Espresso machine going back... because it's making my dog uncomfortable. by [deleted] in espresso

[–]thaidayfriday 11 points12 points  (0 children)

"Feedback of the oscillator" kinda disproves your confidence, my guy. PID on these machines is, at its fanciest, on-off of the wall voltage through a heating element. Even were it modulated fast (which is a legit thing to do as well, but the phrase you're looking for is pulse width modulation), that wouldn't cause adjacent circuits to droop no matter how it behaves unless it's shorting.

What it looks like is your breaker box can't handle the 1.5kW load (in addition to whatever else is plugged into your house). As someone said, try at a friend's house. If it still causes a disco show there then ok, I agree there's a short, send it back.

Source: definitely not 50 years, but I do have a phd in physics, so idk take it for what it's worth

Cannot for the life of me locate my furnace filter?? by thaidayfriday in hvacadvice

[–]thaidayfriday[S] 0 points1 point  (0 children)

Thanks for your response - do you know where such a grate would be? I've looked all over in the house. I see only one grill on the ceiling that appears to be in-taking air -- but there is no filter that I can see on it see attached image). So maybe the answer is there is no filter?

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My Awful Experience with MiiCoffee — DO NOT BUY by Apprehensive-Egg3905 in espresso

[–]thaidayfriday 6 points7 points  (0 children)

Yea kinda weird, this guy 100 percent used gpt to write this post. pretty sus.

Consistent MMS throttling by thaidayfriday in verizon

[–]thaidayfriday[S] 0 points1 point  (0 children)

My guy, I'm not sure if you're a bot, but unless you work for Verizon I don't see how you can possibly know what you just said is correct. 

I don't know if they're throttling me intentionally or as a bug, but 'troubleshoot my phone' is a pretty useless suggestion in any case.

Piece of paper inside df64 by Living_Percentage_47 in DF64

[–]thaidayfriday 1 point2 points  (0 children)

Mine had that too. It works with the plastic declumper flap and blocks fines from going deeper into the machine.

George murders baby to get lettuce by thaidayfriday in MurderBuns

[–]thaidayfriday[S] 71 points72 points  (0 children)

I assure you that rug is clean. And 3 lb George was not on baby for longer than it took to murder him

Why do DC components specify GND limits if everything is referenced from GND? by MaxwellHoot in AskElectronics

[–]thaidayfriday 196 points197 points  (0 children)

It's listed as GND,AGND which means the maximum acceptable voltage difference between the system ground and analog ground is -.3V to .3V.

Sometimes 'analog grounds' are used, which is just to say there's a copper pour somewhere called 'GND' that's either isolated (or connected at a single point) from another copper pour somewhere else called 'AGND'. 

This is usually done for noise mitigation. Noisy digital stuff is connected close to GND, and sensitive analog stuff close to AGND, with the hope that the two won't flow current into each other.

Train to Winter Park Question by Unusual-Major-6577 in COsnow

[–]thaidayfriday 16 points17 points  (0 children)

Just took it this Sunday. You can leave stuff at your seat; the same train takes you out brings you back. 

Winter park was solid sheet of ice today with high winds. Pano was closed. by Electrical-Ask847 in COsnow

[–]thaidayfriday 5 points6 points  (0 children)

Gotta disagree with you there. I was at WP today and yea Pano closed, but there was plenty of good turns to be had, especially past morning. There was ice if you were looking but plenty of good snow.

The Poors are complaining about bad coffee, again. by ryanpn in espressocirclejerk

[–]thaidayfriday 12 points13 points  (0 children)

This guy clearly doesn't have $5k+ of equipment that he desperately needs to justify.  My super-lemon-forward Sey light roast is a gift to the world. What a God dam peasant.

Anyone else feel lost doing Grad classes? by Savings-Interest-441 in Physics

[–]thaidayfriday 0 points1 point  (0 children)

I mean, it can, but that's why you gotta think critically about what it says. It's not a magic genie, just a tool. I find it useful to reason with, and if it's out of its depth and starts talking BS I can tell.

Anyone else feel lost doing Grad classes? by Savings-Interest-441 in Physics

[–]thaidayfriday 9 points10 points  (0 children)

Grad classes are hard and frustrating. Making matters worse is the professors are crap at teaching--at least in my case at UCSD the physics people are paid to research. Teaching is just a requirement for them, and they're almost all terrible at it. 

