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The Hierarchy Of Infinity

ABI`TAMIM✒️
ILLUMINATION
Published in
4 min readJun 10, 2023

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It’s a bit complex. But if you like complexity.

Infinity, the concept of limitless expanse,

However, did you know that there are various levels or hierarchies within infinity itself?

A Concept Beyond Measure

Infinity is a complex concept that challenges our finite perception of the universe.

It denotes a state of boundlessness, where there is no end or limit.

The notion of infinity has fascinated mathematicians, philosophers, and thinkers across time, inspiring contemplation about the nature of existence and the vastness of the universe.

Some infinity are bigger than other infinity

  • The Levels of Infinity: Within the realm of infinity lies a hierarchy or levels that distinguish different magnitudes of the unbounded. Mathematicians have developed a framework to understand this hierarchy, known as transfinite numbers, which was pioneered by the German mathematician Georg Cantor in the late 19th century.
  • Countable infinity: denoted by ℵ₀ (aleph-null), represents sets that can be matched one-to-one with the natural numbers 0, 1, 2, 3, and so on, extending to Infinity. It encompasses sequences that never end, like the integers or the collection of all even numbers.
  • Uncountable infinity: denoted by ℵ₁ (aleph-one), represents sets that cannot be matched one-to-one with the set of natural numbers. The set of real numbers is a prominent example, encompassing both rational and irrational numbers.

Easy With Example

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Now imagine you have a basket of apples. Let’s compare the number of apples in that basket to the concept of infinity.

Countable Infinity (ℵ₀) - Imagine you start counting the apples in the basket: 1, 2, 3, 4, and so on.

If you can keep counting and assign a unique number to each apple in the basket, then the number of apples in the basket represents countable infinity. It means you can match each apple with a natural number (1, 2, 3, and so forth).

Uncountable Infinity (ℵ₁) - Now, let’s consider a different scenario. Suppose you have a second basket with apples.

but this time it is filled with all possible real numbers between 0 and 1, including fractions and decimals. Between 0 and 1, there are infinitely many fractions and decimals.

In fact, the number of fractions and decimals between 0 and 1 is uncountably infinite. This means that there is no way to count or list all of them in a sequential manner.

To understand why this is the case, consider that between any two distinct numbers, you can always find another number.

For example, between 0 and 1, you can find fractions like 1/2, 1/3, 1/4, and so on. And between any two fractions, there are more fractions. This pattern continues infinitely.

Furthermore, between any two fractions, there are infinitely many decimals. For instance, between 0 and 1/2, you can find decimals like 0.1, 0.01, 0.001, and so forth. The same holds true for any other fraction.

Since there is no limit to how many fractions or decimals can be found between 0 and 1, the total number of them is considered uncountably infinite.

If you try to count and match each real number to an apple, you’ll find it impossible because there are infinitely many real numbers between 0 and 1. This represents uncountable infinity, which is a larger size of infinity than countable infinity. It means there are more real numbers between 0 and 1 than there are natural numbers.

To put it simply, countable infinity is like counting apples one by one and matching each apple with a natural number. Uncountable infinity, on the other hand, represents a bigger infinity that cannot be counted in the same way.

The continuum hypothesis

This was proposed by Cantor, suggests that there is no infinity between countable and uncountable infinity. In other words there is no set whose cardinality falls between ℵ₀ and ℵ₁. This hypothesis however remains unproven and continues to be a topic of research and debate within mathematics.

Note that the concept of infinity goes beyond the physical example of apples. In mathematics, it is used to understand and describe the behavior of limitless quantities.

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