xkcd.WTF!?

Explanation ➲

Much human jewelry is made of gold for several reasons. It's rare enough to represent a symbol of prestige, but common enough that the working class can reasonably afford to buy it for a special occasion. It's hard enough to survive handling by people, but soft enough that jewelers can easily repair or resize it. And it's virtually immune to weathering and corrosion so it won't degrade during the wearer's life. Most wedding rings contain gold.

In this comic, Cueball points out another reason to make wedding rings out of gold, one he finds more poetic — though the symbolism in this poetry, in true Randall fashion, is couched in astronomy and science. As the comic states, gold is most commonly created by r-process nucleosynthesis in the mergers of neutron stars (the process entailing the rapid capture of free neutrons before either the atom or free neutron decays, therefore requiring a high density of neutrons); something which could be seen as analogous to a marriage. About 94% of the gold on Earth was created this way, with the rest made by supernova nucleosynthesis.[1][2]

Wedding receptions sometimes have a theme, which is used to style the decorations and activities of the party. If the couple has a shared interest in something in popular culture (especially if this is how they met), they might use that as the theme. Megan suggests that "Binary Neutron Star Merger" would be a fun theme; this would probably only be true for astronomers or cosmologists.^{[citation needed]}

Cueball adds that an activity at such a wedding would be ejecting the bouquet at relativistic speeds; this is a reference to the traditional activity of the bride throwing her bouquet into the crowd, with whoever catches it predicted to be the next to get married. The collision of neutron stars ejects material with enormous amounts of energy and therefore at high speeds. So, for a "Binary Neutron Star Merger" theme wedding, the ejected bouquet would therefore be traveling "relativistically" (i.e. at a high fraction of the speed of light). If you caught such a bouquet while at rest relative to the merger point, you would be destroyed by the energy, so everyone tries not to catch it in that fashion. Of course, as shown in the what if? link above, everyone in the room and the surroundings would be vaporized if such a feat was possible. This would make the theme appropriate in addition to being "fun" as the wedding would be just as bright and energetic as a binary neutron star merger.

Continuing with the cosmological theme, the title text suggests that the wedding photographer would be a spectroscopist. Spectroscopy, which determines the composition of materials, including those far away such as exoplanets, stars, binary neutron star mergers and other astronomical phenomena, by measuring and analyzing the wavelengths emitted, to see which wavelengths are strong and which are missing/have a weak intensity, and comparing these to the characteristic spectra of different elements. After the relativistically-ejected bouquet is thrown, he would be able to make a nice spectroscopical image/photo of the entire wedding ceremony if he stood far enough away. (He would, of course, not be able to present it to the bride, as she was part of the system which was destroyed in the process of the light and energy being emitted.)