As funny as those misLED fails are, when signs actually do their job, they’re a pretty incredible reminder of how far we’ve come as humans. Think about it, we took something as simple as light and figured out how to bend, channel, and color it into glowing words and shapes.
Even if you’re not an expert, you’ve probably admired how pretty neon and LED signs look. But the way they actually work? It’s fascinating.
Let’s start with the basics. LED stands for “light-emitting diode,” and according to Energy Star, these tiny sources of light produce illumination up to 90% more efficiently than old-school incandescent bulbs.
Instead of heating a filament like traditional light bulbs do, LEDs work by sending an electrical current through a microchip, which lights up microscopic diodes to produce visible light. The result is a bright, steady glow that doesn’t waste energy as heat.
Because they don’t “burn out” the same way older bulbs do, LEDs have a much longer lifespan. They slowly lose brightness over time—a process called lumen depreciation.
As Energy Star explains, the lifespan of an LED is based on when it loses about 30% of its brightness, not when it completely stops working.
One of the coolest parts about LEDs is how flexible they are. They’re tiny, so designers can put them almost anywhere—inside a bulb that looks like the ones we grew up with or in sleek, futuristic fixtures. They can even be built right into signs, letters, or shapes.
This versatility has made LED technology a dream for both engineers and artists, who now use it for everything from traffic lights to art installations.
Of course, even small lights can get hot. That’s why every LED setup includes a heat sink, a clever bit of design that absorbs and disperses the heat they produce.
As Energy Star points out, this “thermal management” is crucial to keeping LEDs bright and long-lasting. Without it, the light would fade faster, and your favorite glowing sign might not survive too many late nights.
But LEDs aren’t the only stars of the show. Long before they arrived, neon lights were dazzling cities around the world. According to science writer Anne Marie Helmenstine, Ph.D., real neon lights are glass tubes filled with a small amount of neon gas under low pressure.
When high voltage—around 15,000 volts—is applied, it gives the gas enough energy to release electrons, creating plasma that glows. That reddish-orange light we all associate with classic “Open” signs? That’s pure neon at work.
Different gases can create different colors. Helmenstine explains that helium glows pink, krypton is green, and argon shines blue.
Sometimes, the glass itself is coated with phosphor, which glows in different colors when energized. That’s how we get the rainbow of glowing signs lighting up downtown streets, each color a little chemistry experiment.
