Sat in my little van , homeless , suffering from ptsd and the only people that help me recover and find peace are you two. So I was watching you that day. Like I do everyday because I learn about the most important thing in my life , space. I don’t know why but it’s the only thing I’m smart at. Thankyou for your channel. It makes a difference to a lot of peoples lives. I hope I get to shake your hands and Thankyou in person some day.
Wowing my friends, who didn't believe me that this was a rare(ish) event. They were too busy worrying about outdated computer programs that used 2 decimal digit years to calculate dates.
I would love to see these guys address news articles such as James Webb Telescope finds star older than 13.8 billion years old... i remember all the leap year info from when i was in school (mostly i remember how the teacher said 2000 would have a leap year but 2100 would not) Respectfully, (from the NASA website) one year = 365 days, 6 hours, 9 minutes - i guess you inspired me enough to look up the exact amount of time...
It's the year 4721 currently according to Chinese Culture. Was it really even the year, 2000? Without the orbit of the planets around the sun. Say, out in space somewhere. How do we measure time then?
I love this explainer! Brilliant! Just a correction: Neil said we return to exact point after a sidereal year, but because of the elliptical precession we actually never really return to that exact point right? And since Jupiter causes the angle of the plane of Earths orbit to change, it causes even more chaos. And then we orbit around the centre of the galaxy, which is in it's turn moving through space, so this means my brain is now left somewhere in space at a place I will never return to. I give up!
He did it for didactical reasons. As for your question: I think we "return" after a full turn of precession; (its own "year") however now that I think about it, it's unlikely at the exact "time" (the point in the year?) Good question! I already wrote to him, that the precession topic would also have been cool to be more indepth - how does it affect our calendar? Do we actually "return"? I mean in theory there we won't be in no exact same place ANYWAYS, because our solar system also moves... It's all relative. For didactics I opine the "return" is very appropriate though. Probably deserves its own video, but would have best fit here, still. What mainly counts in the end is our position relative to the sun and what season it is from that, too: So, seasonal climate repeating and btw climate changing based on those other factors that were mentioned in the end in the video and which you even added! I think. And as a thought-provoking impulse.
Some people mistakenly think that Summer is hotter because we're closer to the Sun, when in fact we're actually father away from the Sun (for those of us in the northern hemisphere).
Maybe those people were born some 13,000 years ago, when the northern hemisphere summer actually occurred in perihelion. I can understand how that might have confused them back then.
I was born on Leap Day back in '88 and when I was in school during the leap day of 2000 the city ran an article that featured 3 people from the city that had that birthday. Wish I would've known how significant it was back then.
"A year is a trip around the sun." 👌👌 Genius! Regardless of calculations, speed and other factors that may affect on the "Calendar", this is the simple and accurate answer.
06:58, actually the year 1600 WAS a leap year, as it's a multiple of 400. I think in that whole enumeration, Neil wanted to say 1900, 1800, 1700, but since he started from 1800, he went a bit too low and included the one that actually was :) Also, at 10:06 it's the exact OPPOSITE: we're closest to the sun in January (perihelion) and furthest in July (aphelion).
So if we’re further from the sun in the northern hemisphere’s summer, and closer in the southern hemisphere’s summer, would that make the temperature variance between seasons greater in the southern hemisphere? Cheers
Caroline from New Zealand found through Google says: No, they are less extreme. The fact that the sun is closer to the earth during the Southern summer and further away during the southern winter would make the southern hemisphere seasons more extreme if all other things were equal. However, all other things are not equal. The main reason why southern hemisphere seasons are less extreme is because the southern hemisphere has more sea, and the high specific heat of water means that this moderates the temperature variations. 🎉😂
@@YTsuuuucks indeed, for both your posts! also, there are a lot of other factors that make things very complicated to evaluate, such as vegetation, pollution, population etc.
@ PixelsLab: Yeah, I noticed that boo-boo, too. Neil inadvertently skipped the year 1800. He said "There was no Leap Year in 1900, 1700, or 1600..." He meant to say there was no Leap Year in 1900, 1800, or 1700...."
@@YTsuuuucksit does seem counter intuitive,but the explanation lies 8n the angle of the earth relative to the sun. The tilt of the axus means when you are in a part of the earth that has the sun shining directly each day it will be hotter, and in the areas that light us dispersed over more land it will be cold. Witness the fact that at the north and south pole there is a light season and a dark season.
This makes life more special, I learned this a little while ago but before that I always questioned how perfect it was to have a day according to the sun. This explanation helps
The length of a year is commonly defined as the time it takes Earth to complete one orbit around the Sun, which is approximately 365.25 days. This period, known as a tropical year, is the basis for our calendar year. However, there are different types of years used for various purposes, such as the sidereal year (about 365.25636 days), which is based on Earth’s orbit relative to distant stars. Understanding these variations helps us appreciate the complexity of timekeeping and the astronomical factors that influence our calendar. How do the different definitions of a year such as the tropical year, sidereal year, and anomalistic year affect our timekeeping systems, and why is it important to account for these differences in astronomical and scientific calculations?
