YEAR AGO, A GOLDEN EAGLE approaching the Glenrock/Rolling Hills wind farm in Wyoming might have seen a dangerous optical illusion: A turbine’s blades, spinning at more than 150 miles per hour, would appear not as solid objects to be avoided, but as a blur the bird could fly through. Scientists believe this disorienting visual phenomenon, known as motion smear, contributes to the collisions that kill an estimated 140,000 to 679,000
