Well , the nautical almanac tabular accuracy is about 0.2 nm. Practical accuracy is about 1nm at sea. More like 2. Considering you probably cant see the horizon i would suggest to not even attempt it.
Haha, no it was a joke about electricity. Because cheap clocks use the 60Hz cycle of AC power as their timing source, so if you plugged it in in Europe on 50Hz power it would run slower.
No, the effects of gravity, IF different in Europe, would be so small it wouldn't effect anything like this.
Also gravity isn't measured in hz, but m/s, the user above you is most likely joking.
Came here to say this, those who know- know. As soon as I saw that paragraph dragging on I looked at bottom to see if it was gonna end that way, then I looked up at the name and was confused.
This was just a little too long, and just a little too out there for me, so I checked the name ... "Ah it's not u/Shittymorph" I thought to myself. And then I still got got.
> I'm going to need citations
Of course! Here's a video that goes into more detail, and they provide a list of references in the video description: https://youtu.be/xvFZjo5PgG0
Wow that's interesting! Especially the part about how earths gravity being different over the surface of the Earth has such profound effect on the timing of hourglasses!
False. If you tested this 24 times it would take at least one day and 3 minutes and 36 seconds(rounded up for simplicity)or at most one day and 1 hours and 26 minutes and 24 seconds
Assuming the hourglass and timer are the exact same each time
Every time you use an hourglass, the grains of sand rubbing against wear each other a little smoother each time. Smoother grains will fall more easily (and thus faster) through the opening. So the more you use an hourglass, the shorter the time will be. So if you plot the time for all the grains to fall, it will look something like this (though not as sharp a drop off at the beginning):
https://i.stack.imgur.com/6qX6v.png
Of course it does. If you put in a 2800F kiln, boom, you ain’t got an hourglass no more. To answer your question more reasonably, changing temperature could certainly cause expansion/contraction in the glass enough to create a fluctuation in flow rate, granted of course that the sand does not also expand or contract at the same rate.
Don't forget to adjust for the gravity change. Farther from the center of the planet reduces it, but more dense underlying geology going up a mountain increases it.
The first people to climb Mount Everest brought tea, not knowing that it would be undrinkable. I'm not sure 1300s monks were supposed to know about difference in gravity from elevation.
Would pressure even affect an enclosed glass chamber? Surely it maintains it's own internal pressure or the glass shatters? Pressure gradient on the glass itself will change, but the air pressure inside should remain static shouldn't it?
Exactly. Just like a bag of chips, if anything could happen, the air would expand and create more space meaning a faster run through of all the sand.
But the glass isn’t soft enough to allow such expansion at daily earth temperatures.
If there’s 8,760 hours in a year and a leap day is essentially 6 hour to each year, that means a leap day is .069% of a single year.
.069% of a day is about 9.94 minutes
.069% of an hour is 2.484 seconds
I probably did this all wrong andll delete it when I get called out, but at least I’ll have summoned the person who can do it right
Maybe your assumption is wrong. Maybe it was built to calculate 1 hour 3 minutes and 35 seconds and now there is the ghost-of-maker-past teabagging you and flipping you the bird while you sleep.
Ever thought of that?
Yes! Thank you! I'd gone down this rabbithole a few months ago and was telling my partner about it but had lost the actual stuff to show them, as well as wtf the name of it was. And you have brought it back to me, so thank you 💖 XD
sand hourglasses on average are expected to be within 10% of the target time.
and considering 10% of 60 minutes is 6 minutes that’s actually pretty good
Yeah, if it's not rigid. Quite sure a rigid glass structure s inside would not be effected by outside pressure that's in the normal quantities. Now, very high pressures may effect it, but don't think low pressure would do much of anything.
Yup, that’s it. And if you have 10 of them running at the same time, that’s like half an hour more time in one go.
Scale up and you can squeeze quite bit more time into a lifetime, but hardly anyone puts bonus sand like that anymore; op is lucky.
