My geometry columns have SRID of 0. Can I simply convert them to geography as such:

routes.geom::geography <-> pc.geom::geography as distance

in order to get "distance" in metres?

P.S - "routes.geom" is a linestring column, and "pc.geom" is a point column.

here is a snippet of how it is used, (extracted from my main query):

    FROM point_center as pc
    
    CROSS JOIN LATERAL (
      SELECT routes.id_num, routes.geom::geography <-> pc.geom::geography AS dist