Five Sigma

by Pauline Barmby

The drop-dead date for submitting my thesis was coming at me like a retrograde asteroid. If I didn’t get the analysis for this last paper completed, I’d miss the defense window, lose the job I’d been offered, and disappoint everyone who’d believed in me. The jerks who said I’d gotten into grad school because of “diversity, not merit” would claim they were right. And I’d get scooped on one of the biggest scientific discoveries of our time.

On my monitor a cursor blinked in the command-line window. The plot above it seared itself into my optic nerves, showing a narrow bandwidth signal with the right kind of frequency drift and an information content too high to be natural. My fingerprint-smudged screen showed very strong evidence of an extraterrestrial radio signal produced by technological means. Holy shit! Had Jocelyn Burnell felt like this? She must have. Surely it couldn’t be real. There must be some stupid mistake in the code, a signal I’d somehow injected into the data. I blinked and shook my head.

My fingers flew over the keyboard like a meteorite skimming the top of the atmosphere. It was one of those rare occasions when I could write code that worked the first time. And not even your usual physicists’ ugly-but-functional programs. This was elegant code: clever, spare and beautiful. Another checksum, another unit test, another calibration run: still the same output. A different version of the dataset and the log-likelihood came out at about what I’d expected. Try a third version.

The program crashed. What?! I slammed a hand down on my mouse and it skittered. I glared at the screen. What had I done? So much for my mad programming skills. A sound somewhere between a choke and a groan escaped from my throat and my officemate Fadi glanced in my direction. He looked terrible: pale, slightly grimy, in desperate need of a haircut.  Were the bags under my eyes as bad as his?

“Did you forget to convert from degrees to radians, again?”

“Shut up,” I growled.

“Remember how Darcy submitted her paper and then had to withdraw it because one of her collaborators screwed up the unit conversions?”

“I remember. And that’s why I already double-checked this code.”

“If you say so,” he grunted, and turned back to his own computer.

Muttering to myself, I reverted a couple of changes in my program to make sure I hadn’t created this problem while fixing another one. Not that I could see. The whiteboard held the checklist of items I’d upgraded (at least that was the intention) in the pipeline last week. Running down the list, I didn’t see how any of those could be responsible for the crash. Comparing the metadata in the input … ah, there it was! Fadi was half-right—there was a unit-conversion problem although it was in the data files, not in my code. I wasn’t going to give him the satisfaction of telling him.

Some rapid-fire keystrokes, a whack of the return key, a deep breath, and the program ran to completion. The plot demanded my attention on the screen. My eyes went unfocused as I stared at it. The numbers seemed a little funky. The frequency was a harmonic of the local oscillator. Shouldn’t the amplitude be a factor of two lower?  Giving up trying to do Fourier transforms in my head, I pulled the relevant textbook from my bookshelf. Scribbling on a piece of scrap paper, furiously erasing, scribbling again. I glanced at Fadi, who was perusing a webcomic instead of solving the mysteries of the universe. Although he was so good, he could probably do both simultaneously.

“What’s the integral of cosine-squared from zero to two pi?” I asked.

“One half. No, wait! Pi. But you knew that.”

“Right, sure I did, thanks.”

Fadi yawned.

“You could go home, you know. It is after nine,” I said.

“What, and miss bearing witness to your genius?” he snarked.

“Besides, this run is almost finished, and I might as well see if it worked.”

“Some genius,” I grumbled.

Why wasn’t this expression working out the way I expected? Had I forgotten most of third-year physics and all of first year calculus? Apparently, yes. What was I doing in grad school again? And how was I going to convince anyone I deserved a PhD when my defense rolled around?

In reaching for my water bottle, I knocked over the cup of days-old coffee aging next to the scrap paper pile. The flood threatened to saturate the piece of paper with my calculations. Yanking the sheet from the desk, I rolled back in my chair, grabbed a marker, and transferred the calculations to the whiteboard. The coffee dripped onto the floor, adding to the many stains on the ancient low-pile carpet. Fadi eyed the drip, shrugged, went back to poking at his keyboard. He’d mostly learned to ignore my clumsiness. I crumpled the wet scrap paper into a soggy ball and threw it at the overflowing trash bin. It missed and hit the floor.

Tapping my nose with the whiteboard marker, I finally saw the mistake. Circling it, I pulled the chair back to the desk, and set to fixing and re-running the code. The program ran and the signal was there. It was real and it was not produced by anything that I could imagine. It had survived everything I’d managed to throw at it. The Shannon entropy was way too high for it to be natural. This was an artificial signal, not noise.

The log files showed that no one else was analyzing this dataset. I was the only person on Earth who knew about the signal. If I dropped dead from a stroke or a comet strike right now, someone else would eventually figure it out, wouldn’t they? The data were archived, after all. But I should tell someone just in case, right?

Turning to Fadi, I opened my mouth. No sound came out. What if I was wrong, what if I had made some stupid mistake that anyone with a brain and a little training in radio astronomy would notice? They’d take it as one more reason I didn’t belong in this field where almost no one looked like me and for sure no one was as stupid. The whole collaboration would think I was an idiot, and I’d get kicked out of the program. I closed my mouth, hard. My teeth clicked.

Fadi started at the sound, turned toward me again. He glanced at my screen with raised eyebrows.

“I think … this might be it?” I squeaked.


“A real signal.”

He let out a low whistle.

“Are you sure? Because I just had to tell you some pretty basic stuff and that makes me concerned about your level of genius.” He said it with the little grin that I knew so well.

“I’ve done every test I can think of. It’s still there.”

“You gotta be sure, though, right? I mean, if I screw up my simulations and get the luminosity function prediction wrong and publish it, other people just publish a rebuttal paper and I get a few more citations.”

I nodded slowly, unsure where this was going. My stomach churned. Fadi continued, “This … the word is gonna get out, in your collaboration if nothing else. If you get this wrong and make the project a laughingstock…” he trailed off. His tired eyes were sincere and concerned.

“Can I run it past you?” I asked.

“Sure.” Fadi yawned again.

I rolled my chair to where I could reach the whole whiteboard and started describing my analysis, step-by-step. Fadi’s yawn frequency dropped as he interjected questions and comments. I finished the description pointing to the final plot where it glowed on my screen. He sighed.

“I don’t see anything obviously wrong. But this is your baby. You have to be sure.” He turned back to his own computer once more.

I rubbed the back of my aching neck and swiveled it toward the opposite wall. In the family picture from my college graduation, Nana had her arm around my sister, both beaming. My uncle and his partner looked as proud as if they’d graduated themselves. Dad was slightly bewildered by all the pomp and ceremony, still unsure what this “astrophysics” business was good for but satisfied all the same.

Taped to the wall next to the photo was the giant card from the kindergarten class I’d visited last month to talk about astronomy. They thought I was a real scientist, didn’t they? Because I was, dammit!  I knew this stuff inside and out. This was an excellent candidate signal,  and it was time to tell the rest of the team.

I don’t suppose many people ever get to send an email that could change the world. Maybe, just maybe, I just did.




Pauline Barmby (she/her) is a Canadian astrophysicist who believes that you can’t have too many favorite galaxies. Her science articles have appeared in Utopia Science Fiction and Clarkesworld; her fiction is published or forthcoming in Martian, Tree and Stone, Flame Tree Press’ Compelling Science Fiction anthology, and others. Find her on Twitter @PBarmby.