Hõõgniidid

Hõõgniidid, meaning "incandescent filaments" in Estonian, refer to the fine wires within incandescent light bulbs that produce light when heated by an electric current. These filaments are typically made of tungsten due to its high melting point and resistance. When electricity passes through the thin tungsten wire, it encounters resistance, causing the wire to heat up to extremely high temperatures, typically over 2,000 degrees Celsius. At these temperatures, the filament begins to glow, emitting visible light. The process is known as incandescence.

The thinness and high resistance of the filament are crucial for its function. A thicker wire would allow too much current to pass, potentially overheating and melting, while a wire with lower resistance would not generate enough heat to glow brightly. The filament is enclosed within a glass bulb, which is often filled with an inert gas like argon or nitrogen, or a vacuum. This prevents the hot filament from oxidizing and burning out too quickly. Without this protective environment, the tungsten would react with oxygen in the air and disintegrate.

Hõõgniidid were a revolutionary invention, forming the basis of electric lighting for decades. While more energy-efficient lighting technologies like LEDs and fluorescent lamps have become dominant, incandescent bulbs with their characteristic warm glow and simple design are still used in some applications where their specific properties are desired, or in older fixtures. The principle of hõõgniidid remains a fundamental concept in understanding early electrical lighting technology.