On April 12, 2011, something extraordinary happened. A 58-year-old woman that was paralyzed from the neck down reached for a bottle of coffee, drank from a straw and put the bottle back on the table. But she didn’t reach with her own hand – she controlled a robotic arm with her mind. Uneblievable? It is. But decades of research made the unbelievable possible. Watch this exceptional and moving moment in history here (click on picture for Youtube video).
The 58-year-old women (patient S3) was part of the BrainGate2 project, a collaboration of researchers at the Department of Veterans Affairs, Brown University, German Aerospace Center (DLR) and others. The scientists implanted a small chip containing 96 electrodes into her motor cortex. This part of the brain is responsible for voluntary movement. The chip measures the electrical activity of the brain and an external computer translates this pattern into the movement of a robotic arm. A brain-computer interface. And it’s not science-fiction, it’s science.
During the study the woman was able to grasp items during the allotted time with a 70 % success rate. Another participant (patient T2) even managed to achieve a 96 % success rate. Besides moving robotic arms, the participants also were given the task to spell out words and sentences by indicating letters via eye movement. Participant T2 spelt out this sentence: “I just imagined moving my own arm and the [robotic] arm moved where I wanted it to go”.
In the fast paced online world people are not so patient as in real life. Accordingly, having a large home page size and loading time can negatively affect your blog traffic. Studies have shown that the greater the loading time, the higher the bounce rate. To find out how well my blog performs with respect to this (feel free to use the results for your benefits as well), I did a analysis of 70 WordPress.com blogs. I used iWEBTOOLS’s Website Speed Test and OriginPro for that. With the tool you can analyze ten webpages at once, but note that after ten queries you have to wait a full day (not an hour as the website claims) to do more analysis.
The average size of a WordPress.com blog according to the analysis is 65.3 KB with a standard error SE = 3.0 KB. Here’s how the size is distributed:
The average loading time at my internet speed (circa 600 KB/s) is 0.66 s with the standard error SE = 0.10 s. Here’s the corresponding distribution:
Note that the graph obviously depends on your internet speed. If you have faster internet, the whole distribution will shift to the left. My blog has a home page size of 81.6 KB. From the first graph I can deduce that only about 24 % of home pages are larger in size. My loading time is 0.86 s, here only about 22 % top that. So it looks like I really have to throw off some weight.
Here’s the loading time plotted against the home page size:
In a very rough approximation we have the relation:
loading time = 0.009 * size
In other words: getting rid of 10 KB should lower the loading time by about 0.1 seconds. Now feel free to check your own blog and see where it fits in. If you got the time, post your results (if possible including URL, size, loading time, internet speed) in the comments. I’d greatly appreciate the additional data. For a reliable result regarding loading time it’s best to check the same page three times and do the average.