Speaker 1: Welcome to Tech Stuff, a production of I Heart Radios
Speaker 1: How Stuff Works. Hey there, and welcome to tech Stuff.
Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with
Speaker 1: iHeart Radio and I love all things tech, And you know, guys,
Speaker 1: I was trying to come up with a good idea
Speaker 1: for a holiday themed show. In the past, I've done
Speaker 1: episodes about some of the big tech items that landed
Speaker 1: on holiday wish lists in the past, you know, like
Speaker 1: the greatest tech gifts of all time. But I felt
Speaker 1: like I've been there, I've done that, And besides, a
Speaker 1: lot of those topics are like super timely and aren't
Speaker 1: relevant from year to year, so it makes no sense
Speaker 1: to ever listen to them after the year they published.
Speaker 1: So instead of doing an episode that's going to be
Speaker 1: irrelevant next year, I thought I would talk about Christmas
Speaker 1: lights and how they work and why it was such
Speaker 1: a pain in the neck to rig up special Christmas
Speaker 1: lights for the Netflix series Stranger Things, which I've talked
Speaker 1: about in a previous episode, but I figured it would
Speaker 1: be a good point to return to in this one. Now,
Speaker 1: before I dive into all of that, I want to
Speaker 1: acknowledge a few things First, while I'll be talking about
Speaker 1: Christmas lights, there are many people of different faiths, ethnicities, regions,
Speaker 1: etcetera who celebrates special days during the winter months, and
Speaker 1: lights nearly always play an important part in those various observations,
Speaker 1: which makes total sense because the days are shorter in
Speaker 1: the winter and thus we have more hours of darkness
Speaker 1: for every twenty four hour period, so lights would clearly
Speaker 1: be an important part of any celebration during that part
Speaker 1: of the year. So, for example, the manora in the
Speaker 1: Jewish faith symbolizes how the Maccabees, when rededicating the Holy Temple,
Speaker 1: which they had just won back from the Greeks, used
Speaker 1: a single bottle of oil to light the manora used
Speaker 1: in the rededication ceremony for eight nights, even though the
Speaker 1: bottle should only have lasted a single night. Then there's
Speaker 1: also the celebration of Quanza, where families like candles in
Speaker 1: the cannara and the candles represent the seven principles of
Speaker 1: the holiday. But getting back to Christmas lights, there's actually
Speaker 1: an older tradition than the sort of Christmas tree lights,
Speaker 1: in which Christian families would set out candles within view
Speaker 1: of a window as a symbol to alert fellow Christians
Speaker 1: that the family inside the house was they were made
Speaker 1: up of observing Christians, and that fellow Christians would be
Speaker 1: welcome to come into that house to worship with the family.
Speaker 1: But the Christmas lights we see every year really have
Speaker 1: their roots pun intended in a Germanic tradition of the
Speaker 1: Christmas tree. So why would you ever cut down a
Speaker 1: tree and bring it inside in the first place. Well, again,
Speaker 1: one of those things that makes sense as you start
Speaker 1: to think about all the details. Plants like fur trees
Speaker 1: and holly remain green even in the winter, which otherwise
Speaker 1: pretty much wipes out everything else and makes it brown
Speaker 1: and dead, so or appearing to be dead. So these
Speaker 1: plants became symbols of resilience and everlasting life. So people
Speaker 1: would cut down some of those plants and bring them
Speaker 1: indoors to remind them of that. But you know, then
Speaker 1: the plants would eventually just dry out and turn brown
Speaker 1: and thus negate the whole reason for bringing them inside.
Speaker 1: But you know, humans have never been rational creatures. There
Speaker 1: are some unsupported legends surrounding the origins of the German
Speaker 1: Christmas tree UH, sometimes referred to as the Tannenbaum, but
Speaker 1: really Tannenbaum is more of a word for fur trees
Speaker 1: in general, not just those all decked out with bowls
Speaker 1: of holly and whatnot. But one legend has it that
Speaker 1: Martin Luther, the reformer who caused a bit of a
Speaker 1: ruckus in the fifteen hundreds when he, you know, decided
Speaker 1: to criticize the Catholic Church, that he had started the
Speaker 1: tradition of the Christmas tree. However, the earliest written accounts
Speaker 1: on record that mentioned this tradition date to six oh five.
Speaker 1: Now that doesn't mean that's when the tradition started, of course,
Speaker 1: it's just the earliest written account that we happen to have.
Speaker 1: Scholars think the tradition might date back at least to
Speaker 1: the mid sixteenth century, though that would still be after
Speaker 1: Martin Luther had died. So anyway, that sixteen o five account,
Speaker 1: all it says is that the people would set up
Speaker 1: Christmas trees in their rooms in Strasbourg. There's no mention
Speaker 1: of lights in this particular account, but the decorations consisted
Speaker 1: of things like roses made out of paper and various
Speaker 1: foods being shoved into the tree, things like apples or cookies,
Speaker 1: and sugar. It's very food centricum. In fact, there was
Speaker 1: a tradition of raiding the Christmas tree on one of
Speaker 1: the days of Christmas, where the kids get to go
Speaker 1: and actually grab treats from the tree and eat them.
Speaker 1: The first written account to bring up the detail about
Speaker 1: lights in the Christmas tree dates to sixteen sixty. People
Speaker 1: in Germany would pin or otherwise attached candles to branches
Speaker 1: of these trees, and again, frequently these are trees that
Speaker 1: have been cut down and put up inside a house,
Speaker 1: not just trees out in the woods somewhere. Generally speaking,
Speaker 1: the practice was to light the candles only for a
Speaker 1: very short time before you blew them out again. And
Speaker 1: you were never supposed to leave a tree unattended, because,
Speaker 1: as you can imagine, combining a cut tree that might
Speaker 1: be kind of dry with open flames is a recipe
Speaker 1: for disaster. And in fact, there were more than a
Speaker 1: few cases of fires with these trees, some of them
Speaker 1: ending in catastrophe and tragedy. But I'm sure the effect
Speaker 1: was really nice leading right up to the moment where
Speaker 1: everything went ablaze. Okay, so let's skip ahead to the
Speaker 1: eighteen hundreds. At that point, the tradition extended beyond Germany.
