
"The Sentinel" (1948), originally titled "Sentinel of Eternity" this is the short story which later provided the fundamental ideas for 2001: A Space Odyssey (1968) written by Clarke and Stanley Kubrick. Full text in 10 Story Fantasy, Vol. 1, No. 1 (Spring 1951), p. 41 https://archive.org/details/10_Story_Fantasy_v01n01_1951-Spring_Tawrast-EXciter/page/n39. Two versions of the next to the last sentence have been widely published since at least 1951, the other being: "If you will pardon so commonplace a simile, we have set off the fire alarm and have nothing to do but to wait."
1940s