Did We Find Longitude Thanks To A...Clock?

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The equator is a clear and accurate line around Earth that makes measuring latitude a precise science, but when it came to figuring out how to do that with longitude, British sailors were at a loss. Until they devised a competition.
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Sources:
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cudl.lib.cam.ac...
www.gps.gov/mu...
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www.britannica...
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scihi.org/john-...
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[@SciShow]

Go to Brilliant.org/SciShow to try their Logic course. Sign up now and get 20% off an annual Premium subscription.

[@minnymouse4753]

If females play larger role in offspring how males are not selective what Keeps mitochondrial DNA in shape

[@klyanadkmorr]

@@minnymouse4753 Having viable babies, anyway @Scifi how did all the other ocean faring cultures figure out longitude? Polynesians sailed far & Phoenicians, I thought it was orientation of the constellations around the north star or a fixed point? Not really understanding the need for a clock considering compass & the stars let alone currents & winds helped.

[@secularmonk5176]

@@klyanadkmorr Polynesian seafaring was an oral tradition built up slowly through trial and error across generations, specific to the island archipelagos the navigators were familiar with.

[@klyanadkmorr]

@@secularmonk5176 Polynesians sailed and traveled further than their immediate surroundings and I was asking qualified @Scifi not you in as much I don't really know the facts on mitochondria. Go away or give valid academic sources as to content of oral traditions is STILL teaching people about the sky stars & seas to navigate. My sources based on recent research Hawaiian global sailing vehicle using ancient methods besides modern stated they used the stars and understood the seas wtf who cares trial and error was done by all civilizations why the European vessels crashed, Phoenicians & others documented as well just this article is making Europe trade wanted exact times and tables as changing all sea travel it only helped their economic trade system .

[@secularmonk5176]

@@klyanadkmorr ​ @klyana130 My, my, my ... sorry Europeans did it better than your heroes ... hopefully you have a back brace for that chip on your shoulder

[@4g4m3n0n]

The reason H1 didn't need lubrication was that the wood components were made of Guaiacum officinale also known as Lignum Vitae. The resins secreted by the wood are oily and act a as a lubricant. As an added bonus, it's one of the hardest woods out there. It's a native species to the Caribbean and Central America where it's known by it's indigenous Taino name, at least in my country, as Guayacán. I remember one of these mighty trees saved my grandmother's house from a cat 4 hurricane, it was great to find out they had a role to play in the improvement of oceanic navigation as well!

[@KOKO-uu7yd]

So glad for your grandmother, too!

[@macaroniandtuna]

I've read that lignum vitae was also used as bearings in some of the first nuclear-powered ships and submarines!

[@Vjx-d7c]

I'm jamaican and the flower on the lignum vitae is our national flower and the blue mahoe is our national tree

[@kmcrafting4837]

I bought an old drum sander off a guy that worked in a battleship machine shop. They used to get huge blanks of that wood in and have to use the metal milling machines to turn it down into bushings/bearings for the prop shaft. Self lubricating and will never rot. They still salvage pieces from sunken paddle boats on the Mississippi. Highly recommend full PPE when working it, the oils are nasty and prone to causing allergic reactions.

[@demonflowerchild]

How exactly did it save her house? Not being mean just curious

[@SlavaPunta]

Fun fact: they also tried to use the moons of Jupiter as a clock, based on their positions and orbits. As they built those time tables, they found that the times the moon(s) passed the planet drifted based on the relative position (distance) between the Earth and Jupiter. It lagged when we were further apart, and was early when we were closer together. They quickly and correctly concluded that this demonstrated that light had a speed. Not only that, but this led to the first (extremely) good calculation for the speed of light.

[@UrLeingod]

IIRC they went into this in an episode of SciShow Space.

[@Carewolf]

Ørsted. The hesitation of light.

[@secularmonk5176]

I read all about this in the pop science history book "Longitude", by Dava Sobel. IIRC, Royal France did an accurate survey of its lands using the Jovian moons transit method.

[@pierreabbat6157]

Did Galileo get any prize money for the celatone?

[@talideon]

"Harrison was stiffed!" I write that only half-jokingly. Part of the problem there is that the establishment in the south of England has a lack of regard for the north because of northern England's emphasis on practical engineering, leading to situations like this, which has persisted for centuries. Harrison was stiffed for multiple reasons, but fundamentally, he wasn't taken seriously enough at the time, because he was from the north of England.

