I guess lets start at the beginning of the week: Monday.
Monday was a holiday here, president’s day. I don’t know what it’s really about. All I know is that we can take the day off. And that Darkhan and Hang want to go into work for the afternoon. But at least for the morning, I was feeling a little slow – chalk it up to the cookie from Sunday night. So I did my thing and took the morning slowly before leaving the apartment at 1pm for the site.
At the site that day, I managed to get a whole load of admin things done that I’d been sitting on for a while. Expenses claims, scanning documents, getting some printouts. The works. It was kinda uninteresting. The evening was no more interesting either. So!
So Tuesday was to be the day that we (the Fellows) met with Mike, our supervisor. But I had a few thread that I could follow, making some plots, looking for this and that. It wasn’t really enough to dig my teeth into though. So Tuesday was a dull grind. It sort of felt like it was the first full work day after the announcement of the Event, everybody was still swapping stories.
Eventually, though, whilst in the control room making some plots on a computer, Robert walked in. He was looking to talk to Vinny, but he was also looking for me. And this was one meeting that I had been waiting for. Robert asked if I had a project in mind to talk to him about, and instantly, I replied “Combs”. Combs refer to noise in the detector which present as fixed-frequency oscillations which occur at regular frequency intervals (e.g excitation at nHz, 2nHz, 3nHz, … up to some end frequency).
Can you see why?
It turns out that this is also what Vinny had been looking at too, and it would be great to get to know what I’m doing by following Vinny around and helping him work. So between us, we settled on searching for the 0.5Hz combs, starting with a magnetometer survey, first by looking at the plots, and then by placing a temporary magnetometer in various locations. I don’t know why Robert jumped to magnetometer straight away, but I trust what he says. He is Mr. PEM.
With that, we had a plan. Tuesday, make all the plots we need. Wednesday, go out to the Y-arm with a magnetometer and see what happens, and Thursday, we get into the corner station! I was so excited to start sciencing properly!
So after that, and with some instruction from Vinny on how best to use the relevant software, we make coherence plots and spectra for every single magnetometer channel in the LIGO site. By the time we were done, it was time to go home. Mike hadn’t had time for a meeting, so that was to be tomorrow.
When I got home that evening, with a few hours to kill before bed, I decided to go for a run at the gym in the apartment complex. In my view, treadmills are different to roads, and running indoors is weird – I miss the wind in my face. It turns out that podcasts make a good running companion. 3 miles later, I went home, ate, and chilled for the night.
Gearing up for a good day of science, I headed in looking forward to the day. And after a pitstop at Starbucks, Darkhan, Hang and I got into work pretty early. When Vinny arrived, we rallied around a computer again to reaffirm the conclusions from all the plots the made the day prior. They seemed to show a 0.5Hz comb stronger in one magnetometer than the other, (one computer rack vs the other) in all locations where these racks occur at the site. So that was a clue to start us.
Before we could do anything though, we had to get a work order. The process for getting a work order wasn’t necessarily straight forward. It was just filling in a form, then asking the operator at the time who we needed to sign it. So we run around, trying to find the relevant people to sign it for half an hour. Job done. Next, we gather the equipment that we need, jump into the site car, and make the 4km drive down to the Y-arm.
Now, I’ve been excited about going to the arms. It’s where all of the action doesn’t happen – they have to be specifically quiet, clean and free from disturbances. I got a brief chance to go onto the floor where all of the optics were (but didn’t really look around), before going next door to the electronics bays. Vinny and I ended up spending a few hours in that EBAY, moving the magnetometer, putting it onto a rack, waiting fifteen minutes to take data, move the magnetometer, make plots of the last fifteen minutes. We were there for a few hours, and had some time to kill. It’s a good way to get to know somebody!
We come back for the meeting with Mike, where we all exchange plans for the upcoming LVC (LIGO – Virgo Collaboration) conference coming up next month in Pasadena, and work we’ve done in the past few weeks, as well as just a jovial, informal chat all together. Following that, and a sandwich, we head back out to the Y-arm and continue taking data for the day.
On Wednesday evening, once Hang arrived home, we got cooking. He’s not confident cooking, so for now, we’re cooking together. Tonight, we decided to make a chicken pasta sauce with tomatoes and sardines. It turned out nice, and gave a good chance to get to know each other. Our common thread is anime – he watches a lot of it, and as soon I can,. I will thrust Cowboy Bebop upon him!
And with that, Thursday
On Thursday, Vinny and I spent the day in the EBAY at the corner station. We had noticed some oddities in the data we had taken yesterday – the combs that we were looking for were present, but we hadn’t applied the usual gain onto the magnetometer. So we tried to correct this today. Time passes, doobly doo music, and by the end of the day, our data look even worse! Vinny had to run out at 3pm to grab some lunch, and in the course, locked his keys into his car. Without him, I couldn’t go back into the EBAY to look at the problem, and so it stayed there overnight.
That evening, Evan tells me that I have been invited to Daniel’s house for a dinner party. I have heard whispers of these events, and that if you miss one, you’re struck from the list, and that is NOT what I want! So Evan and I head over, neither of us having been before, and neither knowing what to expect.
Daniel’s house was crowded, maybe 12 people were over! Luckily, Daniel is something of a wine fanatic, so the socialising was not hard at all! There were no unfamiliar faces there, except perhaps Dick and Mary, Dick has been with LIGO for aeons, and Mary has been with Dick just as long.
After the first (delicious) course, Jenne mentions to me, offhandedly, about a forced march around the block between mains and dessert. The talk turn to Aus, Brit and American cultural differences, and to the general election going on across America, standard dinner party talk. The food was beautiful. Daniel is Swiss, and his cooking is very pan-European, an Italian starter, and Austrian main, and then a forced march in the cold rain.
That’s right. You either go for a walk between courses, or you wash up and forfeit dessert. So I chose to walk. Of course, walking permits talking – and the conversation moved from weekend plans, to partying in Pasadena, round back to some work related things. When we got back, dessert was fantastic! And there was still wine and whiskey to be had. I had a fantastic time, and I sincerely hope that I get invited again. [If I knew the walking route, I would plot it on the map, but I don’t. So I can’t]
We had some ideas about how to attack our bad data, so we dived right back into the corner station, bouffant caps and shoe covers in hand, we were prepared for another 5 hours sitting in a loud room full of wires.
But the difference today is that we have good data coming through from the magnetometer! So by the afternoon, with all the data we needed, and all the plots we needed, we left the magnetometer in the EBAY over the weekend to get a different perspective on the problem. Roll on Friday evening!
Nutsinee asked if we fancied food and drink at McCays, (of course we did), so myself, Evan, Darkhan, Nutsinee and Hang all met there. Good food, good times, and good sweet strawberry cider was had. Nutsinee had put in an order for some GW150914 t-shirts, and I had bought a shirt, a hoodie and a tie. They are due to arrive before the LVC next month (excited!)
After the bar, we had hatched a loose plan for a board game night. Evan mentioned a store in Richland that was open late tonight – Adventures Underground. I went there and picked up a couple of games – The Resistance: Avalon, and Boomtown. Unfortunately, the plans for board game night fell apart, but nevertheless, I will put these games to good use.
That night, I went to bed and watched some Tabletop on youtube to check out a few more games, that now, I have my eye on. One day, maybe.