[Image]Simulation when the wind blows from behindRIKEN assumes that the community-acquired infection rate in Tokyo is about 0.1%, and there are four patterns that take into account the front and back of the wind direction in each case where the spectators are seated on the first floor of the National Stadium without any gaps and when there are vacant seats. I calculated it with. As a result, if the spectators sit at intervals and the wind blows from behind as designed by the stadium, the number of newly infected individuals will be as close to zero as possible, while they will be seated tightly and the wind will blow from the front. It is said that 4.7 new infections will occur to all spectators. However, the Ministry of Education, Culture, Sports, Science and Technology has not announced the simulation results when the audience does not wear masks. Koichi Hagiuda, Minister of Education, Culture, Sports, Science and Technology said at a meeting on the 6th, “If the audience does not wear a mask, the risk of infection increases, but in general, the audience is asked to wear a mask and sit at a certain interval. Because it is a premise, it has been scientifically proved that the risk of infection can be reduced as much as possible only in the national stadium. ” Discussions on the number of spectators have reached a climax for the event. Minister Hagiuda asked the press about holding no spectators, saying, “As experts say, there is no risk of clustering in the national stadium, but when a certain number of people gather, there is a flow of people before and after that. It will occur. If it is decided to enter the audience, I think that the Organizing Committee is simulating that the gates are narrowed down and the entrance is made with a time lag. The direction is (including the Organizing Committee and the Tokyo Metropolitan Government). I would like to wait for the result of the five-party talks. ” According to the Ministry of Education, the National Stadium has adopted a mechanism that blows wind into the stadium from fans installed in the audience seats and circulates the air using the updraft of the competition field. At the National Stadium, which is one of the main venues of the tournament, soccer and track and field competitions will be held in addition to the opening and closing ceremonies.