[@ihcfn]

Pretty sure his lack of formal education played a part too, no matter where in the country he came from. Old boys network and all that.

[@dooplon5083]

@@ihcfn Yeah, especially when you've got people like sir Isaac Newton himself backing the rival method, that's bound to drum up even more bias against the guy.

[@adolfofaulkner4684]

That...is higly stupid. And even if it was because it was an "uneducated man", like, bro, this carpenter just made a clock with a quality and maths that rivals an educated engineer, moreover, such educated people, like Newton, couldn't do something of the like for their lives, I doubt they had grabbed a hammer ever in their lives. If this Average Joe could best your best without proper education, the least the government could do was, well, educate him so they would not doubt him anymore. So it boils down to stupid politics and old jeezers affairs, as always.

[@Praisethesunson]

@@adolfofaulkner4684 Meritocracy doesn't and never has existed. Doing the best work doesn't matter when those in power have their egos bruised when a filthy commoner does what they couldn't. Especially in highly class conscious England.

[@secularmonk5176]

@@Praisethesunson PURE meritocracy has never existed. Just like pure capitalism and pure communism. That doesn't change the fact that it is a lodestar to aim for.

[@Hannah_Em]

A big part of the reason Harrison was stiffed on the prize is good old fashioned classism; he was just a poor working class clockmaker, from the *north* no less, how on earth could a mere northern pleb have beaten out the finest astronomical minds of the day (which very much included the people in charge of who got the prizes)? It's a classic example of upper class ego and vanity screwing "less well to do" people over, and in the process refusing to acknowledge and embrace true progress.

[@Praisethesunson]

Wow. I was totally in favor of Harrison. Until you mentioned he was a disgusting NORTHERN Englander. A man from that part of the isles has no business consorting with the finest powdered wigs of London.

[@tim40gabby25]

Nowt rung wi' Northern villages an' that

[@vinniehatcher664]

@@Praisethesunson That's classist.

[@robertbrandywine]

That doesn't sound right. It really sounds like Marxist twaddle. What's your source?

[@SlightlyNasty]

If anyone's confused by the "drive mechanism that allowed it to be wound multiple times a day" at 6:10, he's referring (in a slightly confusing way) to a mechanism called a 'remontoire', which gets around the problem of the driving tension from the clock's mainspring weakening throughout the day as it unwinds. With a remontoire, instead of the mainspring directly driving the clock mechanism, you add another, smaller spring with an automatic mechanism that winds it up using the mainspring's power every time it unwinds a certain amount. That way instead of a constantly decreasing drive force throughout the day, the clock is always seeing a reasonably constant tension from this smaller spring that is regularly being "topped up".

[@damianporter942]

thank you. i love you.

[@tesmat1243]

so basically a mechanical capacitor?

[@boblangill6209]

The A&E series named "Longitude" aired in 2000. It emphasized the intellectual snobbery that played a big role in the board's reluctance to recognize achievement by a non-scientist. At one point it also pointed out that them moon's visibility can be hampered by the phenomenon known as "weather". It occurs out at sea as well as places like Oregon.

[@bevinboulder5039]

That's a great series. I was surprised that the Brits pronounce that word with a hard "g". Sounds weird.

[@Rhaman68]

The video was based on an excellent book “Longitude.” I recommend reading as the author composed it brilliantly. Eventually, I went to London from the US specifically to observe the four clocks on exhibit. To create something from nothing, working each component as to metal, size, function, John Harrison was nothing short of genius. It was a strong emotional moment to see the products of Harrison’s mind since he received no help from the Crown.

[@richdobbs6595]

I suggest that you read the book "Longitude" by Dava Sobel, or the television series based on it, or the movie. This presentation downplays the problems with the lunar table method, and the biases in evaluating Harrison's entry. AFAIK, Harrison's method was one that really solved the Longitude problem, and the Lunar tables method was not used in practice.

[@Jack-ne8vm]

Many other great books by Dava Sobel. Read'm all !

[@vickygraham2444]

Read it! Galileo's Daughter is another great book by Dava Sobel

[@tdurran]

Fantastic book! Funny how angry you can feel towards long dead people just because they're a**holes.

