A 2.6 mile long straightedge that you can use to see the curvature of the Earth

In 2015, Ardent built a 2.6 mile (4.2km) straightedge, which you could use to see the curvature of the Earth. We’re brought it to Burning Man, since the Black Rock Playa is one of the few places in the world flat enough for it to work.

When working with curves or angles, human perception isn’t naturally very precise. To fix that, we sometimes use a visual reference: like a framing square, a ruler, or a plumb bob. These tools allow us to see subtle changes that would otherwise be invisible.

On a clear day at the ocean, or on a flat desert plain, the Earth’s curve is visible to the naked eye. But, it’s hard to perceive it because there is no reference. We built that reference. It was possible to stand alongside the straightedge and see how the Earth curves. From one end to the other, the total elevation change is about 5 feet (1.5m).


The Earth is big: 24,900 miles (40,000 km) around. But, what does that really mean? If there were no oceans and you tried to walk around it, it would take you two years if all you did is walk and sleep. That number is really hard to comprehend, though. Imagine the size of a golf ball. Easy, right? Now, try a basketball. That’s pretty easy too. But the whole Earth? It’s really hard!

When astronauts see the planet from space, it changes them. They talk about a feeling of awe, or a realization of how trivial human conflicts actually are. This experience is so common and profound, it even has a name: The Overview Effect. Astronaut Sally Ride, when speaking of the emotional impact of seeing the Earth from orbit, said it, “makes theory come alive.”

Astronauts talk about many different aspects of the Overview Effect, but a key part is seeing the planet as a single object, floating in the vast emptiness of space. On viewing the Earth from the lunar surface, Neil Armstrong later recounted, “I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.”

It sounds useful to be able to think of the Earth this way, but the experience is very rare. Only about 23 people each year go to space. Fewer than 600 humans have ever had the opportunity to look at our planet in its entirety.

But, we can all see Earth every day. You’re probably looking at it right now. It’s just hard to imagine the whole thing. It could be flat. It could be a cube. It could be ten times its actual size, or a tenth, and it would look about the same from where we’re sitting.

Using this massive tool, it was possible to visualize the size of the Earth in a completely new way. In your mind’s eye, you could easily project the line describing Earth’s curve into a complete circle, and get an intuitive sense for the actual scale of our entire planet. Straightedge was able to connect the abstract notion of that lonely blue dot in the pictures with the reality of the ground you’re standing on.


You can see a more complete description of how we built it on our kickstarter page


Straightedge was built by a team of 50 designers, engineers, fabricators, software developers, stake pounders, and a geologist.

  • Aaron Fishman
  • April Arcus
  • Ashi Krishnan
  • Audrey Penven
  • Ava Pierce
  • Ben Mossbarger
  • Bradford Jewell Bossen
  • Colin Carey
  • Corey Monteith
  • D J Capelis
  • David Fine
  • David Glasser
  • David Shearer
  • E. Morley John
  • Ed Hunsinger
  • Elizabeth Pickles
  • gz
  • Ian Baker
  • Jackson
  • Jamie Kennedy
  • Jonathan Stray
  • KC (KdotCdot)
  • Keaton Mowery
  • Lana
  • Laura Kogler
  • Liana Lareau
  • Mari Hsu
  • Mark Wheeler
  • Mary Wang
  • Mella
  • Micah Elizabeth Scott
  • Moto
  • Nadya Lev
  • Nick Ingolia
  • Nicole Aptekar
  • Okami Stormborn
  • Paul Knight (paulymer)
  • Rebecca Power
  • Reed Kennedy
  • Rennie Lum
  • Rory Aptekar
  • Sara Enright
  • Serene Han
  • Simon Sutherland
  • Steen
  • Stuart Sands
  • Tiff Harker
  • Tini Catone
  • Tom Cauchois
  • Tom Cavnar

Thank you!

