String theory proposes that the most fundamental building blocks of the universe are tiny, vibrating strings. On the other hand, loop theory suggests that the fundamental building blocks are tiny, one-dimensional loops that interact with each other.
Currently, string theory is more widely accepted in the scientific community due to its ability to potentially unify all of the fundamental forces of nature, including gravity.
Some physicists believe that string and loop theory can be reconciled, as they both attempt to explain the fundamental nature of the universe. However, there is currently no definitive answer and the debate continues in the scientific community.
String theory predicts the existence of extra dimensions and supersymmetry, while loop theory does not. Additionally, string theory predicts that the universe is made up of 10 or 11 dimensions, while loop theory suggests that there are only 4 dimensions.
Currently, there are no direct experiments that can test the validity of string and loop theory. However, some physicists are working on developing new technologies and techniques that may be able to indirectly test these theories in the future.