[@Praisethesunson]

@@tdurran I'll always take another excuse to hate the English elite

[@gamorro]

This, and also saying that Greenwich was placed arbitrarily by political reasons as the 0° Longitude reference, is completely wrong. The observatory in Greenwich was used to establish the exact time that was used in Greenwich Train Station, which in turn was used as the reference for the rest of the Stations in the British Islands. Then as the reference for everyone else. Harrison's clocks only started the race to make clocks more and more precise. Nothing political in the why Greenwich, but, if you want political reasons concerning time zones, just look at a Time zone map. THAT is political.

[@ShawnHCorey]

Did you know that ancient mapmakers determined the relative longitude of their cites by using lunar eclipses? Since people in different cities observe the lunar eclipse at the same time, the difference in the azimuth of when it happens is the difference in longitude between the cities.

[@MrVanillaCaramel]

I've heard about this before, the board could not accept that a carpenter had solved the problem, it had to be an astronomer. That was the problem.

[@shaider1982]

Interstingly, the high accuracy needed for the gps clocks meant that time dilation effects needs to be factored in.

[@secularmonk5176]

Yep. Navigation satellites are moving at 8 km/s, so every millisecond of inaccuracy in time agreement corresponds to 8 meters inaccuracy in position on the ground.

[@leogama3422]

Both for speed and gravitational relativistic effects if I remember it wright

[@RAMBO14001]

I quickly navigated myself through oceans of videos to reach Sci-show shores.

[@mal9369]

She sells sci shows by the seashore The shows she sells are sci shows, I'm sure

[@cuzinnnmcgee1782]

She shells seashells at the she shore.

[@thethirdjegs]

Nic: level 69420

[@PronatorTendon]

Caw caw caw-caw caw c-caw caw

[@cuzinnnmcgee1782]

@@jl86_ noice

[@colegreene2153]

This is one of my favorite videos y’all have created in a while (not that precious videos are dull) great video!

[@calladricosplays]

My university did a play called Longitude about this topic. It remains my favorite for how they acted out the Harrison clocks. It's also a delight to see Michael so cheerful about a topic

[@11jokerchen11]

I love this! I'd like to know how seafaring people long before clocks used to be accurate. Polynesians are pretty famous for their accuracy and I know people still sail successfully based on ancient techniques, I would love to hear a similar breakdown of how they do it.

[@JustAnotherHo]

for some reference, modern made watches that are considered highly accurate are like +/- 2 seconds a day (for mechanical, yes atomic and quartz exist too)

[@NathanSMS26]

Longitude lines are all just as long as one another. Latitude is the other one, super easy to remember

[@CaTastrophy427]

latitude is lateral. Even easier.

[@lexington476]

One thing I always wondered about using lunar tables, what if it's cloudy when you're trying to take a measurement?

[@ShawnHCorey]

Same problem with a clock since you need to sight the Sun to determine the local time. Longitude is found by comparing two observations. One is the local position of the Sun. The other is a prediction of where the Sun is at the place where you set zero time. That is, the time of the place of 0 longitude.

[@Yakuzachris10]

The way around this was already found out by Aztecs and later vikings. Its called a show stone or an Aztec mirror. Its like using polarized lenses to see the sun or moon through the clouds.

[@rickkwitkoski1976]

@@Yakuzachris10 birefringence in calcite

[@Yakuzachris10]

@@rickkwitkoski1976 that's an optical quality only found in minerals like calcite. Thin slabs of other minerals will create various optical qualities.

[@joejohns3543]

What a cool episode! And i almost didn't watch it because im catching up after traveling. Im glad I did! ++++++SciShow for another win!

[@stevenemert837]

It is so cool to visit the Royal Observatory in Greenwich to not only straddle the Prime Meridian, but to also see the actual H1 thru H4 timepieces. If I recall, they were actually even running - at least I believe H1 was.

[@flamencoprof]

Yes, in 1996 I had my photo taken with a foot on either side. Well worth a visit to see the clocks.

[@dynamicworlds1]

"LONGitude are the ones that are always long." Since latitude lines get shorter near the poles, while long-itude lines are always the long-est distance to make a circle, you've got it as one by just breaking it down into a root word.

[@mrwess1927]

Latitude is FATitude ie like a belt that goes around. The earth is fat because its big around.

