58 pointsby downbad_9 hours ago11 comments
  • voidUpdate5 hours ago
    > "I barely know what a BTU is"

    Neither does anyone else, its one of those archaic units that changes slightly based on who is using it and hangs on in oil and gas industries, and also air conditioners and heaters.

    It was defined as the amount of energy to raise one pound of water by one degree Fahrenheit at one atmosphere of pressure, but that amount of energy depends on the starting temperature of the water, and different things use different starting points, so it ranges from about 1054 to 1059 joules

    https://en.wikipedia.org/wiki/British_thermal_unit

    • bonsai_spool5 hours ago
      Why would the amount of energy required to increase the temperature of a defined mass of water depend on the temperature? This goes against the idea of specific heat

      (editing to add - I didn't realize that water's specific heat has a temperature dependence and changes around 5% over reasonable indoor temperatures

      https://www.engineeringtoolbox.com/specific-heat-capacity-wa... )

      • kgwgk5 hours ago
        No, it doesn't go against the idea of specific heat. You may be thinking of ideal gases and even then specific heat may or may not be constant: https://en.wikipedia.org/wiki/Perfect_gas
        • bonsai_spool4 hours ago
          A specific heat is the amount of energy needed to raise a defined mass of a substance by a defined temperature.

          What does that have to do with a perfect gas?

          • Tade04 hours ago
            The ideal gas model assumes point particles with no interparticle interactions, while all the interesting stuff with regards to all kinds of specific heat happens due to these things in... particular.
          • kgwgk2 hours ago
            The question was

            > Why would the amount of energy required to increase the temperature of a defined mass of water depend on the temperature?

            and the answer is that it does, except if you have a very restrictive model where it doesn't. (Edit: I see there was an edit to the previous comment, I had missed that.)

            • bonsai_spool2 hours ago
              Yes, I wrote both comments.

              Why does water relate to the ideal gas law?

              • kgwgkan hour ago
                It doesn't. Your initial assumption that the heat capacity is a thing that doesn't depend on temperature did (because it may apply to ideal gases as opposed to water where it just doesn't stay constant as you noticed later).
      • PowerElectronix4 hours ago
        Specific heat usually varies with the temperature itself.
      • defrost5 hours ago
        Traditionally it's not a "mass" of water, it's a pound (unqualified) of water.

        There's an issue right there and one that cracks the door open to "how is pound of water created".

        Leading into (depending on path to above) the issue of density of water, while famously and often described as incompressible, water reaches max density at 4 C, 3.99 degrees (Kelvin or Celsius) above water's triple point.

      • simonebrunozzi2 hours ago
        See water's triple point.
      • actionfromafar5 hours ago
        Phase change?
      • willis9364 hours ago
        They're not saying the rate varies but the starting point. Going from 30C to 100C takes less energy than going from 20C to 100C even if specific heat remains physical. Both might get labeled a BTU.
        • stavros3 hours ago
          They specifically said "one degree Fahrenheit", so the GP's question was "why does going from 30 F to 31 F take a different amount of energy than going from 20 F to 21 F?".
    • out_of_protocol5 hours ago
      I blessed to live in a country that uses kilowatts. That works wonderfully (and advertised as such) for AC units
      • Ekaros5 hours ago
        Kilowatts as in power consumption or as in refrigeration or heating power? AC is somewhat not straightforward.
        • Gigachad3 hours ago
          It is pretty simple and standardized. The spec sheet will list the cooling and heating output in kW, and then also the input in kW. The number they have displayed most prominently is the cooling output while the others will be in the specs.
      • quickthrowman2 hours ago
        One ton (HVAC unit) is 3.5kW of heat moved for each 1kW of input power under relatively ideal conditions, assuming a max COP of 4. The unit chosen to represent the amount of heat that can be transferred is irrelevant, you get the same information.
        • dzhiurgis2 hours ago
          So it's a gallon of kilowatts?
  • helzinia32 minutes ago
    > there has also been a decent amount of research about the calming effect of weighted blankets, which can weigh up to 30 pounds. Studies indicate that they can curb anxiety and even be used in the treatment of autism.

    What odd phrasing, "the treatment of autism". Wouldn't it suffice to say a lot of autistic people find them comforting? This may just be my bugbear, but I notice a lot of these depersonalising statements in anthropology, psychology, etc when an author wants to hold up some supporting example about a group of people they are not experts on.

  • ahmedfromtunis5 hours ago
    Is this a common thing? Sleeping without any sort of cover during the hot summer months (notably July and August) is the norm here (North Africa) and never heard of anyone who does it (AC or not).

    Is this an American thing? Do people in warmer regions of the country (Texas, Florida, ...) also feel the same?

    • zeta01343 hours ago
      Speaking personally, I have the "must be covered" gene along with the "overheats easily at night" gene, so it's been a bit of a struggle hitting a balance. Right now a thin breathable quilt is the way to go, even in deep winter. Hard to explain really, but I feel anxious (and cold!) if my body is exposed, even if it's actually pretty hot in the room.

      The best mitigation for this conflict seems to be those knitted blankets with the enormous holes. Terrible heat retention, and they're pretty heavy. That got the job done during a Texas summer on more than one occasion.

