Universal Limits: Are There Other Natural Boundaries?

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Discussion Overview

The discussion revolves around the concept of universal limits in nature, exploring whether there are additional boundaries beyond the well-known speed of light and absolute zero. Participants examine various theoretical and physical limits across different domains, including astrophysics, quantum mechanics, and thermodynamics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants assert that the speed of light in a vacuum is the ultimate speed limit, while noting that absolute zero is a theoretical limit that cannot be achieved.
  • One participant introduces the Planck length as a limit below which distance measurements lose physical meaning.
  • The Chandrasekhar limit is mentioned as the maximum mass for a white dwarf star, beyond which it may undergo a supernova or collapse into a neutron star or black hole.
  • Another participant points out the Pauli exclusion principle as a limit related to the filling of atomic orbitals.
  • The Heisenberg limit is discussed in relation to wave behavior, indicating that a pulse cannot be both very short in duration and narrow in frequency spread, with implications for data transmission in fiber optics.
  • The Bekenstein bound is proposed as a limit on the maximum entropy and temperature of a substance within a fixed volume.

Areas of Agreement / Disagreement

Participants present multiple competing views on what constitutes universal limits, with no consensus on a definitive list of such limits. The discussion remains unresolved as various limits are proposed without agreement on their universality.

Contextual Notes

Some claims depend on specific definitions and interpretations of physical concepts, and the discussion does not resolve the implications or interrelations of the proposed limits.

Sturk200
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The speed of light is the universal speed limit and absolute zero is the universal temperature limit. Are there any other universal limits like this in nature?
 
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speed of light in a vacuum is the speed limit

although it is (presently) not possible to reduce the temperature of a body to 0 K it is possible for a body to have negative temperature
other limits

Plank length - below which distance measurements are said to have no physical meaning.
 
Chandrasekhar limit.

The maximum mass for a white dwarf star.
If the white dwarf accumulates a greater mass through accretion or merger it will become unstable, usually producing a supernova explosion.
Other possible outcomes are a collapse into either neutron star or black hole.
 
There are limits in filling of orbitals(Pauli exclusion principle)
 
When dealing with quantum or classical waves, there is the Heisenberg limit.
A pulse of light or any other wave cannot both have a narrow frequency spread and be of a very short duration.

For example, one cannot create a pulse of green light that is shorter than a femtosecond or so long. The pulse will necessarily be "white", containing all frequencies of the visible spectrum.

This comes into play, say, in fiber optics, where there's only a certain spectrum of colors that optical fibers can transmit well. If we transmit data as optical pulses, the Heisenberg limit shows us that we can only send data through the fiber so quickly. If we make the pulses too short, the more extreme parts of their color spectrum will get absorbed by the fiber, and the pulses will get all distorted as a result.
 
What about the Bekenstein bound, the highest possible entropy a region of space can have?

For a given substance, this should also translate to the highest possible temperature the substance can have, trapped in a fixed volume.
 

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