[@Karolomen]

@@mrwess1927 Or FLATitute, as Vsauce once said.

[@CaTastrophy427]

or LAT(eral)itude

[@icarusbinns3156]

~blinks at 0:13~ Hometown, you say? You are right! Golden is my hometown!!! I’d know that M anywhere!

[@joruslinnenbank1822]

Awesome video! You guys deliver great content! Do you have more nautical science history and/or development content for us to enjoy? Keep it up and thank you for years of informational entertainment!! ^-^

[@ixiairisborne1695]

My trick of keeping longitude and latitude straight: latitude and ladder start off sounding similar and so latitude is the "rungs" to "climb" north.

[@LadyAnuB]

Board of Longitude: a bunch of mathematicians who couldn't grasp that a clock could do the job

[@massimookissed1023]

Well they could, but clocks with that accuracy didn't exist.

[@Praisethesunson]

@@massimookissed1023 It did though, they just didn't want to believe some filthy uneducated commoner is the one who made it.

[@CallMeMimi27]

@@Praisethesunson class war class war never changes

[@TomClarke1995]

As a navigator, I appreciate the explanation of this nautical milestone.

[@DaggerSecurity]

What did ancient navigators do for fresh water on long journeys?

[@TomClarke1995]

@@DaggerSecurity Off the top of my head, they probably avoided long journeys away from shore. They would’ve probably used oilskins to store some water and had a means to collect rain.

[@DaggerSecurity]

@@TomClarke1995 I recently watched a vid on KZbin discussing how the ancient Polynesians would navigate the pacific ocean and be able to accurately find small islands at enormous distances. It just boggles the mind. Im sure they must have had some creative ways to get their water out in the middle of nowhere. Thank you for your answer.

[@Keeper963]

There is a fantastic miniseries called Longitude with Jeremy Irons and Michael Gambon that delves into the life of John Harrison and his pursuits.

[@zeideerskine3462]

The lunar position method for calculating longitude may be the principle behind the machine of Antikythera. That would explain why it was on the ship to begin with.

[@twocvbloke]

The spring-driven balance wheel mechanism, it just goes boingy boingy back and forth for as long as there is tension in the springs, cos boingy boingy things are awesome... :D

[@trakirius]

If you are more interested in this story I would very much recommend Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time by Dava Sobel. Very good (and relatively short) read. I imagine that book was probably some of the inspiration for this episode.

[@stanrogers5613]

Interestingly, the voyage of the Beagle, which we remember because Charles Darwin happened to have been hired on as a conversation partner for the ship's captain to keep him sane, was actually tasked to be the first chronometric survey of the world. The ship carried a ridiculous number of chronometers, most to check against one another, many others as spares, to ensure that the time was as accurate as possible. (And there's more than just knowing the clock time involved in the process. You also need to know the "going rate" of the chronometer - the _expected_ loss or gain for that particular timepiece - and have to know the equation of time for the date, since Earth's orbit isn't a proper, well-behaved circle, so solar days are all of different lengths.)

[@ailivac]

2:22 "...a 15 degree per hour drift..." thanks, Bob

[@scottg6564]

Hey Michael, jsyk it's pronounced Leonard, the h is silent. Like leo-nhard -> leo-nard The name comes from lionheart, or more specifically leo-hart, where leo is greek for lion and hart is german for hard/strong/tough. The reason for the insertion of the 'n' is is related to rules in sanskrit, which are technically derived from the nature of the mouth structure itself. Basically because overtime the 'n' sound always emerges simply because the word becomes smoother/easier when the tongue pivots on the rough of the mouth, rather than trying to having 2 vowels back to back with leohard The reason we pronounce leonard/leonhard like lennerd is due to our accent in English. Ironically if the French were to spell leonard in the way that we say it, it basically be "le nerd". Which may be an ironically self-fulfilling prophecy, because as one of the most famous mathematicians, Leonard Euler was indeed, "the nerd" haha. Which becomes even more ironic when considering that the name means strong lion, essentially the king of the jungle. Curiously related: While the etymology of nerd is uncertain, some say it comes from "knurd", which is drunk spelled backwards, referring to people who would rather study than party. An unintended consequence of this meaning paints a picture of a person who is tripped by a bully, whom then falls like a drunk person. But at the end of the day, nerds rule the earth, arguably all thanks to Mr. LeNerd Euler due to the significance of his theorems and his students like Lagrange. Even more ironically it's exactly like the "Lion of Judah" (Jesus) said it would be, "Blessed are the meek: for they shall inherit the earth." In fact, the first person to use the name Lionheart was King Richard I of England, whom even more ironically was given the name "Lionheart" for his bravery during the third crusades to recapture the conquered Jerusalem. Kinda weird how that all works out tbh.

