Virgin Physicists

Comments

• NocturnalMorning@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

  First of all, why are they in the chip aisle looking for resistors? Everybody knows they’re in the bread aisle…

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  • Tolookah@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

    If you’re breadboarding this, you’ve already lost

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  • Routhinator@startrek.website ⁨3⁩ ⁨weeks⁩ ago

    He’s going to make potato chip resistors to get the right number of course.

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    • Blum0108@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

      Just count the ripples!

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• yucandu@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

  I used to make shunt resistors out of a pencil and a piece of paper. Rub pencil all over paper, cut strips to size of required resistance.

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  • SupaTuba@lemm.ee ⁨3⁩ ⁨weeks⁩ ago

    I admire it but also…wtf lol

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  • jerkface@lemmy.ca ⁨3⁩ ⁨weeks⁩ ago

    I made a potentiometer with paper and graphite clay once

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    • TangledHyphae@lemmy.world ⁨2⁩ ⁨weeks⁩ ago

      Confuses me that anybody would downvote you for this. I’ve made makeshift capacitors out of rolled aluminum foil. It’s dumb, but it worked for what I wanted (triggering a trackpad via stepper motors for testing microcontroller code.) Plus I just wanted to see if it even worked. Life = science experiments.

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  • RogueBanana@lemmy.zip ⁨3⁩ ⁨weeks⁩ ago

    That’s cool, could you share some photos? The theramin I mean

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  • xthexder@l.sw0.com ⁨3⁩ ⁨weeks⁩ ago

    This is exactly how high precision resistors are calibrated. A laser is usually used to notch out bits of the resistor to tune it after it’s made.

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• Zagorath@aussie.zone ⁨3⁩ ⁨weeks⁩ ago

  What’s the significance of that number? It’s less than 0.1 away from tau, but somehow I doubt that’s it…

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  • easily3667@lemmus.org ⁨3⁩ ⁨weeks⁩ ago

    I assumed the number is not significant, figure it’s just supposed to mock the idea that physicists don’t know what tolerances are.

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    • Ziglin@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

      An experimental physicist should know as far as I know meanwhile a real (theoretical) physicist would probably not even touch numbers that have those scary decimals.

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  • AlbinoPython@lemmy.world ⁨2⁩ ⁨weeks⁩ ago

    I can’t be arsed to check but I think it’s 2 pi which is useful when dealing with sine waves.

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    • Zagorath@aussie.zone ⁨2⁩ ⁨weeks⁩ ago

      2 pi is tau, which is what I said it’s less than 0.1 away from, but still not equal to.

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• JohnDClay@sh.itjust.works ⁨3⁩ ⁨weeks⁩ ago

  There is if you have a potentiometer and a steady enough hand!

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  • muntedcrocodile@lemm.ee ⁨3⁩ ⁨weeks⁩ ago

    U probably need a climate controlled box as well.

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  • SaharaMaleikuhm@feddit.org ⁨3⁩ ⁨weeks⁩ ago

    Can you even measure that accurately? Like is it physically possible?

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    • xthexder@l.sw0.com ⁨3⁩ ⁨weeks⁩ ago

      Based on some rough calculations… no. A precision of 0.0000000000001 ohms is 1000x less than the resistance of 1um of copper with a diameter of 1cm (A piece of wire 10,000x wider than it is long).

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    • Adalast@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

      I thought it had to do with physicists working off theoretical calculations finding precise values for the circuit and not realizing that components come in discrete values.

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• skisnow@lemmy.ca ⁨3⁩ ⁨weeks⁩ ago

  Simple, all you need is a 6 ohm resistor and a 0.18457216 ohm resistor in series.

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  • Spacehooks@reddthat.com ⁨3⁩ ⁨weeks⁩ ago

    No just get a bunch in parallel!

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• TheBroodian@hexbear.net ⁨3⁩ ⁨weeks⁩ ago

  I’m too dumb for this joke

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  • StThicket@reddthat.com ⁨3⁩ ⁨weeks⁩ ago

    To a mathematician, pi is 3.1415926535897932384626433832795028841971693993

    To an engineer, pi is 3

    The joke is basically the same, since you get resistors in certain values, and it’s necessary to select the value closest to the one you need

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    • Schadrach@lemmy.sdf.org ⁨3⁩ ⁨weeks⁩ ago

      To an engineer, pi is 3

      No, to an engineer pi is 22/7, 355/113 if your tolerances are really tight. 3 is pi to a theologist, because that’s what the Bible uses.