Milutin Milanković entered the chat.😊 Serbian scientist made a most precise calendar ever - the Revised Julian calendar. He was a great scientist. I don't know why they excluded him in StarTalk.
I just had an epiphany. March was named for the God of War Mars because that is the best time to go to war. The solstice in March would be the best time because the snow has melted and the summer is starting. WOW!
8:12 “Crap” is a very apt word to use in an agricultural context. This is because it did not originally have any rude connotations at all: it was similarly a synonym for “chaff”, the stuff you throw away when harvesting a grain crop, as in “separate the wheat from the crap”.
Kenyan here. When I was in school (I'm turning 45 on Sunday), we were taught that is 365 an a quarter days, and those quarters are what made the leap year every four years.
This just shows “Time”, and the Calendar, are constructs of mankind… When the Gregorian Calendar was implemented, 10 days were added to correct the old calendar’s errors… The Mayan Calendar had an 819 day cycle would match the planets’ alignment every 45 years!! I remember “leap seconds” back in the 1970’s as Atomic Clocks got so accurate, we had to adjust what time it was/is… Thanks guys!!
Errata: At 10 minutes , the Doctor said that we are closest to the Sun in July, farthest in January. It's just the opposite. Our seasons come from the tilt of the axis, not the distance to the Sun. The change in distance actually moderates the effect of the seasons in the Northern Hemisphere.
This tells me that we need to metricfy our calendar into units of tens with all of these leaps built in from the start. The current calendar is ancient, built on care and priorities that most of us no longer even know about. While we are at it, we should also create time units based on 100 second increments instead of this archaic system of 60 seconds, 60 m,inutes and 24 hours.
What your asking for is ridiculous. We have the best system right now. All scientists will tell you. Only units that are completely arbitrary can be switched to metric. Like length, weight, etc... The rotation of the earth on its axis and around the sun are not arbitrary, they are fixed.
@@JasonWW2000 it's not ridiculous. It's whatever we want it to be. And I have never heard a scientist say that our current time pattern is 'the best' . This whole video just proved that it isn't.
@@philipberthiaume2314Niel himself has explained all about the different calender systems and how the current one has lasted so long because its so well thought out. I'm sorry I don't have the link to the video, but you can search this channel. Its very interesting the history of calendars. 👍
Great explanation, still they should've mentioned that when we shifted to the current calendar, called Gregorian calendar, back in 1582 the previous Julian calendar has had a seasonal drift (due to the lack of those normal years in centuries that can't be divided by 400) of 10 days which was necessary to correct. And they did it by shrinking the month November of 1582 by 10 days: after the 4th of November the 15th of November followed.
There were riots in the streets, because some people though they had lost 10 days of their lives. Also the Protestants didn’t trust the Catholics over this issue, so some of them didn’t switch until much later. E.g. Britain (and its empire) only switched in 1762 I think it was. And the Orthodox Christians ... do you know why their Christmas now falls on about January 7?
Close, but the Julian calendar didn’t even account for century years at all. It simply approximated solar years to being an even 365.25 days, putting in a leap day every four years without exception. The Gregorian calendar took out the leap days on century years EXCEPT for those evenly divisible by 400, approximating the solar year to being 365.2425 days. This is much closer to the actual solar year, although it’s still slightly off. The difference, though, is that it would take about 7,200 years (when accounting for the precession of the earth among other things) for the Gregorian calendar to drift by a full day, as opposed to the 128 years that it would with the Julian calendar. To drift 10 days like the Julian calendar did in 1582, it would take tens of thousands of years. The Gregorian calendar is far more stable. I’m sure by the time the Gregorian calendar drifts ahead by a full day, people can just not observe a leap year when they otherwise would, and everything would become synchronized again.
I figure high-level physicist-math is all greek letters, vectors, and orders of magnitude. So folks who do that get caught off guard sometimes when plain honest-to-goodness countin' numbers show up.
This was the best "explainer" ever. None of it accounts for the fact that we will NEVER return to the same point in space that we occupied at any given moment because we're SPIRALING through space. It seems that the only way to accurately account for time is to begin at an agreed-upon arbitrary zero, and painstakingly accurately enumerate time. This would soon negate the notion of conventional "days", weeks", "seasons", and similar units such as seconds and microseconds, etc. Even the smallest time period that man can conceive of can be subdivided infinitely. Even infinity itself cannot exist, because you can always add to whatever value "infinite" is. Time will always be an analog function, but man has, from the very beginning, digitized it (incorrectly, but to the limits of our intelligence). Every instantaneous point in time will never happen again. Heavy. All I know for absolutely sure is when "it's time for a nap!"
@@slyblack6574 Actually, no. The Earth is closest to the Sun in January. The seasons are caused by Earth’s tilt. The axis of rotation is not perpendicular to its orbital plane. So we have summer in July because the northern hemisphere is facing the Sun more directly. In the southern hemisphere it is winter in July.
it's interesting to know that mayans were incredibly right with their calculations of year time, and they didn't had super computers, atomic clocks or other modern marvels we have to keep time tracking as we do now.
