At a security checkpoint two barriers are simultaneously lowered and immediately

Question

At a security checkpoint two barriers are simultaneously lowered and immediately raised. A passenger notes that her spaceship, at rest at the checkpoint, is slightly smaller than the distance between the two barriers. Now assume that the spaceship is moving toward the checkpoint at 80% the speed of light. According to the guard at the checkpoint there will be a moment when the spaceship passing through the gates will fit comfortable inside the two barriers when they are lowered and raised because of length contraction. But the passenger reasons that in her moving frame the distance between the two barriers will be contracted, therefore her spaceship will not fit inside the two barriers. Who is right? Is the interpretation of the passenger correct? Is there any possibility to reconcile the two viewpoints? Please explain in detail what does happen in each frame. Write your answer in the allowed space. References: SE and class notes only.

Explanation / Answer

Length contraction is the phenomenon of a decrease in length of an object as measured by an observer which is traveling at any non-zero velocity relative to the object

This means that the passenger is right, she will see   the distance between the two barriers as contracted (Length contraction is only in the direction parallel to the direction in which the observed body is travelling so she will see it as long as this condition fulfils)

And the passanger will also experience time dilatation in her fram the time of closing the gates is less than the guard time

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