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.
Venus is the answer to âwhat is the closest planet to Earthâ. It is similar in diameter, mass, and volume, but you can see how it is a scary world compared to ours. There are several missions headed to Venus.