How Long is a Year, Actually?

Рет қаралды 195,904

Күн бұрын

How long is a year? Neil deGrasse Tyson and comedian Chuck Nice explain the real length of a year, leap days, and our orbit around the sun. Is a year what we think it is? Find out why the year is not 365 days and why Leap Day does not quite solve the problem. Are there other types of years we could go off of? Learn about the sidereal year and how Earth's orbit precesses around the sun. Plus, what made the leap year in 2000 so rare?
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Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up!
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Timestamps:
00:00 - How Long is a Year?
03:42 - Does Leap Day Fix the Problem?
06:30 - Why 2000 Was a Rare Leap Year
8:15 - Seasonal Calendars, The Sidereal Year, & Other Kinds of Years

Пікірлер: 588

@StarTalk 9 ай бұрын

Where were you during the leap year that wasn't?

@user-zl7vu6kp9h 9 ай бұрын

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.

@michaeljohndias 9 ай бұрын

Time is an illusion to it's interpreter.

@riblets1968 8 ай бұрын

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 They were too busy worrying about outdated computer programs that used 2 decimal digit years to calculate dates.

@Orangeflava 8 ай бұрын

@@riblets1968nowhere, I was born in 2015

@AusTxMale 8 ай бұрын

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.

@redonk1740 9 ай бұрын

I love answers to questions people don't ask. It encourages you to actually think about what you already know.

@user-vu2zh8pv2r 9 ай бұрын

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...

@silvercloud1641 8 ай бұрын

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?

@dre3k78 9 ай бұрын

10:06 Small mistake here. Neil got this backwards. We are farthest from the sun in July and closest in January.

@zeexenon2240 9 ай бұрын

Yup, it must be a trick to count the number of smart folks watching.

@KingCobbones 9 ай бұрын

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).

@greendragonreprised6885 9 ай бұрын

Yes Neil had me doubting for a minute.

@DannyJoh 9 ай бұрын

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.

@thecraigster8888 9 ай бұрын

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.

@shawnrcurrie 9 ай бұрын

These two have the best chemistry!

@panhalt5604 9 ай бұрын

No, they have the best physics.

@DannyJoh 9 ай бұрын

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!

@fmb909 9 ай бұрын

Well said

@UC-4 9 ай бұрын

😂😂

@guidodenbroeder935 7 ай бұрын

Indeed this exact point doesn't really exist, it is all relative.

@rdspam 5 ай бұрын

Anything can change depending on you define your frame of reference

@alexanderxyz6146 5 ай бұрын

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.

@paynec1374 9 ай бұрын

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.

@tristenhood3167 9 ай бұрын

My bday is leap Day in 2000. It's cool to see others with the same birthday

@Arturo-hc9pl 9 ай бұрын

@@tristenhood3167Yoo that’s crazy my birthday is leap day 2000 aswell

@lovelywaz 9 ай бұрын

"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.

@rdspam 5 ай бұрын

Except for the fact that it never is….

@PixelsLaboratory 9 ай бұрын

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).

@dillcifer 9 ай бұрын

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

@dillcifer 9 ай бұрын

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. 🎉😂

@PixelsLaboratory 9 ай бұрын

@@dillcifer 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.

@Milesco 9 ай бұрын

@ 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...."

@jimlipscomb3236 8 ай бұрын

@@dillciferit 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.

@likemeordont5951 9 ай бұрын

These guy never fail to make me laugh and learn.

@avi12 9 ай бұрын

9:38 "but we don't have to worry about that anymore because we have climate change" -Chuck Nice, 2023

@jofftiquez 8 ай бұрын

LMAO

@kcf881 9 ай бұрын

Always great to get a new explainer

@TallinuTV 9 ай бұрын

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.

@Max_Jacoby 9 ай бұрын

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.

@AceSpadeThePikachu 9 ай бұрын

I can only imagine Chuck's reaction to learning about leap seconds.

@acidcatfish8315 9 ай бұрын

I never go an episode without laughing thx guys

@morbidmanmusic 9 ай бұрын

I read that as "without laughing gas" at first glance.

@michaelccopelandsr7120 9 ай бұрын

Neil and Chuck for 2024!

@OrcinusLaryngologist 9 ай бұрын

Feels illegal to be this early..

@aximilian15 9 ай бұрын

The Earth is closest to the sun in January and farthest in July.

@zeexenon2240 9 ай бұрын

But only by a tiny percent.

@richardgratton7557 9 ай бұрын

That’s correct. NDT got it backwards in the video.😮

@matthewgoetter3127 9 ай бұрын

Depending on your hemisphere….

@slyblack6574 9 ай бұрын

Yeah... closer to the sun in July, just like he said. That's why it's the hottest part of the year.

@richardgratton7557 9 ай бұрын

@@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.

