Do spiral galaxies and cyclones follow the same equations?

[Zeynel]

There’s an obvious resemblance between a spiral galaxy and a cyclone. They have the same spiral shape. I was wondering if the equations describing both motion are the same. I googled vortex motion but equations and concepts looked very specialized and complex for me to understand easily. Thanks.

 

[sophiecentaur]

They have the same spiral shape.

They 'look' similar but the galaxy shape is not there because of a 'vortex' the lines you see are lines of density due to resonances in all the stellar orbits. There's no cosmic washing machine at work.

 

[Zeynel]

Great, thanks. I didn’t know that. So how do we compute these resonances? And is there a simple equation giving the motion of an ideal cyclone? Is this covered in fluid dynamics?

 

[sophiecentaur]

I really don't know enough about Fluid Dynamics but there are dozens of google links to Cyclones - and also to density waves in galaxies. The two phenomena are very different and the spirals in some galaxies are visibly different in structure from the relatively simple shapes of weather system cyclones.
Happy reading.