• 0 Posts
  • 176 Comments
Joined 2 months ago
cake
Cake day: June 5th, 2025

help-circle


  • Yeah, you’re probably right. I’m in over my head on this discussion.

    I am reminded of my first day in an electrical engineering circuit theory class, when the professor made very, very clear that he was teaching us theory and fundamentals, and that the real world of electricity required a lot more safety built into the procedures and designs, because not everything behaves the way the undergrad textbook describes.

    So I’ve learned something new. Thanks.


  • A simple lamp can demonstrate.

    You have both live and neutral lines in the cable, coming up to a switch, which can either open the circuit on the live line or the neutral line. Then, the lamp itself has a single light bulb as the load.

    If you place the switch on the live line, then the energy of the live line stops at the switch, with only whatever lower voltage is in the neutral line to actually be connected to the light bulb and lamp assembly.

    But if you place the switch on the neutral line, you’re leaving the entire lamp on the voltage of the live line, which gives the voltage more places to potentially short circuit. If you were to take a non-contact voltage detector, you’d be able to detect a live voltage in the line leading up to the bulb, even when it’s not turned on.

    You generally do this with the in-wall wiring and switches, too, and make the wall switches break open the circuit on the live line, not the neutral line. It’s just a better practice overall.

    And no, the neutral line is not totally grounded, so it can still pose a danger, too. But safety is exercised in layers, and putting the switch on the live line is the better practice.


  • it’s a bad practice to design appliance in such a way to assume that neutral will have low voltage, because in case of neutral failure in three-phase circuit you can get full voltage there,

    Who’s using three phase in a setting where these types of plugs are used? In the US, at least, three phase circuits use very different receptacles and plugs.

    The fact of the matter is that the switch has to be placed somewhere. And it’s safer to place the switch between the load and the live wire, rather than between the load and the neutral wire. Designing a system where the live and neutral can easily be known makes it easier to do the safer thing.


  • The actual electrical device can be designed such that it depends on exactly which direction is live and which is neutral.

    Imagine a circuit loop that, as you follow along the circuit, has an AC power source, then a switch, and then the electrical appliance, leading back to the AC source it started from.

    If you design the circuit so that you know for sure that the live wire goes to the switch first before the actual load, then your design ensures that if there is a fault or a short somewhere in the appliance, it won’t let the live power leak anywhere (because the whole device is only connected to the neutral line, not the hot live voltage that alternates between positive and negative voltage). It’s safer, and is less likely to damage the internals of a device. Especially if someone is going to reach inside and forgets to unplug it or cut power at the circuit breaker.


  • That’s my whole point. If you’re gonna ask the airlines to give different amounts of space for different sized people, don’t expect your tickets to stay the same price.

    The current system is that the ticket prices are the same (price fluctuations happen but not based on the size of the passenger), and that everyone of a particular fare class gets the same sized seat.



  • Which essential amino acids can’t be obtained from plants?

    Soybeans, quinoa, and buckwheat are complete protein sources. More importantly, pretty much any grain (wheat, oats, barley, rice) plus any legume (peas, green beans, beans, lentils, chickpeas, peanuts) are a complete source of amino acids.

    Omega-3 accumulates in fatty fish, who obtain it by eating krill and other small animals, who obtain it by eating algae. Algae oil is available as a supplement. Also, Omega-3 is in tree nuts like walnuts, as well as flax and chia.

    Oh, and B12 supplements come from yeast and mushrooms, not bacteria.

    If you’re gonna go hard at vegans you should at least get your facts straight.


  • Each side has the opportunity to use their own experts to ask those questions and analyze the forensic integrity of the evidence at issue. Even if your side doesn’t have an expert, your attorney still has the chance to question the other side’s expert.

    So if there’s a piece of evidence based on an email sent from Alice to Bob, the way the evidence gets introduced is that it gets authenticated, by someone who would be in a position to speak to whether a particular document is authentic. The other side can seek to exclude the evidence if the basis for authentication isn’t strong enough. Or, it comes in, and the other side might want to challenge that the document actually represents what the other side wants to prove: maybe casting doubt on whether other people had access to Alice’s account, etc.

    Or if you want to use a surveillance camera video, you’d generally have someone who maintains the system testify as to how the system records, where it stores the data, and how it adds timestamps to different videos. Then that technical person can usually testify that the timestamp is accurate, etc., and might have to answer questions about what happens when the system loses power or a connection, etc.

    So it’s not that the courts in the US actually test the validity of evidence. It’s that the parties involved in the case can challenge the validity if the circumstances call for it.









  • Is it really impossible to make a protein bar savory?

    In order to make something that is shelf stable without refrigeration, it needs to be either hostile to harmful microbes or sealed in a way with no harmful microbes inside (and will have to be refrigerated after opening).

    There are a few ways to do it without sealing, including reducing water activity low enough that microbes can’t grow. Flour, rice, oats, nuts, and other bulk dry goods generally follow a dehydration process. Oil doesn’t have water in it, so sometimes there are high oil substances (peanut butter) that don’t have enough water to support microbial activity.

    Another way to reduce water activity is to bind the water molecules with other molecules. Sugar is by far the most common substance useful for reducing water activity, because it’s possible to mix water with a lot of sugar. Honey is shelf stable because it’s something like 15% water and 85% sugar. Maple syrup is about 33% water and 67% sugar. At those sugar levels, microbes struggle to actually resist the osmotic pressure and use the water present in the substance.

    Note that salt can’t really do the same thing. A brine that is 95% water and 5% salt is basically inedibly salty. But 95% water is still top high to really inhibit microbial growth. At most, you hope that good microbes outcompete bad microbes (this is the basis for pickling sauerkraut, Kim chi, certain types of pickled cucumbers, where lactobacillus strains will outcompete harmful bacteria and mold). But even these foods may keep much longer when refrigerated. Even soy sauce, at 16-20% salt, is recommended to be kept in the refrigerator (for quality, not necessary for food safety).

    There are other ways to inhibit microbial growth, or just the harmful microbes: acid or alcohol can do a lot.

    But as a result, the easiest way to make a shelf stable bar is to dehydrate it, maybe add a bunch of sugar, and use ingredients that still have good taste/texture when dehydrated. So they use a lot of things like nuts, chocolate (high enough sugar to have low water activity), trapped air bubbles (good crunch when totally dried out). And the sugar allows it all to bind together.

    And there are other ways to bake savory goods. They just have to be crispy all throughout, and usually thin enough to bake/fry dry without making it too hard to be pleasant. Think chips, pretzels, even savory mixes like Gardetto’s or Chex mix. Even the bread stick components have to be dehydrated to the point of being brittle and crispy, like a crouton. Turning that into a shelf stable bar form that actually tastes good, without adding sugar, would be difficult.