Is there a limit to how small we can go?

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Discussion Overview

The discussion revolves around the concept of whether there is a limit to how small distances can be measured or conceptualized, touching on implications for instantaneous movement and the nature of space at quantum levels. It includes theoretical considerations related to physics, particularly quantum gravity and relativistic effects.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants question whether there is a smallest possible distance, suggesting that if such a limit exists, movement across it would imply instantaneous travel, potentially violating the speed of light constraint.
  • Others argue that instantaneous movement has no physical meaning, referencing the Planck length and Planck time as relevant scales, indicating that even light takes time to traverse these distances.
  • A participant proposes that if there is a smallest distance, there might also be a corresponding smallest duration, which could prevent faster-than-light travel.
  • Concerns are raised about the energy levels required to explore these small scales, with one participant suggesting that such exploration could lead to the formation of black holes.
  • There is a contention regarding the characterization of the Planck length, with some asserting it is not definitively a "quanta of length" and that current experiments have not confirmed the existence of such a limit.

Areas of Agreement / Disagreement

Participants express differing views on the existence of a smallest measurable distance and the implications of such a limit. The discussion remains unresolved, with no consensus on whether a quanta of length exists or what its implications would be.

Contextual Notes

Limitations include the dependence on definitions of distance and time at quantum scales, as well as the unresolved nature of theoretical frameworks like quantum gravity. There are also unresolved mathematical steps regarding the implications of exploring these domains.

bozo the clown
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Is there a point at which you cannot go any smaller ?
if there is, than to move from X to Y (the distance between X and Y being 1 unit of that finite smallness) would be instantaneous right as if it wasnt you would have to move acroos that point indicating smaller units so therefore if there is a point of finite smallness than faster than speed of light would be passed if faster than light is not possible than there must be infinite smallness
understand ?
 
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This pretty much explains it all:
http://www.physlink.com/Education/AskExperts/ae281.cfm
You can't do anything instantaneously because that has no physical meaning. As that page says, even a photon traveling at the speed of light would take some time (planck time) to cover this smallest space (planck length).
 
bozo the clown said:
Is there a point at which you cannot go any smaller ?
if there is, than to move from X to Y (the distance between X and Y being 1 unit of that finite smallness) would be instantaneous right as if it wasnt you would have to move acroos that point indicating smaller units so therefore if there is a point of finite smallness than faster than speed of light would be passed if faster than light is not possible than there must be infinite smallness
understand ?

If there is a smallest possible distance, then wouldn't there be a smallest possible duration as well? These could balance out so that faster than light travel wouldn't happen.

Keep in mind that the energy levels required to explore these domains gets drastically big, and then you've got relativistic effects to account for. I'm not an expert, but it's possible that looking too closely at these domains would create a black hole that you miht fall into, so be careful!
 
Chen said:
This pretty much explains it all:
http://www.physlink.com/Education/AskExperts/ae281.cfm
You can't do anything instantaneously because that has no physical meaning. As that page says, even a photon traveling at the speed of light would take some time (planck time) to cover this smallest space (planck length).

The answer in the link isn't authoritve, it's inaccurate to call the Planck length the quanta of length as we simply don't know. It's the length at which quantum gravity is expected to manifest itself.

So the answer to the original question is that nobody knows if there is a 'quanta of length'. All experiments so far have shown no evidnece of that there is one, but it may well be the case that it will arise out of a theory of quantum gravity.
 

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