Measure of Reals: Countable or Uncountable?

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The discussion centers on the concept of measure theory, specifically questioning why the reals cannot be described as an uncountable number of singletons, each with zero measure. It highlights that while the measure of a singleton is zero, the union of an uncountable number of zero-measure sets does not necessarily yield a measurable set. The principle that the measure of a disjoint union equals the sum of the measures applies primarily to countable sets. The conversation emphasizes the importance of understanding how to define the sum of an uncountable set of numbers in measure theory. Engaging with foundational resources on the topic is encouraged for clarity.
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I was reading a little about measure theory, and the measure of a singleton is zero.
So why couldn't we just describe the reals as an uncountable number of singletons which each have zero measure and then union all of these singletons.
Maybe the union only works for countable sets when talking about measure.
 
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You are trying to apply the principle that the measure of a disjoint union is the sum of the measures of the components, right?

How do you define the sum of an uncountable set of numbers?
 
Literally looking 5 seconds at the wikipedia page on measure theory answers your questions: http://en.wikipedia.org/wiki/Measure_theory

Please do some research yourself before asking questions.
 
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