Tidbit #58 - June 14, 2011

Continuing on the subject of data storage, I'd like to familiarize you all with the system of units we have to measure electronic information:

• Bit: The smallest of the electronic storage spectrum, a bit is basically the building block of data. Ever hear of binary code? (0010101001100110) Every 1 in binary code is a single bit being turned on by a computer. Bits are small, even in the most primitive computers.
• Byte (B): Still one of the smallest units, a byte is made up of eight bits.
• Kilobyte (KB): Back when computers were first invented, if you had a kilobyte of space, you were the life of the party. A kilobyte consists of 1,000 bytes, 8,000 bits. (8,000 ones in binary code)
• Megabyte (MB): Whoa, slow down, there, speed racer. In the early days of computing, megabytes didn't even exist unless you counted the most advanced mainframes of the day, which could only hold a few hundred megabytes. Nowadays, a single song's electronic size ranges from 3 to 20 megabytes. A megabyte consists of 1,000 kilobytes, or 1,000,000 bytes, or 8,000,000 bits.
• Gigabyte (GB): Let's skip forward a few decades, to 1980. That's when the first gigabyte hard drive was introduced. A gigabyte is 1,000 megabytes, 1,000,000 kilobytes, 1,000,000,000 bytes, and 8,000,000,000 bits. Think about how much that would've shocked the people from 1953.
• Terabyte: This is still a lot of space for today's standards, although not shocking. A terabyte is 1,000 GB, 1,000,000 MB, 1,000,000,000 KB, 1,000,000,000,000 B, and 8,000,000,000,000 bits.
• Petabyte (PB): This is big boy stuff, even at today's standards. Only enormous companies like Microsoft and Apple use petabytes to measure their total storage. A PB consists of 1,000 TB, 1,000,000 GB, 1,000,000,000 MB, 1,000,000,000,000 KB, 1,000,000,000,000,000 B, and 8,000,000,000,000,000 bits.
• Exabyte: Don't mess around with the exabyte. An exabyte of information is a LOT of storage. An exabyte is 1,000 PB, 1,000,000 TB, 1,000,000,000 GB, 1,000,000,000,000 MB, 1,000,000,000,000,000 KB, 1,000,000,000,000,000,000 B, and 8,000,000,000,000,000,000 bits.
• Zettabyte: Here's where we start getting into the units that no one's ever heard of. Not many amounts of information can give themselves the prestigious name of zettabyte. A ZB is 1,000 EB, 1,000,000 PB, 1,000,000,000 TB, 1,000,000,000,000 GB, 1,000,000,000,000,000 MB, 1,000,000,000,000,000,000 KB, 1,000,000,000,000,000,000,000 B, and 8,000,000,000,000,000,000,000 bits.
• Yottabyte: Starts to sound funny, doesn't it? A YB is 1,000 ZB. 'Nuff said.

Tidbit #57 - June 14, 2011

Some Information on Data Storage: Five Charts on Electronics that will Blow Your Mind


The world of electronics has increased HUGELY since first being introduced in 1956, with IBM's 350 systems, which only held 5 million bits. But just how much have humans increased their capability to store information since then? As of 2011, the results could be stunning. Take a look at these charts and find out what you've been missing:

Look at all of those, and search up many more with Google Images.

Tidbit #6 - April 1, 2011

Question: How do DVDs work?


Answer: Yeah, you've thought about it before. You've popped a movie into the player and thought about how amazing it was that that little disk could play entertainment for you.

Strictly speaking, a DVD is just a CD with more space on it. The data on the disk is encoded in little valleys and bumps on the surface. The reason you can't feel those little imperfections on the surface is because during their production, they're covered with a few layers of polycarbonate plastic.

A scanning-electron-microscope image of a DVD. See the
bumps? That's your movie. (PC: optics.rochester.edu)

You can't see them, either, because a reflective layer (which I assume is the back of the DVD that we know so well) is put over them, covering them.

Essentially, the data on a DVD is bundled into an extremely long, condensed spiral of data. Your DVD player is designed to read the bumps on the spiral of the DVD.


So your DVD is basically a prettied-up coiled string of data with plastic around it. Doesn't sound all that fancy, right? It's actually more complicated than I summarize it to be, as you've already found by reading above.

Just a heads-up: The string is something like 740 NANOmeters thick. And just letting you know, 1 meter is 1,000,000,000 nanometers. The wavelength of red light is 650 nanometers. So your DVD's data is only slightly thicker than a wave of light. That's really small!

If you want to learn more about DVDs and how they work, click here.