[pleasant music] (host) Whether it's snowy and white or a balmy 85 degrees in the shade where you live, in December chances are pretty high that you'll see twinkling electric lights lining the street and circling dozens of Christmas trees.

And even if we're not celebrating the holiday ourselves, many of us enjoy basking in their comforting glow.

But did you know that Thomas Edison is behind the invention of electrical Christmas lights, and that he used his holiday breakthrough to promote the implementation of electricity across the country?

And while Edison was busy spreading light and holiday cheer, he was also drumming up press for his new inventions and business interests by staging elaborate electrical stunts all around the globe.

And although this story can easily be dismissed as a Christmas novelty, Edison and his collaborators were actually taking part in the early history of science explainers that stretches back a lot longer than your favorite YouTube science explainer channels.

So, this week I'll be covering a small story about Edison's Christmas inventions and a big history that encompasses how science explainers, demonstrators, and journalists have served as a bridge between research communities and the general public for around 150 years.

Well, to kick off this story, we have to start with how we got from Edison's electric light to explainer videos.

The tradition of spreading cheer, joy, and light during December has antecedents in pagan tradition.

Historians debate the specifics of how pagan usage of lights, logs, and evergreens directly influenced Christian celebrations.

But as Christianity spread, regions began developing their own Christmas celebrations involving trees and lights.

Germans were the first to light up Christmas trees with candles in the 17th century.

And in the early 19th century, German immigrants to the U.S. brought the Christmas tree stateside along with some candles to light up their evergreen boughs.

Flash forward to December 31st, 1879, in Menlo Park, New Jersey, at the laboratory of inventor Thomas Edison.

While Edison is often credited with inventing the light bulb and inadvertently inspiring all of those cartoons where light bulbs go off over people's heads, this isn't the full story.

Edison's contributions lay in improving previous experiments and designs to create the ecosystem that allowed his light bulbs to be implemented successfully.

But along with his role as an inventor, Edison was interested in monetizing and spreading his inventions.

This led him to conduct a series of public demonstrations of his latest finds to spread the word about something the vast majority of people at that time had never heard of.

And to demonstrate how these newfangled inventions could better people's lives.

And what better way to spread the word than a big fancy show?

A December 21st, 1880, article in the New York Times describes Edison's demonstration in particularly glowy terms.

"Darkness had settled down upon the bleak "and uninviting place which Mr. Edison has chosen "for his home.

"But the plank walk from the station "to the laboratory was brilliantly lighted "by a double row of electric lamps, "which cast a soft and mellow light on all sides.

"The incandescent horseshoes gave out a yellow light, "which shown steadily and without the least painful glare, and were beautiful to look upon."

This evening, which started off sounding more like Dr. Frankenstein's lab and ended up as a winter wonderland, was almost at exactly the same time as when the Big Apple began to get electrified, with electric lights being a safer alternative to candles, fires, and gas lamps.

In December of 1884, Edison enlisted the help of a man named Edward H. Johnson, the vice president of the Edison Electric Light Company in New York City, to help him spread some light during the holiday season one more time.

A reporter came to Johnson's New York City home, which was located in the first part of the Big Apple to get electricity to show off a new wonder-- electric Christmas-tree lights.

And so, a new Christmas tradition was born, or really evolved out of an already existing one.

But science explanation and demonstrations were well on their way to growing in popularity.

But as interesting as the tagline, "Edison Invented Christmas Lights" sounds, it doesn't really get to the heart of a larger story about the late 19th century, technological innovation and how Edison helped create explainer videos.

Because Edison wasn't just busy lighting up walkways in December, he was hard at work during the end of the 19th and early 20th century becoming an international celebrity by cornering the market on not only new inventions, but also the title of "Inventor."

He amassed a large media presence through his prolific inventions, some of which he started from scratch, and some, like the light bulb, that he picked up from previous inventors and improved upon before introducing them to the general public.

But Edison's tree-light demonstrations weren't a standalone anomaly, and neither were they only about wow factor and entertainment.

According to Professor Bernard Lightman of York University, this was part of a trend in bringing new science to the general public in the late 19th century.

In 1834, William Huell even coined the word "scientists" to assign a catchall expression for what he called the "students of the knowledge of the material world."

Lightman also notes how British science explainers or journalists, writers, artists, and performers of the Victorian era were often tasked with translating these new inventions to the public.

Science demonstrators and educators worked in different mediums, sometimes relying on detailed illustrations, other times focusing on newspaper articles or live performances.

Demonstrators often stressed the wondrous and exciting world of science innovation by acting as translators between original researchers and the general public, often because new inventions were also met with a mixture of excitement and fear, like people who worried that electricity could be more dangerous in their homes than candles.

I'd argue that Edison's light demonstrations in the late 19th century fall within this world of science fascination and demonstration because although his Christmas lightings were primarily geared towards selling people on his newly patented bulbs and electricity, they also focused on the themes of scientific wonder that other science demonstrators of his era used to sell new ideas.

And his December 31st, 1879, display was the first one that kickstarted his electrical Christmas fad and was the first in a series of similar stunts that he staged around the world.

He took his inventions to public exhibitions, like the International Paris of 1881, London's Crystal Palace exhibition of 1882, and the exhibition of the Ohio Valley and the Central States in 1888.

And no, I didn't forget about Topsy the elephant, who was famously put to death by electrocution on Coney Island in 1904 before rising to the stuff of urban legend.

And that's because some historians are now claiming that it wasn't Edison who sentenced her to death in order to show off different uses of electricity, but rather it was her handlers who had Topsy electrocuted after she was abused and killed several people.

But Lightman also notes that the science demonstrators of the 20th and 21st century owe a huge debt to their 19th century predecessors, because while 19th century demonstrators largely relied on the media available to them to spread the good news about awesome science, namely live performance, print magazines, and newspapers, science educators today use the tools largely available to them and their audiences, meaning you.

He points to well-known demonstrators like Carl Sagan, Bill Nye the Science Guy, Richard Dawkins, Stephen Hawking, and Mr. Wizard as examples of modern science educators who tapped into the power of television, film, and radio to educate and excite the public about science.

But unlike Edison, science educators weren't in it only to sell products, but also just to promote new inventions and science in general.

That means the next time you click on YouTube videos by some of my awesome colleagues at PBS Digital Studios, like "Eons," "It's Okay to Be Smart," "Brain Craft," "Physics Girl," "Hot Mess," "Deep Look," and "Nourish," which is about food but is straight-up hosted by rocket scientists, then you're watching the latest iteration of something that started way back in the 19th century.

They're using their skills and expertise to show you new concepts and inventions in science in a way that's digestible, entertaining, and bridges the gap between behind the scenes research and how that research can improve our lives.

In some cases, these inspiring figures straddle the world between independent research and public education by splitting their time between their own lab work and their public platforms.

And in others, they have backgrounds in science, journalism, art, filmmaking, and communication.

And they use that specialized knowledge to bring all of the wonder of the science world into the general domain.

So, Edison and his contemporaries hit the world stage and pushed the word through newspapers, demonstrations, and science fairs.

Bill Nye crashed in through our TV screens, and your favorite science-ed YouTubers picked up the baton today on your cell phones and laptops.

So, have you thanked a science educator today?

So, an attempt to spread the word about new tech and science helped inspire some of our favorite holiday decorations and our favorite science explainer videos.

And it also gives us insight into why watching someone teach us about physics, or how to properly prepare homemade slime on YouTube is so addictive and exciting, because humans are naturally curious, and science taps into that sense of magic that brings out the geek in all of us.