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Natural Science Forum / Earth Science / Earthquakes / July 2008SeisMac detector...
In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, reports on the Sudden Motion Detectors in new Macintosh laptops. Originally designed to detect motion and lift drive heads from disks, Daniel Griscom of Suitable Systems in Wakefield Massachusetts has written software to visualize machine motion. After consulting with IRIS, he rewrote the software, and added SeisMaCalibrate to increase the accuracy of the graph. In 2007, Quake Catcher Network was set up in Calif to coordinate data from computer accelerometers. Ms. Rossbacher, who is president of Southern Polytechnic State U in Marietta, Ga., reports that since a highspeed network travels faster than seismic waves, the possibility of an early warning system from an already integrated network may be possible. Apparently, UC-San Diego has written some software called iSeismograph, which uses the iSight camera to record the data. It's a novel idea. Of course, there needs to be a way to weed out data from those times when you really *do* drop the laptop. > In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, > reports on the Sudden Motion Detectors in new Macintosh laptops. [quoted text clipped - 14 lines] > It's a novel idea. Of course, there needs to be a way to weed out data > from those times when you really *do* drop the laptop. Since the idea is to park the HHD heads, it won't be easy. Not for the quakes that count. >> In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, >> reports on the Sudden Motion Detectors in new Macintosh laptops. [quoted text clipped - 17 lines] > Since the idea is to park the HHD heads, it won't be easy. Not for the > quakes that count. Apple could eliminate the need for this feature if they switched to (admittedly more expensive) ram drives. Hey, they are supposed to be top - o - the - line, aren't they? George > >> In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, > >> reports on the Sudden Motion Detectors in new Macintosh laptops. [quoted text clipped - 21 lines] > (admittedly more expensive) ram drives. Hey, they are supposed to be top - > o - the - line, aren't they? Hey, that's an astonishingly good idea! Since the resulting MacBook would be a lot lighter and thinner, they could call it the MacBook Air, and Steve could introduce it by bringing a manila envelope with him onstage, and pull the Air out of it. Why don't you send Steve an email with your suggestion? Woh! Too late! He already thought of that: http://www.apple.com/macbookair/  SignatureTimberwoof <me at timberwoof dot com> http://www.timberwoof.com "When you post sewage, don't blame others for emptying chamber pots in your direction." ‹Chris L. >> >> In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, >> >> reports on the Sudden Motion Detectors in new Macintosh laptops. [quoted text clipped - 34 lines] > Woh! Too late! He already thought of that: > http://www.apple.com/macbookair/ Ouch. I stand corrected, though it is an option, not a standard feature. George >>In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, >>reports on the Sudden Motion Detectors in new Macintosh laptops. [quoted text clipped - 14 lines] >>It's a novel idea. Of course, there needs to be a way to weed out data >>from those times when you really *do* drop the laptop. The Quake Catcher website addressed this question - if they get one report from a network member in one spot, it's just a point. As they say, "your sister running past the computer". If they get a lot of near-simultaneour reports from multiple member locations in the same area, then it's a quake. > Since the idea is to park the HHD heads, it won't be easy. Not for the > quakes that count. The software is looking at shocks below the threshold required to force head-parking. A quake's intensity (even a big one) is going to be waaaaaay less than the shock of dropping the laptop, which allows it to send out the quake intensity reports and still perform its primary function of protecting the HD. Jim > >>In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, > >>reports on the Sudden Motion Detectors in new Macintosh laptops. [quoted text clipped - 29 lines] > send out the quake intensity reports and still perform its primary > function of protecting the HD. Just exactly what forces are involved in the negative force of free falling? I mean free, free falling. Yes free, free falling. In article <73336bf5-c059-4e24-9493-dadf16e249ed@79g2000hsk.googlegroups.com>, > > The software is looking at shocks below the threshold required to force > > head-parking. A quake's intensity (even a big one) is going to be [quoted text clipped - 4 lines] > Just exactly what forces are involved in the negative force of free > falling? When the iBook is sitting on a desk, it registers one G of acceleration. If it gets dropped, it registers 0 G of acceleration. It then panics and parks the disk drive heads, hopefully in time for whatever lithobraking it encounters. SignatureTimberwoof <me at timberwoof dot com> http://www.timberwoof.com "When you post sewage, don't blame others for emptying chamber pots in your direction." ‹Chris L. > In article > <73336bf5-c059-4e24-9493-dadf16e249ed@79g2000hsk.googlegroups.com>, [quoted text clipped - 12 lines] > parks the disk drive heads, hopefully in time for whatever lithobraking > it encounters. My understanding of the software is that it's looking for the sudden intense (>1G) shock level of the impact, and that the head-parking is fast enough to avert disaster even thought the impact is basically "in progress" when detected. Of course, I could be wrong and Timberwoof be 100 percent correct. Without looking at the underlying software I'm just going by what I've heard/read (no I don't recall where I read it). Jim "J. F. Cornwall" <JCornwall@cox.net> wrote in news:wBwbk.11862$Fj5.3027 @newsfe23.lga: > The software is looking at shocks below the threshold required to force > head-parking. A quake's intensity (even a big one) is going to be > waaaaaay less than the shock of dropping the laptop... Some strong motion detectors during the Northridge quake recorded accelerations in excess of 1g. Brian Signaturehttp://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html Sed quis custodiet ipsos Custodes? > "J. F. Cornwall" <JCornwall@cox.net> wrote in news:wBwbk.11862$Fj5.3027 > @newsfe23.lga: [quoted text clipped - 7 lines] > > Brian But my impression is that an impact of laptop meeting desk is a very sudden high intensity jolt that is several Gs or more (no I don't have a reference for that)... Only way to find out would be to look into the sensing code and see what it does. Jim "J. F. Cornwall" <JCornwall@cox.net> wrote in news:m4xck.14711$rH1.10940 @newsfe20.lga: > But my impression is that an impact of laptop meeting desk is a very > sudden high intensity jolt that is several Gs or more (no I don't have a > reference for that)... Only way to find out would be to look into the > sensing code and see what it does. You're right. Once the laptop begins "lithobraking", the peak G's are several. During it's trip to the ground, it's experiencing very close to zero G's. This is what the system is looking for - the sudden near zero-G. But in a strong quake, if motions approach or exceed 1G of acceleration, the laptop's crash protection may be triggered. Of course, if the quake is that strong, I'm not going to be too worried if the laptop shuts down and the seismic program stops recording data. Brian Signaturehttp://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html Sed quis custodiet ipsos Custodes? In article <0567452a-9ae1-4c14-bfd8-e2508c508902@k30g2000hse.googlegroups.com>, > > In the July Geotimes, Lisa Rossbacher, who writes the Geologic Column, > > reports on the Sudden Motion Detectors in new Macintosh laptops. [quoted text clipped - 17 lines] > Since the idea is to park the HHD heads, it won't be easy. Not for the > quakes that count. No biggie. Store up the images in RAM, then save them to disk. Actually, the software probably uses the accelerometers to record the shaking. That produces a lot less data, which means it's more likely possible to allocate the RAM needed to store it until the HD is available again. SignatureTimberwoof <me at timberwoof dot com> http://www.timberwoof.com "When you post sewage, don't blame others for emptying chamber pots in your direction." ‹Chris L. Yes I posted this here on April 2, 2008. Another point is that new, interesting seismology can be done with as crude seismometers as this should the network reach 10,000 or 100,000 installations. Current seismic networks are measured in the hundreds to low thousands of high quality sensors. The goal is to convince each grade school in the country to make at least one installation. |
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