Eyeglasses made of nylon were introduced in the late 1940s. Because of brittleness and other problems, eyeglass manufacturers switched to blended nylon (polyamides, co-polyamides and gliamides). Today's blended nylon frames are both strong and lightweight.
Venus is the closest size to Earth and is sometimes called Earth's sister planet.. Its diameter is 95% of Earth's but its mass is only 81% as much.
About a half dozen claims of bigger Earth-size (or still larger super-Earth) planets orbiting in habitable zones around red dwarfs have been made in recent years, Boss says. Still, it once again proves what Kepler can do.. The next closest thing to Kepler-186f has a width 1.4 times that of Earth, Quintana says. According to Seager, a planet whose diameter is less than 1.75 Earths is likely to be rocky. The Kepler report looks particularly reliable because of the spacecraft's track record.