Thursday, March 25, 2010

New hominin

Today's scientific buzz is about the discovery in Siberia of a finger bone found in a cave. Based upon DNA analysis, scientists have determined that the human-like creature, living between 30,000 and 48,000 years ago, was distinct from both Neanderthals and modern humans.

From the finger, scientists were able to reconstruct the appearance of this human-like creature:

Thursday, March 11, 2010

Putting a byte back into hard drives

A good article in Ars Technica: Why new hard disks might not be much fun for XP users explains a lot about the technology behind hard drives and how that is changing. It also includes a second partition devoted to explaining how manufacturers are trying to overcome the current 2TB partition limit.

I never really considered that digital data is actually encoded as an analog signal. Magnetic data on a hard drive is supposed to be 1s and 0s, but magnetism can be unreliable at the microscopic level of a hard drive platter. Those 1s and 0s have to be stored in larger groups, so that if a few individual bits flip, the end result will still be mostly 1s or mostly 0s. Error checking is introduced into each section of data, and that overhead means that only about 81% of a disk can consist of your data -- the rest is error checking. New drive technology is striving for 4% overhead, so that you'll get to use 96% of the disk drive.

And Windows XP won't support the new drive format.

Monday, March 8, 2010

The carpenter is a tool

So, I got a decent tripod and a nice set of Cokin filters for my digital SLR. Now all I have to do is to figure out how to take decent pictures.

Last Friday, I shot this panorama from the building where I work.

Raw, f/5.6, ISO 400, using a polarizer and a graduated filter. Compared to my earlier panorama attempts -- hand-held camera and no filters -- this picture sucks. The sky is noticeably grainy at 100% resolution, and you can see obvious vertical bands where the photos were stitched to create the panorama.

What caused these problems? I'm inclined to think it's the filters, because they're the major difference from previous attempts. As a matter of fact, I quickly discovered that the filters were wreaking havoc with my camera's autofocus -- unlike all previous attempts, I had to disable autofocus and shoot this with manual focus.

This is a classic example of how better equipment does not assure better photographs. :-(