this post was submitted on 08 Sep 2024
162 points (98.2% liked)

What is this thing?

5242 readers
1 users here now

Let us help you identify that mysterious object you’ve found.

Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.

founded 1 year ago
MODERATORS
 

Any ideas?

all 39 comments
sorted by: hot top controversial new old
[–] FartsWithAnAccent@fedia.io 142 points 1 week ago

That is a surveyor's mark called an Above Ground Marker. It is used as a point of reference when they survey they land.

[–] solidgrue@lemmy.world 89 points 1 week ago

Its called a benchmark, used by surveyors as a known point from which to take readings. We had a benchmark on the edge of of our property in the town where In grew up. It was a square, white marble column, like a truncated obelisk with the point cut off to make a 4" square flat top, buried at the roadside and standing a couple inches proud of the grass. It had a cross with a dot in the middle, and a geodetic ID number engraved on the top.

Nailed it with the lawnmower once or twice. That'd really put the Fear in you.

[–] SpaceNoodle@lemmy.world 78 points 1 week ago (2 children)

Control point for ley lines. Keeps the magic channeled to prevent chaos from breaking out.

[–] chemical_cutthroat@lemmy.world 30 points 1 week ago

Yeah, this. You can step on one, and it's fine. Just don't step on two and complete the circuit, it's like boofing the third rail.

[–] dsilverz@thelemmy.club 73 points 1 week ago (1 children)

A marker point for geodetic marking. Also known as triangulation station or trigonometrical point, it's fixed to the ground with its known coordinates.

[–] catch22@programming.dev 14 points 1 week ago (1 children)

Cool! Interesting, I thought True North meant that they somehow pointed north given another reference. Thanks for the info.

[–] PapaStevesy@lemmy.world 62 points 1 week ago (1 children)

They hold the sidewalk down, don't pick it up or the whole block could blow away.

[–] unknowing8343@discuss.tchncs.de 19 points 1 week ago

Yep, these are the measures that keep the underworld locked for the rich and I am tired of pretending it's not.

[–] wise_pancake@lemmy.ca 43 points 1 week ago (1 children)

It controls where true north is, and if you remove it that will really mess with geographers and surveyors

[–] Empricorn@feddit.nl 19 points 1 week ago (1 children)

Please don't, people! I don't want to have to re-learn geography with different orientations...

[–] ada@lemmy.blahaj.zone 10 points 1 week ago (1 children)

You shouldn't be afraid of different orientations. Embrace difference!

[–] Empricorn@feddit.nl 5 points 1 week ago

Sorry, DEI is banned in my state.

[–] espentan@lemmy.world 38 points 1 week ago

Survey marker, used by surveyors to calibrate equipment. So I've been told, anyway.

[–] Typotyper@sh.itjust.works 19 points 1 week ago (3 children)

Canada’s look different. They have a reference number

[–] eltrain123@lemmy.world 10 points 1 week ago

This is a survey monument vs the original post being a control point. Survey monuments are established on a larger scale.

When you need to reference a known elevation or XY coordinate, there is a network of survey monuments with known coordinates, usually installed and documented by governments. You reference a known location’s elevation and north x west coordinates and then use instrumentation to determine angle changes to transfer the known elevation to a series of other locations.

When you section off property or build things, like roads or buildings, you use this network of points and triangulate paths off of them to the job site by calculating angles and distances. Since you have to maintain line of sight while traversing the distance, you add points you can use to pivot on and travel great distances. These points are called ‘control points’ or ‘benchmarks’.

The main post pic is a control point. Your picture is a survey monument.

[–] stoly@lemmy.world 8 points 1 week ago* (last edited 1 week ago) (1 children)

You see those in the US too. I think the one in original photo is for temporary use. I.e. embed it for your project and leave when done.

[–] Typotyper@sh.itjust.works 3 points 1 week ago

That would make sense given the lack of refrence numbers.

[–] Maeve@kbin.earth 0 points 1 week ago (1 children)

Just more proof they're* holding us down.

*Blessed autocorrect

What was the original text?

[–] No_Eponym@lemmy.ca 14 points 1 week ago (1 children)

< We reach/tether >

< through Control Points >

< into the Bureau/House >

The Rule of Three applies, of course.

[–] Glowstick@lemmy.world 8 points 1 week ago (2 children)

What city is this in? Because I've never noticed one in nyc

[–] catch22@programming.dev 10 points 1 week ago
[–] KreekyBonez@lemm.ee 2 points 1 week ago

once you start to notice them, you'll never stop seeing them everywhere.

this one is a magnetic nail, so it can be found more easily with a metal detector, which is pretty handy when there's a foot or two of snow on the ground.

you'll also see crosses, squares, and triangles carved out in stone, as well as the super common drill holes in concrete, which are typically only for temporary points.

I've found 100+ year old control points drilled into old stone walls, and they can still check within like ¼" of the new maps.

[–] Feathercrown@lemmy.world 7 points 1 week ago

Mind control relay. You can try to remove it but are mentally incapable unless you have a tinfoil hat.