Speaker 1: UH Harvard professor named Charles Fallen, inspired by stories that
Speaker 1: he had heard in Europe, did a lit up Christmas
Speaker 1: tree in America. This was believed to be the first
Speaker 1: lit Christmas tree in America, or at least the first
Speaker 1: one on record. In the eighteen forties, in England, Queen
Speaker 1: Victoria and Prince Albert had a Christmas tree famously depicted
Speaker 1: in an illustration that was published in a newspaper that
Speaker 1: likely helped boost the practice over in England. Prince Albert
Speaker 1: brought this over from his homeland in Saxony. So people
Speaker 1: came up with new ways to attach the candles to trees,
Speaker 1: you know, they found more improved methods that would catch
Speaker 1: the wax and things like that. However, there was still
Speaker 1: very much a danger of fire with this particular approach. Then,
Speaker 1: in the later eighteen hundreds we get to Thomas Edison,
Speaker 1: the inventor and entrepreneur who was spending a lot of
Speaker 1: time and resources trying to perfect the light bulb. Which
Speaker 1: he did not invent the light bulb, but he did
Speaker 1: improve upon it, or rather, I should say his lab
Speaker 1: improved upon it. So when he and his engineers managed
Speaker 1: to make a light bulb that could last more than
Speaker 1: just a few hours and could be suitable for general use,
Speaker 1: as opposed to stuff like the more dangerous arc lamps that,
Speaker 1: while extremely bright, were not practical for everyday applications. He
Speaker 1: then had to figure out a way, how do I
Speaker 1: sell this idea to cities, right to city officials, and
Speaker 1: then further onto the general public. So he wanted to
Speaker 1: convince Manhattan officials that his company should be the one
Speaker 1: to provide electricity and light all of Manhattan. So he
Speaker 1: had his employees hang lights during the holiday season in
Speaker 1: eighteen eighty on the outside of Menlo Park, which was
Speaker 1: an easy view of trains passing by, and it got
Speaker 1: a lot of attention. Now, one of the inventors who
Speaker 1: was working at his Menlo Park facility was Edward Hibbert Johnson.
Speaker 1: Johnson had actually been responsible for giving Edison a job
Speaker 1: at the Automatic Telegraph Company, but later on Johnson would
Speaker 1: end up working closely with Edison to develop Menlo Park
Speaker 1: itself and became an inventor and executive at the Edison
Speaker 1: Light Company. So it's funny because he helped get Edison
Speaker 1: a job early, and then he ended up working for Edison.
Speaker 1: Later it was at the Menlo Park facility where Johnson
Speaker 1: developed string lights, and these were lights that were wired
Speaker 1: together in series and would serve as the basis for
Speaker 1: Christmas lights. Just moving forward from that point, he used
Speaker 1: those lights to decorate a Christmas tree, and so Johnson
Speaker 1: is sometimes referred to as the father of electric Christmas
Speaker 1: tree lights because the original version, the earlier version that
Speaker 1: Edison did that was a string of lights they hung
Speaker 1: up on a building. This was the first time where
Speaker 1: someone was using electric Christmas lights to replace the candles
Speaker 1: that were found on the Germanic Christmas trees. His lights,
Speaker 1: by the way, had bulbs that were red, white, and blue.
Speaker 1: Is quite the patriotic Christmas tree. And like Edison, Johnson
Speaker 1: intended that for this not just to be a festive
Speaker 1: display in the spirit of America and the holiday season,
Speaker 1: but also a marketing effort to get more people to
Speaker 1: support and want and adopt electric lights. There was a
Speaker 1: general distrust in electricity around this time, so these were
Speaker 1: the ways in which Edison and his associates could try
Speaker 1: to win people over to this new technology, and adoption
Speaker 1: did not take off right away. So for one thing,
Speaker 1: no New York based reporters wrote about this Christmas tree
Speaker 1: at all, but one reporter for a Detroit newspaper did
Speaker 1: publish an account of what it was like seeing the
Speaker 1: Christmas tree all lit up. The next big development in
Speaker 1: the adoption of Christmas lights would come in eight when
Speaker 1: US President Grover Cleveland incorporated them in decorations for the
Speaker 1: Christmas Tree at the White House. So we're gonna go
Speaker 1: off on a little tangent here some fun trivia facts
Speaker 1: about Grover Cleveland. So he's the only US president whoever
Speaker 1: served two non consecutive terms, meaning he was both our
Speaker 1: twenty second and our twenty fourth president of the United States.
Speaker 1: The lighting of the Christmas tree would be during his
Speaker 1: second term as president. And just in case you're wondering
Speaker 1: the twenty third president, the one who interrupted those two
Speaker 1: terms was Benjamin Harrison, the grandson of our ninth President,
Speaker 1: William Henry Harrison. Sorry, recently, I've been showing up on
Speaker 1: a lot of ridiculous history episodes, and sometimes that stuff
Speaker 1: just gonna sticks with you anyway. Cleveland's Tree. Grover Cleveland's
Speaker 1: tree featured one hundred lights with bulbs of various colors,
Speaker 1: and it must have been a really impressive site for
Speaker 1: the time. Some of the movers and shakers in America,
Speaker 1: in other words, people had a ton of cash to burn.
Speaker 1: They began to put up their own decorated and lit
Speaker 1: Christmas trees. But it was not something the average person
Speaker 1: could do because at that time most of the United
Speaker 1: States wasn't wired for electricity, so to even have a
Speaker 1: lit Christmas tree with electric lights, you would have to
Speaker 1: set up a generator. You'd also typically have to hire
Speaker 1: an electrician to actually wire it up, and in today's money,
Speaker 1: that would mean that decorating a tree could cost at
Speaker 1: least a couple of thousands of dollars, so only the
Speaker 1: hoity toity folks who wanted to show off their wealth
Speaker 1: could really afford to have a Christmas tree with electric
Speaker 1: lights at that time. Anyway, over the course of the
Speaker 1: early nineteen hundreds, electric lights began to gain popularity as
Speaker 1: people became more comfortable with the idea of electricity. And
Speaker 1: it's really no wonder that folks were nervous at first.
