Relativistic Stick: Can the Hole Contract Enough?

In summary, the conversation discusses a stick of length L moving at speed v passing through a hole of diameter L cut into a thin sheet, with the sheet being raised as the stick passes through. The scenario is questioned in terms of frames of reference and the possibility of the stick passing through the hole, with calculations showing that it is possible despite the stick being longer than the hole.
  • #1
boardbox
16
0

Homework Statement


A stick of proper length L moves at a speed v in the direction of its length. It passes over a thin sheet with a hole of diameter L cut into it. As the stick passes over the sheet is raised and the stick moves through the hole so that it is underneath the sheet.

Is this a reasonable scenario? In the lab frame the stick is contracted and should easily make it through. However the hole is contracted in the stick frame.


Homework Equations





The Attempt at a Solution


I know that events that are simultaneous in one frame are not in others. So I expect part of the sheet to rise before the rest in the stick frame. Because of that I also expect the stick to be able to pass through (despite being "longer" than the hole) but I'm having difficulty showing it quantitatively. In the stick frame the front of the hole moving and the back of the hole moving should be separated in time by Lv/c^2.

Now if I take that time, and multiply by v, get Lv^2 / c^2 as the distance that the hole would traverse in the stick frame which is less than L and would mean to me that the proposed scenario is impossible. What bothers me with this is it goes against my intuition. Can anyone see where I'm going wrong?
 
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  • #2
boardbox said:
… I know that events that are simultaneous in one frame are not in others. So I expect part of the sheet to rise before the rest in the stick frame. …

Hi boardbox! :smile:

If the sheet is at an angle, surely only the width of the stick matters?
 

Related to Relativistic Stick: Can the Hole Contract Enough?

1. What is the theory behind the relativistic stick and its contraction?

The theory is based on Einstein's theory of relativity, which states that the laws of physics are the same for all observers in uniform motion. This means that an object's length will appear to contract when it is moving at high speeds relative to an observer. The degree of contraction depends on the speed of the object.

2. Can a relativistic stick contract enough to create a hole?

Theoretically, yes. According to the Lorentz transformation, as an object approaches the speed of light, its length will approach zero. This means that at the speed of light, the object's length would theoretically contract to zero, creating a hole. However, this is not possible in reality as an object with mass cannot reach the speed of light.

3. How does the speed of the stick affect its contraction?

The speed of the stick is directly proportional to its contraction. This means that the faster the stick is moving, the more it will appear to contract. This effect is only noticeable at speeds close to the speed of light, as objects at low speeds have negligible length contraction.

4. Is the contraction of the stick visible to the naked eye?

No, the contraction of the stick is not visible to the naked eye. This is because the speed at which an object needs to move for its length contraction to be noticeable is incredibly high, close to the speed of light. At these speeds, the time dilation effect would also come into play, making the stick appear to move in slow motion.

5. What practical applications does the relativistic stick theory have?

The relativistic stick theory has practical applications in fields such as particle accelerators and space exploration. In particle accelerators, the length contraction effect is utilized to accelerate particles to high speeds. In space exploration, the theory is used to understand the effects of high speeds on objects, such as the contraction of spacecrafts and the time dilation effect on astronauts.

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