40 digits of pi

You only need 40 digits of pi to calculate the number of atoms in a circle the size of the entire universe:

Why? Consider this:

Dividing it out, it takes about 1037 atoms to span the universe. So, around 40 digits of pi would be enough for an exact count of atoms needed to surround the universe. Were you planning on building something larger than the universe and precise to an atomic level? (If so, where would you put it?)

And that’s just 40 digits of precision; 80 digits covers us in case there’s a mini-universe inside each of our atoms, and 120 digits in case there’s another mini-universe inside of that one.


It’s not the user’s fault

Jonathan DiCarlo (from Mozilla Labs) about developers, users, and user interfaces:

5. Are users dumb?

User interface design is not about dumbing things down for the poor stupid user.

We software developers, understanding the software as we do, find it easy to look down upon those who lack our understanding.

This is wrong.

Users aren’t dumb. They just have better things to do with their lives than memorizing the internal data model of our screwy software.

When software is hard to use, don’t make excuses for it. Improve it.

When a user makes a mistake, don’t blame the user. Ask how the software misled them. Then fix it.

The user’s time is more valuable than ours. Respect it.

Good UI design is humble.


How to hack a password

How to crack a password? Bruce Scheier, of Wired Magazine, has some inside info on how to do it.

According to Eric Thompson of AccessData, a typical password consists of a root plus an appendage. A root isn’t necessarily a dictionary word, but it’s something pronounceable. An appendage is either a suffix (90 percent of the time) or a prefix (10 percent of the time).

So the first attack PRTK performs is to test a dictionary of about 1,000 common passwords, things like “letmein,” “password1,” “123456” and so on. Then it tests them each with about 100 common suffix appendages: “1,” “4u,” “69,” “abc,” “!” and so on. Believe it or not, it recovers about 24 percent of all passwords with these 100,000 combinations.

But wait, there’s more.