Normally, I would say that a strain of 1 would be way too much. A strain of 0.1 would already mean a change of length of 10%, which is probably more than enough

Normally, I would say that a strain of 1 would be way too much. A strain of 0.1 would already mean a change of length of 10%, which is probably more than enough to destroy your body. But we are talking about orders of magnitude here, so the comparison of 10^-20 with 1 seems precise enough.