eli5: Why is it not possible to build bird-like attachable wings that account for body proportions to allow humans to fly or glide around?

Question

eli5: Why is it not possible to build bird-like attachable wings that account for body proportions to allow humans to fly or glide around?

In: 2102

Answer 1

some people have had slight success with it, but the problem is that our arms arent stong enough, and our fingers arent elongated, like a birds are (yes, birds have finger bones in their wings.)