"What began as a way to prevent damage to the hard drive from a dropped laptop has led to an innovative project that lets seismology and engineering students or researchers study, store and share data to better understand the science of structural dynamics -- be it a gentle tap or a full blown temblor."
Article on Machines Like Us.
4 comments:
I'm thinking the accelerometer might make these laptops difficult to use in, say, the Space Shuttle or the International Space Station. It seems to me they would interpret zero-G to indicate that the laptop was in free-fall, and would want to keep the drive constantly in "safe" mode, waiting for impact.
I would volunteer to go up on the next Shuttle launch to test this, but if I'm right, it would mean days without being able even to check email, so I guess this is destined to remain one of life's mysteries.
From the name of the tech, it seems it measures acceleration, not gravity... ?
What it really measures is deflections of a mass suspended inside the accelerometer. If your laptop is stationary on a table, the mass is pulled toward the earth by gravity. If the laptop falls off the table, the mass isn't being deflected -- it's dropping at the same speed as the rest of the accelerometer.
I'm imagining that software sees this lack of deflection and says, "Yipe! We're falling!" and parks the drive heads, because when the computer hits the ground, there's gonna be a rapid deceleration.
But maybe I'm wrong. Maybe the software doesn't consider a lack of deflection to be the problem. Maybe it responds only to changes in the current amount of deflection -- actual acceleration -- in which case the stable zero-deflection of zero-G would be just fine.
This uncertainty is why I think NASA should launch me into orbit with one of these laptop computers to find out for sure. Of course, it might also be possible just to ask Apple how the software works, but I think going into orbit would be a much cooler way to find out.
What you are saying is correct. The accelerometer is affected by gravity, but that reading is canceled out by high-pass filters. The system thus reacts only in sudden variations, allowing the hard disk to be used in any orientation.
Post a Comment