The origin of the cosmic radiation has been a mystery since its discovery by Victor Hess in 1912. The cosmic-ray energy spectrum extends from a few GeV to above 1020 eV. As yet there is no experimental proof of the transition from Galactic to extragalactic cosmic rays, though it is believed that cosmic rays below about 1017.5 eV are of Galactic origin. While there is a consensus that supernovae (SN) explosions accelerate cosmic rays up to energies of ~1015 eV, experimental evidence has been difficult to obtain. The theoretical arguments are based upon the energy released in SN being sufficient to maintain the observed cosmic rays in the Galaxy, and the creation of strong shocks by SN enabling first order Fermi acceleration. Thus the tasks for future experiments are to confirm that supernovae are sites of the acceleration of hadronic cosmic rays up to the knee, and to determine the sources of the Galactic cosmic rays above 1015 eV. Galactic diffuse emission The diffuse gamma radiation from our Galaxy also probes the origin of cosmic rays. This radiation is due to the interaction of hadronic cosmic rays with interstellar gas and subsequent decay of neutral pions, and the interaction of high-energy electrons with gas and radiation fields (radio, microwave, infrared, optical, UV and magnetic). If the distribution of matter and radiation is known through other measurements, knowledge of the diffuse emission allows one to measure the cosmic-ray flux and spectrum throughout the Galaxy. This information can be used to determine the regions within the Galaxy where particle acceleration has recently occurred. Transient emission from AGN and the Crab Over 20 Active Galactic Nuclei (AGN) have been detected in very high energy (VHE) gamma rays and extreme flares of up to 50 times the quiescent flux have been observed. Gamma rays are produced via interactions of the high-energy electrons and/or protons with lower energy photons. There exist several models to explain the source of photons including: synchrotron emission by the same population of electrons, radiation from the accretion disk, and cosmic microwave background photons. Simultaneous observations using multiple wavelengths and multi-messenger approaches are required to distinguish among these models. Monitoring at VHE energies is an efficient mechanism to initiate such observations because the highest energy gamma rays exhibit the most extreme variability and probe the highest energy particles. HAWC will have the sensitivity to detect strong flares, such as those that