[HN Gopher] Using Euro coins as weights (2004)
       ___________________________________________________________________
        
       Using Euro coins as weights (2004)
        
       Author : Tomte
       Score  : 130 points
       Date   : 2024-10-20 10:18 UTC (12 hours ago)
        
 (HTM) web link (www.rubinghscience.org)
 (TXT) w3m dump (www.rubinghscience.org)
        
       | RadiozRadioz wrote:
       | Water is also a convenient and accurate measure of weight if you
       | know its volume.
        
         | diggan wrote:
         | I guess it depends on what kind of accuracy you're aiming for.
         | The density/weight of water changes depending on temperature,
         | salinity, pressure, impurities and probably other factors.
         | 
         | So if you're either deep into a volcano or on the top of a cold
         | mountain and need 0.001g precision, you might want to find an
         | alternative way :)
        
           | RadiozRadioz wrote:
           | I think the volcano might be useful - we could use the heat
           | to steam distill the water, then on our trip up the mountain
           | we could take a quick stop at sea level to conduct our
           | measurements.
        
       | Luc wrote:
       | Neat. Also, all the copper coins (1, 2, and 5 cent) are 1.67 mm
       | thick, so three stacked is half a centimeter to good accuracy.
        
       | drug_trw wrote:
       | Very useful information, I used it around that time period with a
       | lego balance scale to measure weights of various drugs in high
       | school.
        
       | rchowe wrote:
       | I built a computer vision device that used the top-down area of a
       | penny as a calibration standard. Coins are useful, easy-to-get
       | items that have relatively tight manufacturing tolerances.
        
         | cassepipe wrote:
         | What about wear ? Were they only new coins ?
        
           | Retric wrote:
           | I've never seen significant ware on a coin in circulation.
           | 
           | Have you?
        
             | seqizz wrote:
             | I've seen enough wear to prevent them to be calibration
             | material at least.
        
               | MadnessASAP wrote:
               | Depends on what your tolerances are. If you only need to
               | be within a mm a coin is going to beat that by an order
               | of magnitude.
               | 
               | We use a pack of cigarettes as a gauge for one of the
               | jobs we do. Quick, (not so) cheap, and readily available.
               | May have to standardize on a vape though in the near
               | future.
        
             | swores wrote:
             | I have often, though I suspect not enough to make a
             | significant difference to someone who is already OK with
             | the slight variance between un-worn coins.
        
             | xboxnolifes wrote:
             | I have coins that originally had milled edges that are now
             | completely smooth.
        
             | fanf2 wrote:
             | Only on counterfeit PS1 coins, before the coins were
             | redesigned to make them harder to fake
        
           | wongarsu wrote:
           | Ever since coin clipping got out of hand in the 1700s most
           | coins feature milled edges or edge inscriptions. They make
           | the edges more resistant to wear and make any wear easy to
           | spot.
           | 
           | Of course there's a limit to the precision you can get from
           | coins, but considering the scale of their production and the
           | account of handling they see they are surprisingly good
        
             | rrr_oh_man wrote:
             | _> in the 1700s_
             | 
             | It's been happening since ever.
        
           | rchowe wrote:
           | Our area measurement application did not require that tight a
           | tolerance (we were estimating yield on broken material). If I
           | needed that tight a tolerance, I could have gotten proof
           | coins from the mint, or potentially switched to using a real
           | calibration standard like a gauge block.
        
         | qup wrote:
         | Also a penny is .750 exactly. None of the other US coins have a
         | "useful" diameter.
        
           | dotancohen wrote:
           | The US nickel is so close to 5 grams that I've seen them used
           | as weights in a laboratory.
        
       | nathell wrote:
       | Euro coins circulating in various countries of the Eurozone have
       | different obverses - I wonder whether that affects weight?
        
         | simonjgreen wrote:
         | I was thinking similar, but then it occurred to me that they
         | may be debossed, rather than engraved, so no change to
         | material? Not a coin expert :D
        
           | HighGoldstein wrote:
           | Any additive/subtractive method at that scale for coin faces
           | sounds like a huge waste of time and effort compared to just
           | pressing the design, but also not a coin expert.
        
             | kd5bjo wrote:
             | Striking/pressing with a shaped die is the traditional
             | process, not least because the material itself used to be
             | the store of value rather than the provenance of the mint--
             | The coin shape was really there to certify how much
             | gold/silver it contained and that the government had been
             | paid whatever tax (seignorage) was owed on the ore.
             | 
             | Now that we've lived in a fiat-currency world for decades,
             | it's possible that new processes are being used as the
             | concerns are different-- anti-counterfeiting measures are
             | more important than anti-shaving ones now, for instance.
        
