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BOINC Project to Search for Gravitational Waves
Buzz Skyline writes "Einstein@Home is a new, BOINC-based distributed computing project that will analyze data from the Laser Interferometer Gravitational wave Observatory (LIGO). The goal is to perform a whole-sky, gravitational wave survey of pulsars. Beta-test versions of the Einstein@Home screen saver should be available by the end of the summer, and final release is planned for early 2005."
For one thing, on most of the workstations BOINC would appear to work very quickly on the data only to crash out well before the computation was created. Indeed, sometimes it would actually crash before any data was processed by the application. At other points it would work for hours and hours without actually achieving anything; closing down the workstations at the end of the day without getting one computed dataset off was quite frustrating. On the workstations that were actually computing datasets we discovered a few started to become bloated past the point of peak functionality within a few months of even casual use.
While it's possible that it's the inhouse .NET code that could be creating the problem, after several weeks of debugging we're pretty sure it's BOINC related. My suggestion is to steer clear and look for a safer and more reliable API (or roll your own).
Try not. Do or do not, there is no try.
-- Dr. Spock, stardate 2822-3.
No. You'd have the effect before the cause would be visible. The cause, however, would still precede effect.
No, for at least some moving observers you do wind up with the effect preceeding the cause. It's all part of relativity. Two observers moving in opposit directions can dissagree about the order of two events. If anything exceeds the speed of light one of the observers will see the effect preceed the cause on the time line.
There is no such thing as "simultaneous", it's all relative.
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For a while I worked as a research programmer for one of the General Relative Groups working on the GEO600 Gravitational Wave Detector in both the UK and Germany. GEO600 is a UK and Germany co-project.
The interferometer is a typical Michaelson interferemoter using lasers with two orthogonal branches 600 metres in length. These gravitation events are small. Movements are ~10-E24 metres. It is expected that only one or two events a year will be detected. So it must run 24/7, 365 days a year.
Naturally you have to remove as much of the noise from the data as possible to detect an event. Mirrors are hung on glass threads as they are thermally inert. It runs in a vacuum. It is temperature controlled. Everything is monitored from air pressure to sisemology. The amount of data being produced is incredible. I assume LIGO is the same hence the distributed analysis.
GE0600 uses a microwave link to transmit data from the site to Hanover where it is backed up and fat pipes pass it on to partner universities. The 'head end' on site uses triple redundancy and enough bufferage for 24 hours back-up on site.
You are talking many gigabytes a day and many terabytes a year and some where in this lot will be an event. This is truely the domain of super computing or distributed processing.
Of course, even LIGO which is larger, is unlikely to spot many events if any and we will probably have to wait until LISA, the NASA/JPL/ESA spaced based interferometry project is up and running to get decent results.