SubJeff on 20/4/2009 at 06:53
I can't exactly describe the noise it makes when there is no motion detected? Thwop?
Sulphur on 20/4/2009 at 06:53
Quote Posted by Yakoob
You mean the machine that goes PING!
It's a
radar thing. Pay attention! :mad:
Yakoob on 20/4/2009 at 06:59
someone needs to watch their monty python :nono:
Sulphur on 20/4/2009 at 07:14
I would've got the reference if it was was an audio sample. Your text just isn't high-pitched enough. :(
Rogue Keeper on 20/4/2009 at 10:27
Quote Posted by Sulphur
It's a
radar thing. Pay attention! :mad:
No, actually it's SONAR.
SubJeff on 20/4/2009 at 10:49
But they aren't underwater, so...
Rogue Keeper on 20/4/2009 at 11:14
Yes but I just meant that sonar does PING. ;)
Knowledge courtesy of Wikipedia :
Motion detectors as we know them today are
* Infrared (Passive) Look for body heat. No energy is emitted from the sensor.
* Ultrasonic (Active) Sensor sends out pulses and measures the reflection off a moving object. Basically SONAR.
* Microwave (Active) Sensor sends out microwave pulses and measures the reflection off a moving object. Similar to a police radar gun.
I remember though that in original Alien, Ash explains that the motion detector he manufactured measures "micro changes in air density" what sounds like a real sci-fi to me, not to mention reliability of such thing in most practical situations. Of course the more advanced trackers which marines use can be based on a different principe. Ultrasonic/Microwave?
SubJeff on 20/4/2009 at 11:40
Problem with any sort of echo detection is if YOU move the whole thing needs to recalibrate with the static parts of your surroundings. The motion detectors could, theoretically, use microwave or ultrasound echos but they would need some amazing software to filter out the static stuff. And it would have to be amazing as any errors would be very dangerous.
Vivian on 20/4/2009 at 12:07
It measures the infinitesimal changes in local gravity caused by moving mass bodies. Duh.
You know what, I pulled that straight out of my arse, but I'm going to go a bit further with it - they mention space navigation at near light-speed (or over light speed?) several times during the series, so they would have to have workable and highly sensitive mass/gravity sensors in order to avoid running into planets they couldn't see. Ye ping machine is simply a miniaturised version of their spaceships planet-sensors.
Rogue Keeper on 20/4/2009 at 12:14
1mN per Vivian