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    • bluewing@lemm.ee ⁨3⁩ ⁨weeks⁩ ago

      Maybe round it up yo 4 just to be safe…

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    • lennivelkant@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

      I mean, depending on your calculations and scale, you might go a little more precise with it. At a diameter of, say, 10m for a semicircular bridge arc, that’s a difference of 1m.

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  • mic_check_one_two@lemmy.dbzer0.com ⁨3⁩ ⁨weeks⁩ ago

    I think it’s a joke about physicists not understanding tolerances.

    I remember hearing an old story about a company buying signs from a contractor. The contractor produced all kinds of things, so it was fairly straightforward to send them the CAD file and stop worrying about it. One manager did an audit, and realized they were paying hundreds of dollars each for these basic signs. They weren’t fancy or anything, and were just signs throughout the facility that got updated regularly. So why the hell were they paying so much for what should have been a simple print job?

    After some investigating, the manager discovered it was because the engineer who did the original design for the signs forgot to change their default tolerances from 3/1000 of an inch. The contractor was busting out calipers and meticulously measuring the spacing and sizing on each letter before it shipped out the door.

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    • keepcarrot@hexbear.net ⁨3⁩ ⁨weeks⁩ ago

      Damn, engineer time isn’t cheap either. Contractor was doing pretty well though

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• A_A@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

  Quantum based resistors :
  en.m.wikipedia.org/wiki/Quantum_Hall_effect
  Quantum Hall effect →
  Applications →
  Electrical resistance standards :

  (…) Later, the 2019 revision of the SI fixed exact values of h and e, resulting in an exact
  R~K~ = h/e^2^ = 25812.80745… Ω.

  (this is precise to at least 10 significant digits)

  Quantum Ampere Standard
  www.nist.gov/noac/…/quantum-ampere-standard
  .
  there also been research for defining a quantum volt and quantumly stable resistors

  www.nist.gov/noac/technology/current-and-voltage

  Quantum-based measurements for voltage and current are moving toward greater miniaturization

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• Fossifoo@hexbear.net ⁨3⁩ ⁨weeks⁩ ago

  A 11.8 and a 13 in parallel is 6.1854838709677 which is 0.01% off from that resistance. Of course even using matched 1% would screw you as soon as someone opens the door.

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  • xthexder@l.sw0.com ⁨3⁩ ⁨weeks⁩ ago

    You could get exactly 6.1854838709677 for an instantaneous moment by heating up a 6ohm resistor.

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    • lennivelkant@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

      So you just need to figure out the precise amount of prewarming, then subsequently cooling in coordination with the circuit’s load to make sure it stays at the right temperature?

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• Naich@lemmings.world ⁨3⁩ ⁨weeks⁩ ago

  A 6.2R in parallel with a 2.5K is pretty close.

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  • Tolookah@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

    Add in a 400k and you’re better than most tolerances you can find

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• Fleur_@hilariouschaos.com ⁨3⁩ ⁨weeks⁩ ago

  This implies a physicist would do anything practical ever

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• ShimmeringKoi@hexbear.net ⁨3⁩ ⁨weeks⁩ ago

  miyazaki-laugh I didn’t realize until just now that I missed this comm actually

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• murd0x@lemmy.ml ⁨3⁩ ⁨weeks⁩ ago

  Ohm no !

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• friendly_ghost@beehaw.org ⁨3⁩ ⁨weeks⁩ ago

  And no spherical cows either??

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• Spacehooks@reddthat.com ⁨3⁩ ⁨weeks⁩ ago

  Love how there are so many actual solutions in The comments

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  • frezik@midwest.social ⁨3⁩ ⁨weeks⁩ ago

    But not really. At this level of precision, the heat from electricity passing through it would throw off the actual resistance value.

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  • realitista@lemm.ee ⁨3⁩ ⁨weeks⁩ ago

    Bet they’re all engineers.

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• TangledHyphae@lemmy.world ⁨2⁩ ⁨weeks⁩ ago

  Lol this one was great, thanks for sharing. My partner teaches physics and I do EE on the side, I like rubbing these in her face sometimes.

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• Corno@lemm.ee ⁨3⁩ ⁨weeks⁩ ago

  That’s revolting.

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