           | johannes1234321 wrote:
           | Yes, they stamp/press it and the deformation of that process
           | is also used to fit the inner to the outer part on the 1 and
           | 2 Euro coins.
           | 
           | See this German children's program:
           | https://youtu.be/nBuSmbcp1AE (seems to only have German
           | subtitles, but they are quite visual)
        
         | Someone wrote:
         | Probably not significantly. It would make it too hard to build
         | machines that accept all euro coin variants, yet reject cheaper
         | non-euro coins of similar proportions.
        
         | arlort wrote:
         | The weight is set by law at least to the 10th of a gram.
         | Couldn't find an explicitly set margin of error though
        
       | kd5bjo wrote:
       | At one point, I worked out that US dimes, quarters, and half
       | dollars all weigh $20/lb (iirc), which made the task of counting
       | my accumulated change a lot easier.
        
         | Someone wrote:
         | https://en.wikipedia.org/wiki/Coins_of_the_United_States_dol...
         | confirms that, and shows it works for dollar coins, too (I'm
         | using the weights in grains because that makes the comparison
         | easier; a pound is exactly 7,000 grains)
         | 
         | Dime: 35 gr
         | 
         | Quarter: 87.5 gr
         | 
         | Half-dollar: 175 gr
         | 
         | Dollar: 350 gr
        
           | t-3 wrote:
           | Nickel is ~5 grams. Dollar bill is ~1 gram.
        
             | JKCalhoun wrote:
             | I like how easy it is to remember nickel == 5 g.
        
               | ProllyInfamous wrote:
               | The "ten US nickles is always 50g" mantra has helped me
               | detect several defective scales (whether intentional or
               | not, I want accuracy).
        
           | dredmorbius wrote:
           | Note that the names for the first three coins are all _units
           | of subdivision_.  "Quarter" and "half" most obviously, _dime_
           | comes from the Latin _decima_ , meaning "one tenth". The
           | equivalent Roman coin was the _denarius_.
           | 
           | "Nickel" and "penny" break that pattern, with the first
           | referencing the composition of the coin (originally called a
           | "half-dime"), and _penny_ is a measure of weight, varying by
           | locale. The British penny is 1 /240 of a Tower pound (later
           | decimalised to 1/100 in the 1960s), whilst an American
           | pennyweight (used for example in reference to nails) is
           | 1/1000th of a pound.
           | 
           | <https://www.etymonline.com/word/nickel>
           | 
           | <https://www.etymonline.com/word/penny>
        
         | kragen wrote:
         | That's because that was the price of silver. The mint was for
         | many centuries a way to get your precious metals divided into
         | units of standardized weights that were stamped to certify
         | their authenticity, thus facilitating commerce, though
         | frequently rulers succumbed to the temptation of "debasing"
         | them by diluting the precious metals with so-called "base" (in
         | the sense of "low", "contemptible") metals such as tin, lead,
         | and zinc.
         | 
         | So quarters weren't worth 25C/ because the government said so;
         | they were worth 25C/ because they were made out of 25C/ worth
         | of silver.
         | 
         | That's the same reason "peso" means "weight" and the "shekel"
         | and "pound" take their name from units of weight.
         | 
         | This ended in 01965 in the USA, followed by the end of the gold
         | standard, since which the dollar has lost 96% of its value
         | relative to the precious metals that used to define it. The
         | consensus among economists is that this is a good thing because
         | it prevents deflation. I'm not sure.
        
           | swores wrote:
           | Off topic, but may I ask why you use a leading zero when
           | writing the year? (01965 rather than 1965)
           | 
           | You're not the only person I've seen do it on this site, and
           | I can't recall ever seeing it not on this site, so I'm
           | wondering if its because you're in the habit (or wanting to
           | be in the habit) for some technical thing you do like working
           | on a database that needs years in that format, or if there's
           | some reason you feel that its better to write them that way
           | in prose?
        
             | mandmandam wrote:
             | It's a Long Now Foundation concept [0]. The idea is to
             | encourage people to think on a more civilizational time
             | scale, and avoid another 'millenium bug' problem in ~7095
             | years.
             | 
             | 0 - https://longnow.org/about/
        
               | swores wrote:
               | Ah, thanks for the explanation.
        
