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The problem of predicting tides was so important that it attracted many Physics and Maths heavy weights. You can well imagine how important predicting tides wou

by srean 1y ago

The problem of predicting tides was so important that it attracted many Physics and Maths heavy weights. You can well imagine how important predicting tides would have been for D-day landing. One related fascinating historical artifact is the special purpose analogue computer designed by Lord Kelvin in the 1860s based on Fourier series, harmonic analysis. Think difference engine in it's cogs and cams glory, but special purpose. https://en.m.wikipedia.org/wiki/Tide-predicting_machine https://en.m.wikipedia.org/wiki/Tide-predicting_machine Possibly one of the first examples of Machine learning, with Machine in capital 'M'. It incorporated recent tidal observations to update it's prediction. Note that sinusoids are universal approximators for a large class of functions, an honour that is by no means restricted to deep neural nets. George Darwin (Charles Darwin's son) was a significant contributor in the design and upgrade of the machine. https://en.m.wikipedia.org/wiki/George_Darwin https://en.m.wikipedia.org/wiki/George_Darwin Other recognizable names who worked on tide prediction problem were Thomas Young (of double slit experiment fame) and Sir George Airy (of Airy disk fame).

neilfrndes 1y ago
Veritasium made a video on this topic a couple of years ago: https://www.youtube.com/watch?v=IgF3OX8nT0w https://www.youtube.com/watch?v=IgF3OX8nT0w
CGMthrowaway 1y ago
Have you seen the SF bay model? https://www.youtube.com/watch?v=i70wkxmumAw https://www.youtube.com/watch?v=i70wkxmumAw
- srean 1y ago
  That was so fascinating. Thank you.
  - synalx 1y ago
    If you're ever in SF, it's really worth going to see. Such a cool mixture of art and technology.
- trillic 1y ago
  Check out current lab Hyperlocal ocean modeling for science, defense, and recreational applications. https://www.current-lab.com https://www.current-lab.com Anecdotally works very well in Tidal harbors with multiple rivers.
rhdjsjebshjffn 1y ago
> You can well imagine how important predicting tides would have been for D-day landing. Is this intended to communicate positivity or negativity? Predicting tides was known to the ancients; it would be lovely to explore the hubris of the modern narrative. Edit: fundamentally, if hacker news has taught me anything, it's that "downvote = makes me feel bad and doesn't want to answer questions". The entire concept of democratic news aggregation was a lie.
- grues-dinner 1y ago
  I think there are two ways to interpret that sentence: "it would have been important": one which implies tidal prediction was unavailable at D-day but would have been useful, and one that implies it was indeed available (subjunctive conditional or "the Anderson case", apparently, per Wikipedia) I don't think anyone is claiming tide times were so unpredictable in 1945.
  - pfdietz 1y ago
    They were predictable. Interestingly, Rommel misunderstood how tides affected landings. He thought the landings would be done at high tide, so the invading troops wouldn't have to advance across wide expanses of beach. In reality, the allies wanted to invade on a rising tide, so the landing craft, grounded to let out troops, would refloat and be able to move back out. Also, invading at lower tide meant beach obstacles would be exposed and unable to damage the landing craft.
- krisoft 1y ago
  > Is this intended to communicate positivity or negativity? It just says it was important to predict the tides. There is no positivity or negativity to it. Your question doesn’t make sense, hence the downvotes. > Predicting tides was known to the ancients Good. To which ancients? With what accuracy and how far into the future? What techniques did they use? Tell us more. > it would be lovely to explore the hubris of the modern narrative. Explore it then! Would love to read it. It is not like there is some conspiracy holding you back.
TomK32 1y ago
The Battle of Clontarf on April 23rd 1014 springs to mind. While the high tide was of favour for the invading Vikings (who had already founded and still ruled Dublin) at 5:30 in the morn, the battle lasted all day and the next high tide at 17:55 cut off their way to a nearby wood and many killed or drowned as their were pushed against the tide. The times were calculated in 1860 by Samuel Haughton. There is of course an In Our Time episode https://www.bbc.co.uk/programmes/m0029qh3 https://www.bbc.co.uk/programmes/m0029qh3

by srean 1y ago

neilfrndes 1y ago

Veritasium made a video on this topic a couple of years ago: https://www.youtube.com/watch?v=IgF3OX8nT0w https://www.youtube.com/watch?v=IgF3OX8nT0w

CGMthrowaway 1y ago

Have you seen the SF bay model? https://www.youtube.com/watch?v=i70wkxmumAw https://www.youtube.com/watch?v=i70wkxmumAw

srean 1y ago
That was so fascinating. Thank you.
- synalx 1y ago
  If you're ever in SF, it's really worth going to see. Such a cool mixture of art and technology.
trillic 1y ago
Check out current lab Hyperlocal ocean modeling for science, defense, and recreational applications. https://www.current-lab.com https://www.current-lab.com Anecdotally works very well in Tidal harbors with multiple rivers.

rhdjsjebshjffn 1y ago

> You can well imagine how important predicting tides would have been for D-day landing. Is this intended to communicate positivity or negativity? Predicting tides was known to the ancients; it would be lovely to explore the hubris of the modern narrative. Edit: fundamentally, if hacker news has taught me anything, it's that "downvote = makes me feel bad and doesn't want to answer questions". The entire concept of democratic news aggregation was a lie.

grues-dinner 1y ago
I think there are two ways to interpret that sentence: "it would have been important": one which implies tidal prediction was unavailable at D-day but would have been useful, and one that implies it was indeed available (subjunctive conditional or "the Anderson case", apparently, per Wikipedia) I don't think anyone is claiming tide times were so unpredictable in 1945.
- pfdietz 1y ago
  They were predictable. Interestingly, Rommel misunderstood how tides affected landings. He thought the landings would be done at high tide, so the invading troops wouldn't have to advance across wide expanses of beach. In reality, the allies wanted to invade on a rising tide, so the landing craft, grounded to let out troops, would refloat and be able to move back out. Also, invading at lower tide meant beach obstacles would be exposed and unable to damage the landing craft.
krisoft 1y ago
> Is this intended to communicate positivity or negativity? It just says it was important to predict the tides. There is no positivity or negativity to it. Your question doesn’t make sense, hence the downvotes. > Predicting tides was known to the ancients Good. To which ancients? With what accuracy and how far into the future? What techniques did they use? Tell us more. > it would be lovely to explore the hubris of the modern narrative. Explore it then! Would love to read it. It is not like there is some conspiracy holding you back.

TomK32 1y ago

The Battle of Clontarf on April 23rd 1014 springs to mind. While the high tide was of favour for the invading Vikings (who had already founded and still ruled Dublin) at 5:30 in the morn, the battle lasted all day and the next high tide at 17:55 cut off their way to a nearby wood and many killed or drowned as their were pushed against the tide. The times were calculated in 1860 by Samuel Haughton. There is of course an In Our Time episode https://www.bbc.co.uk/programmes/m0029qh3 https://www.bbc.co.uk/programmes/m0029qh3