What was the first photograph?

Welcome to Science Is Not Boring by kidopoly.com. I'm Mira and I'm Finn. Before we dive in today, we want to say a massive hello to six-year-old Arthur in Budapest, four and a half-year-old Evan in Chicago, and Josh, who is turning ten, along with his brothers Caleb and Isaac.

Arthur, Evan, Josh, Caleb and Isaac all wanted to know the exact same thing. How do cameras work? And how are photos made? This one is for all of you.

If you haven't already, tap follow wherever you're listening so you never miss an episode.

Okay, Mira, I am ready. Hit me with the science.

Imagine having to sit perfectly freezing cold still without moving a single muscle for eight entire hours. Just to take one single blurry photograph.

Eight hours? I can't even sit still for eight minutes. My nose would itch, I'd have to sneeze.

Exactly. But that's exactly how long it took to capture the very first permanent photograph in the world. Today we are travelling through time to uncover how cameras actually work.

From an eight-hour staring contest to snapping pictures on a phone in a split second.

You got it! We are going to explore the ancient discovery of the darkroom, the French inventors who finally trapped light on a metal plate, and the mind-blowing digital pixels that capture our world today.

So, where do we start? I know my dad's phone just clicks and boom, there's a picture. But what actually is a camera?

At its most basic level, a camera is just a box that catches light. You see, when you look at an object, say a bright red apple, you aren't actually seeing the apple itself. Wait, what? Then what am I looking at? You are seeing the light bouncing off that apple and travelling into your eyes. Light travels in perfectly straight lines at a mind-blowing speed of 299,792 kilometres per second.

Whoa, that's fast enough to circle the earth seven times in a single second.

Exactly! So to take a picture, scientists needed a way to trap that bouncing light. And the first person to truly figure out how to project this light was a brilliant scientist named Ibn al-Haytham over a thousand years ago. A thousand years ago? That's around the 11th century. Where did he live? He lived in Cairo, Egypt, around the year 1020.

At the time, Greek philosophers thought our eyes worked like flashlights, shooting out invisible laser beams to illuminate things. Right. Ibn al-Haytham wanted proof of how vision really worked, so he conducted a genius experiment inside a completely dark room. He called this room Al-Baytur Muslim in Arabic, which translates to dark room.

In Latin, it became known as the camera obscura.

Camera obscura? That sounds like a magic spell. What did he do in there?

He made one tiny pinpoint hole in the window shutter. Because light travels in completely straight lines, the light rays from outside bounced off objects, travelled through that tiny hole, and hit the opposite wall inside the dark room. And what did it look like? Did it make a picture? It did! It projected a perfect, full colour, moving image of the outside world onto the wall.

But there was one massive catch. What was the catch? Was it blurry? No, it was perfectly sharp. But because the light rays cross over each other like an X as they squeeze through the tiny hole, the image on the wall was completely upside down.

No way. So if a horse walked by outside, it looked like it was walking on the ceiling.

Exactly! The light from the horse's hooves travelled straight up through the hole to the top of the wall, and the light from the horse's ears travelled down to the bottom. People used the camera obscura for hundreds of years. Did they use it to take selfies? Not exactly. Astronomers used it to safely watch solar eclipses without hurting their eyes.

Later, artists built portable wooden boxes to trace landscapes. But it was just a projection. As soon as you close the hole, the picture vanished.

Aw, so they couldn't actually save the photo to show their friends?

Not yet. It would take another 800 years of chemistry experiments to figure out how to freeze that light and keep it forever.

Okay, skip forward 800 years.

How did they finally save the picture? We travel to France to the year 1826. An inventor named Nisophore Nieps decided to mix chemistry with the Camera Obscura. What kind of chemistry? He took a shiny piece of pewter metal, about 16 by 20 centimetres. That's about the size of a small tablet screen. He coated it with a special, naturally occurring asphalt called bitumen of Judea.

He painted a metal plate with asphalt, like what they use on roads. A form of it, yes. This bitumen was special because it hardened when sunlight hit it. Nieps put this sticky metal plate inside a wooden camera obscure, pointed it out the window of his estate called Le Gras, and uncovered the lens. And that's the one that took eight hours?