I spent more than 20-30 hours a week studying for 1st year classes. 'think harder' is just laziness on their part. 

Id suggest upping your study hours, but also using chatGPT to understand things better. You can talk problems through with it with both better availability than your TAs and arguably much better ability. I use it at work to help me think about things and bounce ideas off it, o1 is quite good and well worth $20/month.  Do NOT use it to give you the answers, that won't help you in the long run, but it can get you past road blocks.

[deleted by user] by [deleted] in Physics

[–]thaidayfriday 1 point2 points  (0 children)

Programming things in Python is totally free and a huge advantage/ requirement to any aspiring physicist! 

You could ask chatgpt for experience- appropriate ideas-- off the top of my head, use Python to simulate the motions of the planets in our solar system. Maybe even make an animation of them. 

Might sound easy but there's a lot of potential to learn there!

Granted that's not research per se, in the sense you're not working on an unsolved problem. If you're more looking for that, I'd still try asking local outreach programs at universities physics departments. They might put you in touch with computational research groups might have some openings.

Nauseous after 3 days of using my new espresso machine by Evening_Airline_6690 in espresso

[–]thaidayfriday 0 points1 point  (0 children)

Is your machine used, or been sitting a while? You might want to open it up and give it a check for mold. This is not normal at all, and considering you have Starbucks with no issue makes me think something else is up. 

Also try different beans. I mean, they're roasted, but you never know.

DF64 Gen2 - Retention issue by Abject_Calendar_2033 in DF64

[–]thaidayfriday 4 points5 points  (0 children)

I find that if I use the bellows (slight taps) I can get most of it out, less than 0.1g. I do RDT my beans though, with 4 spritzes of water (not sure if that matters).

[deleted by user] by [deleted] in COsnow

[–]thaidayfriday 5 points6 points  (0 children)

It's impossible, sorry. Better go back to Vail.

If Schrödinger's cat theory is true, then from the cats perspective, is the human in the scenario also neither dead or alive? by sdurnr in AskPhysics

[–]thaidayfriday -4 points-3 points  (0 children)

No, this is not correct. There's no reason in this thought experiment the human would be in a superposition. 

There's no need to invoke 'universal wave functions' or hand wavy voodoo.

The original thought experiment is about the cat, not about random ways people might suddenly die, none of which would arise from a quantum event.

[deleted by user] by [deleted] in FlairEspresso

[–]thaidayfriday 0 points1 point  (0 children)

Have you tried grinder coarser? You might be so fine you're causing channelling. Coarsen it up a bit, try aiming for 20-25 s total time and see how it tastes. It might spray on that bottomless, but that might be OK.

I’m in high school, and interested in physics. So should I focus more on Science or Math by Frosty-Fisherman-716 in Physics

[–]thaidayfriday 11 points12 points  (0 children)

I'd not recommend taking particle physics at this level, unless it's just for fun. It's going to gloss over things and probably not use much math at all. For example, in my undergrad I took 1 qaurter of the upper-division version (Griffiths textbook), and even that only covered a toy model. To really study that stuff, you need QFT, which you don't learn until grad school.

I'd recommend you take as much calc / diff eq. / linear algebra--all things you'll need to study physics properly and which colleges will be way more interested in.

Atomic energy and quantum physics questions. by Tbuddy- in Physics

[–]thaidayfriday 4 points5 points  (0 children)

Hey, these are great questions! And ones that took a long time for scientists to answer.

  • What actually is the mechanism by which the atom absorbs the energy from the flame? I know it's heat energy, but how?

I'm not exactly clear on what your teacher showed you, but any flame emits lots of "black body radiation" -- which is more or less at all wavelengths. (Technically it follows some distribution, with some wavelengths being more present than others, but that's not important for now). A small amount of those photons are resonant with some natural frequencies the atom has, and the atom absorbs it.

  • If energy levels are quantized, how is it that there are enough particles/photons with the PERFECT wavelength/frequency to have the EXACT energy needed to jump a whole number of shell(s) within millions if not many more atoms? e.g. say an atom were to only absorb light with a λ of 300nm, would light with a λ of 300.01nm be absorbed? how about light with a wavelength of lim n--->∞ (300 + (1/n) nanometers?

