The Future of Far-Infrared / Submillimeter Astrophysics with Single-Dish Telescopes

Although far-IR -- mm-wave astronomy has now been developing for several decades, access to this portion of the spectrum remains difficult and limited. Relative to their optical-wavelength counterparts, the submillimeter observatories are both small in units of wavelength and hot in units of photon energy, which imposes limits on their angular resolution and sensitivity. Nevertheless, even the modest far-IR and submillimeter observations obtained in the last two decades have revolutionized our understanding the physics and chemistry of the ISM, the formation of stars, and the cosmic history of these processes. The demonstration by COBE that about half of the radiant energy released in the universe since decoupling comes to us in the submm/far--IR has further underscored the scientific necessity of observations in this wavelength regime. The next decade promises even greater discoveries, as new observatories and detectors are still pushing toward fundamental limits. The paper briefly outlines some of the exciting capabilities and scientific roles of new single-dish far--IR -- mm-wave telescopes and their instruments.