Scientists do mind experiments just for fun, or when real ones are impossible or too expensive. Infinity is not the largest number, it is not a number at all. That is, it does not obey the laws of the numbers. For example, when you add 1 to a number, you get a larger number. If we move one step to the right on the number line, we will be farther from zero, which means larger number.
Mentor shows on the line .
To understand it all better, people invented a good model. Well, sometimes we do not use the real thing, we use a smaller or simpler model, something people build to understand or to explain how the thing works. On this model an engineer will see if the real house will look good. He can also use the model to explain things about the future house to people who will live or work there. Half of the egg carton and marbles or beads work well.