应----From sky to window

Yesterday, I found a master calligraphy piece consists of clouds, a character of "应".
I recalled that in 1927, my grandfather disputed with a professor regarding of that "Xinhai Revolution" is not a revolution, translating Mr. Shao Lizi's idea, said that the definition of revolution is, by example of “汤武革命， 顺天应人”, is 顺天应人, responding to the will of the people, thus, Xinhai Revolution is indeed a true revolution. The Russian professor only smiled.

And I serched google finding this news:
微软发布全新中文搜索品牌“必应”--bing.com.cn