Best Answer XeduR @Spyric , 18 January 2019 - 10:03 AM
Your question isn't as clear as you may think.
After a physics object has been created, you can no longer change it. If you want to turn a static object dynamic, then you'd need to delete the physics body and create a new one with a dynamic body to begin with.
The reason why two static objects can't collide is due to computational efficiency based on the assumption that if an object is static, then it shouldn't be moving in the first place, i.e. it shouldn't be able to collide with another static object.
What you could do is create a dynamic body but turn it into a sensor. If your app uses gravity, then set the object's gravity scale to zero. This way the object will be able to detect collisions with other objects, but won't physically collide with them (and will be unaffected by the possible gravity).