Scene: Mamie and Solly stare at their moth-eaten-looking front lawn from their sidewalk and debate about what might be happening there in another reality.

Solly (pointing): I think it’s a sinkhole, Mamie. Forming on our front lawn. Covered it with a tarp. City engineer coming to take a look. Plumber might be able to fix it.

Mamie (staring): Are you sure this isn’t a black hole, Solly? I’ve been reading. 

S (stepping forward):  Whatever you’re reading lands in our conversations. You read too much.

M (pulling him back): No! Don’t step where the ground is soft. You could get sucked in by gravity. That force increases as you get closer to the event horizon.

S (speaking slowly): Mamie. That’s out in space. We’re standing on the sidewalk here on Earth next to our front lawn. When you hear hoofbeats, think sinkholes, not black holes.

M: Talking with you is an important event on my horizon, Solly, but in physics, an event horizon is a black hole’s point of no return. Maybe that’s true of our conversations…anyway, we shouldn’t get close to a black hole. The gravity is so great we can’t walk away.

S (thinking aloud):  Technically, if we got close enough to a black hole, we would be drawn in. Physicists thought that nothing going in comes out. However, that Porphyrion black hole we read about has jets detected as radio waves: likely particles in streams millions of miles long.

M (questioningly): If nothing can escape a black hole’s gravity, how can jets come out?

S (eyebrows raised): Beats me. 

M (frowning): Can you see these jets?

S (shaking his head): No. 

M (quizzically): How do you know invisible radio waves aren’t coming out of our lawn holes?

S (reasonably): Because they’re likely sinkholes, not black holes.

M: Why?

S: The spots in the lawn have pockets of air space.

M (tangentially): Why can’t the black holes be so tiny we can’t see them?

S (mildly): Their powerful gravity would still suck us in.

M (smiling): That’s why I’m hanging onto you.

S (shaking his head, trying to clear it): There’s airspace in the sinkhole. The soil washed away, maybe from an underground leak.

M: So, once the plumbers stop the leak, replace the leaky pipe, then they just fill in the sinkhole? All’s right with the world?

S: Once that’s done, I guess they assume it’s fixed. If the lawn collapses, we’ll know it needs more work.

M: Do plumbing schools teach the difference between black holes and sinkholes?

S: Probably they teach excellent plumbing skills, so plumbers can replace cracked pipes and fill in sinkholes. In physics schools, they likely teach black holes, not sinkholes.

M (straightening up): So, black holes mean immense gravity. Sinkholes mean gravity doesn’t change.

S (nodding): People who pass a black hole’s event horizon would be crushed, wouldn’t come back. If sinkholes are big enough, people might fall in, might not come back.

M (assertively): Black holes have a solid core. What they draw in is compacted into a tiny mass. Sinkholes either have air space or are mushy, with shifting ground.

S: Black holes are out in space—we hope—but sinkholes are here on Earth.

M (reaching): Seems anticlimactic, but if it’s a sinkhole, it can be fixed. Let’s look. I’ll pull back the tarp…yikes!

S (startled): Wait…did you see that?!

M: An animal peeking up! A ground hog! If this is a quantum universe, maybe he’s trans-dimensional!

S (dampeningly): Mamie. We’re right here on Earth. Hear hoofbeats, think…there he is again! Beady little eyes! He looked at me!

M:  There he goes, into the earth! Won’t that big boy be floored when the backhoe bursts in? 

S (measuredly): This supports the sinkhole theory. 

M (crestfallen): Maybe I shouldn’t mention possible black hole event horizons to our neighbors. 

S (leaning in): Don’t be disappointed, Mamie. You and I will have a future consolation conversation.

M (happily): Maybe an Earthly talk about climate science is on our personal event horizon.

About the author: Linda Lemery llemery@gmail.com welcomes reader comments.