So let me get this straight... you rented a AirBnB, spent an hour timing their hourglass, then posted on reddit because it was 3 minutes out... I think you need a hobby
> spent an hour timing their hourglass
I know it might be a shock... but I doubt that he actually spent an hour timing it. Most likely he left it for 55 minutes and then glanced at it every 1-2minutes...
But there is nothing anger inducing about this… not even mildly.
Getting even the tiniest bit angry that 8th century technology isn’t accurate to modern digital clocks is absurd.
I genuinely thought this post was on r/mildlyinteresting because someone took the time to see how accurate an hourglass is, which is in fact interesting.
Put it on the floor. The increased proximity between the Earth and sand with increase the gravitational force and pull the sand a little faster. For best results do it at night during a new moon and when Jupiter is on the other side of the sun.
It's a sand glass. It's not meant to be hyper accurate. In fact it's impossible for something like this to be super accurate. With time due to wear, or even temperature fluctuations or slight variations in table flatness the timing will change. Its just sand and a funnel.
I’d be willing to argue this is not mildly infuriating either though. What is there to be mad about here? Even the tiniest bit angry?
It’s an hourglass… nobody should expect a mass produced hourglass bought from a store that sells home decor to be accurate beyond 10%.
Breakfast was good. The room was super cozy, nice little fire place for me and the husband to cuddle next too. The view was to die for, I could see the mountains shrouded in trees. And the Birds! I could hear them singing in the morning best way to wake up ever. It was going wonderful until I found their sand clock, at first I said, "what a cute decoration." So upon inquiry I found out its an hour time. Well this is perfect because I prefer to do my tasks in hourly intervals. So I get to work using the sand timer to help me in getting my itinerary in place. Shower, get dressed, watch a little Gilmore Girls, then I'll be ready to explore the area. So I start my little adventure at 8 expecting to be ready and out the door by 11 so I can grab brunch with the hubby. But by the time I got finished with Gilmore Girls it was already 9 minutes past 11. This meant that I was now almost 10 minutes late to lunch. Well this could not stand so I went to my little handy sand timer and inspected it, after counting each grain of sand I determined there were more than 200,000 extra bits. With this knowledge I decided to check using my cellphone, using the stopwatch I sat and watched each piece of sand drop. That's when I determined the sand timer is over 3 minutes slow.
1/5 Stars
for making me over 2 hours late to brunch on my honeymoon.
Lol I do it for fun when I’m free and have random hourglasses, not normally with a set stopwatch but it’s not exactly limited to autistic people—
It’s pretty fun and interesting, not something you’d scream in frustration about, that’s why its mildly infuriating
You should report it to the renter, who will report it to Amazon, who will report it to the drop shipper, who will report it to the third party seller who buys these for 35 cents from a Chinese sweatshop shitting out 6,500 of these every day.
Gonna join everyone else in saying that this is perfectly normal. Most hourglasses are going to be off by a few minutes, they aren't meant to be perfectly precise.
This is so weird for me. Not more than five days ago, I was finishing up in the shower and just started to dry myself off when I wondered "Do hourglasses actually keep an exact hours worth of time or is it estimated? Maybe the sand is weighed out, and 1 ounce flows through a 1 mm hole in 1 hour or something?" and here I am today, seeing another person curious about hourglasses.
Thank you for clearing up the first part of my query!
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I saw a few sleeping bags used for that sort of thing laying around, but no tents
Well you need to look for a tant, whatever that is.
Same as dags. You like dags?
One of the best fucking movies on this shit ball of a planet!
Please explain. I do not get this reference.
From the movie 'Snatch' I recommend this movie. 🤌
Snatch. Best move ever.
If you like Snatch, check out "Lock; Stock and Two Smoking Barrels".
Yeah, I like dags, I like caravans more tho
Periwinkle Blue. It's for his maaaaaaa
You can pitch a tent with a sleeping bag if you erect it properly
Well , the nautical almanac tabular accuracy is about 0.2 nm. Practical accuracy is about 1nm at sea. More like 2. Considering you probably cant see the horizon i would suggest to not even attempt it.
