• wuphysics87
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    53 months ago

    Quick ‘proof’ the taller the can, the more material used:

    Consider two cases ignoring the top and bottom only focussing on the surface area. In the first case, you flatten so much the can has no height. This forms a ring that when unwrapped makes a length of 2 pi R.

    Now stretch the can to be ‘infinitely’ long. By construction, this is longer than 2 pi r. Given both are made of aluminum, and have the same density, the larger can has more mass requiring more material.

    The total mass must be a continuous function ranging from the linear mass density times the circumference of the circle to the same mass density time times the ‘length’ of the infinite line. This must remain true for any small increase in length between the two.

    I’ll leave this as an exercise to the reader. What if the circle has an infinite radius?

    • oni ᓚᘏᗢ
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      23 months ago

      Isn’t the larger the can proportional to how does both top and bottom shrink? like, being the same amount of material, but with a different distribution.

      • @[email protected]
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        43 months ago

        No he’s right. The solution for an optimal surface area to volume ratio is a sphere. The farther you deviate from a sphere the less optimal you become. The actual math for this is finding deltaSurfaceArea in respects to cylinder radius for a given volume and then finding the maxima, which is a Uni physics 1 problem I really don’t feel like doing. Long story short, optimal is when height = diameter, or as close to a sphere as a cylinder can be.

          • wuphysics87
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            23 months ago

            It’s not really ‘right’ or ‘wrong’ it’s under a fixed set of assumptions. You raise a valid point. What does happen to the top and the bottom? I was ignoring them considering only the sides in the two most extreme cases.

            If I understand your case when the can is flatted the area gets much larger and when it gets taller it shrinks to a pin point. An equally valid approach

            • oni ᓚᘏᗢ
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              13 months ago

              If I understand your case when the can is flatted the area gets much larger and when it gets taller it shrinks to a pin point.

              Yes, that was what I meaning.

    • JackbyDev
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      73 months ago

      Yes! I love this comic (well, I guess it wasn’t originally) and reference it all the time. I was randomly very curious which shot glasses we own are the biggest and was trying to use this as an example because we have some tall skinny ones and short fat ones. “You know! The thing where kids think the tall one is bigger??”

      • @[email protected]
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        53 months ago

        This is Piaget’s conservation of volume test. I did this experiment at school (we went to the elementary school next door and ran tests on the kids). Most of the kids said the higher one held more liquid because it was ‘taller’, though some said the short one had more because it was ‘fatter’.

    • @[email protected]
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      223 months ago

      The liberal media wants you to think that the two volumes of liquid are equal using their woke science, but if you use your common sense, you can clearly see that the narrow tube is filled higher and therefore contains more liquid. There is nothing wrong with the economy, real Americans just need to use narrower glasses. Checkmate, leftists. /s

  • @[email protected]
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    453 months ago

    Just straight up stop buying shit. Drink filtered tap, and live off only what you need and shrug off ppl that think buying expensive shit will make them cool.

      • @[email protected]
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        83 months ago

        Just a heads up Brita filters do basically nothing it’s mostly just a carbon block which will help remove chlorine flavor which makes it taste a little better but in terms of actually removing contaminants it does very little to almost nothing.

        Zero water is the closest thing in brita drip form that actually removes things but getting a counter top reverse osmosis is the way to go if not getting a dedicated under sink unit

        • @[email protected]
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          53 months ago

          Just remember! Reverse osmosis filters are NOT eco friendly, it cost 3 to 4 gallons of waste water discard to gain 1 gallon of drinking water.

          • @[email protected]
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            3 months ago

            Using modern filters, and using a pressure booster pump to ensure proper pressure level this is actually nowhere near as bad it’s now possible to achieve a one-to-one clean to waste ratio.

            If you don’t want any waste you can go to nanofiltration which is roughly as effective as Reverseosmosis and does not have the Wastewater issue but they are significantly more expensive.

            And it’s not as if that Wastewater is sewage it’s just the same water that came in with a higher concentration of the stuff that you didn’t want that was already present in the water so that Wastewater can be reused for gardening, or gray water such as showers and toilets

            I get that they aren’t perfect but everything has a trade off and reverse osmosis or nanofiltration is really the only way to get rid of many different sources of water contamination especially things like microplastics and pfas

    • Lovable Sidekick
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      3 months ago

      Also stop paying for filtered tap water when there’s nothing wrong with your specific tap water.

      • @[email protected]
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        83 months ago

        Sadly not everyone has great chlorine-free water. One of the most annoying experiences every time I go abroad (for example to Italy)

        • @[email protected]
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          53 months ago

          Chlorine is the least of my worries.

          After growing up near a superfund/dump site where benzene, toluene, phthalates, etc. were found in the water….I will take the chlorine.

        • Lovable Sidekick
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          113 months ago

          Quite true. Not everyone has lead-free water either. But people whose water is perfectly great do not need to pay for filtered water - especially not in single-use plastic bottles.

          • @[email protected]
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            43 months ago

            Absolutely. I’m always drinking tap water at home, we have perfectly clear, chlorine-free, mineral-rich water directly from the mountains. One of my favourite aspects of Austria.

        • @[email protected]
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          63 months ago

          I would have been more than happy to drink tap water and have my kids drink tap water.

          We’ve had a couple lead warnings though and I don’t want to fuck with it. They’re going to have a hard enough time with the misfortune of getting my genes. I don’t want to make it even harder for them.

      • @[email protected]
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        53 months ago

        Where I live has heavy agriculture and oil industry presence. People here are concerned over pesticides and random chemicals randomly seeping into the water system.

          • @[email protected]
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            43 months ago

            They’re shutting down federal testing requirements in the U.S. - a lot of people do need to start thinking about this.

          • @[email protected]
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            13 months ago

            The water is tested and 99% of the time it is probably safe to drink. But who knows how much of it you will drink before it is discovered (and then even longer to reveal) that there was an issue with the water.

  • @[email protected]
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    3 months ago

    yeah but also that’s too much coke. 355ml? jesus, are you eating lava wtf do you need that much sugar water for

  • @[email protected]
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    3 months ago

    Weird what happens when 40% of the currency was printed in the last few years.

    Are we blaming the government who control interest rates, gamify the CPI to depress inflation, and who control the corresponding new money supply that drives up the price of basic goods?

    If housing, gold, and crypto are any indication people have far too much money than they know what to do with. You’d have to be a fool to not accumulate some cantillon effect for yourself when you’re government is throwing money away.