But I do not understand the reference to the train. Where was it, in Louisiana, Washington State or Germany? As far as I know, there is no train running near VIRGO, the Pisa to Florence rail line is farther away.
I thought it referred to a problem with seismic vibration at first, but on second thought maybe it refers to the wave train of the GRB signal? Good question, Tullio, hopefully someone here will clarify it... LIGO Hanford (LHO) is in Washinton State, and LIGO Livingston (LLO) is in Louisiana.
But I do not understand the reference to the train. Where was it, in Louisiana, Washington State or Germany? As far as I know, there is no train running near VIRGO, the Pisa to Florence rail line is farther away.
I thought it referred to a problem with seismic vibration at first, but on second thought maybe it refers to the wave train of the GRB signal? Good question, Tullio, hopefully someone here will clarify it... LIGO Hanford (LHO) is in Washinton State, and LIGO Livingston (LLO) is in Louisiana.
I just saw the webcast from VIRGO. Seems very impressive.
Tullio
...But I do not understand the reference to the train...
Hi, Tullio
I had a chance to check on the question about the 'train'. It's a train as in a bunch of massive, ground-shaking railroad cars being pulled or pushed by one or more locomotives. One goes by usually around two in the morning, local time. When you visit the Livingston Observatory and look at the Detector Group Logs, you can do a search through the entries, which I did looking for entries with the word 'train' in them. I found many, and in one from 14 Nov 05, there are some nice graphs of what happens in the Alignment Sensing and Control system when a 'choo-choo' goes by. (Here's a link to the specific log entries on that day. See the ones 'A quiet moment before the choo-choo', 'AS3 says hello', 'As the train passes by the X end', and 'Full force of the train: EY seismic peaks'. Click on the yellow box with 'View External Object' in each log entry, to see the graphs. NOTE: If prompted for a username and password when clicking this link, enter "reader" and "readonly". LLO Detector Log 14 Nov 05)
Also, here a link to a topological map showing the LLO as a red dot, and you can see to the south (~5 km) some tracks running east-west. LLO Topo Map (Note that you can zoom in and out, and change to aerial photo view, although I think the photo data is from 1999.)
...But I do not understand the reference to the train...
Hi, Tullio
I had a chance to check on the question about the 'train'. It's a train as in a bunch of massive, ground-shaking railroad cars being pulled or pushed by one or more locomotives. One goes by usually around two in the morning, local time. When you visit the Livingston Observatory and look at the Detector Group Logs, you can do a search through the entries, which I did looking for entries with the word 'train' in them. I found many, and in one from 14 Nov 05, there are some nice graphs of what happens in the Alignment Sensing and Control system when a 'choo-choo' goes by. (Here's a link to the specific log entries on that day. See the ones 'A quiet moment before the choo-choo', 'AS3 says hello', 'As the train passes by the X end', and 'Full force of the train: EY seismic peaks'. Click on the yellow box with 'View External Object' in each log entry, to see the graphs. NOTE: If prompted for a username and password when clicking this link, enter "reader" and "readonly". LLO Detector Log 14 Nov 05)
I like trains more than airplanes (I live near an airport). But I understand the problems they might cause to a GW observatory. Thanks, Chipper.
Tullio
Also, here a link to a topological map showing the LLO as a red dot, and you can see to the south (~5 km) some tracks running east-west. LLO Topo Map (Note that you can zoom in and out, and change to aerial photo view, although I think the photo data is from 1999.)
RE: But I do not understand
)
I thought it referred to a problem with seismic vibration at first, but on second thought maybe it refers to the wave train of the GRB signal? Good question, Tullio, hopefully someone here will clarify it... LIGO Hanford (LHO) is in Washinton State, and LIGO Livingston (LLO) is in Louisiana.
RE: RE: But I do not
)
I just saw the webcast from VIRGO. Seems very impressive.
Tullio
RE: ...But I do not
)
Hi, Tullio
I had a chance to check on the question about the 'train'. It's a train as in a bunch of massive, ground-shaking railroad cars being pulled or pushed by one or more locomotives. One goes by usually around two in the morning, local time. When you visit the Livingston Observatory and look at the Detector Group Logs, you can do a search through the entries, which I did looking for entries with the word 'train' in them. I found many, and in one from 14 Nov 05, there are some nice graphs of what happens in the Alignment Sensing and Control system when a 'choo-choo' goes by. (Here's a link to the specific log entries on that day. See the ones 'A quiet moment before the choo-choo', 'AS3 says hello', 'As the train passes by the X end', and 'Full force of the train: EY seismic peaks'. Click on the yellow box with 'View External Object' in each log entry, to see the graphs. NOTE: If prompted for a username and password when clicking this link, enter "reader" and "readonly". LLO Detector Log 14 Nov 05)
Also, here a link to a topological map showing the LLO as a red dot, and you can see to the south (~5 km) some tracks running east-west. LLO Topo Map (Note that you can zoom in and out, and change to aerial photo view, although I think the photo data is from 1999.)
RE: RE: ...But I do not
)