Nendo's sun-like cauldron lights up the opening ceremony of Tokyo Olympics 2020

The spherical white cauldron for the Tokyo 2020 Olympics, which Japanese tennis player Naomi Osaka lit on July 23, 2021, during the final leg of the Games' opening ceremony, has been designed by Tokyo-based Nendo studio. The flower-like cauldron bloomed to reveal the shimmering 2020 Olympics flame – the sight expressing itself as 'a symbol of hope'.

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Reverberating the opening ceremony’s manifesto of 'All gather under the Sun, all are equal, and all receive energy', Nendo’s founder Oki Sato gave the cauldron a form that resembles the shape of the sun. As per the studio, a total of 85 drafts were made, from flames trapped in a heat-resistant glass sphere to spinning the flames to create a spherical appearance, before arriving on the final design. The studio referred the cauldron lighting ceremony as synonymous to the "energy and vitality that can be obtained from the sun", paving way to "plants sprouting, flowers blooming, and hands opening wide toward the sky".

The structure of the cauldron features upper and lower hemispheres with five aluminium panels each that represent the Olympic rings. The overall form weighs 2.7 tonnes with a diameter of 3.5m obtained when the lighting is initiated by the final torchbearer. The interiors reveal reflective surfaces that create a beautiful contrast against the yellow flame that burnt in hydrogen energy. As stated in a press statement, the hydrogen was obtained through the electrolysis of water powered by solar power. The whole production process took place at a facility in Japan's Fukushima Prefecture. As hydrogen energy singularly burns with a colourless, transparent flame, the desired colour of the flame was achieved by spraying sodium carbonate to it.

"The amount and direction of the aqueous solution sprayed from the vicinity of the burner were repeatedly examined along with the amount of hydrogen and the angle of the valve, in order to adjust the movement and shape of the flame to shimmer like firewood was stoked; such an attempt to “design flames” was unprecedented,” explained the design team at Nendo.

The Tokyo 2020 Olympics, which previously announced 5,000 medals for the Games made by retrieving metals from used electronic devices among various other initiatives, embraced the use of hydrogen – a next generation energy – to reduce the event's impact on environment. The games which are on till August 08, 2021, are being hosted inside the newly built 68,000-seat Japan National Stadium designed by architect Kengo Kuma.