Thursday, May 25, 2006

Motion Blur

The sheer diversity and ingenuity of today's programs never cease to amaze me. A new wave of programs that take advantage of the motion sensors in laptops have cropped up, and it just got really wierd and "interesting". MacBook Pros and Thinkpads have motion sensors built in to take care of impact-scenarios. "Nominally, it's there to protect the internal hard drive. The basic idea is if the accelerometer suddenly notices that the gravitational pull of earth is no longer present, the most likely explanation is that the laptop, sensor and all, is currently accelerating at 9.81 m/s² towards the earth. In that case, it will (wisely) try to turn the hard drive off in preparation for impact." So, now we have programs that let us switch between virtual desktops at a tap on the screen, squeal when the laptop is lifted of a table(to protect against thefts) and make light-saber noises as it's hurled across(ala Star Wars). Brace yourself, 'cause the next-gen of programs might just arrive like a fleet of warships hurtling through space. Oh, that reminds me, gotta grab my towel today. "Happy Towel Day" everyone!


Krishna said...

I have one doubt here -

"if the accelerometer suddenly notices that the gravitational pull of earth is no longer present.."
How on earth, can the earth not exert the gravitational pull on objects.Infact,the laptop is hurling at 9.8 m/s2 bcos of this very pull.. :-)
The explaination I think, is that because the accelerometer detects a non-zero acceleration(g,in this case),then it comes to the conclusion that the laptop might be falling down.And not because,it notices the absence of a gravitational pull..
Correct me if my understanding is not right.

ash said...

Yup, I think the pull actually refers to the reaction force exerted on all bodies by the surface they rest on. Also, during a free-fall, the reaction force is 0 which causes weightlessness. You're right. The abscence of a pull makes no sense.