What Do the Olympic Rings Mean?


"It represents the five inhabited continents of the world, united by Olympism, while the six colors are those that appear on all the national flags of the world at the present time."

In 1894, Pierre de Frédy, Baron de Coubertin—a French aristocrat and intellectual who had previously attempted to incorporate more physical education in schools—convened a congress in Paris with the goal of reviving the ancient Olympic Games (an idea Coubertin first introduced at a USFSA meeting in 1889). The congress agreed on proposals for a modern Olympics, and the International Olympic Committee was soon formalized and given the task of planning the 1896 Athens Games.

After the 1912 Stockholm Games—the first Games featuring athletes from all five inhabited parts of the world—a design of five interlocked rings, drawn and colored by hand, appeared at the top of a letter Coubertin sent to a colleague. Coubertin used his ring design as the emblem of the IOC's 20th anniversary celebration in 1914. A year later, it became the official Olympic symbol.

The rings were to be used on flags and signage at the 1916 Games, but those games were canceled because of the ongoing World War. The rings made a belated debut at the 1920 Games in Antwerp, Belgium.


Coubertin explained his design in 1931:

"A white background, with five interlaced rings in the centre: blue, yellow, black, green and red ... is symbolic; it represents the five inhabited continents of the world, united by Olympism, while the six colors are those that appear on all the national flags of the world at the present time."

Coubertin used a loose interpretation of "continent" that included Africa, the Americas, Asia, Europe and Oceania. He never said nor wrote that any specific ring represents a specific continent.

Because the rings were originally designed as a logo for the IOC's 20th anniversary and only later became a symbol of the Olympics, it's also probable, according to historian David Young, that Coubertin originally thought of the rings as symbols of the five Games already successfully staged.


Popular myth (and an academic article) has it that the rings were inspired by a similar, ancient design found on a stone at Delphi, Greece. This "ancient" design, however, is really just a modern prop.

For the 1936 Summer Games in Berlin, Carl Diem, president of the organizing committee, wanted to relay the Olympic Flame from its lighting point in Olympia to the Olympic stadium in Berlin. Diem, it seems, had a flair for theatrics, and included in the relay a stop at Delphi's ancient stadium for a faux-ancient Greek torchbearers' ceremony complete with a faux-ancient, 3-foot-tall stone altar with the modern ring design chiseled into its sides.

After the ceremony, the torch runners went on their way, but no one ever removed the stone from the stadium. Two decades later, British researchers visiting Delphi noticed the ring design on the stone. They concluded that the stone was an ancient altar, and thought the ring design had been used in ancient Greece and now formed "a link between ancient and modern Olympics."

The real story behind the altar was later revealed, and "Carl Diem's Stone" was moved from the stadium and placed near the ticketed entrance to the historic site.

The inspiration for Coubertin's design seems to be a little more modern. Four years before he convened his Olympic congress, he had become president of the French sports-governing body, the Union des Sociétés Françaises de Sports Athlétiques (USFSA). The Union was formed from the merging of two smaller sporting bodies, and to symbolize this, a logo of two interlocking rings—one red and one blue, on a white background—was created and displayed on the uniforms of USFSA athletes.

"It seems quite obvious," says historian Robert Barney in a 1992 Olympic Revue article, "that Coubertin's affiliation with the USFSA led him to think in terms of interlocked rings or circles when he applied his mind towards conceiving a logo ... indeed, a ring-logo that would symbolize his Olympic Movement's success up to that point in time.... Circles, after all, connote wholeness, the interlocking of them, continuity."


The IOC takes their rings very seriously, and the symbol is subject to very strict usage rules and graphic standards, including:

The area covered by the Olympic symbol (the rings) contained in an Olympic emblem (e.g. the 2008 Games emblem) can't exceed one-third of the total area of the emblem.
The Olympic symbol contained in an Olympic emblem has to appear in its entirety (no skimping on rings!) and can't be altered in any way.
The rings can be reproduced in a solid version (for single color reproduction in blue, yellow, black, green, red, white, gray, gold, silver, or bronze) or an interlocking version (interlaced from left to right; and reproduced in any of the aforementioned colors or full color, in which case the blue, black and red rings are on top and the yellow and green are on the bottom).
For reproduction on dark backgrounds, the rings must be a monochromatic yellow, white, gray, gold, silver, or bronze; full color on a dark background is not allowed.

This article originally appeared in 2010.

What Do the Numbers and Letters on a Boarding Pass Mean?

iStock.com/Laurence Dutton
iStock.com/Laurence Dutton

Picture this: You're about to embark on a vacation or business trip, and you have to fly to reach your destination. You get to the airport, make it through the security checkpoint, and breathe a sigh of relief. What do you do next? After putting your shoes back on, you'll probably look at your boarding pass to double-check your gate number and boarding time. You might scan the information screen for your flight number to see if your plane will arrive on schedule, and at some point before boarding, you'll also probably check your zone and seat numbers.

Aside from these key nuggets of information, the other letters and numbers on your boarding pass might seem like gobbledygook. If you find this layout confusing, you're not the only one. Designer and creative director Tyler Thompson once commented that it was almost as if "someone put on a blindfold, drank a fifth of whiskey, spun around 100 times, got kicked in the face by a mule … and then just started puking numbers and letters onto the boarding pass at random."

