From: veritasium
The Enduring Incandescent and the Rise of Obsolescence
For a period, it seemed that the lifespan of light bulbs was intentionally shortened, a concept that ran contrary to the idea of continuous improvement in technology [01:28:00]. This notion stemmed from a belief that older light bulbs were superior and were later made worse on purpose [01:30:00].
The Centennial Bulb
One notable example is the incandescent light bulb at Livermore Fire Station number six, which is recognized as the longest continuously operating light bulb in the world [00:21:00]. This bulb has been lit for 120 years, having been switched on in 1901 [00:26:00]. Manufactured by hand shortly after commercial light bulbs were first invented, it has operated for over a million hours, far exceeding the intended lifespan of modern bulbs [00:43:00]. Its remarkable longevity is attributed to being made before the “cartel era” and running consistently at a low power of four or five watts, primarily as a nightlight, which reduced thermal stress on the filament [06:17:00].
Early Incandescent Technology
The design of a typical incandescent bulb involves passing an electric current through a material, causing it to heat up and glow [01:45:00]. However, less than 5% of the electrical energy is converted into light, with the remaining 95% released as heat [01:51:00]. Filaments can reach temperatures of up to 2,800 Kelvin, half as hot as the sun’s surface [02:03:00]. To prevent materials from melting or burning, Warren De la Rue proposed placing the filament in a vacuum bulb in the 1840s [02:17:00].
By 1879, Thomas Edison developed a bulb with a cotton thread filament that lasted 14 hours [02:26:00]. Over time, filaments evolved from carbon to tungsten, a material with a very high melting point, significantly increasing bulb lifespan [02:42:00]. By the early 1920s, average bulb lifetimes reached around 2,000 hours, with some lasting up to 2,500 hours [02:47:00].
The Phoebus Cartel and Planned Obsolescence
A significant shift occurred when the lifespan of light bulbs ceased to increase and began to decrease [02:56:00]. In December 1924, major light bulb manufacturers, including Phillips, International General Electric, Tokyo Electric, OSRAM, and Associated Electric, formed the Phoebus Cartel in Geneva, Switzerland [03:01:00]. Named after the Greek God of light, this cartel aimed to control the global supply of light bulbs [03:21:00].
The cartel’s primary motivation was to counteract the threat of longer-lasting bulbs, which were eating into sales [03:49:00]. For instance, OSRAM’s sales dropped significantly from 63 million bulbs in 1923 to 28 million in 1924 [03:53:00]. To address this, the cartel members collectively agreed to reduce the lifespan of their bulbs to 1,000 hours, nearly halving the existing average [04:06:00].
To enforce this, manufacturers submitted sample bulbs for testing; companies were fined if their bulbs lasted significantly longer than 1,000 hours [04:30:00]. Engineers, who previously worked on extending bulb life, were now tasked with finding ways to shorten it, experimenting with different materials, filament shapes, and thinner connections [05:03:00]. As a result, the average lifespan steadily decreased, reaching 1,205 hours by 1934 [05:15:00]. This strategy led to a 25% increase in sales for cartel members in the four years after 1926, while prices remained largely unchanged despite lower component costs, boosting profit margins [05:29:00].
The Phoebus Cartel claimed its purpose was standardization and efficiency, notably establishing the common screw thread standard used globally today [05:52:00]. However, evidence suggests its primary motivation was profit and increased sales, not consumer benefit [06:07:00]. Although initially planned to last until 1955, the cartel struggled with competition and non-compliance among members, ultimately collapsing with the outbreak of World War II in the 1930s [06:44:00]. Despite its demise, its methods of intentionally shortening product lifespans, known as planned obsolescence, continue to be practiced by various companies [07:01:00].
The Modern Era: Transition to LED Lighting
In the last two decades, lighting technology has seen a rapid advancement, moving from incandescent bulbs, which remained largely unchanged for a century, to compact fluorescent (CFL) and now to LED technology [15:26:00].
Modern LED bulbs represent a significant technological leap. They use just a tenth of the energy of incandescent bulbs and can last anywhere from 10 to 50 times longer [15:34:00]. This dramatic increase in longevity and efficiency means that an LED bulb installed in a home is more likely to outlast the ownership of the house itself [15:45:00]. This advancement effectively brings back the concept of an “everlasting light bulb” through technological obsolescence, where superior technology naturally replaces older, less efficient products [15:53:00].