    • kranner3 hours ago
      Here in India, when I was growing up it was normal to sleep without a cover in the summer (no ACs back then, only ceiling fans and perhaps an evaporation cooler in more luxurious circumstances). I remember when a friend and his cousin from Thailand was visiting and the power had just gone out. The temperature was in the early 40s (Celsius) but the Thai cousin who wanted to take a nap insisted on a thin cotton sheet as a cover. My friend and I were confused and kept telling him it's not a good idea but he couldn't fall asleep without it.
    • roxolotl4 hours ago
      As someone who lives in the Northeast US but travels to Florida somewhat regularly it amazes me how low people keep the AC. It’s common for people and places, or at least those I visit, to keep the AC lower than I keep my heat in the winter(18c). So sometimes I’m so cold I have to ask for additional blankets or bring a jacket to a place like a movie theater.
      • threwrfaway3 hours ago
        Folks in the South don't consciously realize it, but they're setting the AC low to keep it running for its dehumidification.

        These are the same folks who sweaters is its 80F outside. They can handle heat.

        If ACs had the ability to run as dehumidifiers in convinced the temp would rise

        • obsidianbases13 hours ago
          If it's less than 80 outside it's cold. If it's over 69 inside then it's hot and I can't sleep

          -florida man

    • wodenokoto4 hours ago
      Yes, it is totally a thing. We don't have a lot of hot nights in Denmark but when we do, we still sleep under a duvet, or maybe half under one and it is just as awful as it sounds.
      • roenxi4 hours ago
        Are you sure? That seems like the sort of thing people might just not do. It can't take that many brain cells for an uncomfortably warm person to work out that more blankets make you more hotter -> less blankets makes you less hotter.

        The article seems to provide very limited evidence that people sleep under blankets on hot nights and it sounds like a silly thing to do in the abstract. A lot of people would just remove the blanket when they get hot.

        • applfanboysbgon3 hours ago
          Sleeping with blankets is very comfortable. If the comfort outweighs the discomfort from being mildly hot, it makes sense. Personally I just run fans and/or AC such that I am still comfortable under my blanket, because the price I pay for electricity is worth far less to me than the comfort of sleeping with a blanket.
        • martin-3 hours ago
          I sleep with a blanket even when it's too hot. 90% of the year the temperature is low enough that I need it, and sleeping without it the other 10% of the year just feels wrong, and I feel exposed.
        • wodenokoto3 hours ago
          I didn’t say we use more blankets when it’s hot.

          But if you are so used to blankets that you can’t fall asleep without one, dropping the blanket because it’s hot is a pretty bad sleeping strategy

    • embedding-shape4 hours ago
      I'm born and raised in Sweden, now live in Spain, cannot fall asleep unless I have something covering me, but I can also not fall asleep while sweating... So in the hottest months (July and August), I tend to just use a bed sheet as the cover, does the trick.
    • elorant3 hours ago
      It is a thing and not only in U.S. I live in Greece and my girlfriend can’t sleep if she’s not covered by something even if it’s in the middle of August and it’s scorching Earth outside. She says she feels vulnerable without a cover. I on the other hand can’t sleep with a cover during summer.
    • SupLockDef4 hours ago
      No, I often sleep on top of my bed during the hot summer days. I also don't put myself under the blankets when I take a nap.

      I don't know what TFA is talking about.

    • jeremyscanvic4 hours ago
      In France some people do and some people don't but it's definitely a thing
    • quickthrowman2 hours ago
      It’s always 20C/68F in my apartment during the summer so I sleep with blankets. I keep it that cold to control humidity.
  • risingsubmarine5 hours ago
    'Go Wild' (John Ratey, Richard Manning) theorizes that the modern concept of bedrooms in which we segregate ourselves to sleep is a mismatch with our evolutionary established state. We would naturally lie in very close proximity of tribe and family for heat, contact and security. Sleeping and resting on one another out in the open. Perhaps pillows and blankets (esp weighted) serve as a proxy for this, not just temperature?
    • etrautmann3 hours ago
      That would result in insanity for me. Is there any argument other than it seems like cave people must have?
      • vanderZwan3 hours ago
        Well, this is probably a thing where humans are very diverse in their subjective experience.

        I'd say this is definitely a noticeable thing with small children at family gatherings, birthday parties and the like. But I grew up in a household where both of my parents came from families where big family gatherings with even extended family was common, and I know not everyone has that kind of experience, so who knows how much of that is nature or nurture as well.

        In my case however this has persisted well into adulthood: despite being a chronic insomniac who has a really hard time falling a sleep normally, at these types of social gatherings I often have to fight off falling asleep precisely because I feel comfortable and safe among friends and/or family (I wonder if that is in any way related to my ADHD).

      • smackeyacky3 hours ago
        Safety. If something creeps up hopefully one of you is partly awake to raise the alarm. I sometimes think cats are still like this, they seem to sleep very soundly around people but only snooze and are easily startled when isolated.
      • Nzen3 hours ago
        If I am to believe the creator of the _History in Taberna_ youtube channel, communal beds were a medieval to early modern practice in inns [0].