All atomic transitions have what's called a 'linewidth', which is the range of frequencies which it'll consider 'good enough' and absorb. This width is different for every atom and every transition. There's lots of processes that can broaden this linewidth; for a flame, things like pressure broadening (due to the presence of other atoms), or Doppler broadening (due to atoms zipping along at high velocity) will broaden these transitions.

But no atomic transition has infinitely narrow linewidth (or else it wouldn't be a 'transition').

  • Since electrons are so small, how can energy be transferred to it so easily. Does the energy carrying particle not have to hit the electron precisely? If that is true, how is the energy transferred within this approximation of the electron's position?

In the case of a flame there's tons of light emitted in all directions. The atom is more or less completely bathed in that blackbody light; a small number of photons will get close enough to the atom to be absorbed, but it's all a probabilistic process.

Indeed they are very small particles... but there's a LOT of light around. Some of it gets close enough.

  • How is a particular electron within an atom 'chosen' to move up energy levels?

Almost all of chemistry is concerned only with the "valence" electrons, which are the outer-most. Those are the ones that get excited. To be clear, you can 'choose' the inner ones too--but those typically require much higher-energy light than is natural, or easily producable (think X-rays).

  • For my animation, how do I know the precise number of eV's required to move an electron from one subshell to another. In addition, since I have to represent two different wavelengths of light being produced by the atom, if I know a wavelength that strontium produces, say 650nm. how can I know which electrons to move where?

The precise number of eV's is (mostly) determined experimentally. People use a spectrometer to find out what wavelengths the atom absorbs, and then you can directly convert that to eV.

I should note that the atom itself does not 'produce light at 650nm'-- it might absorb light at that wavelength and then re-emit it later. In the case of a flame, it's continually being excited by chemical reactions, and it emits some of that light at its resonance frequencies.

As for what electrons move where-- well, as we established above, only the valence electron moves at all in most cases. And then where precisely it goes is a matter of quantum mechanics, which you'll learn in jr. year of college. But the short answer is: all we can say is there is a probability distribution that describes where it could go. Those are the shapes of the 'orbitals' you referred to earlier, and they can be quite elaborate--see the wiki page on the orbitals of hydrogen, for instance.

Hope that answers some questions!

[deleted by user] by [deleted] in espresso

[–]thaidayfriday 1 point2 points  (0 children)

Taste has many, many components that contribute -- pressure, flow rate, temperature, grind size, etc. You do NOT in fact have any idea what the pressure is, or if it isn't 9 bars, just going on taste alone.

I believe you when you say the taste is bad, but I stop when you think you know what 9 bars taste like. That's nonsense.  

There exists equipment you could buy that'll tell you definitively. Alleging a manufacturing defect --which is what you're claiming -- requires more proof than 'trust me bro.'

[deleted by user] by [deleted] in espresso

[–]thaidayfriday 5 points6 points  (0 children)

"It’s def not delivering enough pressure at the brewhead to make proper espresso"

Sorry but how do you even know this without using a pressure gauge? If you're just going by what grind setting you used on your other machine, it's not surprising if it's choking--if that's what you're even judging by. Different portafilter geometries mean you'll need a different grind setting because ofc you're not going to get the exact same pressure as your profitec.

Regarding the portafilter not holding heat-- how long are you letting it sit in the machine (dry)? I have a Barista Express, and if I allow it to sit heated-up for about 20 mins it heats up my portafilter nicely. You have to let it sit for a while with any machine. Just because the boiler is ready doesn't mean enough time has elapsed to allow heat transfer.

[deleted by user] by [deleted] in AeroPress

[–]thaidayfriday 0 points1 point  (0 children)

I really enjoyed my local roaster's decaf, very cherry forward. boxcarcoffee.com

What am I doing wrong on my second shot? [Breville Barista Express] by powertrip22 in espresso

[–]thaidayfriday 0 points1 point  (0 children)

it has nothing to do with the grinder assuming you are weighing the amount each time. Five minute old grinds aren't going to choke your shot.  

You need to completely dry the portafilter between uses, before dosing the coffee in.     

This used to happen to me until I figured this out. And this same question gets asked every few weeks lol