have been observed from Markarian 421, at greater than 10σ in under 30 minutes. Gamma-ray bursts The Fermi satellite has now observed both long and short gamma-ray bursts that emit multi-GeV gamma rays. No high energy cut off is observed in any of these GRBs, and the highest energy gamma ray observed in the three brightest bursts were emitted (i.e. corrected for the observed redshift) at energies of 70, 60, 94, and 61 GeV in GRBs 080916C, 090510, 090902B, and 090926 respectively. The highest energy gamma-rays require a bulk Lorentz factor of the outflow of nearly 1000 in order to have the rest-frame energies and photon densities be low enough to avoid attenuation by pair production interactions. The Fermi-LAT observations show the most intense GeV emission occurs promptly, and also extends longer than the emission at lower energies. A wide field of view, high duty factor observatory, such as HAWC, is required to observe this prompt emission and determine its extent at high energies especially for a burst such as 090510, in which the prompt emission was less than half a second in duration. HAWC has the sensitivity to continue these observations into the VHE range. The effective area of HAWC at 100 GeV (~100m2) is more than 100 times that of the Fermi-LAT. Cosmic rays at TeV energies HAWC is a very sensitive detector for TeV cosmic rays. The large number of cosmic rays detected with HAWC forms an undesirable background in the search for gamma-ray sources, but it also permits precise measurements of small deviations from isotropy in the cosmic-ray flux. Over the last few years, cosmic-ray detectors in the northern and southern hemisphere have found anisotropy in the arrival direction distribution of TeV cosmic rays at the per-mille level. Since we expect the arrival directions of charged particles at these energies to be completely scrambled by Galactic magnetic fields, these deviations are surprising and imply that the propagation of cosmic rays from their sources to us is not understood. Mapping the arrival direction distribution of cosmic rays to study the anisotropy with increased sensitivity is a major science goal for HAWC. Fundamental physics High-energy astrophysical observations have the unique potential to explore fundamental physics. However, deriving fundamental physics from the astrophysical observations is complex and requires a deep understanding of the astrophysical sources. The astrophysics background must be understood in order to determine the deviations from this