I knew about the 6 hours but everything after that it’s mind blowing. 🤯 I was born February 29, 2000 and I had no idea about the rarity of such a leap day.
6:35 i was in the 7th grade when the year 2000 came along; and there was buzz among my schoolmates about having a February 30th that year.... i remember getting excited for it, and then felt disappointed when someone told me "scientists decided it was not necessary to add that extra extra day"
Instead of saying to remove four leap days and then add one, just say remove one when a century is not dividable by 400. I know it's the same result, but it's less complicated.
The 2000 year into blew my mind. Was a freshman in high school and didn't think anything about it. The precession around the sun has been something I've thought about. That each year the seasons are slightly different cause we're not exactly in the same place in space. So from 2000, before that we saw the end of the seasons, and now after we're seeing the start. But who decided when to start the calendar and did we make up the years to reach 0 and then all the billions of years before that?
So how do we know when we are back to the same spot for marking a calendar year? If we are not looking at distance to the sun and not using the positions of the stars, what are we measuring relative to?
Solstices. The shortest and longest days of the years are a good prediction of seasons changing and you can get physical indicators for it after a year in the same place just by watching shadows =) Many Neolithic sites have some structure that should only shine a light on a specific day or few days of the year. Either that or be the only light shining through when all other spots are not lit.
Neil please make a short or explain carbon dating certain types of objects (matter) if you time traveled into past/future...chemistry , composition, woods, metals, etc..😊
Er, 1600/400=4. 1600 was a leap year. I think you meant to say that 1800 was not a leap year. Also, the perihelion is in early January, not July. I know it's easy to slip up, even for you. Love you, Neil! Love you, Chuck!
Only the equivalents of 9 modern countries had adopted the Gregorian Calendar by 1600, so it isn't the best example of a year to use for this system. Nevertheless, both the Julian and Gregorian calendars would assign 1600 as a leap year, it is without question, a leap year.
Fun fact: Persian new year is literally at the new year. So all who celebrate it around the world, they actually do it at the exact same time (Not at 00:00 every year the time is different) at the beginning of Spring .
Earth's orbit is 5 hrs and 48 minutes short of exactly a full day. So every 4 years adding a day means we put 24 hours into the calendar but that is 4 x 12 minutes too much (48 minutes). So every 100 years, that means we have added 1200 minutes or 20 hours too much so we don't add the leap year every 100 years. However, in doing so means we're now 4 hours short. So a further correction is applied, every 400 years we add a day back in. But, if we are short 4 hours every century, then every 400 years that's 16 hours short - by adding a day due to the '400 year' rule (in the year 2000) means we are now 8 hours over. In another 400 years, that's another 8 hours etc. so in the year 2800 the '400 year' rule will not apply as we will be exactly 24 hours over and actually instead of adding a day we'll have to remove it. And then the orbit, Tropical calendar and Gregorian calendar will be aligned. So a new rule will be required: "Every 4 years add a day. Every century don't add a day unless the year can be divided by 400 in which case add a day unless three '400 year' rules have been applied in which case remove a day."
I'm 53 and I've been saying to friends and family for years. I have a great garden. And plants started coming up and flowering earlier and I was told I'm loosing my mind
Considering that time is just a construct that we have created to mark our journey through our lives, we put an extranordinary amount of emphasis on this creation. So much so that we even get into relationship ending disagreements about it, or other life altering situations that affect us. This is all based on stories that we've been told is how life works and we take it as gospel.
It’s a convention, like agreeing which side of the road to drive your vehicle on. It may be arbitrary, but disagreements can cause much pain and trouble.
Q: How old will a person be when they've experienced a leap day on every day of the week? A: 28 years old I found this revelation interesting due to the relation to the phenomenon called the "27 Club", wherein celebrities die before they've experienced a full week of leap years in their lives. Also of note, the World Trade Centers barely missed the eligibility for the 27 Club.
That would depend on their age at the first leap year, at least in our lifetimes. Someone who's less than a year old on Feb 28 on leap year won't be the same age as someone who's 3 years old on the same day, 28 years later. Plus there's years like 2100 to consider, which isn't a leap year. It would be different for someone born on Feb 28 2096 vs someone born Mar 1 2096.
@@jeffidyle4957 sounds legit. you made me realize another coincidence, i.e. that February has 28 days which seems like an allusion to the power of the factor 28 embedded in our lifetimes via the calendar.
@@h7opolo I've always found that stuff fascinating, how a calendar date 28 years later falls on the same day of the week, because there are 7 leap days, regardless of which years the leaps are in. Or that a difference of exactly 4 years will always be a difference of 5 calendar days, again regardless of when the leaps fall (These both excluding the exception years like 2100). If you haven't checked it out yet, you might be interested in checking out the Doomsday system of calculating days of the week for any calendar date in a given year.
