Michael Sinko
1.2K posts
Michael Sinko
@Physburgh
Physicist from Pittsburgh
Walnut Creek, CA Katılım Ekim 2011
650 Takip Edilen534 Takipçiler
Materials selection for dummies:
6000 series aluminum
If too weak:
304 stainless
If too heavy:
Titanium 6-4
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@Physburgh great point. will post a follow-up addressing this. unless you object, i will mention that you are the one who pointed out my mistake
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After COBE, cosmologists didn’t converge on ΛCDM.
We converged on CDM—and knew it didn’t quite work.
The rest was still up for grabs.
A look back at how the fiducial cosmological model emerged ...
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@ScottDodelson Not certain I’m understanding your long paragraph about why it has to be cold
Is it because if it wasn’t cold, it wouldn’t be clumpy enough?
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so we had to solve a bunch of problems. The cells are really really thin so they can like crinkle up. You need to mount them on a surface. That's really really flat and bonded to something that will transfer electricity and conduct heat.
A crucial difficult step is just attaching the cells to the circuit since they're very thin. There's a step called wire bonding.
We were having a frustrating time getting the wire to bond to the cell. That's where the plasma cleaning comes in burns off the stuff blocking the adhesion makes like the surface is sticky and electrically charged activated I think.
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long sought win for us in with our @lightcellenergy cells.
finally mounting works. thermal and electrical
thank you plasma oven we inherited from this intel semiconductor guy. that was it
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Michael Sinko retweetledi
"Like, are we kinda being pricks?"
Jonathan Berk@berkie1
On its third attempt tonight, Marblehead Town Meeting approved an “MBTA Communities–compliant” district largely centered on the 125-year-old Tedesco Country Club, meeting 3A requirements on paper while all but assuring no new housing would be built. This comment says it all.
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@Robotbeat I just think about @Jordan_W_Taylor when reading about oceanic infrastructure
Space is harsh, but at least it’s not quite so actively aggressive
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@CooperZurad @josefprusa @Slant3D Note: I don’t think this is a good idea, I just want to see somebody try it
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Indonesia
And the number where 3DP wins isgetting higher every year📈 @Slant3D @CooperZurad
Josef Prusa@josefprusa
That is big truth now. On top of that smaller runs like the 25k are very uniteresting for the injection molding shops and you have to go to overseas. Especially in countries centered around automotive everyone wants looong-term contracts - 3 years commitment or similar. We had to build out inhouse injection molding and recently acquired a mold making company ... Still takes 6months plus to start production on a part. With 3DP, the prototype turns into a production part after verifications and is instantly in production. Can't beat that 🙌
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@i2cjak A month ago at work I was talking with one of the last guys who worked on the underground nuclear testing who isn’t retired yet. It was pretty cool to learn about the tunnel systems
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btw the reason DOE does this is b/c we signed treaties to not blow up nuclear weapons (test them) anymore so they have to simulate them and apparently this is a difficult problem
LaurieWired@lauriewired
A weird thing about Department of Energy labs is that they’re *forced* to work on novel problems. More specifically, supercomputing work that is: “not well suited to university or private sector research”. This creates odd design choices. DOE compute isn’t “hyperscaler shaped” at all. In fact, they have a rule where they have to use two distinct architectures across each generation of supercomputer. I think the best example of being “weird shaped” is probably Aurora. It was the first x86 CPU with on-package HBM! Intel abandoned the idea after just a single generation. It was so neat though. You could allocate directly into HBM if you wanted, OR run it like a cache in front of regular DDR5 memory, OR if you workload fit…keep the whole thing in HBM. With current HBM supply issues, I don’t think we’ll ever see a CPU with HBM on package again (they’ll all go to GPUs…), but seems fun to play with!
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@boxcardavid Pretty sure it is hysteretic, so there isn’t one specific answer
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Quick, what happens to the permeability of a magnet when it’s magnetized vs. when it’s not?
