On November 30th, for the first time, the world had the opportunity to participate in and contribute to this unique worldwide experiment, with the aim of testing the laws of quantum physics.
Coordinated by ICFO-The Institute of Photonic Sciences, twelve laboratories from around the world came together to put in motion the BIG Bell Test: worldwide quantum experiments powered by human randomness, with the aim of demonstrating experimentally that the microscopic world is in fact as strange as quantum physics predicts: particles that behave in a random way, determining their properties only when we look at them; strange instantaneous interactions at a distance ... predictions that were questioned by Einstein, who rejected them completely.
During the 48 hours in which it was November 30th at some place on the planet, participants contributed to the initiative, generating sequences of zeros and ones through a video game to get participants to create sequences of numbers that were as random as possible. Each of these bits was used to control in real-time the experimental conditions of the labs. They moved mirrors, polarizing filters, waveplates ... elements located on optical tables and that affect the type of measurements that are made on the different quantum systems in each lab.
Together all the participants provided scientists with millions of unpredictable, independent decisions which were used to measure their particles. This independence is a crucial feature for the conclusions of the Bell tests to be valid. Using the sequences provided by the participants, the scientists have been able to verify whether or not their particles were intertwined by the "spooky action at a distance" that Einstein could not accept. In a nutshell, the Bell test states that experimentalists have to do their measurements with the help of human decisions and calculate the "Bell parameter" (also known as the parameter S). If the world is as Einstein believes, predictable and without "spooky actions at a distance", then S cannot be greater than 2. That is, S should always be less than 2. Otherwise, the inequality has been violated, indicating the presence of intrinsically quantum phenomena.
By 13:00 CET, the minimum number of participations needed to assure enough bits to power the experiments had already been surpassed, registering above 1000 bits per second in a stable manner over the course of several hours. By early afternoon CET, some of the labs had been able to obtain preliminary results, confirming violations of Bell's inequality, and thus refuting Einstein, giving their complete support to the predictions of quantum physics.
ICREA Professor at ICFO Morgan Mitchell reflects that "the project required contributions from many people in very different areas: the scientists pushed their experiments to new limits, the public very generously gave us their time in support of science, and educators found new ways to communicate between these two groups. I'm thrilled with all of the different things we have learned through the BIG Bell test. "
Carlos Abellán, researcher at ICFO and instigator of the Project, emphasizes that "the participation we achieved today for the Big Bell Test is absolutely astonishing and unprecedented. I'm excited about all the results we're already receiving from the labs"
In Barcelona, in collaboration with "La Caixa" Foundation, the BIG Bell Test team had the opportunity to share the project with an audience of more than 300 people gathered in the Auditorium of CosmoCaixa, who witnessed in real time through several live connections, the experiments running in different labs in Shanghai (China), Concepción (Chile), Nice (France) and Castelldefels (Spain). This group further contributed to the experiment by participating in mass in a final tournament of the video game, created with Kaitos Games, to find the most random person in the audience. The event was streamed live around the world, and in China alone generated an audience of more than 300,000 people.
The BIG Bell Test has succeeded in uniting the scientific world and society in a common goal -an experiment that has demonstrated the unique value of human randomness to study certain fundamental processes of nature.
The BIG Bell Test team thanks the thousands of users who have so generously and enthusiastically contributed to this initiative. Without this essential contribution, the experiment would never have been possible.
Finally, we would like to thank all the institutions that have helped support this project, such as the Generalitat de Catalunya, the Universitat Politècnica de Catalunya, the Cellex Foundation, the Mir-Puig Foundation, the Foundation Catalunya la Pedrera, "La Caixa" Foundation, AXA Research Fund , the European Research Council, Catalan Institution for Research and Advanced Studies (ICREA), the Severo Ochoa program of the Ministry of Economy, Industry and Competitiveness.