Spiral arms in protoplanetary disk Sept 30, 2016 6:23:45 GMT Select PostDeselect PostLink to PostMemberGive GiftBack to Top Post by Pincho Paxton on Sept 30, 2016 6:23:45 GMT Link...Spiral arms in protoplanetary disk: They're not just for galaxies any morePincho says...They are really a double spiral, and you might surmise that a bow shock could be a double spiral too...Bow Shock Solar System GeneratorFor a bow shock I have a gravitational inflow, and a magnetic outflow which could be polarised to create a sort of treadmill. A slight adaption to the treadmill can make it into a double spiral.Pincho Paxton