What is the greatest acheivement of science and technology within the last century. What about the next cntry?

Answer 1

In the last century possibly the solid state transistor, the birthplace of what we think of as modern electronics.

The next century will see nanotechnology become the basis for everything from medicine to manufacturing.

Answer 2

Last century = computers & internet
Next century = virtual reality.

Answer 3

genetic coding, i think for the last century
humans going to planets as far as neptune for the next century