@@jeffidyle4957 thanks, i'll check it out. you also helped me discover another factor of 28 embedded in the calendar; did you know that the number of days in a year, 365, divided by 28 yields 13 + 1/28? That means there are 13 (unlucky) segments of 28 days and a reciprocal of a 28 day segment (just one single day out of 28 day segment) within a year. crazy. 🤯
@@h7opolo Very Cool! I didn't know that, thanks for pointing it out! I'd figured out that a year was 52 weeks plus one day, and that would be approximately equal to 13 shorter months (plus a day), but never bothered to figure out that they'd all be 28 days. I wonder if 28 has other significance.
I was half expecting the explainer to be about how long a year is on other planets in our solar system based on the criteria of completing one revolution around the sun. Even more so about how it relates to that planet's length of a day as it relates to it completing one revolution around its axis. Or perhaps even a solar year in regards to how long the sun takes to orbit...the center of the Milky Way? The length of a year as a time keeping method as we know it is truly localized to life on this planet alone. I have no idea how a galactic time keeping method would work.
Several people noted that 1600 _was_ a leap year. I would say: should have been. The Gregorian calendar was only created in 1582, so many countries may not have adopted it yet in 1600.
We are never really in the same space. We travel around the sun, and the sun and whole solar system travel around our Milky Way galaxy, and the galaxy is moving in relationship to the entire universe. 😊
6:49 You mentioned there is no leap year in 1600. You meant to say 1900, 1800, 1700 didn't have leap years based on your explanation. This 1600 should indeed have been a leap year. It's not an error of "you don't know", it's an error of "the thought didn't align with the words at that point". Thanks for the explanation
One thing I would like to point out is that Earth never actually "returns to its starting point in space" in its orbit around the sun. The sun is also orbiting the galactic core, and sort of dragging the rest of the solar system along with it. While the Earth does return to a specific point on a 360 degree index related to the sun, the Earth never actually occupies the same point in space more than once.
Thats amazing...I dont think majority knows about this. By the way you at 6:58 min you said there was no Leap day in the year 1600 which I think is just an error as 1600 is divisible by 400 so it has got to have a leap day.
The precession got me. Would have loved if you had looked at that more indepth; so when is that taken care of in our calendar? But everything else was also really cool explained! 2000 Huh
Where were you during the leap year that wasn't?
Sat in my little van , homeless , suffering from ptsd and the only people that help me recover and find peace are you two. So I was watching you that day. Like I do everyday because I learn about the most important thing in my life , space. I don’t know why but it’s the only thing I’m smart at. Thankyou for your channel. It makes a difference to a lot of peoples lives. I hope I get to shake your hands and Thankyou in person some day.
Time is an illusion to it's interpreter.
Wowing my friends, who didn't believe me that this was a rare(ish) event. They were too busy worrying about outdated computer programs that used 2 decimal digit years to calculate dates.
@@riblets1968nowhere, I was born in 2015
Since 2000 actually was a leap year, I'd say the last leap year that wasn't would be 1900, and I wasn't alive then.
I love answers to questions people don't ask. It encourages you to actually think about what you already know.
I would love to see these guys address news articles such as James Webb Telescope finds star older than 13.8 billion years old...
i remember all the leap year info from when i was in school (mostly i remember how the teacher said 2000 would have a leap year but 2100 would not)
Respectfully, (from the NASA website) one year = 365 days, 6 hours, 9 minutes - i guess you inspired me enough to look up the exact amount of time...
It's the year 4721 currently according to Chinese Culture. Was it really even the year, 2000? Without the orbit of the planets around the sun. Say, out in space somewhere. How do we measure time then?
I love this explainer! Brilliant! Just a correction: Neil said we return to exact point after a sidereal year, but because of the elliptical precession we actually never really return to that exact point right? And since Jupiter causes the angle of the plane of Earths orbit to change, it causes even more chaos. And then we orbit around the centre of the galaxy, which is in it's turn moving through space, so this means my brain is now left somewhere in space at a place I will never return to. I give up!
Well said
😂😂
Indeed this exact point doesn't really exist, it is all relative.
Anything can change depending on you define your frame of reference
He did it for didactical reasons. As for your question: I think we "return" after a full turn of precession; (its own "year") however now that I think about it, it's unlikely at the exact "time" (the point in the year?) Good question! I already wrote to him, that the precession topic would also have been cool to be more indepth - how does it affect our calendar? Do we actually "return"? I mean in theory there we won't be in no exact same place ANYWAYS, because our solar system also moves... It's all relative. For didactics I opine the "return" is very appropriate though. Probably deserves its own video, but would have best fit here, still.
What mainly counts in the end is our position relative to the sun and what season it is from that, too: So, seasonal climate repeating and btw climate changing based on those other factors that were mentioned in the end in the video and which you even added! I think. And as a thought-provoking impulse.
10:06 Small mistake here. Neil got this backwards. We are farthest from the sun in July and closest in January.
Yup, it must be a trick to count the number of smart folks watching.
Some people mistakenly think that Summer is hotter because we're closer to the Sun, when in fact we're actually father away from the Sun (for those of us in the northern hemisphere).
Yes Neil had me doubting for a minute.
Maybe those people were born some 13,000 years ago, when the northern hemisphere summer actually occurred in perihelion. I can understand how that might have confused them back then.
