The history of light (classic) | Planet Money

This message is from NPR, sponsor Microsoft.

Imagine if everyone at your company had their own AI tutor to help them learn new skills.

Khan Academy's Sal Khan is making that a reality.

Learn how on the WorkLab podcast from Microsoft.

Find it wherever you get your podcasts.

This is Planet Money from NPR.

Light.

It's amazing, isn't it?

We have it at our fingertips with the flip of a switch or a button on our phones these days.

It's a technology so convenient, so ubiquitous.

You almost forget it's a thing.

But the ways humans have captured and used lights have evolved over the centuries.

And with each advancement, we've been able to work longer, travel farther and vent whole new industries.

You could even say that as the technology of light progresses, so does humanity.

Back in 2014, David Kestinbaum and Jacob Coltsin wanted to understand that exact correlation.

So they asked the question, at different points in history, how much did light cost?

Here's Jacob.

Long before there were light bulbs, there was fat.

For thousands of years, if you wanted to light up your cave, your mud hut,

or if you were really lucky, your castle, you had to find some fat, something to use for a wick,

maybe some moss, maybe a piece of fabric, and you had to light it on fire.

This was not easy.

Even today, it's a hard way to get light.

How do I mind?

Yeah, hi.

Do you sell fat, maybe beef fat?

No.

I don't carry that.

No.

Okay, thanks very much.

Thank you.

Hi.

Do you sell fat, like beef fat?

No, I'm not selling either.

Sue it.

Nope.

Okay.

I'm not selling it.

It's a little harder to chop than...

It might think...

And I'm David Kestinbaum.

Today on the show,

The story of how we got

From dim little candles made out of cow fat

To as much light as we want

At the flick of a switch.

And I don't think I'm exaggerating here.

This one little story...

It explains why we are where we are today.

Why billions of people don't have to worry about starving today.

Why we aren't all subsistence farmers.

Why we can afford to have artists

And massage therapists and plumbers.

And yes, radio reporters doing stories about the history of light.

This message comes from NPR sponsor, American Express.

Take your business further

With the smart and flexible American Express Business Gold Card.

You can earn four times points on your top two

Eligible spending categories every month,

Like transit, US restaurants, and gas stations.

That's the powerful backing of American Express.

For example,

The American Express

This message comes from NPR Sponsor, American Express.

Take your business further

And give us a backing of American Express.

Four times points on up to $150,000 in purchases per year.

Terms apply.

Learn more at americanexpress.com slash business gold card.

This message comes from NPR Sponsor, Tufts University,

Now offering its Doctor of Physical Therapy program in Seattle, Washington.

Tufts accelerated DBT program can be completed in seven semesters

Through a hybrid curriculum of online coursework

And in-person clinical skills labs.

Start a rewarding career in physical therapy.

Learn more at go.tufs.edu slash Seattle.

Jacob, you brought these scraggly little candles in the office.

I'm holding them up here. They look...

They look a little marbled.

They're definitely not straight and they're not like sleek.

Now, it looks like some mold has grown on a string.

Oh, a string.

So you brought these candles into the office here

And we wanted to show them to an expert.

And we sat down with this woman, Jane Brockes.

Jane wrote a book called Brilliant,

The Evolution of Artificial Light.

So I made a few different candles.

I tried...

Oh, they're beautiful!

I thought you were a little disaster.

In the olden days.

If a mother was trying to teach her daughter to make candles,

She would not be pleased with these candles.

But we'll see what happens.

I was afraid when we lit these things that we might set off the fire alarm

Or the sprinkler system in the office.

I mean, that is how weird it is to have light from fire these days.

I was afraid we weren't going to be able to light them at all.

I mean, it's just be fat and twine.

But we pulled out a lighter.

Oh, we have... we have light.

That's not too bad.

Should we see how long it lasts?

It's not pretty, but I'm very impressed.

It's a beautiful color.

Look at that nice yellow flame, wouldn't you say?

Dude, you made a candle.

Jane says that the quest for this,

For something that gives you light after the sun goes down,

Drove people to do all kinds of things.

In the United States, in the Pacific Northwest,

Native Americans used dried salmon.

They basically made a salmon candle.

In the tropics, people would catch fireflies

And try to make a kind of firefly lantern.

And then there's this bird called the petrol.

The storm petrol in the north of Scotland,

which is a very oily seabird,

which they'd catch and dry,

and thread a wick down its throat,

and then light it, and that was a lamp.

Just carry on a dead bird with it.

We'll be on a table.

And I would imagine they'd have a little storage area

with a lot of dead storm petrol.

Martha, we need another petrol.

The petrol supply is getting low.

These ways of making light were all a huge hassle.

They took a lot of work.

It was not just that I didn't know what I was doing

when I made those candles.

The writer Harriet Beecher Stowe said,

making candles from animal fat was seven times as bad as washing clothes.

