Can an ordinary person learn to build an atomic bomb by hand? Of course they can! Step 1: Have your buddy head to the mountains of Yunnan and dig up 3000 tons of uranium ore with grade above 0.5%, then have him crush all 3000 tons of uranium ore. Step 2: Have your buddy help you buy 20000 tons of hydrofluoric acid. Mix, stir, separate, filter and dry 3000 tons of uranium ore with the acid until it becomes golden yellow powder. At this point, you have uranium oxide. Step 3: Have your buddy get flooring gas and mix it with uranium oxide to purify it. In the end, you get high-purity uranium. Step 4: Have your buddy get a super washing machine spinning 100,000 revolutions per minute. Put high-purity uranium in it for a second purification. Spin it three to five years, using about 5 billion kilowatt hours of electricity, and you'll end up with a chunk of high-purity on way colored U-235. Step 5: Have your buddy shape the uranium into 2 hemispheres. Go to a hardware store and ask the owner to make an atomic bombshell, following the little boy blueprints at full scale. Place the two enriched pieces of uranium you made at each end of the shell, keeping them separated in the middle. Then, install a high explosive detonator at the tail end. Finally, you can visit your annoying neighbor next door, bring your homemade little boy, set the time fuse, and get as far as possible. If your craftsmanship is good, the detonator will push the two pieces of enriched uranium together. When it explodes, as long as the total weight exceeds critical mass, an explosion occurs, and a massive mushroom cloud will rise. Congratulations, you made an atomic bomb!