How Ancient People Kept Time
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- čas přidán 22. 06. 2024
- From sundials to crystals-how did early humans keep time, and what exactly is a "leap second?" Join Michael Aranda on SciShow as we dive into the long and strange history of timekeeping. Let's go!
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Nice! I can get an extra second of sleep on June 30th! I knew Earth's rotation was good for something!
That's my birthday 😅😂
ol' father time can offer a milli-second, & that's being generous.
@@ruchikabiswal3632 omg sameeee twinsiesss. I love that we got that extra second good for us
Technically .9 second
I want a smell clock.
"smells like 4pm"
"...wait...4...30"
you missed the chance to say 420 and have the perfect pun
Lily R And the microwave had 4:20 on the clock =]
***** the microwave was set to 4:20
BOBdotEXE CAN YOU SMELLLLLLLLL when The Rock is cooking?
jish b i was born on april 20th the year 420 at 4:20 AM
So if humans went back in time to the big bang and they left an optical clock behind, it would only be off by one second as of now? Damn that's accurate.
Geoffrey Brunell Well... kinda. Depending on where that clock is, if it travels or had traveled, where we are in relation to it and other space timey wimey things. Time is relative to your location, and in the big bang the area of space wouldn't have existed at the beginning.
Joel Crawford True, but it could be possible assuming it had not moved and had not been influenced by any outside forces or celestial bodies. But I guess that would be impossible anyways.
Geoffrey Brunell
I have that same picture as the background on my phone.
Lucian Willi the space clock would actually be late and it feels almost the same g as the earth clock, it's not related to this. what happens is the space clock travels way faster than the other which makes its relative time "dilates", making it late compared to the earth clock.
***** yes you're right to notice it, however in the case of gps satellites, their speed is approximately constant so it's really the speed that dilates time in this case.
I thought that this video could have proved very difficult to host, for any host but fantastic job done by Michael Aranda. Thank you for immaculate and accurate hosting and explanation, just like an optical clock.
So are we just going to ignore the hourglass?
***** The hourglass is a very inaccurate method of keeping time because it has to be reset every hour... It's also dependant on humidity, local gravity, temperature, etc...
Jordan O'C Regardless of how well they worked, they were still a big part of our time keeping history. Also, they were fairly accurate for their time period, wouldn't freeze in the winter, and were generally cheap enough for anyone to own. They also worked great at sea.
***** I'm not sure about your last point, i think the constant motion and high humidity would screw with a hourglass.
Yijuwarp Let me rephrase that: they were popular at sea when the only other options were no clock at all or a pendulum clock. Ferdinand Magellan had 18 of them on his trip around the world.
***** There was a designated person to turn it every hour, right? They work well for short-term time measurement
The stock market already sets billions of dollars on fire.
Lol
Titus Fridell one lol for your comment and one more lol fir your profile pic...!!
Titus Fridell yeah they don't need the wrong time, they do what they want
The people who loose money on the stock market give their money to people that are smarter than them.
That's because it was hacked, atleast once.
I love these videos that last more than 7 minutes. They are very fun, informative and they are well made. Thank you!
This got recommended to me in 2020
After 5 long years
"10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 1, happy new year." i dont know... just doesnt sound the same.
0
That's why they add the second at the end of June, not December.
It was added literally in the middle of the year
Nobody will notice. They are all drunk already.
@@ExistentialNathan it's to remember the fallen... (second)
This is awesome, I've been trying to figure out this stuff on my own and here you go making a video for me, thanks guys.
Why is it so funny that the microwave is at 4:20?
Ze Rubenator 420, 4:20, or 4/20 is a code-term that refers to the consumption of cannabis and by extension, as a way to identify oneself with cannabis subculture or simply cannabis itself. Observances based on the number 420 include smoking cannabis around the time 4:20 p.m. and a.m. everyday, as well as smoking and celebrating cannabis
William Johansen It's 10:47am here in Australia. This theory must be flawed because I'm already celebrating cannabis.
***** well, i mean, don't let a clock tell you what to do
A Giant Space Monster hahaha. It's always 4:20 somewhere, I guess :)
420 hype!
Sharp, articulate, and concise. Love it.
So we have clocks that are more accurate than Earth itself. SCIENCE!
Butt Poopington That is not true.
Butt Poopington As clocks revolve around earth.
Tony joe
uhhhh, what?
Tony joe Did you watch the video?
Tony joe Did actually watch the video? He said that we have clocks that are more accurate than the Earth, because the earth is inconsistent. That was the whole point of the leap second!!!
I love scishow so much. I'm a visual learner and you guys are endlessly entertaining
The atomic clock is mind-bending to me! That's so cool.
