Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey Brainstuff, Lauren
Speaker 1: bolbabam here. Because language is a wide and wondrous thing,
Speaker 1: we humans encounter new or new to us words all
Speaker 1: the time. Anything from a book you're reading for fun,
Speaker 1: to an article about a subject you're only sort of
Speaker 1: familiar with, to a fancy restaurant menu might have you
Speaker 1: diving for a dictionary, and even dictionaries have to update
Speaker 1: all the time to accommodate our linguistic innovations. For example,
Speaker 1: just in March of twenty twenty six, the Oxford English
Speaker 1: Dictionary added a definition for doom scroll. But on the
Speaker 1: flip side, there are some words or abbreviations that we
Speaker 1: know the practical meaning of that we might even use
Speaker 1: every day without having any idea of what they actually mean. Today,
Speaker 1: let's talk about a few of those. AM and PM
Speaker 1: and sos. First, up, AM and PM. Okay, many parts
Speaker 1: of the world use a twenty four hour clock instead
Speaker 1: of one o'clock in the afternoon. Someone in Turkey or
Speaker 1: Brazil might tell you it's thirteen hundred hours. But in
Speaker 1: places that use the twelve hour clock, like the United States,
Speaker 1: we use the concept of AM and PM. One of
Speaker 1: the inconvenient things about breaking your twenty four hour day
Speaker 1: into two twelve hour chunks numbered one through twelve, which
Speaker 1: turnover at midday and midnight, is that it becomes necessary
Speaker 1: to tell someone which chunk you're talking about. Are we
Speaker 1: meeting at eight in the morning or eight at night?
Speaker 1: You can often use context clues, but it is for
Speaker 1: this reason that the two periods are called AM, which
Speaker 1: is short for the Latin term anti meridium or before midday,
Speaker 1: and PM, which is short for post meritium or after
Speaker 1: mid day midday or meridium. Here is in the astronomical
Speaker 1: sense of when the sun passes the meridian overhead. The
Speaker 1: meridian is an imaginary circle that runs around our planet
Speaker 1: from any given point of view from wherever you're standing,
Speaker 1: the meridian passes through the north and south celestial poles,
Speaker 1: you know, the north and south points of the planet's axis,
Speaker 1: and it's also perpendicular to the horizon, so it includes
Speaker 1: the highest point in the sky above you. The sun
Speaker 1: passing through the meridian is essentially high noon. But let's
Speaker 1: back up a little. Why are we complicating things with
Speaker 1: a twelve hour clock in the first place, When the
Speaker 1: twenty four hour clock seems so much more straightforward and convenient.
Speaker 1: The answer to this has a lot to do with
Speaker 1: early clocks. The concept of AM and PM comes from
Speaker 1: the fact that ancient people used the convenient dark light
Speaker 1: contrast of each twenty four hour cycle to talk about
Speaker 1: what time it was. The sun pulled them what time
Speaker 1: it was in the day, and the moon and stars
Speaker 1: did the same at night. As early as thirty five
Speaker 1: hundred BCE, the ancient Egyptians built shadow casting obelisks that
Speaker 1: shaded sections of the ground throughout the day. These sections
Speaker 1: weren't as precise as modern hours, but the concept was
Speaker 1: the same. By fifteen hundred BCE, they had invented the
Speaker 1: more precise sun dial, and with it the hours we
Speaker 1: still know and love, ten daytime hours with a sunrise
Speaker 1: and sunset hour tacked on to either end. By six
Speaker 1: hundred BCE, that invented a timekeeping instrument for the night
Speaker 1: time as well. A person could align it with a
Speaker 1: pole star to track the passage of other stars through
Speaker 1: the meridian to tell time. Later clockmakers used the circular
Speaker 1: model of the sun dial to base the layout of
Speaker 1: their new technology. Although the first mechanical clocks in Europe
Speaker 1: built for medieval clock towers were twenty four hour devices.
Speaker 1: By the thirteen hundred CE, mechanical clocks began to be
Speaker 1: built with twelve hour faces, perhaps to save space and
Speaker 1: eyestrain for people carrying pocket watches. By the mid fifteen hundreds,
Speaker 1: English speaking people in the maths and sciences like John Deeve,
Speaker 1: who were using twelve hour cycles, had adopted the Latin
Speaker 1: phrases anti meritium and post meridium, Latin being the scientific
Speaker 1: lingua franca of the time. By the mid sixteen hundreds,
Speaker 1: the abbreviations AM and PM were in use by scientists
Speaker 1: like Nicholas Culpepper. Both the full terms and the abbreviations
Speaker 1: trickled into common usage after that, even though these designations
Speaker 1: didn't have much to do with the astronomical bodies anymore. However,
Speaker 1: by the late eighteen hundreds, starting with the Canadian Pacific
Speaker 1: Railway in eighteen eighty six, more countries and military entities
Speaker 1: started telling time based on the twenty four hour clock. Again.