@oscarmedina1303 9 ай бұрын

Very nicely explained. Easy to understand. Thank you!

@carlozmrc 9 ай бұрын

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

@danfat5288 9 ай бұрын

Always great content, always something to learn, always entertaining! You are the best !

@heronimousbrapson863 9 ай бұрын

There WAS a leap day in 1600. 1700, 1800 and 1900 were common years.

@MikeBramm 9 ай бұрын

Yep, when he was counting back centuries at 6:53, he skipped 1800.

@thomaslane1547 9 ай бұрын

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.

@lawrencedoliveiro9104 9 ай бұрын

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.

@Thiago100Zwetsch 9 ай бұрын

I love this videos!! Thanks for sharing!!

@oii0712 9 ай бұрын

It was things you thought you knew i thought i knew it but i learned a lot thanks Neil thanks Chuck

@raywright4799 9 ай бұрын

Hysterical and informative. Love it

@Tacitus_Kilgore1 9 ай бұрын

These are awesome.

@tarsha1020 9 ай бұрын

Always informative and entertaining 😅

@jofftiquez 8 ай бұрын

You guys are so funny to watch, I enjoy learning and having fun!

@gjsherr 9 ай бұрын

Small mistake: 1600 was a leap year (eligible) because it is divisible by 400. Like the year 2000.

@djantouahmed7319 8 ай бұрын

Yeah he inadvertently skipped 1800.

@nathanrussell2158 9 ай бұрын

You guys are great teachers.

@ChrisSmith-gx4bz 9 ай бұрын

Love you guys!

@Ben-kh2rh 9 ай бұрын

I love explainers!

@williamjones7163 9 ай бұрын

I thought I knew all about the seasons and calendar days. Now I am just happy to get up in the morning.

@ctcboater 9 ай бұрын

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.

@kirandeepchakraborty7921 9 ай бұрын

Good Stuff ⭐

@shakesrear7850 9 ай бұрын

Absolutely fabulous

@yasserd86 9 ай бұрын

Thank you for the examples you added to the video!!! finally !!!!!

@Causemoi 9 ай бұрын

Excellent!

@alrunesapuri3659 9 ай бұрын

Nice video.

@mariusmacas380 9 ай бұрын

Love explainers the most ❤

@Dauti_ 5 ай бұрын

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.

@fromnorway643 5 ай бұрын

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.

@TinyHouseHomestead 9 ай бұрын

It is as long as you define it! ACTUALLY! 😱😁😝🤪🤣👍👍🇺🇲

@dawnhansen7886 9 ай бұрын

Educational Entertainment to the MAX ❤ I LOVE STARTALK ❗️

@Arturo-hc9pl 9 ай бұрын

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.

@ilmaio 9 ай бұрын

Literally, you have a birthday every 400 years...

@djantouahmed7319 8 ай бұрын

@@ilmaioAnd since the life span of an average human being isn't 400 years. The year 200p was a rare leap year.

@hetk 9 ай бұрын

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.

@Teo117 9 ай бұрын

Always a pleasure!

@dayhawk12 9 ай бұрын

Whenever the video starts with chuck I've got an explainer I know it's gonna be good

@--Z-g-ube-c-k-- 9 ай бұрын

Awesome! 👍🏻 I love science! 🤓

@kariannecrysler640 9 ай бұрын

🥰💗🤣 Bright spot of my day award goes to you two gentlemen! Thanks🤭

@jag731 9 ай бұрын

Just when you think you know your days/year ... Dr. Tyson & Chuck in unison... "Psyche!"

@milosterwheeler2520 9 ай бұрын

OK. Now THAT was interesting. I think guys will be using these facts for bar bets.

@DipenDas-nf7ho 9 ай бұрын

Do you know Hindu Calendar has a leap month. Every 4th year is a 13 month year.

@marinalomanova8077 25 күн бұрын

This is Amazing🙏🙏🙏🙏👌👌👌👌

@jayjames8026 9 ай бұрын

Very cool.

@chejda6066 8 ай бұрын

Thanks!

@lawrencedoliveiro9104 9 ай бұрын

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”.

@erikklein7618 9 ай бұрын

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!

@prajaymaru4390 9 ай бұрын

Thank you

@PokeMarieee 8 ай бұрын

8:05 he’s basically saying we reset our seasonal calendar every century lol. Took me a sec. 😂

@supersportblitz 9 ай бұрын

Just love u guys...

@vykintasmorkvenas6839 9 ай бұрын

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.

@lawrencedoliveiro9104 9 ай бұрын

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?

@PianistTanooki 7 ай бұрын

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.

@Tom-vt4pw 9 ай бұрын

The older you are the shorter the year

@nilo70 9 ай бұрын

Amen

@charlessoukup1111 9 ай бұрын

And, not just because it SEEMS like it.