Speaker 1: Fire is something you can see, at least in most cases,
Speaker 1: but electricity could be deadly but was also invisible, and
Speaker 1: Edison's company had already engaged in some pretty heavy smear
Speaker 1: campaigns against alternating current, since Edison was pushing direct current
Speaker 1: as a means to distribute electricity regionally, and a lot
Speaker 1: of those events and demonstrations that his company held involves
Speaker 1: showing off how deadly electricity could be, so they were
Speaker 1: kind of feeding into that fear. But the allure of
Speaker 1: the lights was undeniable. And with that, I mean not
Speaker 1: just Christmas lights, I mean you're run of the mill
Speaker 1: light bulbs now. Even in nineteen o three when General
Speaker 1: Electric introduced string Christmas light kits, which will let people
Speaker 1: string up their own lights at home without necessarily the
Speaker 1: use of an electrician, it was still really expensive a
Speaker 1: string of lights, and General Electric actually referred to these
Speaker 1: strings as festoons anyway. The string of lights consisted of
Speaker 1: eight whole light bulb sockets and they would hold Edison
Speaker 1: light bulbs, and it cost the equivalent of about three
Speaker 1: hundred dollars today. That's just the lights, and this was
Speaker 1: not something that the average family would necessarily spring for. Also,
Speaker 1: you wouldn't buy these kits, you would rent them for
Speaker 1: three hundred dollars, So after the rental period you would
Speaker 1: actually have to return them, so yikes. Now, the bulbs
Speaker 1: on these things were small, round bulbs, almost like manature
Speaker 1: incandescent light bulbs. Actually that's exactly what they were, but
Speaker 1: I'm talking more about the form factor rather than the
Speaker 1: actual lighting mechanism. In nineteen nineteen, General Electric introduced a
Speaker 1: new bulb shape and filament. It was more of a
Speaker 1: flame shape, is that sort of classic, large, kind of clunky,
Speaker 1: retro looking light bulb. That was the general shape that
Speaker 1: they introduced, and it had a filament made out of
Speaker 1: Mazda toungusten. The filament is the part of the incandescent
Speaker 1: bulb that actually glows. The company would use Mazda filaments
Speaker 1: in all sorts of lamp bulbs, not just Christmas ones. Now,
Speaker 1: there were a couple of possibly apocryphal stories about some
Speaker 1: smaller companies around this time that played an important role
Speaker 1: in popularizing Christmas lights. One of those stories is about
Speaker 1: a telephone company employee named Ralph E. Morris who at
Speaker 1: some point. Different versions of this story can date it
Speaker 1: to either eight, the same year that Grover Cleveland was
Speaker 1: lighting up the White House, or nineteen o eight. There's
Speaker 1: a pretty big discrepancy, but the stories say that he
Speaker 1: looked at a telephone switchboard, and telephone switchboards had these
Speaker 1: little tiny light bulbs mounted in them that would light
Speaker 1: up when you were making connections, and he thought those
Speaker 1: little light bulbs might make nice Christmas decorations. So he
Speaker 1: took a bunch of those little lightbulbs, a bunch of
Speaker 1: telephone wire, wired them all together, electrified the wire, and
Speaker 1: made up a little lit Christmas tree, a little fake
Speaker 1: lit Christmas tree, because the story says that he made
Speaker 1: a makeshift Christmas tree out of feathers. I don't know
Speaker 1: exactly how he did it, but that's what the story says.
Speaker 1: His son would later write an article claiming that his
Speaker 1: father invented Christmas lights, which wasn't quite accurate. They predated this,
Speaker 1: but I'm pretty sure it was an honest mistake, not
Speaker 1: something that was done, you know, maliciously. Now. The other,
Speaker 1: possibly an apocryphal story involves a guy named Albert Sadaka.
Speaker 1: This story goes that when Sedaka was fifteen, he heard
Speaker 1: about a terrible tragedy involving a deadly fire that began
Speaker 1: when a Christmas tree lit with candles caught fire and
Speaker 1: be died. As a result. His family made novelty lights
Speaker 1: with white bulbs, So he thought, hey, how about we
Speaker 1: change out those regular bulbs with bulbs of different colors
Speaker 1: and we use electric lights instead of candles to light
Speaker 1: up a Christmas tree. According to this story, he and
Speaker 1: his brothers began to do just that, and a few
Speaker 1: years later they led an effort to bring together several
Speaker 1: small competing light companies. They're all going for the same customers,
Speaker 1: and they formed the National Outfit Manufacturers Association, or NOMA,
Speaker 1: which would become its own company and by became the
Speaker 1: leading manufacturing company for electric Christmas lights. Now, as power
Speaker 1: companies wired up the United States for electricity, the popularity
Speaker 1: of electric Christmas lights began to grow. In nineteen twenty,
Speaker 1: a hardware store owner in California named Frederick Nash decorated
Speaker 1: trees outside his establishment, and that quickly grew into a
Speaker 1: tradition in which a nine block stretch of the road
Speaker 1: in front of his business would end up having trees
Speaker 1: just draped in lights, and it became the first big
Speaker 1: documented door Christmas lights display. When we come back, i'll
Speaker 1: talk more about the evolution of Christmas lights, and then
Speaker 1: we'll dive into how the heck they work, and in
Speaker 1: the case of traditional Christmas lights, how they don't work
Speaker 1: if just one bulb goes bad. But let's take a
Speaker 1: quick break. I've got a little bit more to go
Speaker 1: on to the history of Christmas lights and some of
Speaker 1: the interesting things about them before we get into how
Speaker 1: they work. So by the late nineteen thirties, electric Christmas
Speaker 1: lights had become a popular new tradition, with homeowners and
Speaker 1: businesses alike uh using them to create bright, colorful displays,
Speaker 1: and in some cases they went a little bit overboard.