Marvelous! The later half really kicks up the knowledge
That 4:20 on the microwave, thanks for reminding me of the most important time
Enigmorus yolo420 propaganda strats bro
Enigmorus I'm guessing that you're going to be baked by the end of the video.
Happy Hippie Christmas, today!
"Time is an illusion. Lunch time doubly so."
Douglas Adams
The first billion years were the worst.....
This channel is amazing. Thank you SciShow!
This is going to make me seem like a massive nerd but I've wanted to see a video about timekeeping and it's history for while now. It's just something I thought about one day-"How did we keep the time in the past?"-but I was too lazy to actually research it myself. Thank you, SciShow!
An episode on the exact definition of the standard units as they are defined today would be awesome.
"If the stock market is off by 15 seconds, you might as well set billions of dollars on fire."
*****
The value of money goes up and down. If a Canadian dollar is worth half a penny less, and you american money to switch to 20 000 000 Canadian dollars, then it goes back up (half a penny more) then you got the money at 100 000 $ less than it's worth. You've made 100 000 from a half-penny difference.
These values can go up and down really quickly.
*****
No problem. Glad I could help :)
some person Very informative, I was wondering about this as well. Thanks!
Christian Kjeldbjerg Kristensen
:)
Raina Ramsay LOL That is why we need to get computers out of the equation. Trades should not be made by machines.
I've been waiting for this video for so long!
You people are amazing . Keep doing what you're doing
Good video and explains a few things that other similar videos avoid. Have one question though. For mechanical watches / clocks, what did they use as reference time. E.g. John Harrison's watch had an accuracy of 1 sec/ day (pretty impressive!). How did they know that? How did they know that the watch was off by that much time? What was the reference marker or baseline against which they compared it? thanks!
I think they were measuring the clock against itself. Several clocks of the same time would vary over time. If they were perfectly accurate they wouldn't vary at all.
Great video, but much more should have been said about the telegraph, the establishment of time zones, and the implication of clocks being synchronized with each other.
Covering all that would have taken too much time.
It was actually the railroad is the reason time was synchronized. Telegraph helped to make it possible to communicate across the distances needed to sync the clocks.
This is a good baseline. It's sometimes difficult to find what clocks would be allowed in which periods, so this is helpful. Thanks, scishow!
An excellent and very thorough explanation. Thank you.
Michael Aranda has the single weirdest youtube trajectory I've seen. It started in that charlieissocoollike video where he was a funny guy and his thing was being American. Then all youtubers had him like some kind of guru, the guy that made music and edited videos and knew about writing. Now he does scishow? (Well he has being doing so for a while but still. Just who is Michael Aranda?
He looks like he could be the son of Seth Mcfarlane.
So if an optical clock had been activated at the beginning of the universe's existence it'd only be off by about one second now? Damn, that's pretty freaking accurate.
I learn so much from this channel (as well as Crash Course and SSS), I can't believe it's free:-)
one of the best episodes in a long time
♡♡♡♡ Love Sci Show! ♡♡♡♡♡
No hourglass?
Cool, thank you so much for this detailed explanation. It was clear and concise 😀
Very interesting episode. Thanks! I especially enjoyed the title :) Nice little parody of Hawking's.
How do you determine how accurate a clock is? Unless you have something more dependable to measure it to??
***** So time in which we use is in relation to the Earth's orbit around the sun. What about in a galactic scale? How would . let's say, a person on this solar system convert a time of alpha centauri?
Qermaq There is a standard atomic clock somewhere in the UK.
Might be some other atomic clock, there arent that many en.wikipedia.org/wiki/List_of_atomic_clocks
Qermaq my guess is you make many identical clocks time the same thing and the amount it varies is the accuracy
Qermaq Usually by how long it takes to be off by whatever amount of seconds.
Qermaq clock's based on the internet use a few common servers that keep up to date with the most accurate clocks
You forgot RC oscillators. My company can use quarts crystals or a low power RC oscillators. They use the time it takes for a capacitor to charge given a certain resistance. This goes into and inverting opamp and causes oscillations. They are stable, just not always very accurate(but cheap). Quarts crystal oscillators are accurate, but can change with temperature making them less stable.
It'a amazing how the time between leaps of progress keep getting smaller and smaller. We make more advancements in 100 years than humanity took in 500 to 1000.
this is very educational it blows my socks off!!!!!!
hmm I will just use the good old mississippi approach. It hasn't failed me yet.
ragmondead I know, right? We do the same here with the justice system. Paper covers rock, you hang. Non of that "DNA profiling" rubbish.
jaaasgoed yeah or like if a baby laughs it wants attention but if it cries u kill it because euthanasia
Nice episode. Thanks.
