poopsmith

joined 1 year ago
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[–] poopsmith@lemmy.world 6 points 14 hours ago

I remember these. Tried them once and never again. It's a cool gimmick but pricey.

[–] poopsmith@lemmy.world 3 points 1 day ago

Nah, just the basics is fine. I would recommend Griffith's and then moving on to Shankar.

[–] poopsmith@lemmy.world 6 points 1 day ago* (last edited 1 day ago) (3 children)

It's also really important to remember that QM is really a formalized algebra of probability/stats, so it's really really important to get a good grasp of that. QFT and all that comes after understanding the basics. It's a fuck ton of work, but I think it's rewarding.

[–] poopsmith@lemmy.world 5 points 1 day ago* (last edited 1 day ago) (4 children)

I'd really recommend going through the basics about learning QM. Specifically: classical mechanics, a very good stats & probability math course, calc prereqs, intro to QM, intro to thermal/stat physics, maybe an atomic course, intro chem course. I'm not sure of the exact steps, but as a physics undergrad major, it'll "click" after a certain amount of prereqs and if you need any help, feel free to PM me and I'll gladly be of assistance (as far as I can remember, at least).

[–] poopsmith@lemmy.world 51 points 3 days ago (7 children)

Yep. I'm so over American politics and I think the nation is headed in the wrong direction. I feel that the people are powerless against changing our trajectory. I had been considering doing a PhD abroad and this is really pushing that decision now.

[–] poopsmith@lemmy.world 2 points 5 days ago (1 children)

It's spam. OP is blasting the link everywhere

64
submitted 1 week ago* (last edited 1 week ago) by poopsmith@lemmy.world to c/nostupidquestions@lemmy.world
 

Assuming my municipality accepts it, are they actually being recycled?

I see them being touted as recyclable. However, it seems like it would be difficult and resource-intensive to recycle but I'm not a recycling expert.

[–] poopsmith@lemmy.world 0 points 1 week ago

What are you talking about? I've witnessed it several times now at work, especially regarding programming or EE. Have you not yet suffered through a programmer condescendingly explain trivial matters to others, especially to women?

The post is obviously a hyperbole but it's not too far off from reality.

[–] poopsmith@lemmy.world 1 points 1 week ago (2 children)

I don't think anybody is obsessed with it. It's a problematic behavior in many men, enough so that it's become a meme, particularly in the US.

[–] poopsmith@lemmy.world 2 points 1 week ago

I've tried this. It's drinkable but not very enjoyable. 5/10

1
submitted 2 weeks ago* (last edited 2 weeks ago) by poopsmith@lemmy.world to c/support@lemmy.world
 

Does anyone have any advice on routing some high speed signals on flex PCBs? I'm looking at jlcpcb because of the low cost but I'm having difficulty getting impedances to be decent.

My requirements are:

  • 45 ohm single ended impedance (maybe? Def doable)
  • 90 ohm differential impedance (usb spec)
  • 5A current on power pins

But if we look at the capabilities: https://jlcpcb.com/capabilities/flex-pcb-capabilities

  • 2 layer
  • substrate thickness (PI) = 25 um
  • 1 oz pour thickness = 35 um
  • min trace width/spacing = 4/4 mil = 0.101/0.101 mm
  • ε = 3.3

Is this feasible with this stackup? I'd like to do a 1 oz pour because of power traces, but there's also 0.5 oz (18um) and 0.33 oz (12um).

For the differential signals, when I'm doing impedance calculations, I can get to roughly 70 ohms using W=100um, S=200um. I don't think this is good enough. I think I can get away using a 0.33 oz pour but then I'm worried about the power pins.

And for the power traces, I'm needing 2.2mm, which is reasonable for the pins on a USB-C connector. But if I try using the 0.5 oz or 0.33 oz pour, it gets to be 4.2 mm and 6.3 mm, which seems impossible given the pins are tiny and very closely spaced together. Even with vias to the bottom layer, this seems problematic.

Anyone have any advice here? This is just for a hobby project, so I'm really not looking to change fabs because of costs.

 

I submitted a video request for any body worn video and in-car footage for the incident where SPD officer Anthony Belgarde pulled over a bus in West Seattle. But I was told by Edward Ocampo that no video existed for this incident. Is this a normal practice, to not record any video during a traffic stop?

Edit: I filed a complaint as I believe this violates 16.090-POL-2, where cops in uniform performing traffic stops are required to have their cameras on.

Edit 2: I did not get a confirmation email though.

Edit 3: had to email them again to get a complaint number

[–] poopsmith@lemmy.world 1 points 1 month ago (8 children)

If you have a Dremel, I bet you could take out the center bit and use a regular slotted screwdriver.

 

It might be back tomorrow if you missed it tonight!

[–] poopsmith@lemmy.world 1 points 3 months ago

If you have a memory-mapped peripheral where there's a readonly register, I could see it being const volatile.

 
 
 

New promo from their Ween's channel. Description:

Witness Ween's debut at The Mann in Philadelphia on Friday, September 27, 2024, celebrating 30 years of "Chocolate and Cheese." The band will perform a full set, including the classic album released on the same day in 1994.

 
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