"Length contraction" prior to observation/measurement

In summary, special relativity argues that the length of an object or distance is not constant and depends on the observer's frame of reference. However, the actual physical diameter of an object remains unchanged over billions of years. This leads to the idea that there is no objective world, but rather an infinite number of possible subjective perceptions. However, relativity still describes the real and objective universe we live in. Therefore, the premise of this conversation is incorrect and the discussion is now closed.
  • #1
Michael Mooney
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Since special relativity insists that length is not invariant but rather depends on the frame of reference from which an object or distance is observed... and since the cosmos is many billions of years older than any possible observer, then objects and the distances between them must exist independently from all varieties of referential frames.
Example: A frame of reference approaching Earth at .86c will, according to SR, measure its diameter to be about 4000 miles in the direction of the approach. But Earth hasn't changed much from its 8000 mile diameter in billions of years, so how it might appear from such a frame has nothing to do with its actual, physical diameter, which does "vary" with how it is measured.
It all comes down to the fact that SR denies an objective world in favor of an infinite number of possible "subjective" perceptions of the world. Open for discussion.
 
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  • #2
Before you write off length contraction as something subjective, you should study and understand Bell's spaceship "paradox" - google will find many references.

In any case, it simply untrue (and probably based on a misunderstanding) to say that relativity "denies an objective world". It describes the real and objective universe in which we live - it just so happens that that universe doesn't behave the way our common sense, which is biased by a lifetime surrounded by objects moving at speeds that are small compared with the speed of light, leads us to expect.

As this thread is based on a faulty premise, it is closed
 
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Related to "Length contraction" prior to observation/measurement

1. What is length contraction?

Length contraction is a phenomenon in physics where the length of an object appears shorter when it is moving at high speeds relative to an observer. This is an effect of special relativity, which states that the laws of physics are the same for all observers in uniform motion.

2. How does length contraction occur?

Length contraction occurs because of the time dilation effect of special relativity. As an object moves at high speeds, time slows down for it relative to an observer. This causes the distance between the front and back of the object to appear shorter to the observer, resulting in length contraction.

3. What is the equation for calculating length contraction?

The equation for calculating length contraction is L = L0 * √(1 - v2/c2), where L is the contracted length, L0 is the rest length of the object, v is the relative velocity between the object and observer, and c is the speed of light.

4. Does length contraction only occur for objects moving at the speed of light?

No, length contraction occurs for any object moving at high speeds relative to an observer. However, it becomes more noticeable and significant as the speed of the object approaches the speed of light.

5. Can length contraction be observed in everyday life?

No, length contraction is only noticeable at extremely high speeds, such as those reached by particles in particle accelerators. In everyday life, the effects of length contraction are too small to be observed without highly precise measurement equipment.

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