3 ms·
I agree it is easy to design the system with 10 ns precision. Just like it is easy to calculate trajectories using different units, yet the $125 million dollar
by mrb 15y ago
I agree it is easy to design the system with 10 ns precision. Just like it is easy to calculate trajectories using different units, yet the $125 million dollar Mars Climate Orbiter space probe crashed due to a metric mixup that could have easily been avoided. Another way I look at it is that the OPERA experiment is either going to be concluded by brand new physics, or by a statement like "doh! I can't believe we screwed that simple thing". Out of all the systems they described, this one seems the more likely to be erroneous to me.
- juiceandjuice 15y agoI understand that it's very possible the FPGA is the problem. However, it's a cakewalk to continuously monitor and calibrate FPGA latencies. In fact, it's probably done in conjunction with the calibration of APDs/PMTs. If they aren't doing this, then the whole experiment has much bigger problems. My point is that I personally feel it's incredibly wrong to single out the FPGA DAQ systems, as the discrepancy of 60ns is so incredibly large compared to what is easily attainable, and the delay is something that's always compensated for in calibration. I think that there's some other error in the system, and my gut feeling is that it's due either to geometry or calibration.