

A 2.7 mile long straightedge - jasonmp85
https://www.kickstarter.com/projects/966222131/straightedge-a-new-way-to-see-your-planet

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bmir-alum-007
In case anyone were wondering, gravitational lensing would only account for
1.6030569323305754e-13 m or 0.16 picometers of laser deflection when the laser
would be tangent to earth and the ruler is extended from that same point.

Deflection approximated by:

    
    
        tan( G * mE / (r * c(air)^2) ) / 4345 [m]

