For over a century, a single invention painted every picture the world watched — one glowing line at a time. Step inside the tube.
From a physicist's glowing glass experiment to the screen in every living room on Earth — and the dramatic fall that followed.
German physicist Karl Ferdinand Braun builds the first cathode-ray tube: a glass bottle with the air pumped out, firing invisible electrons at a glowing chemical screen. He used it as a lab instrument — he had no idea it would become television. The name never left: in German and Japanese, a picture tube is still called a "Braun tube" today.
In St. Petersburg, physicist Boris Rosing wires a spinning-mirror camera to a Braun tube and coaxes four blurry bands of light onto its tiny screen — the first television picture ever received on a CRT. Helping in the lab: a student named Vladimir Zworykin, who will carry the dream to America and build the tubes that make TV real. That same year in London, engineer A. A. Campbell-Swinton lays out the complete recipe for all-electronic television — electron beams at both ends, camera and screen — a blueprint nobody on Earth can build yet.
Philo T. Farnsworth dreamed up electronic TV at age 14, while plowing a potato field — the neat back-and-forth rows made him imagine painting a picture with an electron beam, line by line. At 21 he transmitted the first all-electronic image: a single straight line.
RCA unveils the TRK-12 at the New York World's Fair. Its picture tube was so long it pointed at the ceiling — you watched the reflection in a mirror inside the lid. President Roosevelt becomes the first president ever on TV. Fairgoers suspected a hidden film projector, so RCA also showed a "Phantom Teleceiver" in a see-through Lucite cabinet — nothing inside but glowing glass. Cost: $600. A new car was $700.
After World War II, TV explodes. In 1946 America had ~6,000 sets; by 1951, 12 million. Families crowd around tiny round screens in giant wooden boxes. Restaurants empty out on Tuesday nights when Milton Berle is on — theaters called it "the Berle effect."
The RCA CT-100 brings color home using a brand-new trick: three electron guns and a screen made of microscopic red, green, and blue dots. It cost $1,000 — half the price of a new car — and only a handful of shows were even in color — but the future had officially arrived.
Zenith engineer Robert Adler invents the Space Command — the first wireless remote that really worked, with no batteries at all. Each button swings a tiny hammer against one of four aluminum rods, ringing them like tuning forks at ultrasonic pitches the TV picks up with six extra vacuum tubes (which added about 30% to the price). That mechanical click-click is why remotes are still called "clickers" — decades after the clicking stopped.
The Philco Predicta yanks the picture tube out of the box entirely — a swiveling screen floating on a pedestal, straight out of The Jetsons. It was gorgeous, futuristic… and broke down constantly. Today it's one of the most collectible TVs ever made.
Sony's Trinitron replaces the dot screen with vertical stripes and an "aperture grille" — the picture gets dramatically brighter and sharper. It becomes the best-selling, most-loved tube ever: over 280 million sold across 40 years. Spot an impossibly faint horizontal line across one? That's a hair-thin "damper wire" steadying the stripes — proof of a real Trinitron, not a defect.
An estimated 600 million people — roughly one of every six humans alive — watch Neil Armstrong step onto the Moon, live, on their CRTs. The Moon camera spoke a strange slow-scan dialect no home set could display, so ground stations in California and Australia converted it the most delightfully crude way possible: pointing a regular TV camera at a monitor showing the feed, and broadcasting that. Every ghostly grey frame you've ever seen of that night is a picture of a picture.
First the Magnavox Odyssey plugs a tennis game into living-room sets; months later Atari's Pong lands in a California tavern and within weeks "breaks" — its coin box jammed too full of quarters. The CRT has spent decades as a window you look through; now it answers back when you turn the knob. Soon vector arcade monitors (Asteroids, Lunar Lander) skip the pixel grid entirely and steer the electron beam like a pen, drawing spaceships in pure lines of light.
Remote controls, Saturday-morning cartoons, and video games. The CRT becomes the canvas for Nintendo, Sega, and PlayStation — consoles were literally designed around how tubes draw a picture. Wood grain gives way to black plastic, and screens grow bigger every year.
CRTs make their final stand: flat-faced Trinitron WEGAs, widescreen HD tubes, absolute monsters. Sony's 40-inch KV-40XBR700 WEGA weighed 304 pounds — more than a full-grown panda. (The all-time champ, 1989's 43-inch PVM-4300, hit 440.) Moving one up a staircase ended friendships. Meanwhile, thin little LCDs were quietly getting better…
Factories switch off. Sony ends Trinitron production; by the early 2010s the last major CRT lines fall silent after billions of tubes. But the story doesn't end — retro gamers, artists, and collectors keep tubes glowing, and working CRTs now sell for more than ever.
A CRT is a glass cannon that shoots electrons at your eyeballs (safely). Tap each part of the cutaway to see what it does.
