MagAO-X 2024Aa Day 21: Time To Offload

Offloading is a major, but sometimes under-appreciated, part of an AO system. It makes sense when you really think about what we’re doing. The moving part of the Magellan Clay Telescope weighs more than 100 tons (I don’t know the exact number, but that is the OOM that has stuck in my head from somebody telling me that once). But what we actually do for a living is wiggle tiny little pieces of silicon with a few atoms of gold or silver on top, in response to massless particles streaming through the atmosphere, all in a quest to achieve nanometer or better control over the universe. Over time the little wiggles turn into big wiggles, and we have to send them to the next bigger thing. We call this offloading, and in MagAO-X there’s a whole chain of it from our coronagaph deformable mirror to our pyramid+tweeter DM system (where the real magic happens) to our woofer, and from there to the telescope itself. Inside those main control loops there are other control loops that are adding steps to the dance. Loops on loops. There’s a certain absurdity to our little concerns getting dumped onto the majestic Clay telescope and pushing it around.

A way to analogize offloading: imagine flying to the other side of the world to a remote mountain top, being given a bunch of urgent tasks (some of which are impossible but nobody knew that until you failed), then suddenly switching to a night schedule, sleeping for 4 or 5 hrs a day (not night) for two weeks straight, and then suddenly switching to a day schedule so you can undo everything you spent the last two weeks doing. You can imagine that you’ll build up a little … stress… that’s hard to hold and you need to … offload it. Well it’s time to hit the ol’ dump button. You might not hear from us for a while.

Maybe as long as six weeks.

The last sunset.

So that’s it. MagAO-X is off the telescope after a truly amazing run. We’ve really hit our stride as a productive scientific instrument. I lost track of how many new things about the universe we discovered on this run, and #nospoilers anyway. At the same time I am leaving, as always, a little frustrated by the ways in which MagAO-X isn’t yet perfect, not yet meeting my expectations. Every new discovery comes with a lesson for how to do it better next time.

An image of Crux and Alpha & Beta Centauri rising over the Babcock Lodge at Las Campanas Observatory

Without a doubt the best thing about this project is that it is fun. The fun started with MagAO, and a long running tradition on this blog is the “quotes of the day”. It comes and goes, even during this run. Back “in the day” it became a problem because we realized people were just saying things hoping to get famous. Later on, it got us kicked of the Steward front page (still banned AFAICT, ¯\_(ツ)_/¯). As a reader, you should know that some fraction of the quotes have always been just straight made up. The lessons are that the quote log can be used for good, for evil, and sometimes it gets things done. Well, so anyway, here’s a PI-curated selection of quotes from this run. #overheard

“The control room is likely to be completely overrun. Keep calm and make sure you have a chair”

“take that speckles”

“This is a public cheese. Everyone has to use this cheese.”

“Who is Jahlishus?”

“Blog ops is completely unrecognizable. All it is is fucking penguins and Dall-E viscachas.”

“Which is almost a triggering thing for Jared… I’m kind of disappointed he’s not here to hear that”

“Let’s see if I can install zoom before the sun sets”

“Oh. My. God. We’re over 2 arcseconds.”
“We’re going to need a bigger plot.”
“This is just all sadness…”
“I don’t want to go up there to the sadness party”

“When conditions are like this, it feels like nothing works… because nothing works.”

“I have way too many laptops”

“I spent my whole postdoc finishing my Ph.D.”

“If you’re okay I’m going to take a break … for breakfast … what time is it?”

“the units are ‘play around and find out’”
(Ed: shortly thereafter the SI unit FAFO was coined)

“We had everything wrong”

“g band is horrible.  I wouldn’t wish this on my worst enemy”

“We deserve strehls better than 20%”

“I’m not doing science, I’m doing AO”

“But I thought AO was easier in the visible?!”

“You see that?”
THAT?!
“I know.” 

“what’s that second speckle???”
“…. OH that’s Pi Pup B!”

“Who knew it would actually work?”

“You cannot hit the grad students”

“that is a really large blueberry”

“… ah this is the 4th time I’ve heard about ‘The little guy’, Can I see what you’re talking about?”

“I stared at him and thought ‘Why are you not making my salad’ “

“oh that tingled. oh wait I am electrocuting myself.”

“So the only thing misaligned in your system was the cardboard?”

“except that it imploded during shipping, it works really well!”

“You don’t do that with geese but I didn’t know that at the time”

“I’m stealing fruit for my next couple days of breakfasts. I’ve been stealing a little bit every day. I have a little pile of fruit in my room.”

“Zernike polynomials, you’re my bitch now”

“I found our nuts at Baade! Those Bastards!”

“I appreciate that you’re always working on bullshit when you’re here”

“I love it here”

“I’ll bet you all your empanadas for the rest of the run”
“… nothing is worth that”

“More people will read your blog than your PhD”

“Go ahead and take a dump.”


I love stories about a crew. LOTR, Firefly, The Expanse. I found this song through Yellowstone, which on its surface appears to be about one dude/family but I think is more properly understood as a crew story. The song itself sort of captures my mood about our ongoing attempt to achieve the fundamental limits of wavefront control. If it wasn’t hard, it wouldn’t be worth doing. We have a good crew, so we’ll get there.

or maybe, lol.