Julian date 2459541, Wednesday, 9:10 a.m.
Hu Yisu carried his laptop over, turned the screen toward her, said nothing.
It was a clipped video, two minutes ten. The footage was the Q&A of the briefing: someone asked about the mechanism, and the answer given was that the preliminary finding did not affect the conclusion. Subtitles ran underneath, and the last line of the subtitles was four words—the thing we woke.
Twenty-six hours after posting, 4.2 million plays.
She dragged the progress bar back and watched it through from the start.
She said: who put this out.
He said: no one knows. The meeting materials went around in electronic form afterward. Seven sets. One goes missing, you can't tell.
She said: if it can't be traced, don't trace it.
The word "alarm clock" wasn't said on our side first.
What Hu Yisu showed her was a foreign newspaper's headline, English, one line: Did we wake it up. Within three days the sentence had been translated into thirty-two languages. In the Chinese sphere it finally came down to four characters.
He wrote a script that counted how often the phrase turned up together with astronomy words: 1.4 million entries a day. Newspapers in forty-one countries ran the same question on their front pages on the same day.
She said: forty-one is your count.
He said: my count.
She said: is the sample big enough.
He said: this time it's big enough.
She said: big enough, then write it down.
Julian date 2459542, Thursday, ten at night, the seven-box meeting. This time all seven boxes were lit.
There was one agenda item: whether to respond.
Old Cao of Nanshan spoke first: the line holds, extend it another half year. When he said it he was looking at the lower right corner of the screen, not at anyone.
The funding agency's Guan followed: silence or response, either way the precondition is that the official line not loosen on its own first.
Lu Weiming said: I don't object to the line. I object to substituting a line for an answer.
Old Cao said: answer what. What can we answer right now.
Lu Weiming said: what we can answer right now is that this thing did not begin in the last ten years. Nine hundred years ago, under that step, there were no radio stations.
Old Cao said: that can't be said either.
Lu Weiming said: then don't say it. Not saying and sitting on it aren't the same.
Forty minutes in, someone asked a question that had nothing to do with any of it—whether this meeting required sign-in, because last time the ones who hadn't signed in had been written up.
Nobody answered him.
The meeting secretary later entered that exchange whole into the minutes. When the minutes came back, that passage had been struck through once, lightly, in pencil; who had done it, no one knew. The minutes were filed. Three years on, a graduate student working through the old minutes reached that page and asked what the pencil line meant. No one could answer.
The fifth box on the screen was Las Campanas. Mateo had been listening the whole time. At this point he said three sentences in English.
The first: a hundred days isn't enough for you to finish arguing.
The second: what you want to shut down isn't the machines, it's the mouths.
The third: if you truly do go quiet, you will learn nothing about it—you will learn a great deal about yourselves.
When he finished he muted his own microphone.
At the meeting Zhou Yan fought for exactly one thing.
Guan said: during the silence all transmission stops; reception had better stop too, so there's nothing that needs explaining.
She said: receive, don't transmit.
He said: that is also a form of participation.
She said: a receiving antenna radiates not a fraction of a watt outward. That's physics.
He said: that you'll have to file for approval.
She said: file.
Old Cao smoothed it over: file, then. A hundred days may not come off anyway.
After the meeting she wrote on paper: passive observation does not stop during the silence. Done writing, she worked out that in the past year the station had cut 13.6 percent of observing time over man-made interference. A hundred days without interference meant thirteen and a half extra percentage points of usable time.
She circled the 13.6.
The reckoning began on Friday.
The job she gave Hu Yisu: every coherent transmission humanity had ever aimed at the sky, laid into one table, by year, by power, by duty cycle. He worked two days; when he was done it had eleven rows.
One. 1901, spark transmitters, tens of kilowatts, extremely wide bandwidth, barely beamed at all.
Two. The 1920s, longwave broadcast stations, 200 kilowatts apiece, dozens of them worldwide.
Three. 1936, television picture carriers, London first, tens of kilowatts per station, directional.
Four. 1936 to 1945, military radar, peak power in the hundreds of kilowatts, duty cycle on the order of one in a thousand.
Five. From 1945 on, nuclear tests, more than two thousand of them, nine of them high-altitude, each electromagnetic pulse wider than the last.
