The Formation of Stars -- From Filaments to Cores to Protostars and
  Protoplanetry Disks
  Star formation involves the flow of gas and dust within molecular clouds into
protostars and young stellar objects (YSOs) due to gravity. Along the way,
these flows are shaped significantly by many other mechanisms, including
pressure, turbulent motions, magnetic fields, stellar feedback, jets, and
angular momentum. How all these mechanisms interact nonlinearly with each other
on various length scales leads to the formation and evolution of substructures
within clouds, including filaments, clumps, cores, disks, outflows, the
protostars/YSOs themselves, and planets. In this white paper, prepared for the
2020 Long Range Plan panel which will recommend Canada's future directions for
astronomy, we describe the observational and theoretical leadership in the star
formation field that Canada's vibrant community has demonstrated over the past
decade. Drawing from this extensive background, we identify five key questions
that must be addressed for further progress to be made in understanding star
formation in the next decade. Addressing these questions will improve our
understanding of the dynamics of the dense gas and the role of the magnetic
field in star formation, the optical properties of the dust used to trace mass
and magnetic fields, the sources of variability in star-forming objects on
short timescales, and the physical processes that specifically promote the
clustering of stars. We further highlight key facilities in which Canada should
become involved to continue making progress in this field. Single-dish
facilities we recommend include LSST, trans-atmospheric far-infrared telescopes
like BLAST-TNG and SPICA, and ground-based telescopes like JCMT, GBT, and
CCAT-p. Interferometric facilities we recommend include ALMA, ngVLA, and SKA1.