Speaker 1: A few places became truly famous for their decorated trees
Speaker 1: and buildings. When the United States entered into World War
Speaker 1: Two and there was a concern about the possibility of
Speaker 1: cities being bombed, there were blackout orders in various cities
Speaker 1: like New York, and that meant that Christmas lights would
Speaker 1: actually go dark in nineteen four in New York City.
Speaker 1: But with the war's end the following year, people made
Speaker 1: up for lost time. Meanwhile, tastes began to change in America.
Speaker 1: Families in the late nineteen fifties were introduced to a
Speaker 1: new invention, the aluminium Christmas tree. Yeah, I can't even
Speaker 1: I can't believe this this really happened either, guys. These
Speaker 1: were trees made out of aluminium, a space age material
Speaker 1: that was clearly so much better than a freshly cut
Speaker 1: fir tree. However, the Christmas lights of the day, which
Speaker 1: were still incandescent bulbs in sometimes questionable wires, would get
Speaker 1: way too hot for aluminium trees. They also could potentially
Speaker 1: create an electric shock hazard because aluminium can conduct electricity. Plus,
Speaker 1: those aluminum trees had needles quote unquote made out of foil,
Speaker 1: which would easily melt. So instead of hanging electric lights
Speaker 1: on the tree, companies began to manufacture lamps that had
Speaker 1: a rotating color wheel. And it's just what it sounds like,
Speaker 1: and it's not all that different from what was inside
Speaker 1: old mechanical television sets before electric TV was invented. So
Speaker 1: you've got a bulb that's what provides the light, kind
Speaker 1: of like a projector, and in front of the bulb,
Speaker 1: you have a wheel that has different pains of colored plastic,
Speaker 1: and this wheel rotates past the bulb and different colors
Speaker 1: of light shine out of your glorious lamp towards your
Speaker 1: even more glorious aluminum Christmas tree. It was a thing y'all. Now,
Speaker 1: I can't say I personally found it appealing, but back
Speaker 1: then it was selling like gangbusters. Unfortunately, for companies like Noma,
Speaker 1: the leading manufacturer of Christmas lights, it meant that there
Speaker 1: was a drastic drop in Christmas lights sales as these
Speaker 1: aluminum trees became all the rage. Noma would actually end
Speaker 1: up going into bankruptcy and today it exists as a
Speaker 1: brand name. But that's about it. The era of the
Speaker 1: aluminum tree lasted about a decade, upon which time many
Speaker 1: people either went back to using the previously live trees
Speaker 1: or they switched to more natural looking artificial trees, and
Speaker 1: that meant the electric lights were back baby. However, because
Speaker 1: of the American manufacturers going out of business during the
Speaker 1: rain of aluminum terror, the Christmas lights on the market
Speaker 1: mostly came from other countries, so America would no longer
Speaker 1: be king of the electric Christmas light. All right. Now,
Speaker 1: we're getting up to about nineteen seventy and the introduction
Speaker 1: of the mini light. So for a very long time,
Speaker 1: the typical Christmas light was a five or ten watt bulb,
Speaker 1: typically the size of a night light bulb, those little
Speaker 1: kind of cone shaped bulbs that I was talking about
Speaker 1: the retro style. They're pretty big. Uh. These were the
Speaker 1: type of lights that I grew up with when I
Speaker 1: was a kid. That's the kind we had on our trees,
Speaker 1: the big, big bright lights. I still missed those. But
Speaker 1: they drew a lot of power because a string of
Speaker 1: fifty five what bulbs means that you're consuming two fifty
Speaker 1: what's and most people were using multiple strands, like one
Speaker 1: string wouldn't do it. You might have three strands, three
Speaker 1: to five for a tree, maybe five to ten for
Speaker 1: your house. So you're consuming an enormous amount of power
Speaker 1: when you're having this stuff lit up. So the Christmas
Speaker 1: lights were greedy for electricity. Then they pushed electric bills
Speaker 1: pretty high. They would also get really hot, which you
Speaker 1: know I mentioned back with the aluminium trees. Touching a
Speaker 1: bulb could give you a little bit of a minor burn,
Speaker 1: as I found out on more than one occasion when
Speaker 1: I was a kid, because I had three qualities that
Speaker 1: guaranteed I was gonna get burned. First, I was curious. Second,
Speaker 1: I was foolish or maybe stupid, and third I had
Speaker 1: a really short memory, I guess. Anyway, the bulbs were popular,
Speaker 1: and they were colorful, but they were also wasteful and expensive.
Speaker 1: The many light would become a popular alternative to that bulky, hot,
Speaker 1: expensive Christmas light of the past. The many lights are,
Speaker 1: as the name implies, smaller. They only need two point
Speaker 1: five volts of electricity, and they don't get nearly as hot.
Speaker 1: Although they are still incandescent bulbs, so they still do
Speaker 1: generate heat, they're just not as hot as those larger
Speaker 1: bulbs were. It does, however, raise a question, how do
Speaker 1: you supply electricity to a two and a half volt
Speaker 1: socket if your source is an outlet that's putting out
Speaker 1: a hundred twenty volts. This is a good time to
Speaker 1: transition into a talk about circuits. So a quick reminder
Speaker 1: in electricity, voltage is sort of like water pressure in
Speaker 1: a water system. It's how hard the electricity is being
Speaker 1: pushed through. You can think of it like that. It's
Speaker 1: not exactly the same, but that's a rough analogy. It's
Speaker 1: the behind the movement of electricity, and a volts supply
Speaker 1: are overshadows a two and a half volt load. So
Speaker 1: imagine like having a fire hose of water directed at you.
Speaker 1: You've got a little shot glass that you're filling up
Speaker 1: and dumping out. It would just be way too much.
Speaker 1: But these Christmas lights were chained together in series, which
Speaker 1: meant one bulb socket connects to the next bulb socket
Speaker 1: in the same circuit and so on. So if you've
Speaker 1: got two two and a half volt sockets, you end
Speaker 1: up with a load that requires five volts. If you
Speaker 1: were to multiply two and a half volts by I
Speaker 1: don't know, let's say forty eight, you'd get a hundred twenty.