Six. From 1958 on, satellite-communication uplinks, a few kilowatts per station.
Seven. Deep-space tracking uplinks: seventy-meter dishes, twenty kilowatts, X-band, at most a few hours a day.
Eight. Planetary radar: Arecibo, one megawatt, 2,380 megahertz, since decommissioned; Goldstone, 450 kilowatts.
Nine. Ionospheric heating facilities: effective radiated power up to the gigawatt level, a few hundred hours of operation a year.
Ten. Navigation and mobile communications: tens of watts per satellite, spread-spectrum, power spectrum close to noise.
Eleven. Low-orbit broadband constellations: from 2019, tens to hundreds of watts per satellite, more than 1,800 in orbit at present.
What she wanted was the total.
The two of them computed for two afternoons. Halfway through the first, Hu Yisu found that a number in the 1958 row had been added in twice; they tore it up and started over. The second afternoon they finished and checked each other: he read the numbers, she pressed the calculator; she read, he pressed. Only when both passes matched did anything go down on paper. Average total power of coherent transmission, everything summed: 2.4 times ten to the eleventh watts. The error she marked herself at one order of magnitude, either way. Seventy percent of it was broadcast and television carriers.
The Sun, over the stretch from ten megahertz to ten gigahertz, radiates radio at about ten to the fourteenth watts. Error half an order of magnitude.
The ratio: 0.24 percent.
She tried it another way: all the coherent energy thrust at the sky over a hundred years, summed, comes to 7.6 times ten to the twentieth joules. Divided by the Sun's radio power in that band: 7,600,000 seconds.
She said: convert that.
Hu Yisu pressed the calculator: eighty-eight days.
She said: write it up.
He wrote: the total energy of all human coherent transmission over one hundred years = eighty-eight days of the Sun's radiation in the same band. Error half an order of magnitude.
She looked at that line for a while.
She said: what is this number saying.
He said: it's saying we're not loud enough.
She said: this number says we're not loud enough. Write it into the memo.
He said: write it in and they'll use it to say we're innocent.
She said: that was never ours to judge.
Everything thrust at the sky over a hundred years, laid out in one table, was like the total volume of blood one person has had drawn in a lifetime: a long string of entries on the page, and poured into a graduated cylinder it barely covers the bottom.
She copied the metaphor into the paper notebook, and beside it set down three question marks.
Julian date 2459544, Saturday.
In the morning she sent the eleven rows to Vienna, with two numbers attached: 0.24 percent, eighty-eight days.
The reply came in the afternoon, five lines.
One. The energy line I accept. You are not loud enough; that one can go out.
Two. The time line I do not accept. That 1936 or 1939 fits is not evidence, it is bait. Two things happening in the same year—a year has 365 days to align them against.
Three. I have re-estimated S. 0.31 was a downward-biased rough estimate; corrected, 0.34, error plus or minus 0.03.
Four. Locally I did the 0731 cluster: sixty-two points, sixty-one edges, S is 0.41, error plus or minus 0.05. Local runs higher than global. The same thing shows on a cortical slice—the local goes first.
Five. 0.5 is a global threshold, not a local one. Do not go shouting about 0.41.
She copied the third line into the paper notebook, and under it wrote: 0.34.
Then she wrote: 0.31 → 0.34.
She asked: compute S once a day through the silence?
Vienna answered: once a day, the same clumsy method, do not change the estimator. Change it and there is no hundred-day comparison.
At eight that evening she video-called Zhou Yao. Nineteen seconds after it connected the picture was still swaying—the gait of someone walking.
Zhou Yao said: Mom, I want to ask you one thing.
She said: ask.
Zhou Yao said: was it us who woke the stars.
She said: we don't know yet.
Zhou Yao said: the internet all says it knows.
She said: the internet doesn't count.
Zhou Yao said: then if it was us who woke them, we just get a little quieter and that fixes it.
She didn't answer right away.
Zhou Yao said: just saying.
She said: the idea is right.
Zhou Yao said: then why don't you do it.
She said: because the whole world has to get quiet together.
Zhou Yao said: oh.
The far end walked into a shop, and the sound went jumbled.
Zhou Yao said: I'm here, hanging up.