Mentioning the vernier-scaled heliochronometer and the armillary sphere would've been nice, as well as the folding universal latitude sundial watch. This historical stuff is the most esthetically pleasing.
You guys are amazing! Thank you.
You know what really boggles my mind, how do we know how long it takes for any given time keeping technology to lose time.
If we invent a new time keeping tech, how do we measure it's rate at which it will slow if we don't have anything more accurate to compare it to?
*mind asplodes*
Shadow pin "heliochronometers" were used in the 1800's along with the nautical almanac to find mechanical chronometer error.
But how they know, when atomic/optical clock will not be accurate, or that Earth orbit is off to a second etc.? How do they know the absolute time?
Well, atomic clocks are better synchronized with each other than any known periodic processes.
Excellent job guys!!
Great episode! I've always been boggled by the measurement of time.
Man, CZcams is not having a good time trying to render your shirt buddy, the artifacting is pretty brutal today.
EATSxBABIES Isn't that just the green screen?
His face is worse. It keeps getting deathly pale and then saturating to normal levels again.
Corey Lando That's not CZcams. That's just how his face naturally is.
He keeps saying the leap second is about the Earth moving around the Sun. Am I missing something or did he mess up and it's about the Earth spinning on its axis?
Landon Kryger Clearly, it's the Sun moving around the Earth, not the other way around, you filthy heretics! #Kappa
Landon Kryger - I think he's right. We measure time by distance traveled around the sun (360 degrees = 1 year) and that actual time can vary. I'm surprised it isn't more than a second off.
Chris Randall I don't think so. We add leap days to keep the calendar in sync with the seasons. We add leap seconds so that the sun is directly up at noon.
Yes, I believe you are correct. He did mention somewhere that the second used to be defined as a very small fraction of a day. Of which the length is determined by earths rotation.
Landon Kryger - Yep, you're right. Time is determined by the spin of the Earth rather than it revolving around the sun. Earth's spin is slowing down, so we need to update with leap seconds. I was thinking more about leap days.
Good on you Michael Aranda! Excellent Presentation 😎😎😎. Nice to know about Timekeeping.
Neat! I'm so glad I watched this one!
lol the microwave 420
did anyone else notice the time on the microwave clock is 4:20? (6:44)
Great episode !
Thanks Man. Provides Just What I Needed.
China really is the most technologically advanced country. Even thousands of years ago, they had a way to freeze time. 2:35.
Song Su water clock
they had gears chains machinery long before Europe.
In ancient Egypt the 1st clocks appeared, not in China
That was so bad it hurt my brain. 😔😂
This is cool and all, but why do we break up the day and time measurements into 12ths and 60ths? Why not use tenths?
Sketchy Fella It's conventional. For most of humanity, we counted using base 12 number system, not the decimal system. A Dozen = 12, time is broken up by 12. 12 hrs, 24 hrs. 12 has much more factors : 1, 2, 3, 4, 6, and 12. 10 has less factors: 1, 2, 5 10.
1/3=.3333 In base 12 that's 1/3=4/10/=0.4 It doesn't go on forever.
12 inches = 1 foot
Sketchy Fella The layman's explanation is that we use those numbers because many integers divide into them. You can easily divide a quantity of 12 or 60 into halves, thirds and fourths (even more for 60) without having to deal with remainders/decimals.
Sketchy Fella
Every day is 24 hours long and every hour is 60 minutes.
24*60 = 1,440 minutes.
If you were to divide the day into blocks of 100 minutes, and not 60, there would be 14.4 Hours in a day.
If you were to divide the day into blocks of 10 minutes, and not 60, there would be 144 hours in a day.
Honestly a tenths/hundredths system seems rather fitting, as it fits in with our usual way of counting things like money.
We don't say $1 is ¢60, we say it's ¢100.
:)
TheTaleOfSirRobin Sounds like just as good of an argument for keeping the imperial system of length measurement. Look at that 12 inches to a foot is best because it can easily be divided by 3.
Ghost Yeah, and somehow it's _always_ the inch-to-foot ratio that gets mentioned in this context. I wonder why that .... oh, right. Because it's the _only_ damn twelve in the whole imperial system!
Thanks for this episode, best thing I've seeing all week, fascinating topic.
Does anyone knows about a good book on this subject?
If you want to celebrate the leap second it will be at 23:59:60 Jone 30, 2015 *_UTC_* (7:59:60 EDT). You can listen to it if you have a shortwave radio (or know a ham radio operator). WWV in Colorado and WWVH in Hawaii broadcast the time on 2.5, 5, 10 and 15 MHz. At one time almost every major country had similar stations but most are gone.