               | AStonesThrow wrote:
               | I am relieved that when archaeologists download HN
               | archives 7095 years from now, they won't be confused
               | about which "1965" we were discussing!
               | 
               | https://xkcd.com/1683/
        
               | dredmorbius wrote:
               | A somewhat frequently raised question:
               | 
               | <https://hn.algolia.com/?dateRange=all&page=0&prefix=true
               | &que...>
               | 
               | <https://hn.algolia.com/?dateRange=all&page=0&prefix=true
               | &que...>
        
             | lynguist wrote:
             | If you dig into this person's posting history and also if
             | you read regularly on HN for a couple years you will notice
             | that it is actually this very user that deliberately uses
             | the 0 prefixed 5 digit year numbers, and also goes out of
             | their way to include year numbers into their posts to make
             | people ask this question.
        
       | valianteffort wrote:
       | The 1 JPY coin and (all?) USD bills are 1 gram exactly
        
         | pavlov wrote:
         | Dollar bills are secretly weighted in metric units? Evidence of
         | the Illuminati world government, surely.
        
           | Kon-Peki wrote:
           | The conspiracy is far more vast than you imagine!
           | 
           | Every single customary unit is secretly defined according to
           | the metric system!
        
         | int_19h wrote:
         | Soviet coins were specifically designed with this in mind:
         | 
         | 1 kopeck - 1g
         | 
         | 2 kopecks - 2g
         | 
         | 3 kopecks - 3g
         | 
         | 5 kopecks - 5g
         | 
         | (They didn't keep it proportional for 10+ probably because 5g
         | is already a fairly hefty coin.)
        
       | HPsquared wrote:
       | British coin values are also proportional to weight, within the
       | groupings that can be put together in the little coin bags.
       | 
       | 2p weighs twice as much as 1p.
       | 
       | 10p weighs twice as much as 5p.
       | 
       | 50p weighs 2.5x as much as 20p.
       | 
       | PS2 weighs twice as much as PS1.
        
         | Symbiote wrote:
         | 20p is particularly convenient, at exactly 5g.
        
         | swores wrote:
         | I think you've misremembered a couple of them (or coins have
         | changed since you learned those facts).
         | 
         | In this link is a table of the current weight of UK coins,
         | including the ratio between each coin and the coin below it:
         | https://chatgpt.com/share/67151004-3fd0-800c-b534-b5933a7305...
         | 
         | Confirmed with sources like
         | https://thecoinexpert.co.uk/blog/what-do-uk-coins-weigh/ and
         | https://www.royalmint.com/discover/uk-coins/coin-design-and-...
         | 
         | 2p does weigh double 1p
         | 
         | 10p does weigh double 5p
         | 
         | But 50p weighs 1.6x 20p
         | 
         | and PS2 weighs 1.37x PS1
        
           | HPsquared wrote:
           | Huh, you are right. I must have seen the first two pairings
           | (1p/2p and 5p/10p) and extrapolated.
        
       | 0points wrote:
       | Yep. 1 SEK coin is 7 grams to the dot ;-)
        
       | ojhughes wrote:
       | Weed dealers would commonly use a 1p coin to weigh an 1/8 oz of
       | hash
        
         | rwmj wrote:
         | Google tells me a 1p coin weighs 0.1257 oz, so nearly exactly
         | 1/8 oz.
         | 
         | I knew someone who got caught by the metropolitan police with a
         | fairly ordinary amount of weed (which probably wouldn't have
         | attracted anything more than a warning), but also with a set of
         | weights. I think he got a suspended sentence in the end. Using
         | coins and something innocuous which could be used as a balance
         | would seem to make sense.
        
           | masfuerte wrote:
           | This has always puzzled me. Why would you make a coin that is
           | very nearly, but not quite, 1/8 oz? It's not a nice round
           | metric weight either.
        
             | pessimizer wrote:
             | Metric only has an advantage for precision measurements
             | that have to be operated on arbitrarily, not for dividing
             | things. You're usually dividing things in halves, far less
             | often into thirds and even more rarely into fifths. 1/8 oz
             | is an ounce that has been divided in half three times. Or
             | you can think of it as a pound that has been divided in
             | half seven times.
        
               | masfuerte wrote:
               | I understand why they might have chosen 1/8 oz. I don't
               | understand why they chose not quite 1/8 oz. That's the
               | puzzle.
        
