The Profound Terror of Space

There was no hurry about the report. If anything could be allowed time, it was that. Months, years, decades, even a century would not have been too much. Years, it ended up being, and the public wondered at the hastiness of it.
At last the commission presented the report, all 1,476 pages of it, for the first time at a televised hearing. A representative sat at a table stable enough to hold the thick stack of papers that had been printed out for visual effect, one hand on the pile. The minister questioned him.
"To begin, perhaps we ought to hear a summary. Has the commission reached a conclusion as to the reason behind the greatest mystery in human history that confronts us, this current generation? That is to say, why, when we at long last discovered a sentient alien species, we seem unable to communicate with its members? Or observe them carrying out any of the business of the advanced technological civilization it so obviously is? Why the buildings appear abandoned and the factories silent?"
"We have."
Conversations broke out all around the chamber, to say nothing of what went on in homes and offices across humanity's possessions, many after a time delay of course.
"Silence in the chamber, silence." The minister made his demand at an even volume, without any vehemence or sense of injured dignity. He understood. "In the shortest and easiest to understand words you are able to explain, what is that reason."
"They're ghosts
Take all the noise, double it, triple that, add laughs and shrieks, and that would be the general atmosphere.
"Silence!" There was some feeling in the command that time. "Are you quite serious?"
"Yes. We are confident, entirely confident, that what we have found is in fact an extinct civilization, whether its builders died or simply left their planet altogether. We are less confident in our supposition that perhaps an alien species may be able to see human ghosts, but we offer that as a reason to increase interstellar exploration rather than giving up after this disappointment."
The minister gave up on trying to quiet down the tumult. He wiped his forehead instead. What more could he do? The representative looked sane enough, but the implications . . .
Finis