Straightedge was built with the generous support of hundreds of individual backers. Thank you all so much! We couldn’t have done it without you:

Aaron, Aaron A. Reed, Aaron Muszalski, Adam Nieman, Adam Phelps, Ahmed Amer, Alaric Bergeron, Alex Maki-Jokela, Alex Power, Alice Neels, andrew sullivan, Andy Isaacson, Anna McGeachy, Arlen Abraham, Audrey Penven, Ava Pierce, B. Pier, BDan Fairchild, Ben Rupert, Berit Gilma, Bill Gilman, Bob Buch, Bob Solorio, Brendan, Bruce Rogow, Bryan Culbertson, Carla Riggi, Carolyn Savarese, Carrie Smith, Celina, chris coleman, Chris Dzombak, Chris Schaub, Chris Spurgeon, Christina Kelly, Cody Smith, colin, Colin Deeb, Connie, Connor Graham, Courtenay Cotton, Cradle of Mir crew, D J Capelis, D. O’Brien, Daniel Garcia, Darek, David Dolphin, david fine, David Glasser, david reuter, DebannK, Derek Leverenz, desl, Diane Gordon, Doctor Popular, don riggs, Doug Shire, Doug Thistlewolf, Duane Peterson, Ed Hunsinger, Eden Gallanter, Elaine Buckler, Elise, Elizabeth Pickles, Ellen Wang, Elliot J. Godzich, Eric, Eric Angell, Ernie, Everfalling, Fish, George Kulakowski, George Post, Gideon Wald, Glen Ivey, Glenn Willen, godzero, Heidi Pickman, Ian Baker, Ian Maltby, Isaac Dudek, J A, J Gingold, J Tyler Brown, Jack C, Jacquie Tannenbaum, James Davies, Janet Creech, Jason Coon, jason sylvester, Jasper Smit, Jeanie Conner, Jeff Glover, Jen Darmstadt-Holm, Jen Worth, Jen Zariat, Jered, Jess Hobbs, Jesse Card, Jesse Wolfe, Jim St. Leger, Jimmy, Jody McIntyre, Joe Auricchio, Joe Zarate-Sanderlin, John Blessing, John Edie, Jonathan Cain, Joseph T. Meyerowitz, Josh Smith, joshua pines, jostua, jpm, Judy Tuan, Justin Cummins, Justin Day, Justin Frank Polgar, Kaia Dekker, Kasey Smith, Kayla Kinnunen, KC, Keaton Mowery, KentKB, Laura Dane, Laura Kogler, Lex Nemzer, Liana Lareau, Liz H, liz moore, Logan Rockmore, Lucas Carey, Luke Groesbeck, m k, M. Elizabeth Scott, Marcy Protteau, Margaret B. Carey, maria alovert, Mark Kriegsman, Mark L. Gross, Mark MacLennan, Mark Wheeler, Markus Fix, Matt, Matt Harris, Melissa Piercey, Michael Case, Michael Dewberry, Michael Edgcumbe, Michael Juarez, Michael Prados, Michael wyrick, Mikaela, Mike Ewing, Mike Harrison, Mike Hord, Mike P, Molly Allison, Morgan Davis, Morgan of SLO, Morley Beckman, Nadya Lev, Neil Girling, Neil Kandalgaonkar, Nelz, Nick Ingolia, Nick Morgan, Nicole Aptekar, Nifer Kilakila, Noble and Porter, Nopnop Goose, Norman Jaffe, numist, OkiDokiOkami, Oliver Harris, Paige Dansinger, Patrick Reeves, Paul Franke, Paul Guthrie, Paul Knight, Paul Mans, Paul Williamson, Peter Hosey, Peter Kropf, Peter Privitera, Rachel Binx, Ramon Y, Randall Leeds, Ray Thro, Reed Kennedy, Rennie, Rich Fromm, Robb Walters, Robin Harrison, Rory Aptekar, Ryan O’Hara, Santa Cruz Burners, Scott Snibbe, Serene H, Simon, Skipixie, spongish, Stacey Svetlichnaya, Star St.Germain, Stuart Sands, Stuart Updegrave, Sunny Allen, SuperQ, Susan Aptekar, Susan Buckler, Susan Upchurch, Tad Mayer, Tess Lee, The Desert Wizards of Mars, Theo Danilov, Thomas, Tiffany Harker, Tilde Ann Thurium, Tim Dery, Tim Watkins, toby schachman, Tom Cavnar, Trey Lawrence, Tristan Horn, Triston Cossette, Vanessa Shen, Venkatesh Srinivas, walter, Wesley Chen, William Francis, William Paul Buchanan, Yulia Krashennaya