## If the infinite cardinals aleph-null, aleph-two, etc. continue indefinitely, is there any meaning in the idea of aleph-aleph-null?

Apologies if this isn't a sensible question, I really don't know too much about these infinite cardinals aside from the basics. I did, however, think that the idea of the "aleph-null"th aleph number …

## Who are these people in gray robes and shaved heads with South Korean Passports?

I saw a number of people with gray robes and shaved heads while I was in Seoul recently that looked like this: Is this a religious thing? They had Republic of Korea passports, for what that's ...

## Why can I look at a graph and immediately find the closest point to another point, but it takes me O(n) time through programming?

Let me clarify: Given a scatterplot of some given number of points n, if I want to find the closest point to any point in the plot mentally, I can immediately ignore most points in the graph, ...

## Command that changes its definition the nth time it's used

I need a command to behave differently the first time than the next times it's called. Right now I use \newcommand\foo{First\gdef\foo{Next}}, that is, it redefines itself the first time. Moreover, I …

## How many solutions for this equation?

$$\frac{x-4}{(x-1)} = \frac{1-4}{(x-1)}$$ Can someone tell me how many solutions are there for the above equation? MY APPROACH: I cross multiplied the equations and re-arranged to get a quadratic …

## Why are planes generally painted white?

When planes come out of the factory unpainted, they're green: So why are most painted white? Surely a darker colour would hide dirt better? Is there a reason planes are traditionally white?

## Why are we not to throw these exceptions?

I came across this MSDN page that states: Do not throw System.Exception, System.SystemException, System.NullReferenceException, or System.IndexOutOfRangeException intentionally from your own …

## Dad jokingly told boss that I called him dumb to my shock

So I have a bit of a transportation problem and I work at a startup. It was a Saturday night and my dad came to pick me up but I had my phone on silent. So he came in and had some small talk with my …

## How important is it to clean up someone else's code when faced with a tight deadline?

(I'm talking about HTML / CSS code (not programming languages) but I think we also face the same issue as with programmers.) I am the senior front-end designer in a team and I often have to re-work …

## Which form of Maxwell's equations is fundamental, in integral form or differential form?

I am not sure which form of Maxwell's equations is fundamental, integral form or differential form. Imagine an ideal infinitely long solenoid. When a current is changing in time, can we detect ...

## 4, 8, 15, 16, 23, 42

4, 8, 15, 16, 23, 42 Write a program that outputs this sequence of numbers infinitely. However, The Numbers may not appear in your source code anywhere. The following is not a valid Java program to …

## The reasoning behind book dust jacket while there is a hardcover

I am wondering, what is the reason behind adding a dust jacket when a book has a hardcover as well. Initially, the purpose seems to be obvious: to protect the hardcover below it, so that it does not …