I mean, think about it. You gotta get a cow.

You gotta raise the cow.

You gotta have food to feed the cow.

You gotta kill the cow.

You gotta get the fat out of the cow.

You gotta put the fat in your cuisine art,

which isn't gonna be invented for a hundred years.

From an economic perspective,

if you wanna try to quantify how much of a pain in the butt

it is to make something, or at least how hard it is to get that thing,

you can ask a simple question.

How much does it cost?

Bill Northaus, an economist at Yale a while back,

got obsessed with this question.

He decided he wanted to calculate exactly how expensive light was

thousands of years ago,

and how that cost changed over time.

Because light, you know, light is this thing.

Society has needed and sought forever.

It was a way to track progress,

not just in light, but in all kinds of things.

Unfortunately, in order to do this,

he needed to know how much things cost thousands of years ago,

like an ancient Babylon.

He wasn't even sure those numbers existed,

but they did.

I ran into a woman at Yale,

and she believe it or not.

It's just unbelievable, actually.

She actually had wage data and price data

from the Babylonian era,

so four thousand years ago.

So now he has these numbers,

but he needs to know one other thing.

How much light are people getting for their money?

In ancient Babylon, people used lamps for light.

So, Northaus decided to make one.

I did this in my dining room.

Where else?

He buys an ancient style lamp from a catalog.

He gets it burning to measure how bright it is.

He borrows a light meter from a facility sky at Yale,

and he does some science.

And I would just measure it and write it down,

just the way you see in the old movies

I saw him guy with his lab coat writing down the measurements.

Jacob, odd little note here.

I happened to be taking Northaus'

economics class right around this time,

which I would say was a pretty serious, like, no nonsense class.

And it is so funny for me to think that at night,

he was going home and measuring ancient lamp light

in his dining room with a light meter.

So he does this, the light meter in the ancient lamp,

and he has his numbers.

But now he has to figure out a way to compare

the price of light over thousands of years.

So here's one measure he uses.

If you take a day's wages,

you work all day, you take all the money you earn in that day,

and you spend it on light.

How many minutes could you light up a small room at night,

with as much light as you get from today's modern light bulb?

Here's the answer for ancient Babylon.

Maybe ten minutes.

It was really expensive.

An entire day's wages got you the equivalent of

ten minutes of light from a kind of dim light bulb.

Economists talk a lot about productivity.

How much one person can produce with a day's labor.

And back then, the answer was not much.

I mean, everything was hard.

Growing food was hard, making candles, for instance,

took hours, and they used up fat.

Fat, which, by the way, was expensive,

because raising animals was hard.

This was a world where, when the sun went down,

almost everyone lived in the dark.

And this made town sort of romantic,

but basically it was awful.

The dark was not some beautiful thing you went out and explored.

It was dangerous.

It was something that trapped you.

In Paris, at one point, there was actually a law that said,

every night, everybody has to give their keys to a magistrate,

go home, and lock themselves in the house.

And for basically 4,000 years, very little happens,

with light, or with the economy in general.

Most people work all day, and that gets them enough to eat.

The way things get better, the way an economy grows,

the way people get richer, is that someone comes up

with a better way to do something.

A way that takes a little less work.

Over time, there are small improvements in life and in light.

The Romans figure out how to make a lamp that's a little more efficient.

People start to use whale oil.

This, of course, is very, very bad for whales,

but whales have a lot of fat.

They were like these big swimming sources of fuel.

Still, even when you get all the way to the 1700s,

life still looks more like ancient Babylon than the modern world.

People still travel the same way, by foot, by horse, by sailing ship.

Most people are still subsistence farmers,

usually living in some kind of hut, trying to grow enough food

not to starve to death.

You're after here, there are tiny gains in productivity,

little bits of economic growth, but not a lot.

And light still comes from finding stuff that's lying around

and just lighting it on fire.

Again, economist Bill Nordhaus.

As you look at the picture of what happened here,

it's economic history in a nutshell.

From Babylonian times to around 1800,

there were, even though there were improvements,

as best we can tell, they were very modest.

And then around 1800 in the lighting,

you can see it's so clearly in lighting.

It's just a enormous change in the pace of improvement.

What happens in the 1800s is a few things.

We start to really actively experiment.

We try to discover stuff.

And around 1850, a guy in Canada comes up with something

that's not just a slightly better wick or a slightly more efficient lamp.

It is this magical liquid.

With the right techniques, you can get it from coal or oil.

This big breakthrough?

Caracene, not cutting edge now.

But back then, Jane Brock says,

caracene was a huge deal.

When the first caracene lamps came out,

it was, as one historian said,

it was the kind of oil people had dreamed about for centuries.

It was brighter, it was cleaner,

and importantly, it was much cheaper.

The work of day, you get about an hour of whale oil.

Caracene, you get about five hours.

