If mass structure is the Universe move to indicate the Universe expands radially why not in a spiral?

Question

Is there proof that motion is radial?The motion of mass structures in our galaxy dont move radialy but in a spiral as is the case of our solar system?

Answer 1

Hi. The universal expansion, if it exists, is different from orbital motion. I would guess that all galaxies have SOME non-radial motion, but the overwhelming part seems to be radial.