       | modulovalue wrote:
       | I'm using euro cents as weights in my weighted vest.
       | 
       | When I started doing this I didn't want to afford dedicated
       | weights as it seemed like a waste of money, but I had many cents
       | saved up from my childhood, which I started to use instead.
       | 
       | I have roughly 15kg in euro cents in my vest and I'm regularly
       | talking walks with it.
       | 
       | To get one kilo you need 435 cents and it turns out that in
       | Germany you can also "buy" coins "for free" at the "Bundesbank",
       | that is, you can exchange actual money for weights without any
       | fees. You give 4 euros and 35 cents and you get a kilo. Once you
       | need the money back, you can also sell those coins back to them
       | for free.
        
         | rwmj wrote:
         | What's a weighted vest? Something for diving?
        
           | dmd wrote:
           | It's a way to increase the risk of injury to your knees and
           | ankles and strain your back and shoulders while taking walks,
           | and in general make walking more unpleasant.
           | 
           | Some people think it's an exercise 'life hack'.
        
             | normie3000 wrote:
             | Is it worse than carrying a backpack?
        
             | Ylpertnodi wrote:
             | I went 0' 5' 10' 15, 20kg over 3 years after an embolism.
             | N=1 (rather like yourself: or you spoke to/ read about
             | people that don't quite understand 'pacing'. Do you/ them
             | struggle with 1 bag of shopping? I make three or more
             | light(er)trips.
        
             | t-3 wrote:
             | The risk of injury while walking in a weighted vest is not
             | much higher than walking normally. A very high weight of
             | vest is probably ill advised, but walking on a very
             | flat/regular surface for long periods is far more damaging
             | than walking with a little extra weight. Weighted
             | bracelets/limb weights _are_ dangerous though, and shouldn
             | 't be used unless you know what you're doing and take care
             | not to move too quickly and put excess strain on joints.
        
               | dotancohen wrote:
               | How much weight on a weighted arm band is considered
               | dangerous? I'm considering 500 gram bands for my arms,
               | that's just about twice the weight of a cellular phone
               | today.
        
               | ffsm8 wrote:
               | Ehh, I've been doing fitness boxing and knockout home
               | fitness (Nintendo switch) with 1.5 kg wrist/hand weights
               | for ages now, no issues to speak off. I think he's taking
               | about the 2-5kg weights, these are _way_ more dangerous
               | then you 'd expect from wearing them. (I did that for a
               | while, after getting slightly In shape - at least until I
               | read up on it)
               | 
               | Strong recommendation for Nintendo switch for baseline
               | fitness btw, these games are great for a 1-2 day 20
               | minutes workout/week for unfit office workers. Way better
               | experience then the equivalent VR games.
        
               | archi42 wrote:
               | What are the equivalent VR games? Just curious.
               | 
               | I don't play too much VR these days, but enjoyed Beat
               | Saber for "stationary movement", Gorn for beating up
               | stuff and the VR ports of the original Serious Sam games
               | for "run and shoot like a maniac".
        
               | t-3 wrote:
               | It depends on what you're doing, but 500g shouldn't be
               | dangerous as long as you wear the weights tightly bound
               | so they don't bounce or slide. What you want to watch out
               | for are anything that overextends or puts pressure on the
               | joints - those movements can cause damage even unweighted
               | and having weights just makes the danger worse.
        
               | hakfoo wrote:
               | I'd be worried about blisters/rashes/rubbing if the
               | weights slide around. I use an exercise-bike like device
               | and realised I was getting a blister on my hands from the
               | constant motion of the grip.
        
               | dotancohen wrote:
               | Thank you.
        
             | naming_the_user wrote:
             | If you're injuring yourself by walking around with a few
             | extra kilos then you are so, so hilariously out of shape
             | that any advice you can give is competely disregardable.
        
             | kjellsbells wrote:
             | Some people have no, zero, none understanding of sensible
             | limits. "If X is good then more X must be better" applied
             | to one or more aspects of their life. Hence protein in
             | their diet, vitamin supplements, weight in a vest, and of
             | course, infamously, having a presence on social media.
        
           | swarnie wrote:
           | Used in running to add extra resistance.
           | 
           | I've used them on and off in the past; useful in limited
           | circumstances.
        
           | modulovalue wrote:
           | It's a vest that you can fill with stuff to increase the
           | intensity of a workout.
           | 
           | There was a time in my life when my legs started hurting and
           | shaking from muscle atrophy because I was programming too
           | much and moving too little.
           | 
           | I was looking for a way to fix that issue and I didn't want
           | to waste time going to a gym, so I started talking walks with
           | a weighted vest. Walking is nice because you can think while
           | walking and with a weighted vest you don't have to walk for
           | hours for it to have a useful effect on your body.
        