Question: if timekeeping were more precise accurate back in the days, would it still be June 26 2015 as I'm commenting this? (Because of inaccuracy)
Bram06 no it wouldn't be 26th of June 2015
the calendars were redefined multiple times, just Gregrian vs Julian calendar differences account for over 10 days alone
666Tomato666 From now on I'm going to assume that I live in 2100 because why the fuck not.
Bram06 in Hebrew calendar it's already AM 5775
666Tomato666 On my calendar its Jan 1 0000 0:00:00 Starting now!
Bram06
Yes it would. Dates are number of whole days. And since about 1585, ties to equinox. Which doesn’t creep with tiny fractions. It’s whole days regardless if it’s a few extra seconds long.
The irony is that I watched this video and missed my bus...
Excellent explanation Michael 👍
So amazing.
when is the second happening?
Any second now.
Bread Bro 403,736 seconds from now
Bread Bro In other words 4 days, 16 hours, 7 minutes and 11 seconds, from ...now.
Nilguiri
Ooñllñññññjii
A leap second is inserted between 23:59:59 on December 31st and 00:00:00 on January 1st (thus it is 23:59:60 on December 31st)
Or
Between 23:59:59 on June 30th and 00:00:00 on July 1st (thus it is 23:59:60 on June 30th)
Is there a standard for how far the cesium clock needs to be from the Earth's center of gravity? Because relativity is a thing.
CassesVultus
International Atomic Time is a very high order array of clocks all over the world. And gravity corrections are in there somewhere.
best sci show video yet!
This was really interesting :)
thank god you fix that hair
First?
Awesome vid
Can we get a Crash Course episode talking about the social impacts of changes in timekeeping? Because it's just fascinating.
This is awesome
Very good clip
Cool video, thanks
I highly recommend the book (and documentary) Longitude, by Dava Sobel... the story of Harrison's invention is fascinating!
Great videos! Fast, informative, and egotism-free yet still entertaining.
Mind blown ! Next step : the habitlity to travel in time.
Damn I'm late I didn't know about this. Come to think of it. I do recall feeling extra rested that day. Must've been that extra second I slept.
Interesting episode.
Just to be clear, leap seconds are added on 30-Jun or 31-Dec at 24:00:00 UTC, not at midnight in whatever local time. For example, the 30-Jun-2015 leap second was at 20:00:00 EDT (or it would likely be 19:00:00 EST during Dec).
my head hurts from this SCI SHOW video
Well done Michael.
Don't forget Immanuel Kant as a timepiece; it was said that his neighbors in Koenigsberg set their clocks by his daily walks at 5:00 pm.
Around 2:45 : "Incense that changed smells every so often..." Interesting. I never heard of that one before, but it could have resulted in some interesting conversations:
"What time is it?"
"Cinnamon:45."
"Huh?"
"You know: Quarter to patchouli."
"What?"
"Never mind."
Fun Fact: Not only have clocks got more accurate, but also a lot more expensive. It started with a stick in the ground (cheapest), now to atomic and optical clocks (a LOT more expensive)
Sweet video
SciShow videos run fast, too fast for me to actually understand. I think this earns them more views. 😌
One remark on the stock market example: if you need exact synchronization, you do it by (series of) events, communicated via a protocol. Such one has timers, too, but does not depend on extremely precise clocks, which can't help because there is always a delay in transmission and processing, which also can vary. One of the participants would pace the message exchange and also translate the events' point in time for external use and recording of transactions.
THis was beautifully structured like a well written thesis paper.
You should have mentioned that on September 6, 1522, 18 survivors of Ferdinand Magellan's original crew of 237, were the first to circumnavigate the globe and upon arriving home in Sanlúcar de Barrameda, Spain, and shocked the world that an entire day was missing, even though they kept track of time every day since they left.
The leap second is going to happen in a few days, *l'm SO excited!*
Very cool! I will celebrate leap second! :)
All those babies born on leap second :O they will never be 1 year old ever...
Jesus Hernandez their corpses will
Well, this episode was humorous and entertaining. Michael could barely keeping from laughing. It's hilarious that so much complicated science went into accurately recording time so far into the future no human being will ever be around to actually determine if the atomic clock is as accurate as everyone thinks it is. Lol.
The history or keeping history?
What a moment in history.
Fantastic video! And thanks for the 420 microwave, SciShow!
This was a clever one.
I quite like the Clock Of The Long Now. It's not exactly as precise as a caesium clock or an optical clock, but it can run for ages without maintenance. Pretty cool.
Dave Ellis
The long now will be sun based time. Independent of atomic time.
+CrashCourse Through a bit of research (and taking a bit of interest since my birthday was on that day), I found the element you were looking for was Aluminum-27 in an optical clock.
I made a school presentation on that subject while i was still at school, few years ago. Such memories.
A brief history of time...keeping.
I see what you did there. ;)