In one example of time paradox, a scientist creates a portal that looks into the past one minute, and he shoots himself, at the image he sees, in the past.
This is not a paradox, it is likely the forces that delay the image he sees, as he takes aim, also delays the bullet that has to travel through the portal in reverse. When the bullet emerge from the portal on the other side it is in the present and the scientist has walked away to take aim on the other side. He misses all the time! Forces acting this way prevent a positive feedback loop.
What is technically improbable is by no means limiting in theory.
Have nice day.
