Internal waves in the ocean can be excited by many different processes, including flow over topography, surface wind or thermal forcing, and volumetric forcing by turbulence. Langmuir turbulence and convection can excite internal waves in mixed (i.e., unstratified) regions. This talk with focus on convective excitation of internal gravity waves as a prototypical example of volumetric excitation of internal waves. This occurs in many other geophysical and astrophysical settings, including the Earth's core & atmosphere, some gas giants like Saturn, and most stars including the sun. We will present a joint experimental & computational study of internal wave generation by convection. We describe an experiment using the peculiar property of water that its density maximum is at 4C. A tank of water cooled from below and heated from above develops a cold, convective layer near 4C at the bottom of the tank, adjacent to a hot stably stratified layer at the top of the tank. Our simulations show that waves are excited from within the convection zone, opposed to at the interface between the convective and stably stratified regions.