I was sure that I've also read that story. But I don't remember nor the author, nor title. Started searching and found a thread on stackexchange. It looks like

I was sure that I've also read that story. But I don't remember nor the author, nor title. Started searching and found a thread on stackexchange. It looks like thaere are several stories with such a plot: https://scifi.stackexchange.com/questions/74090/scientists-shown-a-fake-anti-gravity-device-to-motivate-them-to-build-the-real-t https://scifi.stackexchange.com/questions/74090/scientists-s...