How Does An Introduction to Cantor and Infinity Work?

Cantor helped us understand how infinity can come in different sizes, just like how a bag of marbles can hold more marbles than another bag.

Imagine you have two boxes: one has red marbles, and the other has blue marbles. If you take out one marble from each box at the same time, and you never run out of marbles in either box, they both have the same size of infinity, like having an endless supply of candies.

But now think about a hotel with an infinite number of rooms, all full. A new guest shows up, but there’s still space! How? Just ask every guest to move to the next room, the person in room 1 goes to room 2, room 2 goes to room 3, and so on. The new guest can then take room 1. That means even when something is infinitely full, it can still fit more.

Cantor showed us that some infinities are bigger than others, like how a never-ending list of numbers (like counting 1, 2, 3...) is smaller than the number of all possible decimal numbers between 0 and 1. It’s like having two kinds of endless collections, one smaller and one much bigger.

So Cantor didn’t just count to infinity, he counted between infinities! Cantor helped us understand how infinity can come in different sizes, just like how a bag of marbles can hold more marbles than another bag.

Imagine you have two boxes: one has red marbles, and the other has blue marbles. If you take out one marble from each box at the same time, and you never run out of marbles in either box, they both have the same size of infinity, like having an endless supply of candies.

But now think about a hotel with an infinite number of rooms, all full. A new guest shows up, but there’s still space! How? Just ask every guest to move to the next room, the person in room 1 goes to room 2, room 2 goes to room 3, and so on. The new guest can then take room 1. That means even when something is infinitely full, it can still fit more.

Cantor showed us that some infinities are bigger than others, like how a never-ending list of numbers (like counting 1, 2, 3...) is smaller than the number of all possible decimal numbers between 0 and 1. It’s like having two kinds of endless collections, one smaller and one much bigger.

So Cantor didn’t just count to infinity, he counted between infinities!

Take the quiz →

Examples

  1. Imagine counting all the stars in the sky, now imagine there are more stars than you can ever count.
  2. Think of a hotel that never fills up, even when every room is occupied.
  3. If you list all the whole numbers, and then list all the fractions, the second list has more numbers.

Ask a question

See also

Discussion

Recent activity