For this achievement you have to go through an entire level without harming a single scientist. The level would be 1-1 as it's a really small level and there's not many scientists to harm.
#1 + #2 - Run towards the three scientists until two of them join together and stop while the third one runs to the end of the path. Move backwards a fair distance and then triple-jump over the two scientists.
#3 + #4 - Walk over the floating symbol to turn it green, this removes the lock and it turn drops the third scientist to the floor below. Immediately after you do that if you keep running forward, you can run over the 4th scientist without harming him.
#5 - The fifth scientist will run to the end of the pathway and then its just a simple matter of bouncing against the two walls without harming the scientist. I suggest starting directly below where the roof ends.
#6 - The sixth scientist will be walking towards the wall and at the momment you have enough space to jump over him, you should do so.
#7 - The seventh scientist froze in the middle of this path for me but can easily be jumped over with careful timing. I suggest you jump at the first red seat for safety.
#8 - The eighth scientist will be a simple jump of the two walls job. Do exactly as I have said in five and you should be fine. Do the same if the seventh scientist has decided to run further and huddled with the eighth scientist.
#9 - The ninth scientist is similar to eight and five as you have to bounce off the wall and there is a scientist in between you. I suggest jumping at the start of his strange machine.
#10 + 11 + 12 - I simply jumped over the tenth scientist as I have done previously and continued running forward towards the next scientist. The eleventh and twelfth scientist froze like the seventh scientist so simply jump over them with careful timing. I suggest you jump at the start of the strange machine for safety.
#13 - The thirteenth scientist is similar to eight, five and nine as you have to bounce off the wall and there is a scientist in between you. I suggest jumping at the start of his strange machine.
#14 - The fourteenth scientist will be at the end of the gap when you learn to do the triple jump. If you don't harm him after you do your triple jump he should run to the end of the path and into a wall. He is similar to eight, five, nine and thirteen as you have to bounce off the wall and there is a scientist in between you. I suggest starting directly below where the roof ends.
#15 - The fifteenth scientist will be working in chair doing work as scientists do and as soon as you run towards him he will run towards the end of the path and eventually as most scientists do ... hit a wall. This time it's a little different as there is an explosive that you can use to fire you further. Use this bomb and you should not bounce anywhere near the fifteenth scientist.
If you've followed the following steps, Ghandi should be very proud of you.