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.
The planet that is closest to Earth depends on where the other planets are in relation to Earth. Venus can come the closest when it is on the same side of the Sun as the Earth â¦ , but Mars can be closest when Venus is on the far side of the Sun and Mars is on the same side of the sun as Earth.