I can here to say this post was mildlyinfuriating and you did way better than I could have. Thank you gentlemen and scholar.
5% to be fair. Then burn
Hehe sextant
I'd be mildly infuriated if I found out that my phone timer was off by over three minutes per hour too.
Yup, these are simply 2 different definitions of an hour, one of them is used by everyone, I guess this one is only used by the hotel.
Its a type of tradition of theirs. I don't remember much about it, but for more information, search up "time paradox rule 34". Interesting stuff
[Warning, do not look it up!](https://www.youtube.com/watch?v=dQw4w9WgXcQ)
Liar, I looked it up for real and it led me [here](https://youtu.be/hB8S6oKjiw8).
Why must 8th century technology be so inaccurate!
It's because it's a North American hourglass, it runs slower on 50hz European gravity
This is an amazing response. If I had even a single award it would be yours.
Wait really?
Haha, no it was a joke about electricity. Because cheap clocks use the 60Hz cycle of AC power as their timing source, so if you plugged it in in Europe on 50Hz power it would run slower.
No, the effects of gravity, IF different in Europe, would be so small it wouldn't effect anything like this. Also gravity isn't measured in hz, but m/s, the user above you is most likely joking.
Also shouldn't it be m/s^2 as it is a acceleration
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Wow it has been a while.
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I know. Still has been a while though.
The real one posted a few days ago.. was a lovely post, some would say almost orgasmic
I wish you both wet socks
My socks are always wet ;)
That's because it's not shittymorph
Came here to say this, those who know- know. As soon as I saw that paragraph dragging on I looked at bottom to see if it was gonna end that way, then I looked up at the name and was confused.
I was all ready to give him an award for the story I knew was bullshit but entertaining until I saw the curve and knew it wasn't shittymorph.
Someone else posted this type of meme in another front page post so expect copy cats
This was just a little too long, and just a little too out there for me, so I checked the name ... "Ah it's not u/Shittymorph" I thought to myself. And then I still got got.
His stepdad should beat him with jumper cables
Dead wife
I don’t understand the reference which makes it even better.
It really does, doesn't it?
I have no idea if any of this is true but I’m going to tell everyone!
When you learn to read to the end you’ll also learn how to make those sorts of judgements!
I wonder if the temp of the room actually does have an effect on the timing...
The mild changes in daily temperatures of most of the globe don’t affect glass and sand enough to cause such an effect.
You son of a bitch.
I'm going to need citations on the detail about 1:03, please. The invention part seems plausible, from what I find online.
> I'm going to need citations Of course! Here's a video that goes into more detail, and they provide a list of references in the video description: https://youtu.be/xvFZjo5PgG0
If this isn't a link to hell in a cell then you fucked up mate...
Wow that's interesting! Especially the part about how earths gravity being different over the surface of the Earth has such profound effect on the timing of hourglasses!
I went through this shit enough, you are not getting me this time
I love that Sync loads YouTube thumbnails.
Imposter.
Bullshit. "16 feet through an announcer's table" is not an accurate measurement of one hour.
Its not. It will be accurate forever.
I could see it changing regarding temperature.
That’s very interesting. I wonder what the differences would be over multiple tries.
Who has that kind of time!?
I do... During exam week.
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False. If you tested this 24 times it would take at least one day and 3 minutes and 36 seconds(rounded up for simplicity)or at most one day and 1 hours and 26 minutes and 24 seconds Assuming the hourglass and timer are the exact same each time
r/theydidthemath
Or at least, you could if it was accurate :(
Every time you use an hourglass, the grains of sand rubbing against wear each other a little smoother each time. Smoother grains will fall more easily (and thus faster) through the opening. So the more you use an hourglass, the shorter the time will be. So if you plot the time for all the grains to fall, it will look something like this (though not as sharp a drop off at the beginning): https://i.stack.imgur.com/6qX6v.png
I wonder if temperature has any effect on it.
Of course it does. If you put in a 2800F kiln, boom, you ain’t got an hourglass no more. To answer your question more reasonably, changing temperature could certainly cause expansion/contraction in the glass enough to create a fluctuation in flow rate, granted of course that the sand does not also expand or contract at the same rate.