Speaker 1: So yeah, if you string together forty eight light bulb
Speaker 1: sockets and each one of those is a two and
Speaker 1: a half volt socket, you end up with a full
Speaker 1: load what requires a hundred twenty volts. Problem solved now.
Speaker 1: Typically companies would actually bump that up to fifty light
Speaker 1: sockets per series, and those extra two sockets would mean
Speaker 1: that each individual bulb would be slightly, maybe even in
Speaker 1: per sceptibly dimmer than it would be if you only
Speaker 1: had forty eight, but it wouldn't be so dim that
Speaker 1: it would make a huge difference. So imagine a pathway
Speaker 1: from an electric outlet that goes down a line of wires,
Speaker 1: and those wires connect to fifty bulbs in series. So
Speaker 1: bulb one, the bulb, two, the bulb three, etcetera. This
Speaker 1: represents the path that electricity takes, and along the way,
Speaker 1: the electricity is doing work in the form of producing
Speaker 1: light with those little light bulbs. And here's where a
Speaker 1: drawback of Christmas lights comes in. Let's say one of
Speaker 1: those bulbs burns out. Well, a burnt out bulb is
Speaker 1: going to break that pathway for the electricity. It opens
Speaker 1: the circuit, and because the path is broken and electricity
Speaker 1: needs that clear, unbroken path, the whole string of lights
Speaker 1: will go out. This is how Christmas lights used to be,
Speaker 1: where you'd have to go down a line of dark
Speaker 1: lights and you would swap out one bulb for another,
Speaker 1: over and over. You would be searching of the one
Speaker 1: bulb that caused the problem. And often it would lead
Speaker 1: to people chucking out a string entirely and just replacing
Speaker 1: it because trying to find that one bird's out bulb
Speaker 1: and a string of fifty just wasn't fun. And it
Speaker 1: was even worse if more than one bulb had been affected,
Speaker 1: because you might replace one bad bulb and never know
Speaker 1: it because there's a second or third bad bulb in
Speaker 1: that same string. It was infuriating now on top of that,
Speaker 1: later electric lights would have even longer strings like one hundred, hundred,
Speaker 1: fifty or two hundred lights. Not in order to achieve this,
Speaker 1: because I was just talking about how if you put
Speaker 1: these in series it creates that greater load. Well, engineers
Speaker 1: were able to kind of cheat with this. They were
Speaker 1: using both series circuits and parallel circuits for these lights. Now,
Speaker 1: as I mentioned, a series circuit strings one electric load
Speaker 1: after another along the same electrical path or circuit. So
Speaker 1: you can think of that as like one long street
Speaker 1: with houses on either side of the street, and houses
Speaker 1: represent a load on the electric circuit. So in this example,
Speaker 1: with a string that has fifty lights, think of a
Speaker 1: street and there are fifty houses twenty five on either
Speaker 1: side of the street. So to visit a house a
Speaker 1: little further down the street, you have to pass all
Speaker 1: the other ones first. Parallel circuits create multiple paths, a
Speaker 1: an independent pathway for each circuit, so different loads are
Speaker 1: on their own distinct pathways. So with a string of
Speaker 1: one fifty Christmas lights, for example, you would actually have
Speaker 1: three fifty lights series circuits. Right, So you've got one
Speaker 1: string of fifty lights in series, a second string of
Speaker 1: fifty lights in series and a third string of fifty
Speaker 1: lights in series, but all three are then connected in
Speaker 1: parallel with each other in the street analogy, this would
Speaker 1: be like having three parallel streets that all connect to
Speaker 1: the same main road. Now, with this kind of string
Speaker 1: of lights, if one bulb were to go out, only
Speaker 1: the other bulbs in that same series circuit would go dark.
Speaker 1: So with a hundred fifty light string, it would mean
Speaker 1: one third of those lights would go dark. Right, fifty
Speaker 1: lights would go out, but the other one hundred would
Speaker 1: stay lit because they were actually still in those parallel circuits.
Speaker 1: They were independent of that one fifty light string. You
Speaker 1: still have a problem with a third of your lights
Speaker 1: going dark, though, Engineers figured out how to solve this
Speaker 1: issue by creating what's called a shunt. Now, essentially, a
Speaker 1: shunt is an alternative circuitry path that electricity can pass
Speaker 1: through even if a load has otherwise failed. So in
Speaker 1: this case, if a light bulb were to burn out,
Speaker 1: the light bulb would go dark, but the shunt would
Speaker 1: take over as the path for electricity to flow through,
Speaker 1: and that way the other bulbs in that series would
Speaker 1: still stay lit. So how does that work? Well? First,
Speaker 1: the shunt is lined with insulating material and that boosts
Speaker 1: the electric resistance of the shunt. This is important because
Speaker 1: if the shunt had an equal or lower electrical resistance,
Speaker 1: then the filament inside the lightbulb, the electricity would bypass
Speaker 1: the bulb altogether and just go through the shunt. That
Speaker 1: means you wouldn't have a string of Christmas lights insteaid.
Speaker 1: You would have a really bad extension cord that was
Speaker 1: eating up a lot of power. And more than that,
Speaker 1: it would start to heat up and could potentially pose
Speaker 1: as a fire hazard, and that's no bueno. So this
Speaker 1: is a good opportunity to talk about short circuits. A
Speaker 1: short circuit and I am not talking about the movie
Speaker 1: that featured Johnny five the robot. A short circuit is
Speaker 1: when electricity encounters a pathway of lower resistance than the
Speaker 1: path it is supposed to follow. And yeah, the path
Speaker 1: of least resistance is a thing. We see it in
Speaker 1: nature all the time. If there are multiple ways for
Speaker 1: something to happen, the way that has the least obstacles
Speaker 1: tends to be the one we end up with. So
Speaker 1: electricity is going through its circuit. Do do, do, do
Speaker 1: and suddenly there's a detour. Something has made contact with
Speaker 1: the circuit that represents a lower resistance pathway. The electricity
Speaker 1: takes the lower resistance pathway. That's just nature. The electricity
Speaker 1: skips out on doing whatever it was supposed to do,
Speaker 1: like light a light bulb, and rushes down this new path.
