Robert Winter, chief engineer at Kroll Ontrack explains that “the accelerometer itself measures acceleration that recognises sense of gravity. Within the computing world, this technology is used within laptops in order to protect data stored on the hard drive.”
Therefore, if the laptop is reading or writing data when a laptop is dropped, “it is likely that the disk drive read/write head will collide with the surface of the platter (this is where the data is stored) causing an indentation and creating debris that will circulate within the drive enclosure, often resulting in further damage.”
This will most likely cause the computer to crash, and so valuable data could be lost.
“The accelerometer is designed to prevent this, it recognises the change in motion and signals to the hard drive that an impact is imminent. The read/write head is then moved to the ‘parked position’ where damage to the hard drive is minimised.”
You might ask how this sensor would be able to tell the difference between a simple knock and an earthquake – the answer’s simple, the signal from an earthquake is very different as it involves several different shocks.
We shouldn’t all get too excited about being able to save the world while browsing the web though, Winter explains further that “earthquake detection requires the continuous measurement of seismic activity over a long period of time and predicting the location of the epicentre is particularly difficult.”
You would also need separate technology attached to your laptop and obvious expertise in order to read the quake, but other than that get your superman pants at the ready.
Although the laptop is the biggest type of technology to use this accelerometer the Nintendo Wii, iPhone and iPhone 3G also use the same motion detector in order to function.