A doctor suddenly noticed that his patient seems to be indestructible, their injection doesn't penetrate through, until they even conducted basic experiments such as small knife cuts and other blunt damages.

Upon this discovery, the indestructible person was examined thoroughly, until he was really generalized as someone who is indestructible; a person like a very hard rock. His body could also never be affected by any chemical substance that harms him. Upon the series of test, he grew fond of science. In this story, the scientists can never(and would never) understand his body's data for they seem to be changing in a random pace.

Aside from his shield-like gift, he seems to be just a normal person, i.e; he cannot lift heavy objects but cannot be crush by them. Upon reaching his perfect age state, he stopped aging.. Years later when he started to wonder what could he contribute to science given that he is indestructible.

In what field of science does the indestructible yet average person contribute the best and in what way?

Note: Let us not focus on the person himself, but to the what contribution he could give. Lets just describe him as indestructible. If this question is too broad, please specify in which detail it is lacking.

A doctor suddenly noticed that his patient seems to be indestructible, their injection doesn't penetrate through, until they even conducted basic experiments such as small knife cuts and other blunt damages.

Upon this discovery, the indestructible person was examined thoroughly, until he was really generalized as someone who is indestructible; a person like a very hard rock. His body could also never be affected by any chemical substance that harms him. Upon the series of test, he grew fond of science. In this story, the scientists can never(and would never) understand his body's data for they seem to be changing in a random pace.

Aside from his shield-like gift, he seems to be just a normal person, i.e; he cannot lift heavy objects but cannot be crush by them. Upon reaching his perfect age state, he stopped aging.. Years later when he started to wonder what could he contribute to science given that he is indestructible.

In what field of science does the indestructible yet average person contribute the best and in what way?

Note:

1. Let us not focus on the person himself, but to the what contribution he could give. Lets just describe him as indestructible. If this question is too broad, please specify in which detail it is lacking.
2. Even if he reproduce, his offspring will never get his ability so that the story will focus on the main character.