Hypothetical situation of planck length object and lightspeed

In summary, the conversation discusses the concept of length contraction, which states that objects approaching the speed of light appear to contract in length to an external observer. However, this idea has no physical meaning and was later modified with the Penrose-Terrell effect. At quantum scales, the concept of length distortion becomes more complex and measuring rods lose their meaning. However, clock-metrics are still relevant when considering time dilation.
  • #1
Curtis15
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0
Initially known theories:

1. General consensus: Planck length is smallest measurable unit of length

2. Objects approacing light speed contract in length

Scenario: Some hypothetical mass measured to be a Planck length is accelerated infinitely close to light speed.

Questions: Can a length contraction be detected? Does the length contraction actually occur?
 
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  • #2
The problem gets a little stickier than that if the universe is divided up into a spacetime mesh at plank distance.

A light beam or particle moving at some angle to the mesh must do the old computer graphics jaggie (http://en.wikipedia.org/wiki/Jaggies) because you have a grid.

Try get your head around conservation of energy and momentum around that ... or is that why we have Quantum mechanics to take it off grid for the jumps :-).
 
  • #3
1. There is no absolute length contraction. The idea has no physical meaning. There is the appearance of length change to an external observer with a relatively different velocity.

2. Classical relativistic length-appearance change was modified with the introduction of Penrose and/or Terrell effect/rotation (1959).

3. Due to the Penrose-Terrell effect, objects observed transversely to the objects' directions do not contract in appearance. Scientific American made this error a few years ago when they showed colliding heavy ions as shortened into oblate spheroids.

4. We are presumably talking about spherical geometry concerning sub-atomic particles.

5. At quantum scales well above Planck lengths anyway, it's hard to think about length distortion for objects that only have a defined wave-function.

6. At quantum scales, measuring rods lose their meaning. They have meaning only for the classical macroscopic (trains, spaceships, etc.) relativistic textbook discussions. Where are the 'end points' of 'measuring rods' when the end-points have only wave-function 'locations' in space? However, clock-metrics are retained as far as (relative!) time-dilation is concerned.
 

1. What is the Planck length?

The Planck length is a unit of length that represents the smallest measurable distance in the universe. It is approximately 1.616 x 10^-35 meters, or about 10^-20 times the size of a proton.

2. What happens to an object that reaches the Planck length?

According to current theories, an object that reaches the Planck length would experience extreme gravitational forces and would likely collapse into a singularity. However, this is still a topic of ongoing research and there is no definitive answer yet.

3. Can an object travel at the speed of light?

No, according to Einstein's theory of relativity, the speed of light is the maximum speed at which any object can travel. As an object approaches the speed of light, its mass increases and it requires an infinite amount of energy to reach the speed of light.

4. What is the relationship between the Planck length and the speed of light?

The Planck length and the speed of light are both fundamental constants in the universe. However, they are not directly related to each other and serve different purposes in different theories.

5. How does the concept of a Planck length object affect our understanding of the universe?

The concept of a Planck length object helps us understand the limits of our current understanding of the universe. It also plays a role in theories such as string theory and loop quantum gravity, which attempt to reconcile quantum mechanics with general relativity.

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