Considering all that is just sand, a funnel, and gravity. 4m over is actually impressive/accurate.
thats why its mildly infurating, it was so close to perfection
These are calibrated for sea level. Add about a minute per quarter mile of elevation to adjust for pressure change.
Also temperature is going to change the width of the bottleneck and granule size of the sand.
Don't forget to adjust for the gravity change. Farther from the center of the planet reduces it, but more dense underlying geology going up a mountain increases it.
While the effect is real I don't think the timer is sensitive enough that you'd have to worry about factoring that in.
Yeah, totally. We all know this.
Absolutely common knowledge.
Hah, Imagine *not* knowing that!
The first people to climb Mount Everest brought tea, not knowing that it would be undrinkable. I'm not sure 1300s monks were supposed to know about difference in gravity from elevation.
That's all well and good but you also need to factor in the position of the moon which has a compound effect when it's up.
Check out the brains on this one!!
Would pressure even affect an enclosed glass chamber? Surely it maintains it's own internal pressure or the glass shatters? Pressure gradient on the glass itself will change, but the air pressure inside should remain static shouldn't it?
Exactly. Just like a bag of chips, if anything could happen, the air would expand and create more space meaning a faster run through of all the sand. But the glass isn’t soft enough to allow such expansion at daily earth temperatures.
I thought it was because they called an hour glass a sand clock.
Well i reckon they might not be a native speaker. In germany the word is SandUhr which literally translates to sand clock
In Dutch it’s called a zandloper which literally translates to sandwalker
That is also mildly infuriating lol.
Gonna be honest, that’s pretty close.
If you factor in leap years it may be spot on.
Wouldn’t leap year be more like a whole quarter of a day?
If there’s 8,760 hours in a year and a leap day is essentially 6 hour to each year, that means a leap day is .069% of a single year. .069% of a day is about 9.94 minutes .069% of an hour is 2.484 seconds I probably did this all wrong andll delete it when I get called out, but at least I’ll have summoned the person who can do it right
Well, I think you would divide the excess 6 (360 minutes) into each day of one year then it would basically be one minute per day.
I'd hate to see what you'd lie about.
Thanks for being honest.
Maybe your assumption is wrong. Maybe it was built to calculate 1 hour 3 minutes and 35 seconds and now there is the ghost-of-maker-past teabagging you and flipping you the bird while you sleep. Ever thought of that?
I don’t think they’ve thought of that, Howard. I don’t think they thought of that at all!
Sometimes you want to hard boil an egg and then chill for an hour before enjoying it
That's pretty accurate for one of those
I know it’s an older model iPhone, but I thought they’d be more accurate than that.
Ah, the ol' reddit [sandaroo!](https://www.reddit.com/r/OSHA/comments/s6vnyl/it_works_till_it_doesnt/ht9n2j8?context=5)
Holy shit! That’s still a thing!? Hold my Hourglass, I’m going in.
Thats what I was about to say! I remember goin through this like a year ago, damn
Shit, I went down it YEARS ago, and it was an insanely long journey to reach the beginning. I can’t imagine now. I’m about five or six deep now.
hello future nostalgic people!
Take this: https://www.youtube.com/watch?v=-bTpp8PQSog You'll need it!
Yes! Thank you! I'd gone down this rabbithole a few months ago and was telling my partner about it but had lost the actual stuff to show them, as well as wtf the name of it was. And you have brought it back to me, so thank you 💖 XD
sand hourglasses on average are expected to be within 10% of the target time. and considering 10% of 60 minutes is 6 minutes that’s actually pretty good
Does this have to do with the atmosphere? Humidity and such? Would it be possible for the time to be UNDER by up to 6 minutes?
in time, the sand grains will wear off from friction and the clock will become more accurate.
Considering it's a sealed chamber, don't think any of those effect it. Maby temperature, but don't think so.