[@davidc5191]

One second per month accuracy is amazing, considering the accuracy for watches today is the Swiss COSC certification which requires accuracy of -4 to +6 seconds per day for mechanical movements.

[@Rubrickety]

There's another (and hilarious) take on the Longitude Problem on Map Men: kzbin.info/www/bejne/aZ6rdGCGm51gmrc

[@radagastwiz]

That one covers the 'messy politics' in greater detail, certainly.

[@Hannah_Em]

@@radagastwiz And the blatant classism. Which ultimately is what the "messy politics" boiled down to

[@mikefochtman7164]

In grade school, our teacher taught us the meaning of 'lateral' and then explained that lines of 'latitude' go side to side, i.e. 'laterally'. So then the teacher asked which way the lines of longitude go and I simply piped up... "The 'long' way around!!" Teacher looked at me a bit.... oddly. lol

[@popenieafantome9527]

Thats kind of how i remember it. Longitude is “long” like a cooked piece of pasta dangling from a fork (up/down).

[@georgewang2947]

For me, "long" has always been associated with vertical measurements, in my mind

[@Rottingflare]

In high school, one of my classmates coined the phrase "latitude, fatitude, like Santas belt," and I'll never forget it. lmao

[@popenieafantome9527]

@@Rottingflare weird/funny phrases do help with memorizing stuff. One i remember is “Stupid People Die First” for the order of electron orbitals. s, p, d, and f in that order going down the periodic table. Another less funny one is simply “Leo say Ger” for redox reactions. Loss of electron is oxidation (leo) and gain of electrons is reduction (ger)

[@mikefochtman7164]

@@popenieafantome9527 My favorite that I heard once was how to remember the order of the planets. Mercury, Venus, Earth, Mars, Jupiter, Saturn Uranus, and Neptune. "Mary's Virginal Explanation Makes Joseph Suspect Upstairs Neighbor". (no offense to Christians intended)

[@SoughtAnarchy]

1:22 I always remembered it how they taught in school. Longitude is LONG and Latitude is like a Ladder

[@briansquibb999]

Wow, quite a story. Thank you!

[@LFTRnow]

The video says a clock was made that lost less than 1 second per month. How did they measure that? Were there actually pendulum clocks (on land) good enough to compare with? What did they do for a standard "second" back then?

[@styrax7280]

I was wondering the same thing. Maybe "1 second per month" is a modern calcuation? Still begs the questions how they measured the accuracy of the clocks back then

[@dimman77]

Astronomically. Star positions. A special telescope called a "transit" (I think) was used to mark when certain stars crossed set positions in the sky, and those were used to set clocks.

[@TheAwsomeSawse]

My Grandpa claims my family is descended from John Harrison but has no proof. I’ve always found it to be such an interesting story.

[@nffclacey]

Was looking this up the other day

[@swapertxking]

the monicker that was taught to me is longitude is the rails on a ladder and latitude was the steps; but man thats fascinating on how we could make a clock to double check that sort of thing in the late 17th and early 18th century. goes to show that the only thing getting more complicated was only the mechanisms in the machines, not the men, not the problems.

[@kahazaba]

This was amazing! Thank you :)

[@yuvalne]

I recommend watching Map Men's video about the subject

[@bmich9146]

I just listened to this tangents today!

[@thetiniestpirate]

Map Men did a great video on this, can recommend

[@keitmo]

Dava Sobel's "The Illustrated Longitude" is a great account of this story.

[@rolfs2165]

In German latitude and longitude are pretty easy to remember, because latitude is "Breite" (width) and longitude is "Länge" (length). You just need to remember how to hold the tape measure.

[@fourcatsandagarden]

my teacher taught us that LONGitude is LONG and lAtitude is tAll. even though things in any direction can technically be long, it worked for me to remember which one went which way.