Speaker 1: Now at a steady voltage, this means you get a
Speaker 1: spike in current. This is because the voltage is that
Speaker 1: pressure I was talking about, and the pressure remains the same,
Speaker 1: but the reduction in electrical resistance means it's easier for
Speaker 1: electricity to flow through that part of the circuit, So
Speaker 1: the current has to increase. We expressed this mathematically by
Speaker 1: saying voltage is current times resistance. So if voltage is
Speaker 1: staying the same, it's not changing and electrical resistance is decreasing. Current,
Speaker 1: by mathematical definition, has to increase to make up the difference,
Speaker 1: and an increase in current can become dangerous or even deadly.
Speaker 1: Now but because of that risk, engineers began to include
Speaker 1: fuses in Christmas lights. The fuse in a Christmas light
Speaker 1: is kind of a strip of thin wire that's near
Speaker 1: the plug end of a string of lights. The part
Speaker 1: that actually plugs into the wall. That's where the fuse is.
Speaker 1: It's rated for a certain maximum of current, and if
Speaker 1: the current increases beyond that maximum because of a short
Speaker 1: typically then this wire will actually kind of burn through
Speaker 1: and then it leaves a gap, and that gap ends
Speaker 1: up having such a high electrical resistance that electricity cannot
Speaker 1: flow through the string of lights and they all go dark.
Speaker 1: So the fuse is typically replaceable, and in these strings
Speaker 1: of lights you can even open up a little window
Speaker 1: and put in a replacement fuse if the one that
Speaker 1: you have in there has burnt out for any reason.
Speaker 1: So that is sort of a safety measure in case
Speaker 1: of a short circuit. All right, Now let's get back
Speaker 1: to the shunt. So this insulating wire that's around this
Speaker 1: this shunt typically wraps around the base of the filament
Speaker 1: in a Christmas light bulb, and because it has a
Speaker 1: higher electrical resistance than the filament does, electricity is not
Speaker 1: going to go through the shunt normally, it will go
Speaker 1: through the filament instead. Now, if the filament begins to
Speaker 1: burn out, it starts to get really hot, and that
Speaker 1: heat is enough to melt the insulating material off of
Speaker 1: the shunt. So the bulb burns out, the shunt wire
Speaker 1: essentially sheds its insulation. It's melted off. As a result,
Speaker 1: the shunt becomes a lower resistance pathway for electricity, and
Speaker 1: electricity can then pass through the light bulb socket and
Speaker 1: keep the other lights on the series lit. It means
Speaker 1: you can actually spot the burnout bulb in a string
Speaker 1: and replace it. You don't have to worry about one
Speaker 1: bulb going out and everything going out. You'll just see
Speaker 1: that one bulb burnout and you can then swap it out. Now,
Speaker 1: one other thing that can happen that can be frustrating
Speaker 1: is that some of the strings and lights are pretty
Speaker 1: cheaply made, and the bulb can be loose in their sockets,
Speaker 1: and if they're not making good contact with the parts
Speaker 1: of the socket where the electricity flows through, then you're
Speaker 1: not gonna get electricity flowing through the series because it'll
Speaker 1: be like an open circuit or a circuit where the
Speaker 1: switches in the off position. So in that case, you
Speaker 1: have to go down the length of the wire and
Speaker 1: check to make sure that each bulb is plugged in
Speaker 1: properly for electricity to flow through that series of bulbs.
Speaker 1: Some Christmas lights actually put the shunt into the socket
Speaker 1: itself rather than inside the bulb, which helps side stuff
Speaker 1: that problem. So in those cases, just like with a
Speaker 1: burnt out bulb, the affected bulb would be the one
Speaker 1: that was not lit, but the rest of it should
Speaker 1: still be shining brightly. Now, when we come back, I'll
Speaker 1: talk a bit more about how the series Circuits and
Speaker 1: Christmas Lights created a headache for the electricians on the
Speaker 1: Netflix series Stranger Things, as well as a couple of
Speaker 1: other interesting facts. But first let's take a quick break. Okay, So,
Speaker 1: in case you've not seen the series Stranger Things, let
Speaker 1: me explain why Christmas lights are important and why they
Speaker 1: posed a big challenge to the crew of that show.
Speaker 1: So in the show, there's a boy named Will Buyers
Speaker 1: who is trapped in a sort of parallel dimension and
Speaker 1: he can't interact directly with people in our dimension, but
Speaker 1: he discovers that he can affect electrical devices. The show
Speaker 1: is set in the nineteen eighties and Will comes from
Speaker 1: sort of a lower middle class family and they still
Speaker 1: have the big, bulky Christmas lights they haven't switched over
Speaker 1: to the smaller ones, and when Will's mother, Joyce figures
Speaker 1: out that Will can affect these lights, she devises away
Speaker 1: for him to communicate with her. She labels a string
Speaker 1: of Christmas lights with letters of the alphabet, and that
Speaker 1: means Will can effectively type out messages by making individual
Speaker 1: lights go off and on, which is a clever idea
Speaker 1: for a show. It's also not how Christmas lights work because,
Speaker 1: as I've described in this podcast, they're supposed to all
Speaker 1: be in series and you can't turn them off and
Speaker 1: on individually because they're all in a series circuit. They're
Speaker 1: strung in such a way that turning off one means
Speaker 1: they all go off. So how did the show get
Speaker 1: around that? Well, it was surprisingly challenging. The solution was
Speaker 1: sort of straightforward, but it wasn't easy or convenient. The
Speaker 1: electrician had to wire each bulb individually to a switchboard
Speaker 1: that could supply electricity to that bulb. Now, that also
Speaker 1: meant having to control the voltage that was going to
Speaker 1: each bulb since they were no longer in series and
Speaker 1: the load wouldn't be shared across the whole wire, So
Speaker 1: you had to control the voltage to be appropriate for
Speaker 1: the individual bulbs and then isolate it from all the
Speaker 1: other bulbs, and you had to do it twenty six times,
Speaker 1: or at least however many times was needed to make
Speaker 1: sure all the letters that were being used were wired
Speaker 1: up properly. You might have been able to get away
Speaker 1: without wiring up a X or Z or some of
Speaker 1: the other letters that aren't a common The switchboard was
Speaker 1: effectively a keyboard, so you could like press the a
Speaker 1: button that would activate a switch, and the switch would
Speaker 1: open the circuit, meaning it breaks the pathway, and because
Speaker 1: it breaks the pathway, the light would go out. And
Speaker 1: if you close the circuit, if you close the switch,
Speaker 1: that would restore the pathway the light bulb would come
Speaker 1: on again. So that wiring was probably a huge pain
Speaker 1: in the neck because it meant having to do this
Speaker 1: for multiple letters and making sure each set of wires
Speaker 1: had the appropriate label on the switchboard, not to mention
Speaker 1: being sure that no bulb was going to get too
Speaker 1: much voltage for it to handle. And on top of that,
Speaker 1: the wiring had to be hidden so the camera would
Speaker 1: make it look like it was just a normal string
Speaker 1: of Christmas lights. You couldn't see all these individual wires
Speaker 1: going to each bulb. It would break the illusion. So
Speaker 1: while you wouldn't call this a high tech special effect.
