18/05/2026
*Fun fact about light*:
Contrary to popular belief, Thomas Edison did not "invent" the light bulb in a vacuum. The journey to the modern bulb was a relay race spanning over 70 years and involving dozens of inventors.
The primary challenge was finding a filament that could glow for a long time without burning out or melting
1. Davy in 1802 Invented the first electric light (the Arc Lamp) using a high-power battery.
2. Warren de la Rue in 1840 Created a bulb with a platinum filament; it worked but was too expensive for the public.
3. Joseph Swan in 1878 Developed a practical light bulb using carbonized paper filaments in England.
4. Thomas Edison in 1879 Patented a bulb with a carbonized bamboo filament that lasted over 1,200 hours.
5. Lewis Latimer in 1881 Patented a more durable carbon filament, making light bulbs affordable for homes.
6. Nick Holonyak Jr. in 1962 Invented the first visible-spectrum LED (Light Emitting Diode).
Edison's true genius lay in his ability to create a complete electrical system—including power plants, meters, and wiring—that made the light bulb practical for everyday use.
7. Light is ridiculously fast – it travels at 299,792 km/s. That means it can go around the Earth 7.5 times in just 1 second.
8. Light can be stopped and stored. Scientists have slowed light down to 38 mph in cold sodium atoms, and even stopped it completely and “released” it later.
9. You’re seeing the past. The Sun’s light takes 8 minutes 20 seconds to reach Earth, so when you look at the Sun, you’re seeing it as it was 8+ minutes ago. With stars, you’re seeing them as they were years, decades, or millions of years ago.
10. Light has no mass, but it has momentum. That’s why sunlight can push on solar sails in space and why a laser can move tiny objects in a lab.
11. Shadows can move faster than light. If you shine a laser at the Moon and sweep it across, the dot can sweep faster than 300,000 km/s. But no information travels faster than light, so it doesn’t break physics.
12. Your eyes can detect a single photon. In perfect darkness, if one photon hits your retina, your brain can register it. It’s the absolute limit of human vision.
13. Light bends around objects. This is called diffraction. It’s why you see rainbow edges around streetlights on a foggy night, and why telescopes have limits on how sharp they can see.
14. Color doesn’t exist outside your brain. Objects don’t “have” color. They absorb and reflect certain wavelengths of light. Your brain interprets those wavelengths as red, blue, green, etc.
15. Black isn’t a color. It’s the absence of light. White is all colors combined.
16. Light can create matter. If you collide high-energy photons together with enough force, you can actually produce electron-positron pairs. Einstein’s E=mc² in action.
17. We only see a tiny slice of light. Visible light is less than 1% of the entire electromagnetic spectrum. Radio waves, microwaves, X-rays, gamma rays are all just “light” at different wavelengths.
