Hi folks,

I've seen people asking about what's been done and where this project is going. The first part of the answer is: If you've been clicking through the front page of the project, go back and read the recent announcements.

The second part is a more verbose version of what's on the front page: The first search of the S3 data didn't find a pulsar, but it did find a lot of strange effects from the instrument in the data. These need to be cleaned out before there's any chance of detecting an astrophysical signal. You folks, with your hot-running CPUs, did the important work of finding them so that they could be removed. We were expecting some of this (like 60Hz and all its friends from the electric company), but there was more than expected. So now you are all running S3 data again, but it is a cleaner version of S3.

And now an answer to the related question of where this is all going: LIGO has been operational for several years now, in the sense of being able to measure strains. But it is a very complicated instrument (absolutely unprecedented in some respects) and therefore it is not a matter of just switching on. The first time you do that, it's not very sensitive. You track down one of the many subsystems which is giving the most trouble and beat down the noise from that subsystem. Then the instrument is a little more sensitive, and you look for the next thing, and so on. Sometimes you have to invent something completely new to get past a sticking point.

The result of this is that LIGO has been shooting toward its target sensitivity for the last few years. It is now very close to that sensitivity. S3 is within a factor of a few. The S4 data, which is in the can and being prepped for analysis, is within a factor of two. S5, which will start later this year, will be at (or at some frequencies a little beyond) target sensitivity. Also, S5 will not be a few weeks' run between equipment upgrades; it will be a solid year, and that also improves the chances of detection.

Hope this helps,
Ben

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> Hope this helps,
>
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Hello ...... Ed & Harriet ,

yes it does , thanks very much for posting this information :)
science is moving so fast , it's difficult to keep up

byron :)