jorgepullin.bsky.social

The weighted stack we built is mounted on the test stand and we are doing fine adjustments of its position using the FARO laser tracker. @ LIGO - Livingston

Crew getting together to move the clean room seen in the foreground. For safety reasons a five person team is required. One pushing each leg and a spotter. @ LIGO - Livingston

This mural in the city of Córdoba, Argentina depicts a girl looking at the stars. In the star-shaped balloon is a reflection of the Astronomical Observatory of Córdoba, that is 155 years old today.

We disassembled the old weighted stack and wrapped it up in Ameristat for storage. @ LIGO - Livingston

Our weighted stack is coming along nicely. @ LIGO LIvingston.

At the Smithsonian.

We started building a weighted stack today. This is a dummy structure that takes the place of the active internal seismic isolation system during testing when the suspensions are hung in the test stand in the lab. @ LIGO - Livingston

I had a model made from my GPS coordinates of the Petra climb. Race ran clockwise. #petramarathon

We are going to have to vent the vacuum system in a couple of places for repairs. Today it was vent prep, and I was involved in one of its most glamorous aspects. @ LIGO - Livingston

Mi niece Viole got mentioned in the competition organized by my alma mater Instituto Balseiro.

A friend of mine sends me this picture he took of me in Vienna in 1996. The "Subject:" line of his email: "The Kaiser and The King" 😀

I devoted a corner of my new office to the Quantum Gravity in the Southern Cone meetings.

www.islqg.com/post/history-1

When faced with the last few miles of the Petra race, the two runners next to me and I said almost in unison "you've got to be kidding me"...

www.youtube.com/watch?v=cwW3...

The quest for the seven continents continues! Finished the Petra (Jordan) ultra half 25k in 5h20m. Tough race. Still jet lagged, 35C in the blazing desert sun and a vertical gain of 700m in the last few miles. Fifth half marathon in fifth continent. Australia and Antarctica, here we come!

www.lavoz.com.ar/ciudadanos/g...

Cleaning the office, I found this reflection by a student in an old exam I gave during my years at PennState. Note: a lot of people used to make fun of the degree in turfgrass management as "dumb" or "mowing the lawn". In reality it represents a highly developed $200B industry in the US.

The Y arm valves were opened and LIGO Livingston enters the commissioning phase for the next observing run. I couldn't find a picture of the Y arm valves, so here's a picture of me inside the Y-end 😀

220 years ago the British ship Justina was shelling Buenos Aires in an attempted invasion. Then the river dropped and Martin Miguel de Güemes (allegedly) with 60 gauchos charged the ship on horseback and took it.

Gabriela González 25 years at @lsu.bsky.social @lsuscience.bsky.social @lsuphysastro.bsky.social @lsuresearch.bsky.social

I made myself a running shirt combining my two running clubs.

The series of conferences we started with Rodolfo Gambini, Victor Rivelles, Carmen Núñez and Jorge Zanelli 30 years ago is taking place in Chile in its 9th edition. qgsoutherncone.wixsite.com/ixqgsc

My United flight gave us a good view of Corpus...

The partial upgrade started in December is over. Pumping down started at LIGO - Livingston

We moved the cleanroom that was on top of BSC2 to BSC1. @ LIGO - Livingston.

Positioning the crane spreader bar to lift the cleanroom. @ LIGO - Livingston

Gabriela González, en exclusiva con Astronomía Gualeguay www.youtube.com/watch?v=M7jc...

www.lsu.edu/physics/news...

Another B&K hammer test. This time the suspensions were too small to install accelerometers, so we used the laser vibrometer (yellow). The green arrows show some of the vibration dampers I built a few weeks ago, they have installed them. @ LIGO - Livingston

LSU Chancellor visits LIGO Livingston. www.facebook.com/reel/1522133...

The suspension we spent last semester building (green outline) is now installed in HAM6. The optics team has added a bunch of stuff on it and around it. @ LIGO - Livingston

The installation of the suspension we built last semester is now complete. This requires rebalancing the active seismic isolation system it is built on (ISI), so it is within its allowed range. This is done by adding and removing masses, indicated by green arrows in the picture. @ LIGO - Livingston

Topgunning a suspension. We spray suspensions and optics with ionized nitrogen. This blows off dust, but more importantly, it discharges potential buildups of static electricity, which attracts dust and creates other problems. @ LIGO - Livingston

Installing the dome at the X end (accelerated video) @ LIGO - Livingston

The B&K hammer test. A sensor is placed on a structure and it is hit with a hammer also containing a sensor. Software then analyzes the resonances, modes and damping of the structure. @ LIGO - Livingston

Installing back the door in the chamber that hosts the interior text mass Y (ITMY), called BSC1. @ LIGO - Livingston

LIGO jargon: "running a B&K test on a BRD". Brüel & Kjær sell the laser vibrometer (yellow) that it is being used to study the resonances of a Blade Resonance Damper that goes on the Bigger Beam Splitter Suspension (illuminated by the laser on the optical table). @ LIGO Livingston.

Lots of rain in Baton Rouge. Our flooded backyard is a favorite feeding place for egrets apparently.

Building more vibration dampers for the suspensions. @ LIGO - Livingston

Installing the baffles in one of the inner test masses. They look shiny to us, but for the interferometer light they are quite absorbent. They catch stray light and prevent it from reflecting on the walls and other parts of the interferometer that are not isolated seismically. @ LIGO-Livingston

The Bigger Beam Splitter is fully assembled, cabled and in position and its active isolation system is balanced an ready for testing. @ LIGO - Livingston

Raising the clean room that sits on the Beam Splitter Chamber (BSC2), now that it is installed. It had been lowered for installation. Each leg has an actuator (that yellow thing behind the curtain) and is controlled by the box visible in front. @ LIGO - Livingston

Anamaria Effler and Gabriela González make empanadasaurs for the end of semester party of Gaby's LIGO group. @ LIGO - Livingston

Using the autolevel on the keel of the active isolation system (ISI) that holds the Bigger Beam Splitter @ LIGO - Livingston

www.routledge.com/Modelling-Pr... From my friend Hugo Fort.

The optical sensor electromagnetic actuators for the Bigger Beam Splitter are known as qosems. Because they were built in Australia, the electronic chassis that takes their readout bears a koala. @ LIGO - Livingston