Basically...... You should be able to hear a loud click when this happens.
Read about the Sudden Motion Sensor here.
Ah, that is interesting; so they claim that previously, the results were stored for warranty purposes, but that they stopped doing it with the MacBook/MacBook Pro. Of course, this is on Wikipedia with no sources cited...
Here's another way to see the measurements from the sudden motion sensor: SeisMac.
I don't know of any mechanism that would void the warranty.
On iPhones, for example, there's a sensor that can tell whether water has gotten inside, and that will void the warranty. But there is no equivalent to that on laptops that I know of.
Macbooks have multiple moisture/spill stickers inside. They change color when something has been spilled on the computer and gets inside.
Basically, they detect acceleration and park the heads on the hard drive to prevent a crash. You should be able to hear a loud click when this happens.
On my 13" MBP, the sensor gets triggered pretty easily. You can trigger it just by lifting up the laptop a few inches very quickly, for example.
Does anybody know how the SMS interacts with Macbooks configured with SSD drives? Since the SSD is impervious to g-shock it does not need to be protected by the SMS. However, does the SMS tell the SSD to stop writing data if it detects a large jostle (causing unecessary delays in writing/reading of data from the SSD), thinking it is a traditional HD, or since the SSD probably doesn't respond to any command to "park" the heads, the commands from the SMS are just ignored?
Ruahrc
Macbooks have multiple moisture/spill stickers inside. They change color when something has been spilled on the computer and gets inside.
... snip snip ...
Here's another way to see the measurements from the sudden motion sensor: SeisMac.