             | xandrius wrote:
             | For information, the current research shows that the
             | intensity of the exercise is much less important than the
             | duration. So if you did so little exercise that you get
             | muscle atrophy, a weighted vest isn't going to do much for
             | you.
        
               | mr_mitm wrote:
               | > For information, the current research shows that the
               | intensity of the exercise is much less important than the
               | duration
               | 
               | For what goal? Increasing strength? I have my doubts.
        
               | uoaei wrote:
               | They're probably referring to some contrived fitness
               | study on hypertrophy.
        
               | vidarh wrote:
               | Anyone who has actually done both low-intensity exercise,
               | e.g. walking, and high-intensity, e.g. heavy compound
               | lifts, will tell you that statement needs a lot of
               | additional caveats.
        
               | Kirby64 wrote:
               | You're gonna need to provide a source to that. For
               | caloric burning? Sure, I'd agree. For cardiovascular
               | health? Eh, the answer lies in the middle. For strength
               | and muscle building? No, quite the opposite really. At
               | some point the intensity of an exercise is so low it
               | provides no meaningful muscle stimulus.
        
             | karmakurtisaani wrote:
             | FYI going to the gym is hardly a waste of time. You feel
             | refreshed and your body will thank you after a while.
        
               | lupire wrote:
               | Working out without the commute saves time.
        
         | Ylpertnodi wrote:
         | The decathlon weight 500g pakets of sand)jacket is about EUR20.
         | How easy is it to make your jacket 10kg? Are the coins easily
         | removable? Do you have straps to keep the weight 'tight'?
        
           | modulovalue wrote:
           | It's very easy. I'm using the cheapest weighted vest that I
           | could find and it came with blue bags that I've just filled
           | with coins. You don't really need straps to make the weights
           | tight because the money just kind of spreads inside of the
           | bag and doesn't move at all once it's there.
           | 
           | It's on my todo list to 3d print some containers to replace
           | the bags with actual "money rolls" so that I can remove them
           | more easily.
        
             | swores wrote:
             | Maybe you've already considered and decided paper wouldn't
             | work, or maybe you want the fun of working with a 3D
             | printer, but my initial thought:
             | 
             | Would it not be simple to create rolls of coins by simply
             | wrapping a sheet of paper round a stack of them, once or
             | twice around, a little bit of sellotape to hold the paper
             | in place, including folding it over at both ends and taping
             | there too? I'd imagine an A4 sheet would be more than
             | enough for each stack of coins, cutting off what isn't
             | needed, and since you wouldn't care about them being
             | beautiful you wouldn't even need fresh paper and could just
             | use paper that would otherwise go into recycling/trash
             | (letters received, junk mail, etc.)
             | 
             | edit: I did a quick search which both confirmed people have
             | made coin rolls using simple paper, and also that it's
             | highly likely banks will offer pre-made paper holders for
             | the various coin sizes that you can just ask for and get
             | for free (with the bank assuming you'll be bringing them
             | back full of coins - you could either ask for as many as
             | you need, or just one per size and use it as a template for
             | making more from plain paper like this guy does:
             | https://m.youtube.com/watch?v=AvsOkp_WPxY )
        
               | modulovalue wrote:
               | That's a very good point. I wonder about the durability
               | of a paper based solution, but 3d printed rolls might
               | also be suboptimal in that regard. This needs some
               | experimentation.
        
               | swores wrote:
               | I'd imagine that if paper alone wasn't strong enough for
               | long term use, using sellotape to cover the entire roll
               | such that the whole thing has a layer of tape on top of
               | the layer of paper would make them pretty durable and add
               | very little time and cost to it. (But I've not done
               | anything like this, so my guessing could be bullshit -
               | happy experimenting!)
        
               | xandrius wrote:
               | I'd honestly just use some ziplock bags and call it a
               | day.
        
         | thenthenthen wrote:
         | Could you explain more? I do not understand how you can buy
         | coins for free by paying coins for "weights" (what are these
         | weights? What are they made from?). Also, what is the use for
         | this? To check of your coins are real? Calibrate your coin
         | scale?
        
           | thfuran wrote:
           | You give bills and get pennies.
        
           | MadnessASAP wrote:
           | The coins are weights, the actual money is paper or
           | electronic money.
        
             | thenthenthen wrote:
             | How do you pay 35 cent in paper is still a mystery. But OP
             | just means you can exchange/buy coins (and use them as
             | weights)?
        
               | brianshaler wrote:
               | You should be just as mystified about the 4EUR component.
        