@ungodlynun4251 9 ай бұрын

facts

@ungodlynun4251 9 ай бұрын

the busier u r, is what I would say

@nymalinda 9 ай бұрын

The days are long, the years are short

@blessedveteran 9 ай бұрын

I just love you two ❤

@proscruxtj4693 9 ай бұрын

I'm learning everyday.

@hugooc 7 ай бұрын

I LOVE this show! 😂😅 It’s smart and funny!

@stuckp1stuckp122 5 ай бұрын

Hilarious interplay!

@BenjySparky 9 ай бұрын

Niel and Chuck y'all rock! Peace

@sekaramochi 9 ай бұрын

Pure love please please please never stop ❤️

@pqrstsma2011 9 ай бұрын

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"

@mrgreenfull3897 4 ай бұрын

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.

@murdock7112 9 ай бұрын

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..😊

@MrJoseSamuels 9 ай бұрын

I only got half that but makes sense. Don’t know how hahaha. Loved it

@EricRoss57 9 ай бұрын

Another "wow" moment! Thank you, gents!

@anthony..23 9 ай бұрын

Gracias

@TinyHouseHomestead 9 ай бұрын

Sooooooo, ... we need to fix this! 😱😁👍👍🇺🇲

@Marie-by6ot 6 ай бұрын

Imagine being born on February 29, 2000. Your birthday alone makes you a cosmic specialty.

@tombradford7035 9 ай бұрын

What a double act - love this channel.

@Opinion_One 9 ай бұрын

9:38 ❤ 😂

@seantlewis376 9 ай бұрын

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!

@carultch 9 ай бұрын

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.

@SpaceMiner007 9 ай бұрын

6 by 4 always = 24 Thanks for the explainer.

@arubaguy2733 9 ай бұрын

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!"

@charlieboutin3341 9 ай бұрын

Ok Neil.. I just asked what time is it? 😂 This was really interesting thanks a lot! ⏰ 📆 👍👍

@marianagyorgyfalvi3659 9 ай бұрын

Interesting🤔!

@tomdonahoe3539 9 ай бұрын

For the next edition of this perhaps bring up the concept of the "Leap Second" 😀

@fraliexb 9 ай бұрын

Hey Neal 6:55 1600 is divided by 400.

@trekkerj 9 ай бұрын

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?

@SilentKaliSmoker 6 ай бұрын

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?

@chasethepops-n-flix2485 9 ай бұрын

I 💚star talk 😂

@bobbyhockey93 8 ай бұрын

you could be a name that lasts forever, you already will, and Chuck Nice.

@clintjohnson1045 9 ай бұрын

I remember when he explained this on Rogan, he was saying it’s a value conversation days over years or years over days

@Synathidy 9 ай бұрын

Lord Chuck's crayon-work is exquisite, as expected.

@blackncompany9487 9 ай бұрын

Been wondering this since i was a kid

@philipberthiaume2314 9 ай бұрын

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.

@JasonWW2000 9 ай бұрын

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.

@970357ers 9 ай бұрын

A metric week would no doubt see an 8/2 work/leisure days ratio. Surprised our billionaire overlords aren’t pushing for it.

@JasonWW2000 9 ай бұрын

@@970357ers Terrible joke. Plus conspiracy nonsense. 👎

@philipberthiaume2314 9 ай бұрын

@@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.

@JasonWW2000 9 ай бұрын

@@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. 👍

@chrism3784 5 ай бұрын

10:04 We're closest in January Neil and furthest in July, even the animation shows the correct distances and dates.

@eltigrillopintito 9 ай бұрын

gretting fellas thank you for your contribution. Dr. Tyson they say you shouldnt meet your heros or risk disappointment so this is good enough much love

@arashjalali4489 8 ай бұрын

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 .

@scottgalbraith7461 9 ай бұрын

Is there a sync in timing between precession and axial tilt? I was wondering if it would get enough out of sync to either make the seasons the same, or bring on seasonal extremes.

@user-dt5cm6vw2v 7 ай бұрын

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

@sergetheijspartner2005 9 ай бұрын

So I miss 6 hours of sleep a year? No wonder I am tired all the time

@ZenRyoku 9 ай бұрын

0:00 an exact stellar time frame on an exact Earth year is: 365 1/4 days

@hn6294 9 ай бұрын

Fun fact rdg the year/calendar: When Julius Caesar was fighting Pompey, he had to cross the sea to Greece. Most of the Roman world (including his enemies) thought it was January and that he would never make the dangerous crossing in the middle of winter. But because this was before he created the Julian calendar, all these bits of extra "day" mentioned in this video added up to several months so what the Roman's thought was winter was actually the middle of fall. So He came. He crossed. He conquered.