So it's about five times more efficient caracene.

Let the world and save the whales.

So if caracene was so great,

why did it take the world so long to find it?

Science.

This idea of professional scientists,

this idea that there are lots of people

who go to work every day at universities and do experiments.

In the 1800s, this is still a new thing.

If you happen to be president of Yale University,

this is around the time when you're thinking,

you know, maybe we should get one of those science departments.

Why, why, why, what they doing those experiments a century earlier?

Well, Yale didn't have scientists a century earlier.

They were teaching Greek and they were teaching logic.

Now all these scientists are working on better ways to make light.

And light is getting cheaper.

More people are using it.

No more locking yourself in and huddling in the dark all night.

Around this time, street lights start popping up.

And people start going out at night.

So we have caracene. What's the next big advance after that?

Okay, next big advance after that is the electric lamp.

The big one.

Well, you might think so.

This message comes from Applecard.

Reboot your credit card with Applecard.

It has no fees and gives you up to 3% daily cash back on every purchase.

Apply for Applecard now in the wallet app on iPhone.

Applecard issued by Goldman Sachs Bank USA Salt Lake City Branch.

Subject to credit approval.

Variable APRs for Applecard range from 19.24% to 29.49% based on credit worthiness.

Rates as of February 1, 2024.

Terms and more at Applecard.com.

This advertisement comes from our paid sponsor, Fundrise.

How interest rates mean that real estate assets are available at a discount compared to previous valuations.

The Fundrise flagship fund plans to expand its billion dollar real estate portfolio over the next few months.

Add the Fundrise flagship fund to your portfolio at fundrise.com slash money.

Carefully consider the investment objectives, risks, charges and expenses of the fund before investing.

Read the prospectus at fundrise.com slash flagship.

Support for NPR in the following message come from SuperMicro and Nvidia.

Accelerating AI at scale with a wide range of AI servers and the Nvidia AI Enterprise software platform.

SuperMicro, Pioneer, Sustainable, Rack Scale Innovations to drive AI infrastructure breakthroughs.

Hey, it's Whalen Wong. Every couple of weeks we make a pitch about Planet Money Plus.

Sponsor-free listening, bonus episodes supporting the work of Planet Money.

These are all great perks, but you know what's really great? New merch.

T-shirts, tote bags, mugs, hats, even plushies.

We've got them and they've all got the indicators new branding.

And only Planet Money Plus supporters can find out how to buy them.

It's in our latest bonus episode where we also revealed the winning name of the indicator mascot.

So if you're signed up already, get that merch. If you haven't, now's your chance.

Just go to plus.mpr.org slash Planet Money.

You know, Jacob, I thought I knew the story of the light bulb.

You know, Thomas Edison, the great inventor, story about science and innovation.

You know, Edison trying all these different filaments, these different designs,

and finally getting one little glow for hours. But this Eureka light bulb moment,

it is not enough to get you to the world of really cheap light.

Because Edison needed this other thing. He needed money. He needed lots and lots of money.

Why? Because he can't light a light bulb without electricity.

He needed to build a power plant.

So right now we're at the location of the original power plant in Lower Manhattan.

This is Paul Israel. He's an Edison scholar. We met him here in New York City.

We're standing in front of this plaque. It says Thomas Alva Edison in big letters.

And there's this picture, an etching.

And the image that they show is the generator room of the power plant.

Where the bunch of guys in really long mustaches and hats.

Right, this is 1882. So lots of mustaches in that plant.

The money part of building the power plant is so important that when they finally get this historic thing completed in 1882,

they get the power plant built. And they're ready to turn it on. Edison is not here.

He's a few blocks away at a big impressive stone building where today there is another plaque to a guy you may have heard of.

JP Morgan. It reads,

The capitalist capitalist known throughout the world of finance sought out by presidents helped bankroll the industrialization of America.

Can't write that on too many people's plaques.

JP Morgan's bank and a bunch of investors, they put up the money for the power plant.

To be clear, they built this great big expensive complicated power station.

The first central power station in the world, right?

Basically inventing electric light. And when they turn it on, Edison is not there.

Right. Right. He was where he needed to be with the people who had funded the whole thing.

Right. So at 3 p.m. on September 4th, Edison flipped on the switch here at JP Morgan's office.

And what happened? It went on. And as did lights all over the district.

About a square mile of lower Manhattan suddenly was lit by electricity.

You think of Edison the inventor, but even more important is Edison the businessman.

At the time, buildings in lower Manhattan were running off gas lights. And Edison knew that was who he had to be.

So he spent a lot of time thinking about economics.

Yeah. Well, he did. Yeah. In fact, if you look at his notebooks, constantly he's going through and comparing the cost of what he's doing to what the cost of gas system is.

You never think about that. Well, and that's what made him such a good innovator. Right.

