Answer: I think it's Nuclear, sorry if I'm wrong!
Explanation:
Joanna'a therapy is antibiotic therapy.
Antibiotic therapy is the therapeutic way to overcome an infection using one or more anti-infectious drugs, belonging to the class of antibiotics, and whose activity is exerted against the bacteria causing this infection. It could also be used to prevent superinfection (for example after bronchitis, cold, flu, viral infections or ear infections) or to reduce the risk of infection before surgery.
A physical change occur when objects or substances undergo a change that does not change in which the composition of a substance changes or one or more substances combine or break up from new substances.
It slowly gets compressed so I guess you can say it moves slowly as the space gets compressed