Of course, these seemingly secret codes aren't exactly secret, and they aren't random either. So let's break it down, starting with the six-character code you'll see somewhere on your boarding pass. This is your Passenger Name Reference (or PNR for short). On some boarding passes—like the one shown below—it may be referred to as a record locator or reservation code.

A boarding pass
Piergiuliano Chesi, Wikimedia Commons // Public domain

These alphanumeric codes are randomly generated, but they're also unique to your personal travel itinerary. They give airlines access to key information about your contact information and reservation—even your meal preferences. This is why it's ill-advised to post a photo of your boarding pass to social media while waiting at your airport gate. A hacker could theoretically use that PNR to access your account, and from there they could claim your frequent flier miles, change your flight details, or cancel your trip altogether.

You might also see a random standalone letter on your boarding pass. This references your booking class. "A" and "F," for instance, are typically used for first-class seats. The letter "Y" generally stands for economy class, while "Q" is an economy ticket purchased at a discounted rate. If you see a "B" you might be in luck—it means you could be eligible for a seat upgrade.

There might be other letters, too. "S/O," which is short for stopover, means you have a layover that lasts longer than four hours in the U.S. or more than 24 hours in another country. Likewise, "STPC" means "stopover paid by carrier," so you'll likely be put up in a hotel free of charge. Score!

One code you probably don’t want to see is "SSSS," which means your chances of getting stopped by TSA agents for a "Secondary Security Screening Selection" are high. For whatever reason, you've been identified as a higher security risk. This could be because you've booked last-minute or international one-way flights, or perhaps you've traveled to a "high-risk country." It could also be completely random.

Still confused? For a visual of what that all these codes look like on a boarding pass, check out this helpful infographic published by Lifehacker.

Have you got a Big Question you'd like us to answer? If so, send it to bigquestions@mentalfloss.com.

Does Having Allergies Mean That You Have A Decreased Immunity?


Tirumalai Kamala:

No, allergy isn't a sign of decreased immunity. It is a specific type of immune dysregulation. Autoimmunity, inflammatory disorders such as IBS and IBD, and even cancer are examples of other types of immune dysregulation.

Quality and target of immune responses and not their strength is the core issue in allergy. Let's see how.

—Allergens—substances known to induce allergy—are common. Some such as house dust mite and pollen are even ubiquitous.
—Everyone is exposed to allergens yet only a relative handful are clinically diagnosed with allergy.
—Thus allergens don't inherently trigger allergy. They can but only in those predisposed to allergy, not in everyone.
—Each allergic person makes pathological immune responses to not all but to only one or a few structurally related allergens while the non-allergic don't.
—Those diagnosed with allergy aren't necessarily more susceptible to other diseases.

If the immune response of each allergic person is selectively distorted when responding to specific allergens, what makes someone allergic? Obviously a mix of genetic and environmental factors.

[The] thing is allergy prevalence has spiked in recent decades, especially in developed countries, [which is] too short a time period for purely genetic mutation-based changes to be the sole cause, since that would take multiple generations to have such a population-wide effect. That tilts the balance towards environmental change, but what specifically?

Starting in the 1960s, epidemiologists began reporting a link between infections and allergy—[the] more infections in childhood, [the] less the allergy risk [this is called hygiene hypothesis]. Back then, microbiota weren't even a consideration but now we have learned better, so the hygiene hypothesis has expanded to include them.

Essentially, the idea is that the current Western style of living that rapidly developed over the 20th century fundamentally and dramatically reduced lifetime, and, crucially, early life exposure to environmental microorganisms, many of which would have normally become part of an individual's gut microbiota after they were born.

How could gut microbiota composition changes lead to selective allergies in specific individuals? Genetic predisposition should be taken as a given. However, natural history suggests that such predisposition transitioned to a full fledged clinical condition much more rarely in times past.

Let's briefly consider how that equation might have fundamentally changed in recent times. Consider indoor sanitation, piped chlorinated water, C-sections, milk formula, ultra-processed foods, lack of regular contact with farm animals (as a surrogate for nature) and profligate, ubiquitous, even excessive use of antimicrobial products such as antibiotics, to name just a few important factors.

Though some of these were beneficial in their own way, epidemiological data now suggests that such innovations in living conditions also disrupted the intimate association with the natural world that had been the norm for human societies since time immemorial. In the process such dramatic changes appear to have profoundly reduced human gut microbiota diversity among many, mostly in developed countries.

Unbeknownst to us, an epidemic of absence*, as Moises Velasquez-Manoff evocatively puts it, has thus been invisibly taking place across many human societies over the 20th century in lock-step with specific changes in living standards.

Such sudden and profound reduction in gut microbiota diversity thus emerges as the trigger that flips the normally hidden predisposition in some into clinically overt allergy. Actual mechanics of the process remain the subject of active research.

We (my colleague and I) propose a novel predictive mechanism for how disruption of regulatory T cell** function serves as the decisive and non-negotiable link between loss of specific microbiota and inflammatory disorders such as allergies. Time (and supporting data) will tell if we are right.

* An Epidemic of Absence: A New Way of Understanding Allergies and Autoimmune Diseases Reprint, Moises Velasquez-Manoff

** a small indispensable subset of CD4+ T cells.

This post originally appeared on Quora. Click here to view.