Unless they’re listening with a laser interferometer, that is.
Yesterday, scientists at the Laser Interferometer Gravitational Wave Observatory (LIGO … although shouldn’t it be LIGWO?) announced they had detected Gravitational Waves.
Using a miles-long laser that was split into two beams travelling at right angles to each other, the lab detected the distortion caused by the stretching of space-time as a gravitational wave passed through the reflecting mirrors. The wave itself was caused by the collision of two black holes. Naturally, they cut a record of it. It kind of sounds like “Ph’nglui mglw’nafh Cthulhu R’lyeh wgah’nagl fhtagn.”1
And now, we can hear the sound of stars as they turn in the fabric of space-time.
Spring, 1990, Andrew Hill High School: Mr. Boone asks me if I plan on taking his physics course next year.
Ha ha! I will be repeating Algebra II that year, because I am so bad at math my teachers openly weep with despair. The only way I will be “taking physics” is if that is a slang term for “oh hell no.”
But … Mr. Boone had been my geometry teacher. He’d taught my brother and all my sisters, and was the only reason Linda graduated. There was no way I could tell him no … and, being me, once I said “yes,” I had to follow through. Cue three summer months of knee-knocking terror.
From the first day of class, I was hooked. (The first lab’s always free.) Physics challenged me, and challenged my view of the universe, more that anything I’d ever studied up to that point2. But it also gave me a sense of empowerment I’d never known before. The lab I remember most, the one everyone remembers the most, is the Silver Dollar Lab. First, you rolled a steel ball down a ramp and caught it before it hit the floor. From its velocity, you calculated where it would hit, then summoned Mr. Boone over. He’d slap a dollar bill on the table and hand you an ancient dollar coin, nicked and dented from years of collision events. You placed the coin where you’d calculated the ball would land, then you put the ball on the ramp and let it go. If it hit the coin, you kept the dollar and passed the lab.
Wow! With just a calculator and a computer (physics was the first time we ever used computers to do science, too) I could point to a spot and predict the future. I can know reality! That was power.
It was here I first learned about inverse square laws, the Four Fundamental Forces, and the quest to unite them. I learned that the force of gravity is unusually weak, that the other three forces are unusually strong, and that … most exciting of all … we didn’t know why.
We were working on it, though. If only there were some way to know more about gravity … the likelihood of being able to detect something so minute, though … it was the stuff of science fiction and pipe dreams.
We also learned about the motion of objects at constant velocity. When I was told I’d need calculus to learn more, my math grades immediately improved.
I got straights As in math for the next 3 years, and ended up as a math major, with a minor in physical science. My first summer break, Mr. Boone offered me a job as TA for his summer school chemistry course … and from there, I learned there is no higher calling than teaching.
Autumn, 1992, Humboldt State University:
First day of the “Physics For Scientists and Engineers” course – real, calculus-based physics. Finally, I would have the answers I had been dreaming of for two years! In the meantime, knee-knocking terror.
The professor walks in. He says nothing, eyes scanning the class. Eventually he turns around and writes on the chalkboard:
F = mA3.
Newton’s First Law of Motion; more colloquially stated as “an object in motion tends to stay in motion.”
He turns around. “That’s it,” he says. “See you for the final.”
“OK,” he says at last. “Maybe there are some details we can go over. But for the next six months, any time you get stuck, go back to that. F=mA.”
Spring, 2009, New Horizons Tutoring:
In teaching my student about electric fields, I fall back on the old rubber sheet analogy.
I’m talking about how a heavier mass distorts the sheet more than a small mass:
“What would happen if you dropped a Ping-Pong ball on it?” I ask.
“Right. There’s not enough mass. How about a baseball?”
“It would bend a little.”
She’s getting it. Time for the big finish.
“So,” I say, “what would happen if you dropped a bowling ball on it?”
“It would tear.”
“But this sheet is really space-time,” I say. “So what would we call a rip in the fabric of space-time? What would we call a tear in reality?”
Her eyes got big as saucers. “A black hole,” she whispered.
I remembered Dr. Thompson. Whatever I teach, I try to distill it down to its most basic essence, a framework that guides how you think about the material. For chemistry, it’s the Periodic Table and the factor label method. For physics, it’s power laws.
I tell her that both electromagnetism and gravitation obey an inverse-square law: at twice the distance between two objects, the force is four times as weak; at three times the distance, it’s nine times. I also mention that electromagnetism is orders of magnitude more powerful than gravity.
“Why?” she asks.
“Well, that’s where you come in. I’ve taught you all I know; we’re counting on you to discover more.”
“Me?!?” she squeaked. “I just wanna go to college and meet a rich guy to marry.4” (Her senior year had been … challenging, and she was adjusting her expectations.)
“Sorry,” I said. “The future has other plans for you.”
We detect gravitational waves for the first time. The dreams of 1991 are real. The theories I taught are correct. They did it.
Today, I’m proud to be a member of a species, a civilization that can do this, and as a teacher, a part, however small, of the great effort to transmit the wonder and beauty of science to the next generation.
And thank you, Mr. Boone, for talking me into taking a risk with physics. For seeing something in me that I didn’t know was there.
Excuse me, I just have something in my eye … it’s probably a gravitational wave …
- Okay not really. But if hearing the sound reality makes as it bends isn’t Lovecraftian, I don’t know what is.
- Ironically, botany was even more paradigm shattering. You think you know plants? BUDDY, YOU DON’T KNOW FROM PLANTS!
- Technically, the F and the a should have arrows over them, indicating they are vector quantities. But it’s hard enough doing these damn footnotes.
- Hey, don’t blame me for being misogynistic – that’s an actual quote.