There were a ton of comments here telling me that the Facebook bookmarklet that I made broke, and this happened because Facebook changed the name of the file they were using. I’ve updated the post, so the bookmarklet there should work now.
I wrote recently about how everything in computers is stored as 0s and 1s, and the language of computers is binary. You can read about that here. However, one bit or a few bits doesn’t really contain that much information. In general you will be dealing with thousands, or millions, or billions, or even more binary digits!
There are a set of prefixes that are associated with binary data, and here is what they all mean.
First a bit is just a single 1 or 0.
If you take 8 bits and put them together we call that a byte.
One thousand bytes is called a kilobyte (shorthand kB). The prefix kilo means 1,000, like kilogram. One minor thing is that computers always represent things in powers of 2, so although the prefix kilo means 1,000 on a computer it is more likely that a kilobyte is 1,024 bytes, because 1,024 = 2^10– the closest power of two to 1,000. A small text file on your computer is probably a few kilobytes up to a hundred kilobytes.
One million bytes is called a megabyte (shorthand MB). The prefix mega means 1,000,000. For a computer the exact number is the closest power of 2 which is 2^20. A standard mp3 file on your computer is probably somewhere from 3 to 10 megabytes (that is 3 to 10 MILLION bytes, or 24 to 80 MILLION 1s and 0s!).
One billion bytes is called a gigabyte (shorthand GB). The prefix giga means 1,000,000,000. For a computer the closest power of 2 is 2^30. A full-length video of medium quality is probably around a gigabyte in size.
Just for some more reference, the Google homepage just sent 32.1 kB of data. Just loading the home page of thekeesh.com was 440.98 kB, but doing it a second time was only 12.36kB of data. An image file in general is from tens of kilobytes to a few megabytes.
There are more prefixes bigger than giga–
terabyte is one thousand gigabytes
petabyte is one thousand terabytes
exabyte is one thousand petabytes
zettabyte is one thousand exabyte
yottabyte is one thousand zettabyte.
You can buy a terabyte hard drive these days for about $100 or less on a quick Google search, which is pretty crazy.
From the wikipedia page on zettabyte:
As of February 2012, no storage system has achieved one zettabyte of information. The combined space of all computer hard drives in the world was estimated at approximately 160 exabytes in 2006… As of 2009, the entire Internet was estimated to contain close to 500 exabytes. This is a half zettabyte.
So that is a basic introduction to some of the metric prefixes as applied to bytes.
I’ve used this setup so many times now that I wanted to write up a list post explaining how I do it. This method is something I found on this site, but I just wanted to add my own commentary.
The idea is that you are developing a website locally using git, and you want to be able to easily push to your live site with git. We will set up a remote repository on your server, and push to it.
Let’s say you have your local repository already set up. Log on to your remote machine. Navigate to a directory where you want to keep your repository. This does not necessarily need to be the same location as your code, and you actually probably want it to be a different place.
### On the remote machine corn03:/afs/ir/group/paperless2> mkdir repo.git && cd repo.git corn03:/afs/ir/group/paperless2/repo.git> git init --bare Initialized empty Git repository in /afs/ir.stanford.edu/group/paperless2/repo.git/
The way this is going to work, is that we are going to create a post-receive hook. A post-receive hook means you can run some script after this repo has received a push. What we are doing here is checking out the current code to some directory, which we define as the GIT_WORK_TREE. You can make the GIT_WORK_TREE wherever you want. Then we make the script executable.
corn03:/afs/ir/group/paperless2/repo.git> cat > hooks/post-receive #!/bin/sh GIT_WORK_TREE=/afs/ir/group/paperless2/cgi-bin git checkout -f corn03:/afs/ir/group/paperless2/repo.git> chmod +x hooks/post-receive
Now, on your local machine, add the remote you want to push to. On this first one, make sure you include the branch you are including, like master.
## Locally > git remote add web ssh://jkeeshin@corn23.stanford.edu/afs/ir/group/paperless2/repo.git > git push web master
For any future updates
> git push web
It’s pretty basic, easy to use, and works for lightweight deployment for a site by yourself or with a few other people.
The only issue I had was one time, my internet connection went down in the middle of deployment and the git process crashed. Then the next time I tried to push, nothing happened. After a little bit of searching, the fix was that there was a file “index.lock” that was created, and once we removed that file, it worked again.
Hobson’s choice: the choice of taking either that which is offered or nothing; the absence of a real alternative.
Origin: 1640–50; after Thomas Hobson (1544–1631), of Cambridge, England, who rented horses and gave his customer only one choice, that of the horse nearest the stable door, from dictionary.com.
I just joined another site yesterday. Or it was an app, I don’t really remember. It doesn’t really matter what it was. But this site had terms and conditions that you had to accept before using it. If you are just a general internet user, there is really nothing you can do about terms and conditions. If you want to use this site or app, you have to accept them. And if you don’t agree with them (and my guess would be in most cases, you would always be able to find something you don’t agree with), you simply can’t use the site.
This is the classic case of a Hobson’s choice, where there appears to be a real choice between two alternatives, but one of the options isn’t really an option.
Consider a case where you are at work and the boss wants you do to something, and he says to you: “Either you can do this, or you are fired!” In this case, you have “a choice”– you can either do this task or not. But assuming you want to keep your job, you are left with no real alternative, and similarly very little bargaining power.
The end users on the internet face this on basically every site you join. There are way too many terms and conditions for it to be at all feasible and reasonable for you to read them. Almost all sites present terms and conditions in a way where they *expect* you not to read them, but you *have* to agree to them to use the site. The sad state of affairs is that users *have* to a agree to a term sheet that they *almost certainly* never read. Many sites have terms and conditions hidden at the footer of their site that you implicitly agree to just by being there.
If I had to guess I would say that way less than 1% of Apple users read their terms and conditions sheets. I would be very curious to know that number.
So that’s about it. If you want to use the internet at all, just accept the fact that you had to agree to all these really stupid contracts that you have never read.