You know the world is changing in big ways -- or at least our knowledge of it is -- when four new elements are added to the periodic table. That's it, toss out that outdated old one! You no longer need Calcium, anyhow. Just kidding about that last bit. It's good for your teeth.

Anyhow, the four new elements and their atomic numbers will fill out the table's seventh row, and were announced by the International Union of Pure and Applied Chemistry (IUPAC) on the next-to-last day of 2015, in a press release. IUPAC is the ultimate source on chemical science.

"The chemistry community is eager to see its most cherished table finally being completed down to the seventh row," said Professor Jan Reedijk president of the Inorganic Chemistry Division of the IUPAC in the release. 

So far, the elements have stand-in names: Uut 113, Uup 115, Uus 117 and Uuo 118. And yes, don't worry if you don't find those catchy -- because they're temporary.

The Bay Area's Livermore National Lab was part of the discovery of three of the four new elements, and they will likely propose permanent names and symbols for those.

Scientists from Russia and Japan also contributed to the discovery and will likely help name them too.

There are a few perameters for names -- they should be named after a mineral, a place or country, a mythological concept, a property or a scientist. Once the names are proposed, they'll receive scientific and public review before being finalized and set up on the table.

As it happens, the new elements aren't actually found in nature: They're man-made, and they decay into unknown isotopes of elements that are a bit lighter.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

-Follow Catherine on Twitter @TreesWhales