This day in history: Edison "perfects" the light bulb


    October 22, 2019


    We travel back to Menlo Park, New Jersey where inventor Thomas Edison used carbonized cotton thread to make a major lighting breakthrough


    "I haven't failed -- I've just found 10,000 ways that won't work." – Thomas Edison.

    The year is 1878, the place is Menlo Park New Jersey. Hot off the success of his phonograph, Thomas Edison has his sights set on the light bulb. He figures he and his team of 40 researchers can come up with a functioning incandescent bulb in three or four months.


    But it wasn't until more than a year later, on the morning of October 22 (after working all through the day of October 21, 1879) that Thomas Alva Edison and his team finally “perfected” the incandescent light bulb. The bulb cost USD 40,000 (about USD 850,000 in today's money) and burned for slightly more than half a day.

    I haven't failed -- I've just found 10,000 ways that won't work."

    The team had executed approximately 1,200 experiments, testing hundreds of materials in the process before hitting upon the winning design. It turned out that baking a piece of coiled cotton thread until it was all carbon was the winning filament. Inside a glass bulb that was almost a vacuum, it was able to stay lit for 13.5 hours. In the end, Edison’s "three or four month" project had taken him 14 months.
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    The lengthy timeframe was partially because Edison was also busy developing an electric meter, redesigning his telephone receiver (to avoid infringing on the patent held by Alexander Graham Bell) and finessing his electrical generators.


    And yet, with all this going on, in the face of numerous setbacks, Edison got there. And with that first incandescent light bulb he also forged the path for a whole industry.


    140 years later Edison’s legacy is still visible in the relentless innovation taking place in the lighting sector. Signify is proud to be a part of that tradition, continuing to innovate and improve lighting products, even redefining what’s possible with lights.


    The secret to success – as true in Edison’s time as it is today – is perseverance. As Edison himself said, "Genius is 1% inspiration and 99% perspiration.

    About the author:

    Ryan Millar

    Ryan Millar


    Chief Editor

    For further information, please contact:

    Signify Global Integrated Communications
    Neil Pattie
    Tel: + 31 6 15 08 48 17

    About Signify


    Signify (Euronext: LIGHT) is the world leader in lighting for professionals and consumers and lighting for the Internet of Things. Our Philips products, Interact connected lighting systems and data-enabled services, deliver business value and transform life in homes, buildings and public spaces. With 2020 sales of EUR 6.5 billion, we have approximately 39,000 employees and are present in over 70 countries. We unlock the extraordinary potential of light for brighter lives and a better world. We achieved carbon neutrality in 2020, have been in the Dow Jones Sustainability World Index since our IPO for four consecutive years and were named Industry Leader in 2017, 2018 and 2019. News from Signify is located at the Newsroom, Twitter, LinkedIn and Instagram. Information for investors can be found on the Investor Relations page.

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