Yes. Because the bitumen reacted so incredibly slowly to the light, he had to leave the lens open for roughly eight entire hours. When he finally washed the plate with lavender oil, the unhardened asphalt washed away, leaving a permanent image. That is wild! Wait, if it took eight hours, didn't the sun move?

It did! The sun moved so far across the sky during the exposure that in the final photograph, the sunlight is actually hitting both sides of the courtyard buildings at once. But eight hours is way too long for a portrait.

Yeah, people would fall asleep. Which is why we don't have photos of people from 1826. So how did it get faster?

Another French inventor, Louis Daguerre, stepped in. In 1839, he introduced the Daguerre type. He used silver-plated copper treated with iodine, which cut the exposure time down from eight hours to just seven to ten minutes. That's way better. Did he take pictures of people? He did. He took a famous photo of a busy street in Paris called the Boulevard du Temple.

But because the exposure took seven minutes, all the horse carriages and people moving around were a big blur and vanished from the photo. So the street looked totally empty? Almost. Except for one man in the bottom corner who was standing perfectly still, having his shoes shined. That man accidentally became the very first human being ever photographed.

That guy had no idea he was making history. Just by getting his shoes cleaned. That is incredible.

It really is. From there, photography exploded. Scientists found faster chemicals, dropping exposure times to minutes, then seconds, and eventually swapped heavy metal plates for thin strips of plastic called film. But when do we get digital cameras? The ones without film. The biggest revolution happened in 1975.

An engineer at Kodak named Stephen Sassen invented the world's first digital camera. But it was not like your dad's phone. This thing weighed eight pounds, as heavy as a small bowling ball.

Haha, a bowling ball camera? How good were the pictures?

Not great. Instead of chemicals on film, digital cameras use electronic sensors. These sensors are covered in millions of microscopic light-gathering buckets called pixels. When a particle of light, called a photon, hits a pixel, it turns it into an electrical signal.

How many pixels did that first digital camera have?

Just 10,000 pixels, or 0.01 megapixels. It took 23 seconds to record a single blurry black and white photo onto a cassette tape. A cassette tape? That's so ancient. What about today? Today, a standard phone camera sensor has 12 to 48 million pixels, or megapixels, and it works incredibly fast. Wait, millions?

And it takes a photo in what? A second? Even faster! Modern phone cameras can open and close their digital shutters in one eight thousandth of a second. That means you can freeze a hummingbird's wings mid-flap in crystal clear, brilliant colour.

From an eight-hour staring contest to a fraction of a millisecond? Ibn al-Haytham and Nieps would be totally mind-blown if they could see that.

Alright, Finn, quiz time. Let's see how much you remember.

Okay, I'm ready. Let's do this.

First question. Who invented the camera obscura in the 11th century? Next one. What does the Latin phrase camera obscura actually mean? Question 3. How many hours did Nisophore Nieps have to expose his metal plate to capture the first surviving photograph in 1826? Here's number four. In Louis Daguerre's famous 1839 photo, what was the first human ever photographed actually doing?

Last question. What do we call the millions of microscopic light-gathering buckets on a modern digital sensor? Great job! Let's see how you did. The first answer is, Ibn Al-Haytham. He figured out the science of the dark room back in Cairo. I remembered that one. For question two, camera obscura means dark chamber or dark room.

Imagine living in a giant camera.

The answer to number three is eight hours. A painfully long time to leave the lens open. And the sun lit both sides of the buildings.

So cool.

For question four, he was getting his shoes shined. He stood still just long enough to be permanently frozen in time.

The luckiest shoe shine in history.

And the final answer is pixels. Modern cameras use millions of these tiny dots to capture light in a fraction of a second. Yes, I love pixels. What a wild journey, Finn! From dark rooms that projected upside-down horses to metal plates covered in asphalt, all the way to the digital cameras in our pockets.

I'm definitely going to appreciate my photos way more now that I know it used to take eight hours.

If you love learning about wild inventions like the Camera Obscura, please leave us a five-star review. Just scroll down and tap the stars.

Oh, and make sure you follow the show wherever you're listening. And we have sister shows too. History and philosophy is not boring, and maths is not boring. Go give those a listen and a follow as well.

And if you want a shout out on the show, or just want to say hi, email us at hello at kidopoly.com.

Thanks for exploring with us, Arthur, Evan, Josh, Caleb, and Isaac.

See you next time on Science Is Not Boring. Bye.

What was the first photograph?

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