What does Annular Mean?

"Annular”, from Latin ānulāris

adjective

an·​nu·​lar |  \ ˈan-yə-lər \

noun (singular)

an·​nu·​lus |  \ ˈan-yə-ləs \

nown (plural)

an·nu·li | \ ˈan-​yə-​ˌlī

Definition of annular (from Marriam-Webster)

: of, relating to, or forming a ring  

Definition of Annulus (from Wikipedia)

:In mathematics, an annulus (plural annuli) is the region between two concentric circles. Informally, it is shaped like a ring or a hardware washer. The word "annulus" is borrowed from the Latin word anulus or annulus meaning 'little ring'. The adjectival form is annular (as in annular eclipse).”

We’ll get back to that last bit, but to summarize: An Annulus is Circles

Isn’t that funny? A singular word that means something plural! An Annulus has an inherent duality that I find endlessly fascinating.

So, one circle is not annular. Until there is another circle inside it, it’s just… circular. A ring isn’t just one circle, but an outside circle and an inside one.

At first thought, circles might seem rare in nature. However, many natural things are Annular:

Ripples form when an object falls into liquid, displacing and disbursing the surface equally in all directions, creating a series of fleeting concentric circles.

Tree Rings form slowly year over year, with the main circular sections growing during wetter seasons, and the separations between them during the dryer months. They become revealed when the trunk of the tree is cut, and can then be used to determine how old the tree was at the time.

Bighorn Sheep Horns form in very much the same way as Tree-Rings, with the thicker sections made when there is more available for the Sheep to eat, and the indentations separating them reflecting times of scarcity. Also like the trees, the horns can also be used to determine the age of the individual sheep. They are referred to in the plural form Annuli, since there are two horns forming these rings together.

Tropical Storms form when a low-pressure zone of the atmosphere moves over large, warm bodies of water, causing evaporated vapor to form clouds, while rotating and spreading out as they rise higher. This creates a series of swirling circles atop one another, with the smallest circle near the surface of the Earth called the Eye. When these storms become particularly symmetrical, they are classified as Annular.

Saturn’s Rings are one of the most iconic features of the Solar System we inhabit. They were likely formed by an orbiting Moon of Saturn getting shredded to pieces by its fierce gravity, the remnants spreading out into a disk around its axis of rotation (equator). There are different sections to these orbiting rings of ice and rock, with new small moons even forming by collecting all the matter in that part of the ring together. Other gas giants have rings too, like the vertical ones around Uranus, and even faint ones around Jupiter.

Some Solar Eclipses are also classified as Annular, as referred to in the definitions above. This breathtaking phenomena forms due to a coincidence of several convergent factors at this point in Earth’s history. When Earth was young, it gained a Moon large enough to make itself spherical under its own gravity, like a planet or star (called Hydrostatic Equilibrium). Its Moon is nearly 400x smaller than the star it orbits, the Sun. But presently, the Moon is also about 400x closer to Earth than the Sun. Because these two numbers are the same, when these two celestial objects come together at one of the two points in the sky where their paths cross, the Moon can cover the Sun “Totally”.

However, the Moon’s orbit around Earth is itself not a perfect circle, but instead slightly elliptical, coming in closer and getting apparently larger during one part of its orbit, called Perigee, and vice versa, getting further and visually smaller when it reaches Apogee. If Moon is near its Apogee when it crosses in front of the Sun, instead of covering it totally, the black circle of the Moon is seen surrounded by the golden circle of the Sun. This results in an Annulus, colloquially named the “Ring of Fire”.

In the deep past when it formed, the Moon was much closer to Earth, appearing much larger, and covering the Sun more than totally . However, with each year it separated from the planet by a few centimeters, until it got to that equal 400x proportion of size and distance it sits at today. However, as it continues to move away in the future, it will eventually be too far to ever cover the Sun totally again. Thus, we are living in a miraculous place, at an astounding moment of time where both Total and Annular Solar Eclipses are visible to us on Earth. In under 1 Billion more years, a deep breath in cosmic scales, Annular Solar Eclipses will be the only kind to ever be seen again here (if there are intelligent eyes to do so).

Conclusion

By now, hopefully, you have crystal-clear knowledge that an Annulus is Circles. As we’ve explored in the examples, the natural world is surprisingly full of Annuli (multiple things with multiple circles), that have remarkable connections to the passing of time, the growth and age of living things, and the fundamental forces of the Universe at both small and large scales.

Can you think of anything else that is Annular? Now that you know what it means, you will start to see them everywhere around you. You might have eaten a glazed Annulus for breakfast, or had a few Annuli carry you to work. Perhaps you even have one upon your own finger, right now! I do, as I type this inaugural post. If your interest has been piqued, I encourage you to circle-back here to the Annular Blog again for an ever growing library of updates and insights. ⭕️

PS - The Annulet

This article was drafted, edited, and ready for publication when I received a curveball by the Universe, through Netflix’ adaptation of the comic of The Sandman. In the last leg of the series, a woman named Rose Walker is introduced, and in a dream, she overhears the main character Morpheus refer to her as an Annulet.

When she wakes up, she wonders what the heck an Annulet might be. Soon thereafter, she meets a woman who gives her a small golden ring, calling it by the same mysterious term. Y’all can imagine my audible gasp at the absolute, total serendipity.

As the title of a person, it’s revealed that an Annulet has the ability to explore through the dreams of others. And now, if you proceed further into my website, you’ll become an Annulet exploring my dream!