Call record: four minutes two seconds.
She set the phone down and thought of that note—Zhou Yao still hadn't said what was written on it. That night she dug the note out and looked at the corner of it where it lay under the glass plate. The writing was Zhou Yao's, pencil, pressed light. She read it through, and never told anyone what was written there. Not ever after.
At night she changed the tank water. The water change had an order, set by herself: lights off first, wait for Lao Wu to come out on his own, then move. With the lights off, the room held only the machines' few green standby points. Lao Wu came out from behind the driftwood, claws probing ahead, and touched the tweezers once. The shell was still the old one; the whitening around the rim had widened a little since last week. The signs of a molt had been there two months, and no molt. She had read up on it; she still couldn't say why it was so slow. Water twenty degrees.
She dropped in two pellets. The crayfish didn't move.
She sat a while longer in front of the tank, lights still off. In the dark the water sounded clearer than by day, the drip tube going drop by drop, the rhythm uneven. She listened a while and logged that unevenness as a number too—nowhere to use it; keep it anyway.
The hiss in her right ear was on its thirty-eighth day. She counted it through, and regretted it the moment she finished.
Julian date 2459546, Monday, 10:20 in the morning.
Old Tang stood a while in the doorway of her office before coming in, a kraft envelope in his hand.
He said: someone carried this to me. He told me to let you see it, and told me to say nothing else.
She said: who.
Old Tang set the envelope on the desk and didn't answer.
Inside were two photocopies, stapled together, two pages in all. The head of the first page was a single line: Recommendation on Implementing One Hundred Days of Radio Silence Worldwide.
The signature was handwritten, and the date was written not in the calendar but as a Julian date: 2459544.
The second page held the reasons, five in all.
One. Since the 1930s humanity has injected coherent electromagnetic radiation into the sky, increasing year by year, never once interrupted.
Two. The injected power is minute beside stellar radiation, but the coherence of the injection differs in kind from a star's incoherent emission; it cannot be excluded by a ratio of powers.
Three. The evidence in hand is insufficient to establish causation, and insufficient to exclude it.
Four. One hundred days is the longest span executable in engineering terms, not the optimum in scientific terms.
Five. If nothing changes within the hundred days, then at least we stopped once.
She read the fifth item three times.
Old Tang said: do you know about that machine of his.
She said: what machine.
Old Tang said: he found a reel-to-reel, built in 1981. Belts replaced twice. He called me in the middle of the night once, just to say that.
She said: he told me.
Old Tang said: he hasn't told me anything else.
She said: mm.
Old Tang said: what's in there I can't read aloud. You saw it yourself; I'm not the one reading it to you.
She said: I know.
At the door Old Tang turned back: people out there are already proposing this, and not only him. Whether the number one hundred was his own arithmetic or something talked over with others, I don't know.
She said: if he had worked it out, he would have written down how.
Old Tang said: it isn't written here.
She said: then it wasn't worked out. The number is a choice, and what he chose is a long number that can be executed.
Old Tang looked at her once, didn't take it up, and left.
Out in the corridor his footsteps caught on the third step down, then went on. That step had been loose for three years; the station kept saying it would be fixed, and it never was. Today's catch she heard through two closed doors.
She flattened the two pages and photographed them with her phone, into 3t.
After the shot she paused over the filename, named it nothing, and let the system's serial number stand. The number was a string of digits; she never went looking for that file again. An archive has to be findable to count as an archive; this one didn't count. It was only something she had seen.
Afterward she sent Ursula an email, one line only: one hundred days.
The reply came fast, two sentences:
One. The silence will change nothing.
Two. But the silence will get you a number. What you lack now is not a posture. It is a number.
She pressed the kraft envelope down on the tape spool in the drawer. Before the drawer shut she looked once: the short stretch of tape toward the outside was still wrinkled.
The station-office form, twenty-one days overdue. Today no new reminder came. The absence of a reminder she logged too.
In the mailbox the one titled "Shoulder" was still there, last modified 2459483.793. This time she did not open the recipient field.
She started a fresh page in the paper notebook and wrote three lines.
First line: 0.34.
Second line: 13.6 percent.
The third line she thought over a long time, and what she wrote was a whole number.
100.