• 0 Posts
  • 114 Comments
Joined 2 years ago
Cake day: July 26th, 2023
  • eltrain123@lemmy.worldtoNo Stupid Questions@lemmy.world•How are roundabouts made?
    7·
    2 months ago

    I used to be a surveyor! The tripods have different tools you can put on top.

    A ‘level’ is used to look at rod (some distance away) with measurement gradations on it, like a ruler, to add or subtract height from its current position to determine elevation. You can transfer measurements long distances by leap-frogging positions of the level and the rod. If you start or end at a known USGS monument, you can tie into historicity known elevations. This is how elevations were mapped before GPS (but the survey markers are still used today). They have some really fancy auto-levels that read a qr-style barcode and can measure down to very precise heights.

    A ‘thedolite’ is a robot-style machine that uses triangulation to determine elevation, distance, and angle. You benchmark it in place so it knows its location, then uses a rod with a prism it can follow. It calculates degrees it turns horizontally and pivots vertically to calculate where you are with the prism. It will automatically guide you to pre-programmed points to lay out very precise locations. Or you can use it to capture really precise points that are in the field. I haven’t been a surveyor in 20years, but they could easily layout points to millimeter accuracy when I was in the game.

    We also used lidar scanners to capture ‘as-built’ maps or calculate volumes of material. A lidar scanner shoots out a laser a few 100,000 times a second as the scanner turns on the tripod. When it bounces off an object, it returns a x,y,z coordinate and a color of the object it bounces off of. When you get a few million returned, you get a point cloud that represents the physical area you are mapping. When you move the scanner and repeat the process, you can map out large areas to a pretty high degree of accuracy. We once used a scan of a statue that was built in the 1800s to compare against the weight of construction materials so we could calculate the crane load expected to move it. Pretty cool stuff!

  • eltrain123@lemmy.worldtoAsk Lemmy@lemmy.world•What is the absolute last extreme sport you'd be willing to try?
    13·
    9 months ago

    I know you didn’t ask and probably don’t care, but free climbing and free soloing are different things. Free climbing uses a rope, but does not allow you to use artificial means to ascend, like pulling on gear you put on the wall. The gear is just there to arrest a fall.

    Free soloing is where you climb without a rope. Free climbing uses a rope for safety, but upward mobility is hands and feet on wall. Aid climbing is where you climb by fixing gear to the wall and use it to ascend.

    If you know what you’re doing, free climbing is pretty safe. Free soloing is not, but people do it successfully without their huge balls weighing them down.

    As a side note, bouldering is also climbing without a rope, but you don’t climb high enough to make a fall fatal.

  • eltrain123@lemmy.worldtoNews@lemmy.world•As Millions of Acres Burn, Firefighters Say the U.S. Forest Service Has Left Them With Critical Shortages
    2·
    11 months ago

    That only really works if there are funds to pay for it. These firefighters are making $15 (per the article) for doing hot, labor-intensive work in dangerous environment and conditions. It’s hard to get recruitment numbers up for work like that without good pay. Bonuses can help, but it doesn’t sound like they are paying enough to attract the labor they need.

    The article also says retention is hard and one of their biggest problems is the lack of ‘experienced’ firefighters. It’s definitely going to be tough to keep people coming back at pay rates that are less than what minimum wage would be if it had kept up with inflation.

  • eltrain123@lemmy.worldtoWorld News@lemmy.world•EU charges Elon Musk’s X for letting disinfo run wildEnglish
    8·
    1 year ago

    No, but he is finding out why twitter had all of its policies on combatting misinformation before he took over and gutted the staff… to prevent getting sued. You can say anything you want in America and the government can’t tell you that you aren’t allowed to say it, but you are still accountable for the damages caused by what you say… just ask Alex Jones.

    But operating in other countries doesn’t afford the same protections from government scrutiny.

    Disinformation campaigns are part of the reason social media is causing as much social strife in the world. It is not outside a logical line of thought that governments are going to attempt to minimize the damages from platforms like Twitter when they can. You may not beat misinformation, but you can minimize the financial incentive to promote it if you fine the fuck out of it when you find it.