Speaker 1: With the exception of countries like the US, Australia, Canada,
Speaker 1: and the Philippines or where the twelve hour system is
Speaker 1: officially used, most other countries officially use a twenty four
Speaker 1: hour clock, but ancient habits die hard. If you ask
Speaker 1: someone in Ireland, China, or France the time, they're equally
Speaker 1: likely to use AM and PM. But okay, let's switch
Speaker 1: over to another common term, SOS. Even children at play
Speaker 1: know that when you are in a life threatening emergency,
Speaker 1: maybe you need to be rescued from an island filled
Speaker 1: with man eating crabs that's also surrounded by lava. The
Speaker 1: way you let the world know that you're in trouble
Speaker 1: is to shout three simple letters SOS. You can write
Speaker 1: them on the beach, send them via Morse code, or
Speaker 1: write them on your hand and flash them at pastors by.
Speaker 1: We all know that sending out an SOS signal is
Speaker 1: a request for rescue. So what does SOS mean? Is
Speaker 1: it an abbreviation? What did the letters stand for? This
Speaker 1: was new to me today. The letters SOS stand for nothing,
Speaker 1: not save our ship, not save our souls. It wasn't
Speaker 1: even originally designed to stand for letters of the English alphabet.
Speaker 1: SOS came to us as a replacement for visual distress
Speaker 1: signals during the early days of long distance electromagnetic communication.
Speaker 1: Samuel Morse developed what would become Morse code, alongside his
Speaker 1: contributions to a telegraph machine that could send messages using
Speaker 1: electrical signals over a wire in the eighteen forties. In
Speaker 1: Morse code, dots and dashes are assembled in different configurations
Speaker 1: to represent the different letters of the alphabet. In this way,
Speaker 1: messages could be sent across countries via wired telegraph networks, and,
Speaker 1: starting in the early nineteen hundreds, wirelessly across oceans and
Speaker 1: then around the world using radio equipment. SOS came in
Speaker 1: during the transition between the two. In nineteen oh five,
Speaker 1: the German government, but which had leaned into telegraph systems early,
Speaker 1: published their regulations for the control of Spark Telegraphy. It
Speaker 1: mandated that German wireless operator use dot dot dot dash
Speaker 1: dash dash dot dot dot to signal an emergency. This
Speaker 1: didn't really have anything to do with letters of the alphabet,
Speaker 1: but it was quick and easy to type and difficult
Speaker 1: to mistake for anything else. It also happened to spell
Speaker 1: SOS in Morse code. Everyone agreed it was way better
Speaker 1: than SSSDDD, which is what the Italians were pushing for.
Speaker 1: At the International Radio Telegraph Convention in nineteen oh six,
Speaker 1: the term SOS was voted in as the official international
Speaker 1: distress signal and went into effect July first of nineteen
Speaker 1: oh eight. It didn't catch on everywhere immediately. For instance,
Speaker 1: the British Marconi International Marine Communication Company, which outfitted ships
Speaker 1: with radio equipment, preferred the distress code CQD in Morse code,
Speaker 1: and continued using it after the SOS call was established
Speaker 1: as the international standard. In fact, CQD was the first
Speaker 1: distress code sent by the radio operators on the Titanic
Speaker 1: in nineteen twelve when the ship hit Iceberg, although they
Speaker 1: did send the SOS signal as well. Early radios, like
Speaker 1: the Titanics couldn't transmit sounds, only electrical signals. Once inventors
Speaker 1: figured out how to encode speech, the verbal signal may
Speaker 1: day was picked up at the International Radio Telegraphic Convention
Speaker 1: in nineteen twenty seven. As we've talked about on the
Speaker 1: show before, may day is derived from the French madeir,
Speaker 1: which means help me, but SOS cannot be ousted. Although
Speaker 1: mayday is used in voice communication, SOS is still used
Speaker 1: as shorthand or anywhere that non verbal communication must be used.
Speaker 1: Today's episode is based on the articles what do am
Speaker 1: and PM stand for and what does SOS Mean? On
Speaker 1: HowStuffWorks dot Com, both written by Jesslynshields. Brain Stuff is
Speaker 1: production of by Heart Radio in partnership with houstuffworks dot
Speaker 1: Com and is produced by Tyler Playing Before. More podcasts
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