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do the cia have a phased array microphone or anything? let me know
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@adcock_brett @prudent_AI Then you didn’t scale 24x…
If you are doing 1bot/hr and 55/week, then you have a 55hr work week.
So 1 bot was taking 11hrs previously
An 11x speed up is still great!
Fudging easy numbers just makes you look bad
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@prudent_AI We don't run the production lines 24/7 yet, it's based on when the product lines are running
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In the last 120 days, Figure scaled manufacturing 24x - from 1 robot/day to 1 robot/hour
We will manufacture 55 humanoid robots this week
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@fishPointer @sendcutsend does carry 0.5” stainless
That counts as sheet metal, right?
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sheet metal for vacuum
Phoenix𝕏@Xaraphim
blame @fishPointer for this tangent i brought my old electron gun into this assembly just to understand how this camber could work and what not, and honestly im sure this chamber can work rough math says that for high vac, (10^-8torr), the pressure load is still basically just 1 atmosphere from the outside so structurally it is not like the chamber gets crushed harder just because the vacuum level is better the shell would probably need to be around 8–10 mm thick as a starting point, depending on diameter, material, ports, flange design, and how conservative you want to be. the basic idea is two large formed domes with flanges these could be made with a big ass press, spun, or hydroformed depending on the supplier and diameter once the domes are formed, you could either weld on heavy flange rings or design the lip so the flange surface can be machined directly into it the flange is probably the more critical part than the dome itself, because it has to stay flat enough to hold the seal and not become a potato chip under bolt preload or atmospheric load *not modeled but this would need like 30-40 bolts on the flange* reinforcing the chamber would also be pretty simple if needed you could add external stiffener rings around the dome, near the equator/flange area, and reinforce any ports or viewports with welded pads or collars plus the dome shape already helps a lot because it puts most of the load into membrane compression instead of bending you would need a metal that forms well, welds cleanly, and has good vacuum behavior. it needs low outgassing, low contamination risk, and it should not become a pain in the ass during bakeout or cleaning. stainless steel is the obvious option, but there may be cheaper steels that work if the vacuum requirement, cleaning process, and contamination limits are not extreme a 2m diameter chamber machined from billet or thick plate would be absurd a chamber of that size machine from billet would easily become a HIGH six figure part once you include material, CNC time, welding, sealing surfaces, ports, and inspection. a formed dome is just way more economically viable you buy two formed stainless heads, add flange rings, machine only the sealing faces, weld on the ports, and reinforce only where needed savings could realistically be something like 50–80 percent sombody try this at small scale plz
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E: The abysmal dogshit pile.
The Rise of Skywalker was fucked up in only a way JJ Abrams could do it. His ruin was preordained when he didn't make a multiple-film plan despite knowing he was gonna have multiple films. So he had to do two films in one and retcon a bunch of shit.
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Okay let's fix this list. Rationale in comments below.
The Sietch of Sci-Fi |@TSoS_
Star Wars Tier List
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@xsphi Need to specify for that scale, does the matter that makes up all of those planets and organisms continue to exist? Or is it a Thanos snap and it all just disappears
Any rational intergalactic empire builders would rather the matter continue to exist, even in the form of enemies
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New @WSJ report says OpenAI is following behind on its revenue targets, and the board is questioning Altman's efforts to secure compute.
@EpochAIResearch has shown that OpenAI's expectations for growth are historically unprecedented.
Meanwhile, Anthropic has been catching up.
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@patio11 how does the accounting change if I pay for my fantasy sword on a monthly basis?
9to5Mac@9to5mac
Apple is rolling out a new App Store subscription type: monthly billing with a 12-month commitment. Devs get the cash flow of monthly payments while users still lock in for the full year. Live with iOS 26.5 next month, but not yet in the US or Singapore. (Full story 9to5mac.com/apple-introduc…)
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mdpi.com/2673-8724/5/3/…
I’m really tempted to build one of these simple diamond NV magnetometer demos.
I probably have all the stuff laying around except the NV diamond itself … my work doesn’t deal with NV diamond but maybe I can beg / borrow / buy a little bit from a friend
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