Black Holes and the Mysteries of r=0: Understanding the Concept of Infinity

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Discussion Overview

The discussion revolves around the mathematical implications of setting the variable r to zero in the context of black holes, particularly focusing on the expression 1/r and its relationship to infinity. Participants explore the definitions and interpretations of this expression and its relevance to singularities in black hole physics.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions the validity of the expression 1/0 equating to infinity, suggesting it is undefined.
  • Another participant clarifies that it is more accurate to say that 1/r approaches infinity as r approaches zero, rather than stating it directly at r=0.
  • A participant references a TV program, speculating it may have been hosted by Michio Kaku, which led to their own confusion regarding the singularity concept.
  • Another participant reiterates that while 1/0 is undefined, the function tends towards infinity as r gets closer to zero, emphasizing that at r=0, the function becomes meaningless.
  • A later reply expresses amusement at the discussion, indicating a light-hearted engagement with the topic.

Areas of Agreement / Disagreement

Participants express differing views on the interpretation of 1/r as r approaches zero, with some emphasizing the undefined nature of the expression at r=0 while others focus on the limit approaching infinity. There is no consensus on the best way to frame the discussion around this mathematical concept.

Contextual Notes

Participants highlight the importance of understanding limits and the behavior of functions as they approach certain values, particularly in the context of black hole singularities. The discussion does not resolve the nuances of these mathematical interpretations.

Who May Find This Useful

This discussion may be of interest to those exploring concepts in black hole physics, mathematical limits, and the implications of singularities in theoretical physics.

iRaid
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Ok so I was watching this program on TV and the guy ended up getting r=0

With this he put this value into the equation as so:
1/r = 1/0 = infinity


What is up with that? Isn't it undefined.


Also, this is about black holes.
 
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it's more proper, and correct, to say 1/r approaches infinity as r approaches zero.
 


Let me guess: Michio Kaku on 'Who's afraid of a big black hole' describing the equation that led to a singularity?. I remember I had the same question.
 


1/0 is undefined, anything divided by zero is undefined.
But, as AUK 1138 mentioned it is better said that as r tends towards a very small number ( i.e. gets closer and closer to zero ) the fraction will tend towarda bigger and bigger number ( i.e. tend towards infinity ). But at r = 0 the function is meaningless
 


Why didn't he just do that then rofl. Thanks guys :p
 

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