Speaker 1: It was one that required a lot of work and
Speaker 1: trial by error to get it just right to produce
Speaker 1: the effect that the series directors were looking for. Now
Speaker 1: we're not quite done with the evolution of Christmas lights.
Speaker 1: We've got a few more things to chat about. As
Speaker 1: the novelty song The Twelve Pains of Christmas reveals, Christmas
Speaker 1: lights present their own frustrating challenges. If they're not stored properly,
Speaker 1: they become a tangled mess. There's the problem of one
Speaker 1: going out and then they all go out. If you
Speaker 1: have a shuntless kind of string of Christmas lights at
Speaker 1: any rate, Then there's the line that used to make
Speaker 1: me crack up as a kid. This will tell you
Speaker 1: how sophisticated my sense of humor was, And who am
Speaker 1: I kidding? Still is? The line is, now, why the
Speaker 1: hell are they all blinking? Yeah, blinking lights? Okay, there
Speaker 1: are two general ways of creating blinking Christmas lights if
Speaker 1: you're a manufacturer. One of those ways is brilliantly simple
Speaker 1: and kind of jankie. So let's go with that one first,
Speaker 1: all right. So let's say get a couple of different
Speaker 1: metals and you create a strip using these two different metals.
Speaker 1: Maybe one side is copper and the other side is
Speaker 1: you know, iron or something. These two metals have slightly
Speaker 1: different properties, and one of the different properties they have
Speaker 1: is their rate of expansion when they get hot. Because
Speaker 1: one metal will expand faster than the other, it causes
Speaker 1: the strip to bend. It curls as one side of
Speaker 1: the strip expands faster than the other one does. These
Speaker 1: are called bimetallic strips, and they're using lots of stuff
Speaker 1: like thermostats, but thermostats are a different podcast. Alright, So
Speaker 1: you've got this bimetallic strip and you use it to
Speaker 1: make a circuit path to a filament on a light bulb.
Speaker 1: So the strip itself is acting like a kind of wire.
Speaker 1: Electricity is passing through the strip to the filament. But
Speaker 1: then the filament starts to heat up, and when it
Speaker 1: heats up, it causes the strip to start to bend
Speaker 1: because of that expansion thing I was just talking about.
Speaker 1: The strip bends to a point where it no longer
Speaker 1: makes contact of the filament, and since the electricity was
Speaker 1: flowing through the strip, it means the electrical path is broken,
Speaker 1: right because there's no more contact between the strip and
Speaker 1: the filament. No more electricity goes to the filament, and
Speaker 1: so the light blinks out further. This bulb, called a
Speaker 1: blinker bulb, doesn't have a shunt in it, so when
Speaker 1: it goes out, all the other lights in that series
Speaker 1: blink out at the same time. Then the bimetallic strip
Speaker 1: begins to cool down because the filament is no longer glowing,
Speaker 1: so it's no longer putting off heat. And as it
Speaker 1: begins to cool down, it straightens out again. And when
Speaker 1: it straightens out, it makes contact with the filament, which
Speaker 1: causes the circuit to re establish and the lights come
Speaker 1: on again. This process repeats itself over and over until
Speaker 1: the blinker bulb finally burns out and you have to
Speaker 1: replace the darn thing. Now, I love this approach because
Speaker 1: it's a low tech, practical way to create blinking lights,
Speaker 1: and it even includes a little mechanical element in the
Speaker 1: form of those bending strips. I think it's pun intended brilliant. Now,
Speaker 1: the other way to make blinking lights is also brilliant,
Speaker 1: but it's a bit more sophisticated. There are strings of
Speaker 1: lights that come with sixteen function controllers. These controllers have
Speaker 1: four transistors each of which drives a separate strand of lights.
Speaker 1: So the full string of lights is made up of
Speaker 1: four strands of lights. Further, these lights on these these
Speaker 1: full strands are in an interleaving pattern, meaning that you
Speaker 1: don't just get all the lights in one strand followed
Speaker 1: by all the lights in the second strand and so on.
Speaker 1: The string would interleave these strands, so you could have
Speaker 1: something like light one from Strand one, light one from
Speaker 1: strand to, light one from strand three, light one from
Speaker 1: strand four, light two from strand one, and so on,
Speaker 1: And that way you can apply different effects to each
Speaker 1: strand in the full string, and you could get really
Speaker 1: interesting results. Otherwise you might end up with a tree
Speaker 1: in which the first fifty lights are blinking, than next
Speaker 1: fifty lights are fading in and out, the next fifty
Speaker 1: are twinkling, etcetera. So by doing it this way, you
Speaker 1: can have that effects spread out throughout the entire string
Speaker 1: of lights, and you get a more interesting varied effect.
Speaker 1: More recently, we've seen led lights start to replace the
Speaker 1: old incandescent many lights. The incandescent bulbs work by feeding
Speaker 1: electricity through a filament which heats up and gives off light.
