What is a light centrennium?

A light centrennium is a length unit used in the defunct mobile game Origami Flowers to describe astronomically tall flowers. As defined by the game, one centrennium is equal to 100,000 years, and “light” turns it into a length unit similar to light years. However, if you looked this term up before this blog post was published you will find nothing, and if you look up “centrennium” your query will likely be corrected to “centennium” which is simply synonymous with a century.

However, if you push through and search for “centrennium” verbatim, you will still get several obscure mentions of people all using it in the same way that Origami Flowers uses it, despite there being no proper definition behind it. What gives? This blog post goes down the rabbit hole of trying to find the origin of this strange word.

Origami Flowers

The first time I came across this word was, of course in Origami Flowers, as a length unit - the length at which light passes over the span of a centrennium.

The term was undoubtedly added to the game to better represent the increasingly absurd height of flowers that players had in the game as the gradual inflation of MMOs takes place. The length unit would start out at cm, then switch to km, light years and finally light centrenniums.

Back in the day I originally thought this was a strange, potentially Latin, way of writing centuries, and the unit simply meant 100 light years. However, after digging further into decompiled source code of the flower app in later years, I discovered that it is actually 100,000 light years! Which begs the question, what does centrennium even mean?

Centennium or Centrennium?

The term millennium refers to 1,000 years, and comes from a combination of Latin mille- (thousand) and annus (year).

With this in mind, the real definition of centennium (centum- meaning hundred) would be a hundred years. Synonymous with century. This is a real, albeit rare, word to be used. So my initial assumption of it referring to light centuries was not entirely unfounded.

However, this definition does not correspond to the way the term is used in Origami Flowers, where a centrennium refers to 1,000 centuries or 100,000 years. So it is very clearly a distinct separate unit with the “r” being intentional in some way to distinguish it, and not a typo.

The specific placement of the extra “r” is a bit interesting as it creates the word “centre” within it. The creator of Origami Flowers is Canadian, and Canadian English has some influences of British English where American English does not. However when searching in posts from him on the old Attack Games forum, he uses the American spellings of words such as “center” and “behavior”:

On most Nokia’s (half the world), when you use the standard J2ME Canvas the ‘FIRE’ constant is not mapped correctly to the center [emphasis added] of the D-pad / select button.

If the date/time on your iPod was changed, this could cause the game to get confused, and is the only thing I can think of to cause this type of behavior [emphasis added].

However, he also uses the British form of “behaviour” once in the Flower School texts written some years after the above forum posts, so trying to make out any consistent kind of writing style isn’t really possible:

Bad behaviour will result in losing chat privileges or even player-2-player messages and having your name censored.

Regardless, “Centernnium” gives exactly zero results anywhere I could find, so this does not seem like an useful lead for variations of the term. Another potential alternative spelling of “Centrennia”, as an alternative to the plural form centrenniums, gives no useful results either.

However, there are actually some leads when just searching for “centrennium”, verbatim, ignoring any kind of autocorrect that search engines give which correct it to centennium.

So WHERE did this come from?

Searching for explicitly “centrennium”, with the “r” does give some results that show this is not isolated to Origami Flowers, even though it is extremely obscure. Such as an anonymous answer on math.answers.com from 2009, giving the following definitions for larger time units:

Century = 100 years (Ten decades) Millenium = 1,000 years (Ten centuries, Hundred decades) Kilennium = 10,000 years (Ten milleniums) Centrennium = 100,000 years ? Megaannum = 1 Million years (1,000 millennums)

The question mark after “Centrennium” is especially curious, as it seems like even the author of the answer was unsure, but went with it anyway without any citation. Megaannum is a well recognised term referring to 1 million years, but Kilennium seems like another strange mention in the list of otherwise standardised terms. Looking it up gives another answer… from math.answers.com, an anonymous answer from 2010:

What is a kilennium?
Its every 10,000 years. Like milennium is every 1000.

It’s a bit rich to be citing yet another anonymous answer from the same site that gave us the first one, but that’s basically everything on the kilennium for now. Moving on, back to centrennium…

There is a mention of the term in a 2010 post on a religious forum, in a meta thread about whether ProBoards’ user karma system should be activated on the forum. While joking about for how long a certain user would be upset if the karma system were not to be introduced, they gave an increasing progression of time units to represent it:

I was going for a logarithmic progression, years, decades, centuries, millennia, kilennium, centrennium, etc., but I got distracted right after decade and leaped to eons!

Given the mention of kilennium before right before centrennium in the time scale, they likely looked up large time units and found the previously mentioned answer on answers.com, which had been on the Internet for months at this point.

Another mention of it is in a blog post from a jewellery store in 2013, giving well wishes to those who celebrate Thanksgivukkah (28th November 2013, where both Thanksgiving and Hanukkah occurred on the same day). It’s extremely rare for these holidays to coincide, and the text refers to it as a “once in a Centrennium” holiday.