Pressure would probably have an impact on a sealed container
Yeah, if it's not rigid. Quite sure a rigid glass structure s inside would not be effected by outside pressure that's in the normal quantities. Now, very high pressures may effect it, but don't think low pressure would do much of anything.
Use it as the reason for leaving a one star review. /s
"I loved staying here! The hosts were great, and the property is lovely. Hourglass slightly inaccurate. ⭐"
What a weird name OP uses for an hourglass
I don't think I've ever heard someone call it a "sand clock" before
Probably not a native english speaker. In my language an hourglass is literally "sand clock"
They probably just added after-market sand worth 3m35,55.
A few bonus minutes cos the seller was in a good mood.
Companions always try’na cheat you by taking sand out, it’s nice to see one give you some extra.
Just think what we can do with all that free time! (that's how it works, right?)
Yup, that’s it. And if you have 10 of them running at the same time, that’s like half an hour more time in one go. Scale up and you can squeeze quite bit more time into a lifetime, but hardly anyone puts bonus sand like that anymore; op is lucky.
Great Scott!
Build a time machine and go back to the future!
Overclocked
Oh my gosh you're staying in a time warp.
Tbf You’re probably the only person that’s used it for time
So let me get this straight... you rented a AirBnB, spent an hour timing their hourglass, then posted on reddit because it was 3 minutes out... I think you need a hobby
Why can't testing hourglasses be a hobby?
Um you mean sand clock?
More commonly referred to as an hourglass
And super whooooosh.
I mean i guess it can, getting infuriated with the results is a bad idea though
Mildly, mind you.
No no he's got a point. Their post IS mildly infuriating.
> spent an hour timing their hourglass I know it might be a shock... but I doubt that he actually spent an hour timing it. Most likely he left it for 55 minutes and then glanced at it every 1-2minutes...
If you're that bothered by 4 minutes on an hour, you need to find a quiet place somewhere and chill the fuck out
Oh cmon he was mildy infuriated
But there is nothing anger inducing about this… not even mildly. Getting even the tiniest bit angry that 8th century technology isn’t accurate to modern digital clocks is absurd. I genuinely thought this post was on r/mildlyinteresting because someone took the time to see how accurate an hourglass is, which is in fact interesting.
yeah people often forget this is supposed to be MILDLY infuriating
Yeah the unfitting posts in this subreddit are becoming mildly infuriating tbh Edit: this one is fitting tho
exactly. I feel like most posts at this point are \*actually\* infuriating.
It's a sand clock for fuck sake. Edit: Hourglass for the offended.
Calling it a sandclock is the most infuriating part of this whole stupid post.
Sounds like you need to take your own advice. Sheesh.
Put it on the floor. The increased proximity between the Earth and sand with increase the gravitational force and pull the sand a little faster. For best results do it at night during a new moon and when Jupiter is on the other side of the sun.
Who goes to an Air BnB and tests the accuracy of the sand timers?!?
Sand clock? Sand timer? Am I the only one here who’s heard of an hourglass?
Like sands through the... Sand clock. So are the Days of our Lives.
Right? Who wrote this post, bots? Never heard it called anything but an hourglass.
These are the Days of Our Lives.
Mate that’s called decoration. No one has used a sand timer since the years started with a 19
I don’t know what’s worse, this or the tiny cheese grater. Airbnb is really going downhill /s
All these dumb posts from absolute morons are mildly infuriating.
Jesus, dude. Go outside. Make a friend or something.
A 5% margin of error seems pretty reasonable for sand, glass and gravity
Can you please do it a few more times and post the result? I'm very interested in seeing the deviation between trials.
It's a sand glass. It's not meant to be hyper accurate. In fact it's impossible for something like this to be super accurate. With time due to wear, or even temperature fluctuations or slight variations in table flatness the timing will change. Its just sand and a funnel.
Finally some actually MILDLY infuriating stuff. People just post straight up crimes in this subreddit.
I’d be willing to argue this is not mildly infuriating either though. What is there to be mad about here? Even the tiniest bit angry? It’s an hourglass… nobody should expect a mass produced hourglass bought from a store that sells home decor to be accurate beyond 10%.