[@alexhudspeth1213]

This story gets even more dramatic with Kendall's K2 (a simplified version of the K2, a copy of the H4) and its role in the HMS Bounty Mutiny.

[@smoothjazzfails]

Hey that first pic is in Missoula! I live there! :)

[@jeremyblade7561]

I always remembered them because Latitude goes side to side like the steps of a latter while longitude is up and down like the long sides of the latter. I know there is no real up and down on a globe, but if you put the poles on the top and bottom like they tend to be, it works.

[@alpe5801]

Greek astronomer, Hipparchus (190-120 BC), first used longitude and latitude as coordinates. Prior to Harrison's H1 in the early 17th century Galileo showed how sailors, once they were on land could determine Longitude by the moons of Jupiter.

[@safety_sid]

Also Latitude is like the word "ladder" and latitude lines look like ladder rungs

[@Richard_Jones]

You must be American.

[@angryatheist]

Lats are how I remember

[@charlesmoore3390]

This is how I remember it as well. And yes I'm American.

[@randalalansmith9883]

There is no middle-T in american english. No diff between Paddy and Patty.

[@Grizzlythatsme]

I always found it easy to differentiate longitude and latitude because latitude makes a ladder up and down the globe

[@SouthernersSax]

Harrison's land clock design is accurate enough that were one constantly running since then, it would have lost just one hour by now. Thanks to Daylight Savings Time, that hour loss is effectively negated for part of the year.

[@DavidFMayerPhD]

The Earth rotates NOT once per standard (MEAN SOLAR) day, exactly 24 hours, but rather once per SIDEREAL day, 23 hours, 56 minutes, 4.0905 seconds. Telescope clocks rotate the device once per sidereal day, which makes the stars appear to stand still. Word origin is sideris (Latin) = star.

[@michaelmisevich4876]

have a suggestion for a new topic how fast do the fastest man-made objects spin I've heard of turbochargers spinning up to 200 thousand RPMs but do other things spin even faster than that

[@terryenglish7132]

Another way to remember which is which is the Jimmy Buffet song Changes in Latitudes. Hes going south to Key West

[@tma2001]

One important clarification to make is that the Earth rotates once in 24 hours of sidereal time (i.e. relative to the stars) not the mean solar time that we set our civilian clocks to.

[@demonflowerchild]

Michael is my favorite

[@autodidacticartisan]

As someone who regularly lifts the heavy thing and then puts the heavy thing back down again I remember longitude v. latitude because the muscle known as your "lats" goes *up and down* your back

[@meadsky]

Yes, read the book Longitude, it's great

[@colleenkochman9656]

one of my favorite books

[@Benni777]

“Time is relative; it’s only worth depends on what we do as it’s passing.” -Albert Einstein

[@hans_von_twitchy1014]

I learned "latitude, flatitude" as a way of remembering which was which.

[@MorriAelthyn]

Yes! I was taught this one too and it stuck really well LOL

[@isaach1447]

I learned it as ladder’tude…because it’s like the rungs of a ladder.

[@hans_von_twitchy1014]

@@isaach1447 I like that one too. Having defective memories inspires people's creativity.

[@AlexWalkerSmith]

4:04 Dana Carvey, master of disguise and mathematician.

[@haggielady]

Thank you.

[@madsringswaldegan1687]

A better trick for remembering is that LONGITUDE lines are all the SAME LENGTH! The first trick confused me so much I mixed it up more when someone first taught it to me

[@walterbrown8694]

The east or west longitude determination may be made at any time of day or night using a time reference such as a clock or chronometer. Not necessary to perform the observation and calculation of longitude at any particular time of day as long as the chronometer's reference time and location are known, and of course the local time of the observer.

[@dynamosaurusimperious2718]

I like this video very much

[@takumi2023]

I use latitude = ladder, rungs on the ladder. And longitude = long or up down as oppose wide which is left and right.

[@Akumeitakai]

"Lat sat on the Equator," is how I learned that one ...

[@nickkk420]

Latitidue, is the A for around Longitude is O for over

[@dynamicworlds1]

"LONGitude are the ones that are always long." Since latitude lines get shorter near the poles, while long-itude lines are always the long-est distance to make a circle, you've got it as one by just breaking it down into a root word. Edit: not disagreeing in case that wasn't clear. Just the method I was taught that I've found incredibly simple and easy to remember.

