galactic rotation

The observed movement of stars in a galaxy in orbit around the galactic center.

Galactic rotation

Submitted by JH Wierenga on Thu, 10/04/2018 - 09:18

image of a galaxy, by By Nick Risinger [Public domain], from Wikimedia Commons

The speed at which stars in the spiral arms of galaxies revolve around the galactic center remains more or less constant with increasing radius because the scale factor within the galaxy is inversely proportional to the radius. This is because black holes at the centers of galaxies produce new space, which is gradually dispersed into surrounding space. Differences in the scale factor result in differences in gravitational attraction, which in turn affect orbital speeds.

Rotational speeds of spiral galaxies

Submitted by jhwierenga on Mon, 07/30/2018 - 10:37

Newtonian and Einsteinian formulations for the gravitational forces exerted by galactic cores on the stars in the spiral arms is proportional to the square of the distance between them. Accordingly, the speed at which these stars revolve around the core should be proportional to the square root of the radius, and should drop off as this distance increases. However, it is observed that the speed remains almost constant along the whole spiral arm.

The expansion of the universe

Submitted by jhwierenga on Mon, 07/30/2018 - 08:01

The universe expands because quantum fluctuations continually produce new space quantum systems. It expands into itself locally, in such a manner that surrounding space is not directly affected.

Phenomena explained :

Galactic rotation curves: The velocity at which stars in the spiral arms of galaxies revolve around galactic cores is more or less constant, regardless of the radius.

galactic rotation