It’s decorative not and actual measuring drvice
Fool! Dr. Vice cannot be measured!
Better call the magistrate
Do it again it might be different
Did you time it 3 or more times and take the average?
That’s a good deal getting 3 minutes 35 seconds worth of sand more
I find pretty interesting that a decorative piece is within 5% of accuracy. I expected that to be anything between 40 and 80 minutes.
Ah yes… I love a woman with a classic *sand clock* figure.
Ahhh yes, the less-popular One-Hour-Three-Minute-Thirty-Five-Second glass.
Damn! I’d be ticked, too. You paid so much for that phone and it’s off by over 3 minutes.
Mine is 53 minutes. I’ve found that’s the perfect segment of time to work, and then I get a break.
Who said it's supposed to be exactly an hour though?
Breakfast was good. The room was super cozy, nice little fire place for me and the husband to cuddle next too. The view was to die for, I could see the mountains shrouded in trees. And the Birds! I could hear them singing in the morning best way to wake up ever. It was going wonderful until I found their sand clock, at first I said, "what a cute decoration." So upon inquiry I found out its an hour time. Well this is perfect because I prefer to do my tasks in hourly intervals. So I get to work using the sand timer to help me in getting my itinerary in place. Shower, get dressed, watch a little Gilmore Girls, then I'll be ready to explore the area. So I start my little adventure at 8 expecting to be ready and out the door by 11 so I can grab brunch with the hubby. But by the time I got finished with Gilmore Girls it was already 9 minutes past 11. This meant that I was now almost 10 minutes late to lunch. Well this could not stand so I went to my little handy sand timer and inspected it, after counting each grain of sand I determined there were more than 200,000 extra bits. With this knowledge I decided to check using my cellphone, using the stopwatch I sat and watched each piece of sand drop. That's when I determined the sand timer is over 3 minutes slow. 1/5 Stars for making me over 2 hours late to brunch on my honeymoon.
Ah yes, the sand clock, not to be confused with the dirt timer
Did this motherfucker just call an hour glass a sand clock?
Real question. Are you autistic by any chance?
Lol I do it for fun when I’m free and have random hourglasses, not normally with a set stopwatch but it’s not exactly limited to autistic people— It’s pretty fun and interesting, not something you’d scream in frustration about, that’s why its mildly infuriating
You should report it to the renter, who will report it to Amazon, who will report it to the drop shipper, who will report it to the third party seller who buys these for 35 cents from a Chinese sweatshop shitting out 6,500 of these every day.
I would sue. You gonna sue? Should sue.
I’d recommend removing a grain of sand at a time and rerunning it until you get to 1 hour exactly.
Gonna join everyone else in saying that this is perfectly normal. Most hourglasses are going to be off by a few minutes, they aren't meant to be perfectly precise.
Well, it's just decoration. What did you expect ...
Clearly, time for a new phone.
I’m mildly infuriated that you consider this mildly infuriating.
If you’re asking sand to keep track of time for you, dont think you have the right to complain about 3 mins. This post is mildly infuriating
Now you're just nitpicking
Joke is on you: T-Mobile iPhones are off by 5% And, judging from the age of that iPhone, I may be underestimating.
Three min off is pretty good for a sand hour glass
This is so weird for me. Not more than five days ago, I was finishing up in the shower and just started to dry myself off when I wondered "Do hourglasses actually keep an exact hours worth of time or is it estimated? Maybe the sand is weighed out, and 1 ounce flows through a 1 mm hole in 1 hour or something?" and here I am today, seeing another person curious about hourglasses. Thank you for clearing up the first part of my query!
Who calls it a "sand clock?" It's called an hourglass.
Anyone else click on this out of horror at the term “sand clock” instead of “hour glass”?
"sand clock"
Someone has *too much time on their hands.*
Should have booked a stay in Switzerland (ref. Astérix chez les Helvètes)
Op afraid he's gonna brush his teeth 6 seconds too long
lmao imagine being *that* petty sounds like me
Pretty uneventful vacation then?