Yep, and he also misspoke about the year 1600 not having a leap day. Every 100 century year divisible by 400 has the leap day re-added.
I was born on Leap Day back in '88 and when I was in school during the leap day of 2000 the city ran an article that featured 3 people from the city that had that birthday. Wish I would've known how significant it was back then.
My bday is leap Day in 2000. It's cool to see others with the same birthday
@@tristenhood3167Yoo that’s crazy my birthday is leap day 2000 aswell
These two have the best chemistry!
No, they have the best physics.
"A year is a trip around the sun." 👌👌
Genius! Regardless of calculations, speed and other factors that may affect on the "Calendar", this is the simple and accurate answer.
Except for the fact that it never is….
06:58, actually the year 1600 WAS a leap year, as it's a multiple of 400. I think in that whole enumeration, Neil wanted to say 1900, 1800, 1700, but since he started from 1800, he went a bit too low and included the one that actually was :) Also, at 10:06 it's the exact OPPOSITE: we're closest to the sun in January (perihelion) and furthest in July (aphelion).
So if we’re further from the sun in the northern hemisphere’s summer, and closer in the southern hemisphere’s summer, would that make the temperature variance between seasons greater in the southern hemisphere? Cheers
Caroline from New Zealand found through Google says: No, they are less extreme.
The fact that the sun is closer to the earth during the Southern summer and further away during the southern winter would make the southern hemisphere seasons more extreme if all other things were equal. However, all other things are not equal. The main reason why southern hemisphere seasons are less extreme is because the southern hemisphere has more sea, and the high specific heat of water means that this moderates the temperature variations. 🎉😂
@@YTsuuuucks indeed, for both your posts! also, there are a lot of other factors that make things very complicated to evaluate, such as vegetation, pollution, population etc.
@ PixelsLab: Yeah, I noticed that boo-boo, too. Neil inadvertently skipped the year 1800. He said "There was no Leap Year in 1900, 1700, or 1600..." He meant to say there was no Leap Year in 1900, 1800, or 1700...."
@@YTsuuuucksit does seem counter intuitive,but the explanation lies 8n the angle of the earth relative to the sun. The tilt of the axus means when you are in a part of the earth that has the sun shining directly each day it will be hotter, and in the areas that light us dispersed over more land it will be cold. Witness the fact that at the north and south pole there is a light season and a dark season.
Excellent explainer! I knew Sidereal year was a thing but didn't realize the precession of the orbit could be considered another form of year.
Thanks!
Always great to get a new explainer
I'm amazed how such simple and short facts they are able to stretch to 12 minutes and make it interesting. That's a talent.
This makes life more special, I learned this a little while ago but before that I always questioned how perfect it was to have a day according to the sun. This explanation helps
These guy never fail to make me laugh and learn.
9:38 "but we don't have to worry about that anymore because we have climate change" -Chuck Nice, 2023
LMAO
Neil and Chuck for 2024!
I can only imagine Chuck's reaction to learning about leap seconds.
The length of a year is commonly defined as the time it takes Earth to complete one orbit around the Sun, which is approximately 365.25 days. This period, known as a tropical year, is the basis for our calendar year. However, there are different types of years used for various purposes, such as the sidereal year (about 365.25636 days), which is based on Earth’s orbit relative to distant stars. Understanding these variations helps us appreciate the complexity of timekeeping and the astronomical factors that influence our calendar. How do the different definitions of a year such as the tropical year, sidereal year, and anomalistic year affect our timekeeping systems, and why is it important to account for these differences in astronomical and scientific calculations?
It was things you thought you knew i thought i knew it but i learned a lot thanks Neil thanks Chuck
Milutin Milanković entered the chat.😊
Serbian scientist made a most precise calendar ever - the Revised Julian calendar.
He was a great scientist. I don't know why they excluded him in StarTalk.
I just had an epiphany. March was named for the God of War Mars because that is the best time to go to war. The solstice in March would be the best time because the snow has melted and the summer is starting. WOW!
8:12 “Crap” is a very apt word to use in an agricultural context. This is because it did not originally have any rude connotations at all: it was similarly a synonym for “chaff”, the stuff you throw away when harvesting a grain crop, as in “separate the wheat from the crap”.
Kenyan here. When I was in school (I'm turning 45 on Sunday), we were taught that is 365 an a quarter days, and those quarters are what made the leap year every four years.
It's more complicated, but that's good enough!
Most of us alive right now won't be here when we skip the next leap year in 2100.
I never go an episode without laughing thx guys
I read that as "without laughing gas" at first glance.
This just shows “Time”, and the Calendar, are constructs of mankind… When the Gregorian Calendar was implemented, 10 days were added to correct the old calendar’s errors… The Mayan Calendar had an 819 day cycle would match the planets’ alignment every 45 years!! I remember “leap seconds” back in the 1970’s as Atomic Clocks got so accurate, we had to adjust what time it was/is… Thanks guys!!
Errata: At 10 minutes , the Doctor said that we are closest to the Sun in July, farthest in January. It's just the opposite. Our seasons come from the tilt of the axis, not the distance to the Sun. The change in distance actually moderates the effect of the seasons in the Northern Hemisphere.
