CLOSE

Why Are Traffic Lights Red and Green?

Red and green images via Shutterstock

The very first traffic light, installed outside the Houses of Parliament in London in December 1868, had red and green gas lamps for nighttime use. The device was pretty crude, and less than a month after it went operational, it exploded and killed the unfortunate traffic cop who was operating it.

Obviously, we’ve come a long way in traffic light technology, but we’ve stuck with the same color scheme. What is it about red and green that gave them such lasting power?

The guys who made that first traffic light borrowed their palette from the railroads. British railwaymen of the time often used red, green, blue, black and white flags, semaphores and lamps for signaling. In January 1841, faced with Parliamentary investigation over a number of accidents, the major railroad managers met to discuss safety issues. Henry Booth of the Liverpool and Manchester Railway was a driving force at the meeting and recommended standardized hand signals and color schemes. The colors adopted were those used by Booth’s lines: red to indicate danger, white to indicate safety and green to indicate "proceed with caution."

Booth’s use of these colors, in turn, seems to have come from a common practice in heavy industry of the era. Many motors and other industrial equipment had indicator lights that were red when the equipment was stopped and green when it was running. Since people were already familiar with this color scheme and its meaning, it makes sense that it was handed down into the railroad industry and then to traffic lights.

As for why the early industrialists chose red to mean stop and green to mean go, we can only speculate. In color symbolism, red generally evokes danger and makes it a good choice for a warning signal. Green, on the other hand, is calming. While that doesn’t seem to lend itself well to “go,” it may have been chosen for a more practical reason - it contrasts well with red and is highly visible without being harsh or distracting.

nextArticle.image_alt|e
iStock
arrow
holidays
What Are the 12 Days of Christmas?
iStock
iStock

Everyone knows to expect a partridge in a pear tree from your true love on the first day of Christmas ... But when is the first day of Christmas?

You'd think that the 12 days of Christmas would lead up to the big day—that's how countdowns work, as any year-end list would illustrate—but in Western Christianity, "Christmas" actually begins on December 25th and ends on January 5th. According to liturgy, the 12 days signify the time in between the birth of Christ and the night before Epiphany, which is the day the Magi visited bearing gifts. This is also called "Twelfth Night." (Epiphany is marked in most Western Christian traditions as happening on January 6th, and in some countries, the 12 days begin on December 26th.)

As for the ubiquitous song, it is said to be French in origin and was first printed in England in 1780. Rumors spread that it was a coded guide for Catholics who had to study their faith in secret in 16th-century England when Catholicism was against the law. According to the Christian Resource Institute, the legend is that "The 'true love' mentioned in the song is not an earthly suitor, but refers to God Himself. The 'me' who receives the presents refers to every baptized person who is part of the Christian Faith. Each of the 'days' represents some aspect of the Christian Faith that was important for children to learn."

In debunking that story, Snopes excerpted a 1998 email that lists what each object in the song supposedly symbolizes:

2 Turtle Doves = the Old and New Testaments
3 French Hens = Faith, Hope and Charity, the Theological Virtues
4 Calling Birds = the Four Gospels and/or the Four Evangelists
5 Golden Rings = the first Five Books of the Old Testament, the "Pentateuch", which gives the history of man's fall from grace.
6 Geese A-laying = the six days of creation
7 Swans A-swimming = the seven gifts of the Holy Spirit, the seven sacraments
8 Maids A-milking = the eight beatitudes
9 Ladies Dancing = the nine Fruits of the Holy Spirit
10 Lords A-leaping = the ten commandments
11 Pipers Piping = the eleven faithful apostles
12 Drummers Drumming = the twelve points of doctrine in the Apostle's Creed

There is pretty much no historical evidence pointing to the song's secret history, although the arguments for the legend are compelling. In all likelihood, the song's "code" was invented retroactively.

Hidden meaning or not, one thing is definitely certain: You have "The Twelve Days of Christmas" stuck in your head right now.

nextArticle.image_alt|e
iStock
arrow
Big Questions
Where Does the Phrase '… And the Horse You Rode In On' Come From?
iStock
iStock

Horses may no longer be the dominant form of transportation in the U.S., but the legacy of our horseback-riding history lives on in language. When telling people off, we still use the phrase “... and the horse you rode in on.” These days, it’s rare for anyone you're telling to go screw themselves to actually be an equestrian, so where did “and the horse you rode in on” come from, anyway?

Well, let’s start with the basics. The phrase is, essentially, an intensifier, one typically appended to the phrase “F*** you.” As the public radio show "A Way With Words" puts it, it’s usually aimed at “someone who’s full of himself and unwelcome to boot.” As co-host and lexicographer Grant Barrett explains, “instead of just insulting you, they want to insult your whole circumstance.”

The phrase can be traced back to at least the 1950s, but it may be even older than that, since, as Barrett notes, plenty of crude language didn’t make it into print in the early 20th century. He suggests that it could have been in wide use even prior to World War II.

In 1998, William Safire of The New York Times tracked down several novels that employed the term, including The Friends of Eddie Coyle (1972) and No Bugles, No Drums (1976). The literary editor of the latter book, Michael Seidman, told Safire that he heard the term growing up in the Bronx just after the Korean War, leading the journalist to peg the origin of the phrase to at least the late 1950s.

The phrase has had some pretty die-hard fans over the years, too. Donald Regan, who was Secretary of the Treasury under Ronald Reagan from 1981 through 1984, worked it into his official Treasury Department portrait. You can see a title along the spine of a book in the background of the painting. It reads: “And the Horse You Rode In On,” apparently one of Regan’s favorite sayings. (The book in the painting didn't refer to a real book, but there have since been a few published that bear similar names, like Clinton strategist James Carville’s book …and the Horse He Rode In On: The People V. Kenneth Starr and Dakota McFadzean’s 2013 book of comics Other Stories And the Horse You Rode In On.)

It seems that even in a world where almost no one rides in on a horse, insulting a man’s steed is a timeless burn.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios