smaller over time, like a pendulum, or is that stretching the analogy too far?
- exe34 3y agoThere might be some gas in the way that would slow it down slightly, but I expect that to be a very long time scale compared to other things like interactions with other systems and even the upcoming collision with Andromeda.