Small mistake: 1600 was a leap year (eligible) because it is divisible by 400. Like the year 2000.
Yeah he inadvertently skipped 1800.
Greetings from Kosovo 🇽🇰! Very informative and funny 😁!
This tells me that we need to metricfy our calendar into units of tens with all of these leaps built in from the start. The current calendar is ancient, built on care and priorities that most of us no longer even know about. While we are at it, we should also create time units based on 100 second increments instead of this archaic system of 60 seconds, 60 m,inutes and 24 hours.
What your asking for is ridiculous. We have the best system right now. All scientists will tell you.
Only units that are completely arbitrary can be switched to metric. Like length, weight, etc...
The rotation of the earth on its axis and around the sun are not arbitrary, they are fixed.
A metric week would no doubt see an 8/2 work/leisure days ratio. Surprised our billionaire overlords aren’t pushing for it.
@@970357ers Terrible joke. Plus conspiracy nonsense. 👎
@@JasonWW2000 it's not ridiculous. It's whatever we want it to be. And I have never heard a scientist say that our current time pattern is 'the best' . This whole video just proved that it isn't.
@@philipberthiaume2314Niel himself has explained all about the different calender systems and how the current one has lasted so long because its so well thought out. I'm sorry I don't have the link to the video, but you can search this channel. Its very interesting the history of calendars. 👍
Great explanation, still they should've mentioned that when we shifted to the current calendar, called Gregorian calendar, back in 1582 the previous Julian calendar has had a seasonal drift (due to the lack of those normal years in centuries that can't be divided by 400) of 10 days which was necessary to correct. And they did it by shrinking the month November of 1582 by 10 days: after the 4th of November the 15th of November followed.
There were riots in the streets, because some people though they had lost 10 days of their lives.
Also the Protestants didn’t trust the Catholics over this issue, so some of them didn’t switch until much later. E.g. Britain (and its empire) only switched in 1762 I think it was. And the Orthodox Christians ... do you know why their Christmas now falls on about January 7?
Close, but the Julian calendar didn’t even account for century years at all. It simply approximated solar years to being an even 365.25 days, putting in a leap day every four years without exception. The Gregorian calendar took out the leap days on century years EXCEPT for those evenly divisible by 400, approximating the solar year to being 365.2425 days. This is much closer to the actual solar year, although it’s still slightly off.
The difference, though, is that it would take about 7,200 years (when accounting for the precession of the earth among other things) for the Gregorian calendar to drift by a full day, as opposed to the 128 years that it would with the Julian calendar. To drift 10 days like the Julian calendar did in 1582, it would take tens of thousands of years. The Gregorian calendar is far more stable. I’m sure by the time the Gregorian calendar drifts ahead by a full day, people can just not observe a leap year when they otherwise would, and everything would become synchronized again.
So I miss 6 hours of sleep a year? No wonder I am tired all the time
There WAS a leap day in 1600. 1700, 1800 and 1900 were common years.
Yep, when he was counting back centuries at 6:53, he skipped 1800.
I figure high-level physicist-math is all greek letters, vectors, and orders of magnitude. So folks who do that get caught off guard sometimes when plain honest-to-goodness countin' numbers show up.
Some computer software even had this bug where the programmers didn’t know about the every-400-year rule, and thought 2000 was _not_ a leap year.
I love explainers!
Always great content, always something to learn, always entertaining! You are the best !
This was the best "explainer" ever.
None of it accounts for the fact that we will NEVER return to the same point in space that we occupied at any given moment because we're SPIRALING through space. It seems that the only way to accurately account for time is to begin at an agreed-upon arbitrary zero, and painstakingly accurately enumerate time. This would soon negate the notion of conventional "days", weeks", "seasons", and similar units such as seconds and microseconds, etc. Even the smallest time period that man can conceive of can be subdivided infinitely. Even infinity itself cannot exist, because you can always add to whatever value "infinite" is. Time will always be an analog function, but man has, from the very beginning, digitized it (incorrectly, but to the limits of our intelligence). Every instantaneous point in time will never happen again. Heavy.
All I know for absolutely sure is when "it's time for a nap!"
You guys are so funny to watch, I enjoy learning and having fun!
The Earth is closest to the sun in January and farthest in July.
But only by a tiny percent.
That’s correct. NDT got it backwards in the video.😮
Depending on your hemisphere….
Yeah... closer to the sun in July, just like he said. That's why it's the hottest part of the year.
@@slyblack6574 Actually, no.
The Earth is closest to the Sun in January.
The seasons are caused by Earth’s tilt. The axis of rotation is not perpendicular to its orbital plane. So we have summer in July because the northern hemisphere is facing the Sun more directly. In the southern hemisphere it is winter in July.
it's interesting to know that mayans were incredibly right with their calculations of year time, and they didn't had super computers, atomic clocks or other modern marvels we have to keep time tracking as we do now.
Just when you think you know your days/year ... Dr. Tyson & Chuck in unison... "Psyche!"