             | trompetenaccoun wrote:
             | Excuse the nerdy nitpick, I get the point but technically
             | as far as "actual" money goes that's the coins. Electronic
             | entries in bank ledgers are not legal tender.
             | 
             | One can of course go further and question if banknotes and
             | coins should be called actually money. Today the nominal
             | value is completely disconnected from what the metal is
             | really worth, it's not like with gold coins back in the
             | day. And once collective belief in the value is lost fiat
             | money quickly becomes worthless. Zimbabwe and Venezuela are
             | recent examples.
        
               | killingtime74 wrote:
               | Have to correct your nitpick. What you're talking about
               | is currency not money. Not being legal tender doesn't
               | mean it's not money. The majority of money sits as
               | electronic entries in each country's central bank. https:
               | //www.investopedia.com/terms/c/currency.asp#:~:text=Th...
               | .
        
           | flohofwoe wrote:
           | I guess OP means you don't need to buy above or sell below
           | its value when "buying" or "selling" a metric shitton of
           | small coins (like you would for gold for instance).
           | 
           | 15 kilograms sounds excessive though, I bet the bank clerks
           | hate that trick ;)
        
             | thfuran wrote:
             | Banks usually stock pre-counted rolls of coins, and it's
             | not much hassle to count out several of those. Though I
             | guess 15 kg is probably going to be several dozen.
        
         | dangerwill wrote:
         | I have to ask, how do you not sound like ~6500 coins jingling
         | together as you walk? I notice when I have like 10 coins in a
         | backpack. Do you wrap bundles of coins in cellophane or
         | something?
        
           | kqr wrote:
           | I remember back when I used physical coins, banks used to
           | wrap them in paper rolls with known quantities in them. So
           | you could get a $10 roll of ten $1 coins or whatever.
        
         | ffsm8 wrote:
         | You can also go to the beach and get unlimited amounts of
         | weight for free too. That's what's most budget weights are made
         | of
        
           | krick wrote:
           | I don't mean to argue that it's just gimmick and any sane
           | person would just use sand, but to be completely fair, sand
           | is much less dense than steel, so if the coins pack well it
           | does make a better weight.
           | 
           | I do also suspect that there must be some product that must
           | be more cost effective than coins but denser than sand, but
           | cannot think of it right away. I mean, scrap steel is a
           | couple of cents per kg.
        
             | Ao7bei3s wrote:
             | Olympic weight plates for barbells. They're widely used, so
             | competition has brought the cost down, and they're easily
             | available in useful increments. I currently see 4x 10lbs
             | for <$50 on Amazon. That works out to 2,53 Euro per kg. So
             | cheaper than euro cents. They may not have the exact shape
             | you need.
             | 
             | The scrap steel probably didn't cost cents per kg when it
             | was sold for its original purpose. You are paying for a
             | useful shape.
             | 
             | A professional equivalent of weighted vests are ballistic
             | plate carriers. Real ballistic plates can be fragile and
             | expensive, so options for exercising in (or milsim games in
             | airsoft etc.) include expired (and failed to re-certify)
             | real ballistic plates, made for purpose training plates...
             | or plate shaped sandbags!
        
               | another-dave wrote:
               | > That works out to 2,53 Euro per kg. So cheaper than
               | euro cents.
               | 
               | The cents are free though, cause they're legal tender --
               | just deposit them instead of having to sell 2nd hand
        
               | wging wrote:
               | The cheapest plates can be higher variance than you might
               | expect. I've seen reports of 45s that are 10% light.
        
           | toast0 wrote:
           | It's a lot easier to contain coins vs sand, though.
        
           | omio wrote:
           | Just FYI this is illegal in many areas.
        
         | timeon wrote:
         | > saved up from my childhood
         | 
         | Isn't Euro just from 2002? That surely is not _that_ long time
         | ago!
        
           | ttymck wrote:
           | It's 22 years ago, roughly
        
         | johannes1234321 wrote:
         | > you can also "buy" coins "for free"
         | 
         | Free till you count inflation and opportunity cost. (What you
         | could gian as interest with some other investment)
         | 
         | But yeah, probably still cheaper than some product from a
         | store.
        
       | shrubble wrote:
       | For the USA, an unworn 5 cent nickel weighs 5 grams. When I was
       | testing one of those tiny portable scales that are battery
       | operated, I would use 1, 2, and 3 nickels to determine if it was
       | close to being accurate.
        
         | samatman wrote:
         | Indeed. Calibrating scales with nickels is a well-known trick
         | in certain circles, including, but not limited to, organic
         | chemistry labs. It won't do for analytic weighing, but for
         | sanity-checking a scale before weighing out reagents, it does
         | the trick.
        