Because he recognized that these economic questions were just as important in designing what he did in the laboratory.

When you think of economic growth, how much do you think of it as coming from like individual like Eureka moments and inventions and stuff like that?

And how much is it the stuff around it, like the ability to finance these things, the economic structure around it?

So most of it is actually the structure around it. To light a square mile of lower Manhattan, Edison needed a whole financial system.

He needed patents a way to protect his ideas so no one would steal them. He needed a company away a bunch of different investors could come together and risk money, a lot of money to build a power plant and lay wires.

So you could try this crazy thing, light without fire. Edison comes along at a time when all this machinery, patents, corporations, banks is in place.

There were consequences to growth. I mean, those first power plants burned coal and pollution was pretty bad. Edison built a huge power plant on the east side of Manhattan.

And at some point the city health department got involved. And this is according to the New York Times quote when it was found health department men were trying to photograph the smoke stacks.

Scouts were put on the company's roof who ordered the feeding of coal stopped whenever photographers appeared.

On the other hand, you know how the city lit up with cheap electric light trade offs around this time.

Everything is getting faster and cheaper scientists keep making new discoveries. You get the internal combustion engine, the tractor. For the first time in human history, most people don't have to work as farmers.

This went on decade after decade all through the 20th century. All kinds of things got much cheaper like light.

If you look at the really long arc here, it's amazing. I mean, go all the way back to the Babylonians. Okay. Babylonians, you worked all day. You got the equivalent of 10 minutes, 10 minutes of light.

4,000 years later in the 19th century with caracene lamps, things are better.

Days labor gets you five hours of light. And by the time Nordhaus does his light study in the 1990s, if you work a day, how much light do you get?

So maybe 20,000 hours? 20,000 hours. I mean, you basically, you have your house lit up, you have your streets lit up, you have all your equipment on, you have your air conditioner on, you have all the stuff you're doing is.

You're saturated with light. The main thing is you're saturated with light. Economic growth isn't all good. There is pollution, there are environmental consequences. But fundamentally, growth is about things getting faster, getting cheaper, getting more efficient.

It's about doing the same amount of work and being able to buy 20,000 hours of light instead of 10 minutes. And as a result, it's about being able to work less or to buy other stuff that used to be just for the wealthy.

We can buy books, we can take vacations. Even today, there are still people who go to work every day and try to figure out how to make a better light bulb.

This morning, I went to the bulb factory for about an hour.

This is John Edmund. He's one of the founders of a company called Creep. They make LED light bulbs, which of course are much more efficient than regular bulbs.

You'll try an experiment and you'll say, holy crap, we just got more light out of this thing by using this contact material or flipping the chip over.

Jacob, when we talk about economic growth every year, when we say the economy grew a couple percent, that happens because every day out there, someone somewhere in some corner of the economy has figured out how to do something a little bit better or a little bit faster or a little less expensively.

And this process has gone on year after year for hundreds of years now. And one question I always have when I think about this is like, and not just with light, but this whole story of constant economic growth, constant productivity improvement.

My question is, is it going to go on forever or at some point we're going to run out of ways to make things better?

We might double for more we are now, but we're not going to be tripling quadrupling it because there are physical limits.

I mean, will the car go a million miles an hour? No. It just won't. It's not going to happen.

For the light bulb at least, John says we may actually be near the end.

Oh, love that show. It originally aired in 2014.

You can email us at planamoney.npr.org or you can find us on all the socials at planamoney. Today's show was originally produced by Caitlin Kenney and Domiano Marquetti.

The rerun was produced by James Sneed, edited by Jenny Lawton and engineered by Valentina Rodriguez Sanchez.

Alex Goldmark is our executive producer. I'm Nick Bounton. This is NPR. Thanks for listening and throw in a light if you don't have one on already.

This message comes from NPR sponsor the BBC. You can only experience so much firsthand, but that's where the BBC comes in.

They provide information and inspiration because the best stories don't tell you what to think they're made to make you think.

Get the world stories on the new BBC dot com.

Support for NPR in the following message come from Super Micro and Nvidia. Accelerating AI at scale with a wide range of AI servers and the Nvidia AI Enterprise software.

Super Micro pioneer sustainable Rack scale innovations to drive AI infrastructure breakthroughs.

When voters talk during an elections season, we listen. We ask questions we follow up and we bring you along to hear what we learn.

Get closer to the issues and people and your vote at the NPR elections. Visit npr.org slash elections.

[The Price of Illumination: How the Evolution of Light Shaped Human Economic History]-[The history of light (classic)]

📋 Summary

The Evolution of Light: A Proxy for Human Progress

The Era of Scarcity: From Fat to Flame

The Turning Point: Innovation and Professional Science

Edison, Finance, and the Infrastructure of Growth

The Modern Era: Saturation and Physical Limits

🎯Key Sentences

📝Key Phrases

📖 Transcript