You guys are great teachers.
Very nicely explained. Easy to understand. Thank you!
I knew about the 6 hours but everything after that it’s mind blowing. 🤯
I was born February 29, 2000 and I had no idea about the rarity of such a leap day.
Literally, you have a birthday every 400 years...
@@ilmaioAnd since the life span of an average human being isn't 400 years. The year 200p was a rare leap year.
6:54 None in 1600? If the leap day is put back in every 400 years, and 2000 was one of those years, then shouldnt 1600 have also had one?
Yes, he misspoke. 1600 was a leap year. 1800 was not.
Hey Neal 6:55 1600 is divided by 400.
🥰💗🤣
Bright spot of my day award goes to you two gentlemen! Thanks🤭
I thought i was 45 years old. Im 44 and some change. Im young witches!!!🎉
Feels illegal to be this early..
6:35 i was in the 7th grade when the year 2000 came along; and there was buzz among my schoolmates about having a February 30th that year.... i remember getting excited for it, and then felt disappointed when someone told me "scientists decided it was not necessary to add that extra extra day"
I love this videos!! Thanks for sharing!!
I thought I knew all about the seasons and calendar days. Now I am just happy to get up in the morning.
Whenever the video starts with chuck I've got an explainer I know it's gonna be good
Instead of saying to remove four leap days and then add one, just say remove one when a century is not dividable by 400. I know it's the same result, but it's less complicated.
Nice video.
The 2000 year into blew my mind. Was a freshman in high school and didn't think anything about it.
The precession around the sun has been something I've thought about. That each year the seasons are slightly different cause we're not exactly in the same place in space. So from 2000, before that we saw the end of the seasons, and now after we're seeing the start.
But who decided when to start the calendar and did we make up the years to reach 0 and then all the billions of years before that?
I just love you two ❤
OK. Now THAT was interesting.
I think guys will be using these facts for bar bets.
Do you know Hindu Calendar has a leap month. Every 4th year is a 13 month year.
Always a pleasure!
So, what time is it?
Idk
Fr
Hysterical and informative. Love it
It is as long as you define it! ACTUALLY! 😱😁😝🤪🤣👍👍🇺🇲
So how do we know when we are back to the same spot for marking a calendar year? If we are not looking at distance to the sun and not using the positions of the stars, what are we measuring relative to?
Solstices.
The shortest and longest days of the years are a good prediction of seasons changing and you can get physical indicators for it after a year in the same place just by watching shadows =)
Many Neolithic sites have some structure that should only shine a light on a specific day or few days of the year.
Either that or be the only light shining through when all other spots are not lit.
Neil please make a short or explain carbon dating certain types of objects (matter) if you time traveled into past/future...chemistry , composition, woods, metals, etc..😊
Yes I would like to join the timekeepers guild.
They wear flavor flave clocks.
Er, 1600/400=4. 1600 was a leap year. I think you meant to say that 1800 was not a leap year. Also, the perihelion is in early January, not July. I know it's easy to slip up, even for you. Love you, Neil! Love you, Chuck!
Only the equivalents of 9 modern countries had adopted the Gregorian Calendar by 1600, so it isn't the best example of a year to use for this system.
Nevertheless, both the Julian and Gregorian calendars would assign 1600 as a leap year, it is without question, a leap year.
Thank you for the examples you added to the video!!! finally !!!!!
9:38 ❤ 😂
Fun fact:
Persian new year is literally at the new year. So all who celebrate it around the world, they actually do it at the exact same time (Not at 00:00 every year the time is different) at the beginning of Spring .
Earth's orbit is 5 hrs and 48 minutes short of exactly a full day.
So every 4 years adding a day means we put 24 hours into the calendar but that is 4 x 12 minutes too much (48 minutes).
So every 100 years, that means we have added 1200 minutes or 20 hours too much so we don't add the leap year every 100 years.
However, in doing so means we're now 4 hours short.
So a further correction is applied, every 400 years we add a day back in.
But, if we are short 4 hours every century, then every 400 years that's 16 hours short - by adding a day due to the '400 year' rule (in the year 2000) means we are now 8 hours over.
In another 400 years, that's another 8 hours etc. so in the year 2800 the '400 year' rule will not apply as we will be exactly 24 hours over and actually instead of adding a day we'll have to remove it.
And then the orbit, Tropical calendar and Gregorian calendar will be aligned.
So a new rule will be required:
"Every 4 years add a day.
Every century don't add a day unless the year can be divided by 400 in which case add a day unless three '400 year' rules have been applied in which case remove a day."
I'm 53 and I've been saying to friends and family for years. I have a great garden. And plants started coming up and flowering earlier and I was told I'm loosing my mind
Considering that time is just a construct that we have created to mark our journey through our lives, we put an extranordinary amount of emphasis on this creation. So much so that we even get into relationship ending disagreements about it, or other life altering situations that affect us. This is all based on stories that we've been told is how life works and we take it as gospel.
It’s a convention, like agreeing which side of the road to drive your vehicle on. It may be arbitrary, but disagreements can cause much pain and trouble.