A heated cathode boils electrons off its surface, like steam off a kettle.
A huge voltage (up to 30,000V) slingshots them down the tube.
Magnetic coils steer the beam left-right and up-down, thousands of times a second.
The beam smacks into phosphor, which glows — and that glow is the picture.
One more thing about that glass: the tube is a near-perfect vacuum, so the atmosphere squeezes it with a force of several tons — a big reason CRTs weigh so much. The leaded glass also soaked up the faint X-rays the 30,000-volt beam made when it stopped. The screen you watched through was also your radiation shield.
A CRT never shows a whole picture. It shows one glowing dot, sweeping left-to-right, top-to-bottom, so fast your brain glues it into an image. Here's that scan — slowed down millions of times.
Crank persistence down to see what the tube really shows at any instant: almost nothing! Real phosphor glows for just a few thousandths of a second. Interlacing draws every other line first — an old trick to double the smoothness for free. In 2018 The Slow Mo Guys filmed a real CRT at 380,000 frames per second and caught exactly this: Mario painted line by line, each streak fading after only about six scanlines.
Every color a CRT ever showed is made of tiny red, green and blue phosphor dots — too small to see. Drag the loupe over the picture to zoom in and catch them in the act.
A 27-inch TV packs close to a million phosphor dots, in red-green-blue trios. The mask is a metal sheet full of holes that makes sure each electron gun can only ever hit its own color. No mask, no color TV.
A fully simulated tube TV. Twist the knobs, lose the vertical hold, drown it in static — then hit DEGAUSS for the best sound a TV ever made.
Real TVs had these exact knobs. V-HOLD kept the picture from rolling like a slot machine — get it wrong and see why kids were sent to "fix the TV." Drag knobs in a circle (or use arrow keys). Even the Earth's magnetic field bends a real CRT's beam — makers built different tubes for the Northern and Southern Hemispheres, and turning a set to face a new wall could tint the colors until a degauss shook it out.
A CRT draws the picture the instant the signal arrives — there's no computer inside "thinking" about it. Modern TVs can take 5–100 milliseconds to process a frame. For fast games, tube players literally see the future first.
How did the Duck Hunt gun know where you aimed? It's the TV's fault. When you pull the trigger, the game flashes the screen black, then paints a white square where the duck is. The gun is just an eye — if it sees the white flash, the console knows you were pointing at the duck. Try it:
This trick only worked because CRTs draw with zero delay. Point a real light gun at a modern TV and it misses every time — the flash arrives too late.
Retro game art was drawn for CRTs. The soft glow blends chunky pixels into smooth shapes — artists counted on it. On a razor-sharp modern screen, the same art looks blockier than it ever did in the 90s. The tube was part of the art.
Artists like Nam June Paik built towers of glowing TVs as sculpture — museums now keep dedicated CRT repair techs on staff to keep them alive. When these tubes die, there are no new ones. Every working CRT is officially an endangered species.
CRT tech didn't just live in living rooms — radar scopes, oscilloscopes, the Apollo era's mission-control screens, early computer terminals, even airplane cockpits ran on tubes. The whole electronic age learned to draw on a CRT first.
Once engineers could bend a picture tube to their will, designers went gloriously off-script: TVs shaped like space helmets, TVs that rode in a jacket pocket, TVs that outweighed the family fridge. Real photographs of real machines — every one of these actually existed.
CRTs never got thin — they only got heavy. Bigger screen meant thicker glass to hold back the air pressure, until TVs weighed more than the people watching them. Every set on this floor is drawn to the same scale, next to a 140 cm kid (that's you). Tap a television for its stats — then hit SHOW WEIGHTS to see how many of you each one is worth.
Seven short features, hand-picked from across the internet. Press play on any set and the film opens on YouTube — the one room of the museum that needs an internet connection.
At 380,000 frames per second the "whole picture" turns out to be one glowing dot, sprinting.
Two cheerful inventors take a telly to bits and build the picture back up trick by trick — garage science at its finest.
72 seconds of a rainbow-stained screen going THUNK and snapping back to perfect. You will watch it twice.
How does a picture ride a radio wave? Every line of the signal, decoded on real hardware with dry wit.
How grown-ups in 1950 explained the newest machine on Earth — the tube was young once, too.
Inside a 1966 tube factory: molten glass, electron guns, phosphor painted with light — no robots, just steady hands.
Why serious players still haul 100-pound televisions home for their pixels — and why they're right.
You've toured the whole museum — now the museum quizzes you. Ten claims about tube TVs: some are solid engineering fact, some are pure playground legend. Call MYTH or FACT — the studio audience is watching.
Sitting close to the TV will ruin your eyes forever.
All snow, no signal. Take another lap of the museum — the tube believes in you.