[@nickkk420]

@@dynamicworlds1 we all have our tricks, yours is clever I like it

[@LuisAldamiz]

Never before heard Greenwich pronounced as Grenich, why? Also the meridian goes through other places than London, such as quite conveniently Paris and Valencia, that's not very clear in that map however.

[@tag1462]

Sorry for being late to the party, and if nobody has referenced it... Spaceballs: The Movie. Where are we? Right now. And then you have Captain Jack, stepping right off like he meant to be there. I still can't wrap my mind around modern nautology when the science was already there. You knew the earth was a globe, You knew the stars. Divide by twelve, not so hard.

[@instaperil]

Clockmakers rock

[@erikk77]

No, they swing.

[@misterflibble6601]

@@erikk77 They're all wound up though

[@shahbazstailan4361]

superb

[@sarcasmo57]

Nifty.

[@davidhand9721]

I suggest that you listen to the song "latitude" by Good Game.

[@PeterKooimanNL]

Umberto Eco wrote a book about this: The Island of the Day Before.

How I remember which one is which: Latitude is not the one you miss if you're late and it really should be the other way round!

[@einsteinwasright1044]

Determining longitude by comparing the time of local sunrise and sunset relative to an accurate prime meridian clock would suffer from errors due to the latitude, worse as the local latitude is further from the equator. Instead, one should compare the much more accurately measured moment of local apparent noon (solar transit across the north-south meridian, which they were measuring anyway to determine the latitude) with the prime meridian clock. A correction for the equation-of-time would be necessary, but as shown in your video an analemma for that was printed on the maps.

[@Rottingflare]

There is nothing better than hearing about average citizens causing significant improvements in technological advancements, or scientific methods. Especially when they're outside of their main field of expertise!

[@zeideerskine3462]

I think we need an episode on Polynesian Islander navigation.

[@Warden409]

Go look at GM Word of the Week. They have a three part series on navigation. Good stuff.

[@sirrathersplendid4825]

Short answer. YES!

[@dewdroppedrose]

My science teacher taught us the difference as such. Latitude = fatitude, as in how big the earth’s “waist” is. Longitude is…the other one.

[@francispitts9440]

It’s similar to how I taught my kids to remember Port is four letters and so is Left, Starboard or steer-board is more letters like Right is. Anything that helps someone remember is good 👍🏻 😊

[@Catastropheshe]

5:15 * chuckle * 😁🤭

[@marcelogaea1064]

Learned. Again. Thanks, SciShow👍🏼

[@Lord.Kiltridge]

Longitude TV Movie 2000 HIGHLY recommend.

[@jansenart0]

LATTITUDE like LADDER-TUDE like the rungs of a LADDER. And Longitude is the other one.

[@jamiearnott9669]

How funny I live within walking distance to this hypothetical meridian point for longitudinal. Thanks for reminding me how confusing it can be to tell the difference between longitudinal and transverse latitude. Also I like the human story of a self taught person helping to solve a pressing technical scientific challenge from a humble background, this resonates especially for me. Although half the prize sounds fair and no sour grapes, only that there were two reliable methods for solving the longitudinal problem and the stargazing method would require less energy wastage? Also on the social mores of that time period, I suppose you'd need to know your place in the world after once having the largest absolute physical empire in history. That's only my objective position on this scientific/geopolitical story though, no "woke" included ;-)

[@riverwildcat1]

First-rate video. TY

[@romulusnr]

A detail: a GPSr needs at least three satellite signals to determine location as it has to calculate an intersection of each satellite's distance. If you want altitude as well, add another satellite. This is why GPSrs get better accuracy when there's a. more sky visible and thus b. more satellites to get signals from. Also, the satellites transmit *where they are* so that the distance to the satellite has a reference point.

[@steefant]

there is no "constant speed of light"! 9:05

[@MadelineWilson611]

My preferred pneumonic device for latitude and longitude is that LATitude is like the rungs on a LADDer.

[@TMWriting]

I was taught in Scouts that it’s LATitude and FATitude, to remember that it goes around the Earth’s waist

[@LetsTakeWalk]

Harrison managed to go from making the equivalent of the Colossus (the first Electrical computer) to an Iphone in a tenth of the time.

[@RiggingDoctor]

It’s how we find our longitude while sailing across oceans ;)