Always informative and entertaining 😅
(❓) So then Dr.Tyson, what does this heavenly "precession" mean to the Zodiacal configurations & how our birthday [signs] have been decided?
Nothing, because astrology is nonsense and a waste product from male cattle.
Absolutely fabulous
Q: How old will a person be when they've experienced a leap day on every day of the week?
A: 28 years old
I found this revelation interesting due to the relation to the phenomenon called the "27 Club", wherein celebrities die before they've experienced a full week of leap years in their lives. Also of note, the World Trade Centers barely missed the eligibility for the 27 Club.
That would depend on their age at the first leap year, at least in our lifetimes. Someone who's less than a year old on Feb 28 on leap year won't be the same age as someone who's 3 years old on the same day, 28 years later. Plus there's years like 2100 to consider, which isn't a leap year. It would be different for someone born on Feb 28 2096 vs someone born Mar 1 2096.
@@jeffidyle4957 sounds legit. you made me realize another coincidence, i.e. that February has 28 days which seems like an allusion to the power of the factor 28 embedded in our lifetimes via the calendar.
@@h7opolo I've always found that stuff fascinating, how a calendar date 28 years later falls on the same day of the week, because there are 7 leap days, regardless of which years the leaps are in. Or that a difference of exactly 4 years will always be a difference of 5 calendar days, again regardless of when the leaps fall (These both excluding the exception years like 2100). If you haven't checked it out yet, you might be interested in checking out the Doomsday system of calculating days of the week for any calendar date in a given year.
@@jeffidyle4957 thanks, i'll check it out. you also helped me discover another factor of 28 embedded in the calendar; did you know that the number of days in a year, 365, divided by 28 yields 13 + 1/28? That means there are 13 (unlucky) segments of 28 days and a reciprocal of a 28 day segment (just one single day out of 28 day segment) within a year. crazy. 🤯
@@h7opolo Very Cool! I didn't know that, thanks for pointing it out! I'd figured out that a year was 52 weeks plus one day, and that would be approximately equal to 13 shorter months (plus a day), but never bothered to figure out that they'd all be 28 days. I wonder if 28 has other significance.
0:00
an exact stellar time frame on an exact Earth year is:
365 1/4 days
Educational Entertainment to the MAX ❤
I LOVE STARTALK ❗️
Niel and Chuck y'all rock! Peace
Love explainers the most ❤
I was half expecting the explainer to be about how long a year is on other planets in our solar system based on the criteria of completing one revolution around the sun. Even more so about how it relates to that planet's length of a day as it relates to it completing one revolution around its axis. Or perhaps even a solar year in regards to how long the sun takes to orbit...the center of the Milky Way? The length of a year as a time keeping method as we know it is truly localized to life on this planet alone. I have no idea how a galactic time keeping method would work.
What a double act - love this channel.
Thank you
Several people noted that 1600 _was_ a leap year. I would say: should have been. The Gregorian calendar was only created in 1582, so many countries may not have adopted it yet in 1600.
I'm learning everyday.
We are never really in the same space. We travel around the sun, and the sun and whole solar system travel around our Milky Way galaxy, and the galaxy is moving in relationship to the entire universe. 😊
Beat me to it!
6:55 Year 1600 was a leap year coz the error was found in October 1582 and hence correction happened 1600 onwards
6:49 You mentioned there is no leap year in 1600. You meant to say 1900, 1800, 1700 didn't have leap years based on your explanation. This 1600 should indeed have been a leap year. It's not an error of "you don't know", it's an error of "the thought didn't align with the words at that point".
Thanks for the explanation
I remember when he explained this on Rogan, he was saying it’s a value conversation days over years or years over days
Excellent!
10:04 We're closest in January Neil and furthest in July, even the animation shows the correct distances and dates.
you could be a name that lasts forever, you already will, and Chuck Nice.
Sooooooo, ... we need to fix this! 😱😁👍👍🇺🇲
One thing I would like to point out is that Earth never actually "returns to its starting point in space" in its orbit around the sun. The sun is also orbiting the galactic core, and sort of dragging the rest of the solar system along with it. While the Earth does return to a specific point on a 360 degree index related to the sun, the Earth never actually occupies the same point in space more than once.
8:05 he’s basically saying we reset our seasonal calendar every century lol. Took me a sec. 😂
Time is another form of matter. You can know the location but not the velocity, or you can the velocity, but the location.
Basically, the calendar is all F’d up 😂
Thats amazing...I dont think majority knows about this. By the way you at 6:58 min you said there was no Leap day in the year 1600 which I think is just an error as 1600 is divisible by 400 so it has got to have a leap day.
The precession got me. Would have loved if you had looked at that more indepth; so when is that taken care of in our calendar?
But everything else was also really cool explained! 2000 Huh
I thnk it showed it as 112,000 years.
Neal is a worthy successor to the late great Carl Sagan bringing science to the masses.
Arguably, the still utilised chosen calender was not the least bit arbitrary and instead pragmatic and deliberate for societal needs.
Another "wow" moment! Thank you, gents!