         | AStonesThrow wrote:
         | Ah, good! A few years ago, I picked up a "pocket scale" in a
         | legit head shop. I had intended to weigh out doses of Kratom
         | powder I'd picked up there, too. (The Kratom turned out to be
         | nasty stuff, but the scale works fine, even for weighing postal
         | mail.)
         | 
         | I was considering picking up some accurate weights for
         | calibrating the scale properly, but if nickels will work, I
         | could probably figure out how to procure some nickels instead.
         | Right now, I have a roll of quarters and zero nickels in the
         | house. I was using one to open up my electric candles, but it
         | went missing, so I'm using a dime instead.
        
       | Thorrez wrote:
       | >The smallest possible combinations summing to n * 0.5 g are:
       | 
       | It left out 7.5g (it mentioned it above though). I guess if the
       | definition of "combination" requires at least 2 coins then 7.5g
       | doesn't count.
        
       | jamal-kumar wrote:
       | I think it's worth noting the currency term 'peso' for the money
       | used in a lot of former spanish colonies, directly translated,
       | means 'weight'. For example there's a famous mexican singer of
       | recent who goes by 'peso pluma' and it means featherweight, like
       | the boxing classification, not as much to do with money
        
       | georgecmu wrote:
       | Soviet coins (at least post 1961) were designed explicitly with
       | this application in mind.
       | 
       | 1, 2, 3, and 5 kopeck coins weighed their value in grams. They
       | could also be used to estimate lengths; 1 kopeck was 15 mm in
       | diameter and 5 kopeck was 25 mm.
        
       | jmclnx wrote:
       | The US Nickle (5 Cents) ways 5 grams. I personally think that wad
       | done on purpose as a tentative step to move to the metric system.
        
         | samatman wrote:
         | The US uses the metric system, just with very non-standard
         | units. All of the fundamental customary units are defined
         | precisely in SI terms.
         | 
         | The precise five gram weight of the nickel was deliberate, but
         | dates to the Civil War, a time when the US had no intention at
         | all of moving to the metric system. It's rumored that a gram or
         | two of weight was added to the coin on the premise that "five
         | cents five grams" was a nice round number, but actually due to
         | lobbying by moneyed interests who owned a nickel mine, so they
         | could sell more nickel to the government.
        
       | garikz wrote:
       | Would be great to see this table extended also for the case when
       | you put coins on the other side of the balance, i.e. subtracting
       | the coins' weights
        
         | extraduder_ire wrote:
         | I was thinking, since the post mentions not being able to get
         | exactly 10g. But you can get 15g/25g exactly, so you're at 10g
         | net by putting them on either side of the scale.
        
       | consp wrote:
       | Anecdote from the days switching to the Euro with respect to
       | weights: When I was working at a restaurant with high thoughput
       | at the end of the '90s and early '00 we first had a giant coin
       | sorting machine. That thing was innacurate (hello Egyptian coins
       | of same sizes as ours) due to only measuring size and being not
       | that accurate. Bank notes were counted by hand.
       | 
       | After the introduction of the Euro, all coins were counted in
       | standard sized cups which also fit in the cashiers trays so no
       | swapping needed, the error rate reduced to near zero (at
       | counting, difference between amount on bag and what the bank told
       | us was in it). Also, the machine was 500 grams instead of half a
       | small room.
       | 
       | The same was applied to bank notes, as they also have a standard
       | weight due to standerdized size and production method. This
       | reduced the error rate even further as counting is difficult as
       | it turns out if you want to do it at scale. It also made the task
       | way faster. Theoretically the machine could count the notes in
       | one go, but it mostly reported "error check notes" messages if
       | you did that. Things like thick tape (for repair when the bank
       | note was damaged) was enough to throw it off in some cases.
       | 
       | Those were interesting times, with people buying a 25ct item with
       | a 250 note to not go to the bank to exchange old for new
       | currency. (Fyi, you do not have to legally accept that as the due
       | dilligence needed with high notes would outweigh the cost of the
       | item).
       | 
       | Other anecdote: Also a lot of 50 euro fake notes showed up within
       | months after introduction, easilly cought as they lit up like a
       | freshly washed white shirt under UV light.
        
