Unspoken Memorial

"Because this world, out of all the billions, has certain physical characteristics, he thought, my race has made them into standards. Our basic units of length and time and acceleration, our comparisons by which we classify the swarming planets of the Galaxy, they all go back ultimately to Earth. We bear that unspoken memorial to our birthplace within our whole civilization, and will bear it forever."

-Poul Anderson, "The Chapter Ends," IN Anderson, The Complete Psychotechnic League, Volume 3 (Riverdale, NY, July 2018), pp. 195-215 AT pp. 202-203.

Somewhere in Isaac Asimov's Foundation Trilogy - I am not going to look it up now -, people wonder why, e.g., three hundred and sixty five standard days make one standard year. There are speculations about superstitions and numerology. A minority theory is that these quantities correspond to conditions on the original planet - if there was an original planet. Another theory is that human beings originated on many planets and converged with space travel.

That sounds absurd but maybe it would seem feasible in some circumstances. Sandra Miesel has the last word in Anderson's Psychotechnic History:

"To Earth there's no returning. She vanished with the childhood of our race. Yet a poet once said, 'No matter how far we range, the salt and rhythm of her tides will always be in our blood.' One chapter has ended. Humankind's saga flows on." (p. 216)