        [0] https://youtu.be/5IPQIl-FiCY?si=drUMJuR5tLLppWqD&t=738 relevant section is 13:00 - 14:00 of a 30 minute video about various inn / tavern aspects.

      • dzhiurgis2 hours ago
        Not just you. Most are insane already. Temperature, noise, light, other partner, pillows, ventilation, caffeine, wind down (including me as I write this comment) - majority of people mismanage this so badly. We spend 1/3rd of our time on it, it's probably top 5 of most important things in our life, yet we butcher it so badly.
  • amelius4 hours ago
    Recently discovered that "weighted blankets" are a thing.

    https://en.wikipedia.org/wiki/Weighted_blanket

    • lippihom17 minutes ago
      I love weighted blankets but have to be careful that they're not "too" heavy. I used to have sleep paralysis relatively often as a kid and a too heavy weighted blanket often re-triggers this, which is obviously terrifying.
    • voidUpdate4 hours ago
      Weighted blankets are lovely if you have a neurodivergence that likes being enclosed (like me). But they are even more unbearable in hot weather
      • isoprophlex4 hours ago
        I consider the weighted blanket to be a very dangerous invention. Dangerous to my planning, that is. If I try take a quick 20 minute nap under it, I always sleep for 2 hours minimum. It's like an off switch for my brain.

        Extremely comfy.

  • jiggawatts5 hours ago
    They didn't include a common reason for wanting at least a thin blanket on hot summer nights: it keeps the mosquitoes away!
  • Markoffan hour ago
    I like Balkanese approached I noticed in Croatia and Bulgaria, instead of duvets or blankets they just use (in summer) thin empty duvet case judging my multiple Airbnb experience.
  • eth0up3 hours ago
    1. Being properly tucked-in, as a vestige of comfort from the crib, where babs are often protected with at least some form of cloth.

    2. You are from florida, where there's an entire species of insect for every sqr centimeter of the body, and enough mosquitos after 19:00 to write each of them through displacement.

    3. Ideal sleeping temerature is probably so close to 'perfect' that as body temp drops through sleep, it crosses the thin threshold of comfortable to slightly cold.

    Since we've abandoned the penny, I hope that rounds up to a nickel of thought.

  • 4 hours ago
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  • expedition325 hours ago
    I did not realize that things like sheets, blankets and pillows used to cost serious money.
    • boelboel5 hours ago
      Not just bedding but clothing was costly. High quality bedding (as well as clothing) still costs quite a bit of money especially once you take into account you need 2 sets for rotation. A proper quality set will run you $1000-2500 and there's luxury brands which will cost much more.
      • eesmith3 hours ago
        From the 1960 children's novel 'Mike's Mystery' from the Boxcar Children series by Gertrude Chandler Warner, at https://archive.org/details/mikesmystery00warn/page/28/mode/...

        > "Nothing was saved except clothing and bedding. When Mrs. Wood saw that the house could not be saved, she put some sheets on the floor, threw all the clothes from bureau drawers and closets on the sheets, tied them up, and threw the out the window."

        > "Well, wasn't that smart?" said Jessie. "That costs the most of anything, doesn't it, Aunt Jane? The family clothes and bedding?"

      • rsynnott3 hours ago
        … Wait, what? In what sense are my ikea sheets improper?
        • boelboel2 hours ago
          The cheaper sheets in Ikea don't use linen or will use a blend. The ones which do tend to use flax do so with worse characteristics (shorter or uneven fibers). I'm not sure about Ikea in particular but cheaper sheets are more often thinner to save on material costs, same thing happens with T-Shirts where a significant part of the price is just fabric cost.

          They use worse weaving machines which go quicker causing a worse texture, fibers also really limit the weaving. You'd genuinely have to feel to understand the difference. The edges/'insert part' will also be more refined.

          Your linen sheets will be washed more thoroughly before using when you buy luxury linen. Luxury brands will be more strict quality control.

          This doesn't mean the Ikea ones are improper but there's a reason people pay more for quality products, these products tend to be made in countries with higher labour costs as well (Belgium, Ireland, Italy, Baltic countries ...). All my bedding comes from Libeco in Flanders and most of my linen clothing comes from "Not Perfect Linen" in Lithuania which is affordable considering it's custom made.

    • futune3 hours ago
      This is a fascinating topic which was covered in-depth here: https://acoup.blog/2021/03/05/collections-clothing-how-did-t...

      If I remember correctly, it claim is that about 50% of all labour over the course of history has gone into making textiles. More than food!

    • steannean hour ago
      also consider the labor involved in upkeep. this is one of the rationales for nightwear: it's much easier to wash a change of nightclothes every so often than large sheets and blankets.
  • empee5 hours ago
    Clearly for better protection against monsters
    • anonzzzies5 hours ago
      It is the only reason. I asked my wife one time why she sleeps under blankets when it's boiling hot (I do not); she said because there might be 'things in the night' so I asked if she thought these sheets will protect her; nope, but otherwise she doesn't sleep.
    • tristramb4 hours ago
      Its so the monsters can't see you.