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.
This means that Earth is actually approximately 2.6 times the diameter of the smallest planet, Mercury. Another size comparison puts Earth at 3.67 times the diameter of the Moon. 6. Earthâs âtwin planetâ Venus is only slightly smaller than Earth with a diameter of 12,104 km.