       | zczc wrote:
       | Soviet copper kopecks coins (1, 2, 3, 5) weighed their exact
       | nominal value in grams
        
       | sksxihve wrote:
       | Big Ben uses a stack of pennies to keep it accurate
        
       | nikanj wrote:
       | Using coins as precision weights was used in Jules Verne's Off on
       | a Comet, published in 1877
        
       | dredmorbius wrote:
       | Whilst exploring what _money_ is, I had the realisation that
       | almost all units of currency are either measures of _weight_
       | (pound, livre, peso, shekel, penny), divisions of same (denarius,
       | quarter), of _quality_ or its representation (real, crown,
       | dollar, florin. zloty, yen, yuan), or are _descriptive of the
       | state_ in which they 're used (bolivar, afgani, euro), though
       | that last is arguably a form of the second.
       | 
       | That is, traditional specie coin currency is standardised for
       | _quantity_ and _quality_ , or at least is initially. Most states
       | have found a need to devalue specie coin, and virtually any state
       | with a sufficiently advanced financial system and institutional
       | trust either settles on a fiat currency or adopts another
       | country's fiat currency as its own standard. kragen is making a
       | similar point here:
       | <https://news.ycombinator.com/item?id=41895405>.
       | 
       | For the latter, see the U.S. dollar which is either _the_ or _an_
       | officially accepted currency: Turks and Caicos and British Virgin
       | Islands (both British overseas territories); Bonaire, Sint
       | Eustatius, and Saba (all Dutch municipalities); the independent
       | states of Ecuador, El Salvador, Timor-Leste, Federated States of
       | Micronesia, Republic of Palau, and the Marshall Islands; and
       | quasi-official or widespread use in the Bahamas, Barbados,
       | Belize, Costa Rica, Panama, Bermuda, Myanmar, Cambodia, Cayman
       | Islands, Honduras, Nicaragua, Somalia, and Zimbabwe.
       | 
       | I've developed the view that _seignorage_ , that is, the exchange
       | value in excess of specie value of coinage, is effectively a
       | _measure of trust_ in a currency system, and that fiat currency
       | in paper or even more so as ledger entries (written or
       | electronic) express an _extraordinary_ level of trust in a
       | currency, the more so if that currency is widely accepted
       | internationally.
       | 
       | Another interpretation is that _money in a given economic region
       | is the most widely accepted commodity_ , that is to say, the
       | exchange medium which is accepted preferentially to any other.
       | This need not be a conventional currency (e.g., commodity or
       | symbolic exchange of shells, hides, cattle, cigarettes, alcohol,
       | laundry detergent, etc.), or the _official_ currency of a region
       | (though legal sanction and sanction of discharge of debt go a
       | long way to establishing a currency within a given region).
       | Multiple currencies may trade simultaneously, possibly in
       | slightly differing contexts, and through much of history there
       | has been at least some distinction between retail trade (often
       | copper), wholesale (silver), and capital  / government financing
       | (gold). Adam Smith discusses this at great length in _Wealth of
       | Nations_. Multi-metallic systems often involve variable exchange
       | rates between different classes of money, and I 've mused that
       | this might be something worth reintroducing to modern financial
       | systems.
        
       | semi-extrinsic wrote:
       | Maybe this was so obvious the author did not write it down, but
       | you can also use this to measure accurately weight of objects
       | below 10 g.
       | 
       | First you make the stacks for 15.0, 15.5, .. 17.5, 18.0.
       | Preferrably using tiny amounts of superglue.
       | 
       | Then you put one stack on one side of the scales, and the other
       | stack on the other side, and you have accurate weights for 0.5,
       | 1.0, 1.5, 2.0, 2.5, 3.0.
       | 
       | You can make some of these combinations more efficiently, but the
       | more coins you use in total, the better accuracy you get as
       | manufacturing variations average out (up to a certain point of
       | course).
       | 
       | It is a bit more cumbersome to make a quarter gram, but you can
       | make one stack of {5x 0.01, 2x 0.02, 1x 0.1, 1x 0.2} for a weight
       | of 27.46 g, and one stack of {2x 0.02, 3x 0.05, 1x 0.01, 1x 0.2,}
       | giving 27.72 g, for a difference of 0.26 g.
       | 
       | As others have mentioned, using Lego is a nice way to make high
       | precision scales. Take a 1x16 Lego Technic brick with holes and
       | balance it on a thick needle through the middle hole. Needle
       | support can be built from other bricks. Use thin sewing thread
       | and some bricks to hang some 6x8 plates from each end.
        
       | mgaunard wrote:
       | Or you can buy from China a scale with 0.01g precision for next
       | to nothing.
        
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       (page generated 2024-10-20 23:00 UTC)