The first night of Hanukkah does indeed fall on American Thanksgiving this year, and won’t do so again for another 70,000 years. A once in a Centrennium holiday (we Googled)?

Interestingly, this quote also mentions where they found the term, via Google search. Likely they were searching for large units of time that would correspond to the 70,000 year range, found the Q&A answer from 2009, and rounded it up to 100,000 to call it a once in a centrennium holiday.

To put an exact date of the mention of light centrenniums in Origami Flowers, I searched through my collection of APKs for Origami Daisy and found the first mention of it in 4.74, with a build date of 16 June 2014. However it is possible that it could have been used prior to this on the server-side due to the game’s heavy reliance of a server to function.

Curiously, there is a much more recent mention of the word in 2022 in a South Korean, English language newspaper, in an article about radioactive waste. As far as I’m aware, this article was also printed in a physical 2022 number of the newspaper, putting the word along with its definition on printed paper too:

It takes one centrennium (100,000 years) for such waste to lose its toxicity, and our human history is so far shorter than that.

In addition to these mentions, I found some more which I’ll go over more briefly:

• A song by the name of “Centrennium Falcon”, released in 2014 on Newgrounds. The name seems to be a play on the Millennium Falcon from Star Wars, but I cannot find any other Star Wars-related mentions of “Centrennium”, which would have otherwise been a useful lead.
• A post from 2015 on a forum about American Football where they quote someone saying 25,000 and call it a “quarter-centrennium”.
• A project by the name of “Project Centrennium” is mentioned in the work experience on someone’s LinkedIn profile, dating to sometime in 2016. There appears to be no more information about the project in question and is probably not something that is public.
• There are some spammy looking websites which mention the word, but it is almost certainly regurgitated from previous occurrences as an attempt of SEO farming.

I tried to search for occurrences of it on Google Books and archive.org in the hopes that there may be any mentions of it in literature, but came up with nothing. One of the hypotheses I had at this point was that it might be a reference to some cultural work, such as a movie or book, which a regular Google or DuckDuckGo search cannot discover. But I have not been able to find anything to that effect.

Centimillennium

While looking at various large units of time, I stumbled upon the Centimillennium which is a term referring to the same length of time as centrennium:

(rare) A period of time consisting of one hundred thousand years.

Picking apart the word, we get centum- and millennium. A hundred millennia!

Wiktionary labels it as “rare”, but has quotations of it spanning centuries. One of them is a quote from an interview with George R. Stewart in 1972:

A lot of this book dealt with long periods of time. I coined words in there. There was no unit of time longer than a millennium in ordinary usage, which doesn’t do at all. So I coined “decimillennium” and “centimillennium,” and I used “millennium” for a million years. I doubt if you’d find those anywhere else, but it’s pretty obvious what they mean. I really needed them in this book, because I was dealing in periods very much longer than a thousand years.

Stewart claimed to have coined the term centimillennium while writing the book Sheep Rock (1951), even though Wiktionary also lists a quote from Nelson Loverin in 1882. It is not unlikely that multiple people have independently come up with the same terminology for extremely large, seldom used units of time, both thinking they were the first.

Maybe centrennium has its origin in the centimillennium, or some version of it. But this is just speculation based on the words being synonymous.

Words are made up by people like you and me

The final hypothesis I have about the word, and what I’ll end this blog post with, is that the origin point of the word was simply the oldest mention of it I could find online. The unsourced anonymous answer on math.answers.com from 2009, where it was combusted into existence by someone who was trying to come up with a name for 100,000 years. For lack of any other prior mentions, this is what I’ll consider the origin of the word, if there even is an origin.

What is interesting though is that this word was then used by others - people who posted it on forums, a mobile game developer looking for large time units, and a journalist for a newspaper. Anyone can make up anything on the Internet, but at that point when it is used by so many distinctly different people, you cannot really say that it’s a made up word anymore. It’s just a word, albeit an incredibly obscure one that is synonymous with the comparatively more common centimillennium.

While I have exhausted all mentions of it on the public Internet, and have not been able to find any mentions of it in indexed books such as those in Google Books, my search has been almost exclusively in English. I do not know if the term might have its direct origin in another modern non-English language, that the anonymous author of the Q&A answer might have spoken and led to them putting it in the answer.

While asking around on the Fediverse if anyone had heard about the term centrennium, I was suggested to contact the Long Now Foundation, who advocates for a world which operates on the timescale of civilisation, rather than simply years within a single human’s lifetime. Long time units on the magnitude of many millennia seems like something they would know about, but with I have found so far there is likely not anything more that can be obtained about the word. I haven’t received a response yet, but if they respond with some kind of bombshell information about the term, I will likely end up making a follow-up post at that point.

But for now, that is where it ends. All that is left is to lay down the definitions, once and for all:

Noun

centrennium (plural centrenniums)

1. (rare) A period of time consisting of one hundred thousand years.

Noun

light centrennium (plural light centrenniums)

1. (rare) A length unit equal to the distance light travels in one centrennium, or 100,000 light years.