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

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.

Hosted by: Michael Aranda

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[gmnn]

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!

[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.

[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.

[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.

[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".

[boblangill]

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.

[richdobbs]

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.

[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.

[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.

[RAMBO]

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

[dynamicworlds]

"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.

[shaider]

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

[LadyAnuB]

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

[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

[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)

[jokerchen]

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.

[NathanSMS]

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

[colegreene]

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

[lexington]

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

[TomClarke]

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