Speaker 1: But LED lights generate light in a totally different way.
Speaker 1: L E D s have electrons moving through a semiconductor material.
Speaker 1: Now I've talked about this in past episodes, and frankly,
Speaker 1: I'm running out of time in this episode, so I
Speaker 1: don't feel like I can really go into a lot
Speaker 1: of detail here about how it works. But from a
Speaker 1: sub atomic level, here's what's going on. You've got an
Speaker 1: electron inhabiting a certain energy shell around the nucleus of
Speaker 1: an atom. You pour some energy into that atom that
Speaker 1: causes the electron to jump to a higher energy shell
Speaker 1: a little further out from the atoms nucleus. But then
Speaker 1: you cut off the energy that's going into the atom,
Speaker 1: and the electrons natural state is to be closer to
Speaker 1: the nucleus, but in order to move back to where
Speaker 1: it's supposed to be at first has to give off
Speaker 1: that excess energy, which it does so by emitting the
Speaker 1: energy in the form of photons or light, and they
Speaker 1: do it in very specific frequencies, so with different semiconductors
Speaker 1: you can produce different colors of light. One nice thing
Speaker 1: about L E D s is that when an LED
Speaker 1: light fails, which typically takes a long time, LED lights
Speaker 1: tend to last much longer than incandescent lights. Anyway, the
Speaker 1: failed l e ED can still serve as a pathway
Speaker 1: for electricity to flow through, so the other lights on
Speaker 1: the string will continue to stay lit. It's more or
Speaker 1: less that like the l e ED is is in
Speaker 1: itself acting like a shunt. LED lights, just like other
Speaker 1: Christmas lights, tend to be wired in series, and you
Speaker 1: have multiple series of lights wired in parallel on a
Speaker 1: single string. And another great thing about LED lights is
Speaker 1: that they typically require way less energy to run, so
Speaker 1: you can run them longer and for less money in
Speaker 1: the long run than you can with classic incandescent bulbs.
Speaker 1: They tend to be more expensive than incandescent bulb lights
Speaker 1: are on initial purchase, but in the long run you
Speaker 1: actually save money by using those and you save a
Speaker 1: lot of energy. So highly recommended h and one type
Speaker 1: of bulb I didn't mention, I skipped over it, but
Speaker 1: this was a favorite of mine when I was growing
Speaker 1: up are bubble lights, which made a comeback not too
Speaker 1: long ago, but these were like common when I was
Speaker 1: a kid. These lights have a fluid with a relatively
Speaker 1: low boiling point, and it's inside of a glass tube
Speaker 1: and at the base of the tube is an incandescent bulb,
Speaker 1: so when the bulb lights up, it gives off heat.
Speaker 1: Then eventually that heat reaches the temperature sufficient to bring
Speaker 1: the liquid inside the tube to a boil, which produces
Speaker 1: bubbles inside the tube. Now, we had these on our
Speaker 1: Christmas trees when I was a kid, and I thought
Speaker 1: they were super awesome. The early versions of these lights
Speaker 1: used a very lightweight oil as the liquid, but more
Speaker 1: modern versions tend to rely upon I chlora methane, which
Speaker 1: has a boiling point of thirty nine point six degrees
Speaker 1: celsius or a hundred three point three degrees fahrenheit. Oh
Speaker 1: and on the other end of the spectrum are the
Speaker 1: projector systems being used to create all sorts of effects
Speaker 1: on house exteriors, like snowfall or I don't know, an
Speaker 1: ELF strike team descending on a house. These projectors typically
Speaker 1: use LEDs to generate lasers to create the light needed
Speaker 1: for the projection. The light passes through lenses that magnify
Speaker 1: whatever images are being displayed and then shoots them up
Speaker 1: so that they appear on the side of a house.
Speaker 1: And lasers are pretty nifty. They're also super technical and
Speaker 1: I've talked about them another episodes, so I won't go
Speaker 1: into detail here, but I wanted to mention them because
Speaker 1: it's another high tech gadget being used in holiday decorations
Speaker 1: these days. Also, um, if you have one of these things,
Speaker 1: make sure that it's pointed well at your house and
Speaker 1: not the sky, because lasers have been known to cause
Speaker 1: problems for pilots because that light can be seriously powerful,
Speaker 1: so you know, just be responsible. There are other lights
Speaker 1: I can mention. They're like micro lights and mesh lights
Speaker 1: and icicle lights. But essentially all of these are variations
Speaker 1: upon the stuff I've already talked about in this episode.
Speaker 1: And then there are the Christmas light displays that synchronize
Speaker 1: the lights with the soundtrack using various micro controllers and sequencers.
Speaker 1: And maybe I'll do a full episode about that kind
Speaker 1: of stuff in the future, but for now, I say
Speaker 1: it's time for lights out. So that wraps up this
Speaker 1: episode of tech Stuff. If you guys have any suggestions
Speaker 1: for future episodes, reach out to me. You can send
Speaker 1: me an email the addresses text stuff at how stuff
Speaker 1: works dot com, or draw me a line on Facebook
Speaker 1: or Twitter. The handle for both of those is text
Speaker 1: Stuff h s W. You can also visit our website
Speaker 1: that's tech stuff podcast dot com, where you'll find an
Speaker 1: archive of how many episodes? Sorry? Oh all of them? Yeah,
Speaker 1: all of the episodes is what Taria is saying. So
Speaker 1: you can find all the episodes at tech stuff podcast Com.
Speaker 1: You'll also find a link to our online store where
Speaker 1: you can buy merchandise. And if you do, it's like
Speaker 1: you're giving me a little Christmas present, because every purchase
Speaker 1: you make goes to help the show, and we greatly
Speaker 1: appreciate it, and I'll talk to you again really soon.
Speaker 1: Hext Stuff is a production of I Heart Radio's How
Speaker 1: Stuff Works. For more podcasts from my heart Radio, visit
Speaker 1: the i heart Radio app, Apple Podcasts, or wherever you
Speaker 1: listen to your favorite shows.