  We present a pedagogical introduction to some key computations in
gravitational waves via a side-by-side comparison with the quadrupole
contribution of electromagnetic radiation. Subtleties involving gauge choices
and projections over transverse modes in the tensorial theory are made clearer
by direct analogy with the vectorial counterpart. The power emitted by the
quadrupole moment in both theories is computed, and the similarities as well as
the origins of eventual discrepancies are discussed. Finally, we analyze the
stability of bound systems under radiation emission, and discuss how the
strength of the interactions can be established this way. We use the results to
impose an anthropic bound on Newton's constant of order $G\lesssim 3\times
10^4\, G_\text{obs}$, which is on par with similar constraints from stellar
formation.
