Holey street signs? Seen in Maine. Only some signs like this. Why? A: They lower the wind resistance so that the wind does not flex the pole as much as it would with a solid sign.

What are these holes in the ground for? They are in the entryway to the Roman amphitheater in PompeiiA: It is absolutely for a fence to create a separate pathway for workforce and, I would assume, people who get to pass by the crowds of plebeians. Same system is often used today.

This Plastic Annulus below the window on my flight. There is a ridge dividing the two halves in the inner circleA: It’s to make windows go dark. Bottom half darker. Upper half brighter. Also crew can change whole flight settings so you might not be able to change it.

A long thick rope with a metal cylinder with fins that seems to intend it to spin?A: This is a taffrail log, and it is/was used for calculating nautical speed.As you may be aware, for centuries sailors would measure their speed by casting a rope over the side, and measuring how fast the line would spool out. They would tie a knot in the rope at fixed intervals, and if they’re going fast enough that a dozen of the knots would be reeled out in a standard amount of time (e.g. ten seconds), then that’s a speed of twelve knots.

Large/bare/raised dirt mounds on the slopes of a glaciated volcano (Mt Baker)A: Heavy rainfall, snowmelt, or high levels of groundwater flowing through cracked bedrock may trigger a movement of soil or sediments in landslides that continue as mudflows. Floods and debris flows may also occur when strong rains on hill or mountain slopes cause extensive erosion and/or mobilize loose sediment that is located in steep mountain channels.

USFS Structure in Rural Area – Door Opens, Nothing Inside.A: It’s a fire pit to cook your food on top of.

A small oval gold thing with two buttons. They didn’t seem to do anything. One button had M or W on it. It was lightweight and plastic. There was a battery cover on the back. It was about the size of a matchbox.A: Little remote for a vibrator

Old, framed document, starts with the name ‘Elizabeth’?A: It’s an Elizabethan letter patent. The patent rolls for Elizabeth I’s reign offer a colorful insight into the workings of the Elizabethan church and state, and into Elizabethan political culture in general.

Spotted on a walk. Spongy texture when pressed. Any ideas?A: Someone trying to get the covered area to root so they can replant it. Strip the bark, cover in a growth medium (soil, wood chips, etc..) cover & wait for roots to form.

Mysterious vial with amber fluid found inside grocery store. Small as a pill?A: Fire suppressant sprinkler fuse.

What is this small, metal tool with equally sized prongs, but different (even only) numbers?A: They are gold testing needles.

What is that spoon for ? It looks like a ladle but it also looks like it would be used for sauces ? I have no idea.A: Gravy ladle

Button beneath the steering wheel installed by first owner. Blinks once when pressed and held, no other obvious functions. According to the previous owner it had something to do with insurance?A: It’s part of a GPS tracker.

What is this opening on this airplane engine? It opened during landing. Never seen before. It closed itself after the landing.A: Thrust reversers for slowing down.

What is this “box”? Lighter for size comparison.A: It is a razor blade holder for a double edge safety razor, like a Gillette fat boy.

What are these levers near the passenger side doors foot area in my 1969 Impala?A: Fresh air vent controls.

Heavy ferrous metal object painted yellow, with a single hole odd shape. Almost 3 inches wide. This was found buried about 2 inches deep in my backyard, found with a metal detector.A: It’s a pawl, like to keep things in a jaw or stop kickbacks on a table saw.

This divot on my school’s desk. All these kinds of desks have it. It’s about the size of a ping pong ball.A: In this desk with a similar divot they call it a thumb guide. My guess is for moving it more easily, this particular model allows for both right hand and left hand positioning and different belly depths, so it would be nice to have a spot to grip

Hollow brass “walking stick” with spring loaded spike.A: It’s for killing weeds, one leaf at a time.

What is this weird net of cables and weights on the building?A: It’s a wire trellis system for a living wall. The weights at the bottom keep the wires taut.

Small zippered portion on the top of my indoor tent? inside only, no entry to the outsideA: The correct answer is that you are meant to cut the tent behind the zipper and thread a wire/anything you want. The zipper exists so you can re-seal the tent afterwards.

Strange tool found in our Airbnb kitchen. Pressing buttons on sides “opens” it. What is this used for?A: It’s a detachable handle for Tefal oven proof range of kitchen pans.