Badland9085
@Badland9085@lemm.ee
- Comment on Steam is 'an unsafe place for teens and young adults': US senator warns Gabe Newell of 'more intense scrutiny' from the government if Valve doesn't take action against extremist content 2 days ago:
There’s the “this is too woke” gang, and then there’s the “this doesn’t have enough representation” gang. You can’t win.
- Comment on What are the most mindblowing fact in mathematics? 1 year ago:
You are correct. This notion of “size” of sets is called “cardinality”. For two sets to have the same “size” is to have the same cardinality.
The set of natural numbers (whole, counting numbers, starting from either 0 or 1, depending on which field you’re in) and the integers have the same cardinality. They also have the same cardinality as the rational numbers, numbers that can be written as a fraction of integers. However, none of these have the same cardinality as the reals, and the way to prove that is through Cantor’s well-known Diagonal Argument.
Another interesting thing that makes integers and rationals different, despite them having the same cardinality, is that the rationals are “dense” in the reals. What “rationals are dense in the reals” means is that if you take any two real numbers, you can always find a rational number between them. This is, however, not true for integers. Pretty fascinating, since this shows that the intuitive notion of “relative size” actually captures the idea of, in this case, distance, aka a metric. Cardinality is thus defined to remove that notion.