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

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

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

> 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.

> So it's a bunch of complicated splashy water that is excited by the moon moving past

This explanation is so much better.

If people want to use big words they can say fluid dynamics, but yeah, it's a complex system with a big orbiting body pulling on it regularly, that gives the complex system rhythm but not order.

There’s been some backpedaling lately in the astrophysics community about whether a tidally locked planet could still maintain an atmosphere and potentially support life. More modeling on how such at atmosphere might work has turned from “no” to “maybe”.

See also:

https://en.wikipedia.org/wiki/Roche_limit

https://en.wikipedia.org/wiki/Roche_lobe

Indeed given that we now think most of the heavy elements in the universe were created in type 1a mass-transfer supernovae, we can ultimately thank tidal phenomena for the existence of things like rocky planets and humans.

destruction (or nearly) via tidal mechanics happens in several of larry niven's short sf stories

I expect because without the far bulge, 12 hour tides can't be explained. One bulge would mean 24 hour tides. Not that either explanation is actually correct, but the two bulge explanation matches the obseved periodicity, which is all most people would ever need or care to know about tides these days.

I can't for the life of me understand why graduate level oceanography courses would be teaching it though.

It's an idealized model, accurate if Earth had only a single all encompassing deep ocean. Idealized models are good pedagogic tools to build corrections upon.

It's similar to depiction of projectile motions as parabola s. The trajectories of artillery shells ar not like that, but helps get started.

Good point. I'd be curious if anyone actually has the text showing he said this. It's in principia I guess. My bet was that he never gave a full description, but rather just said that it is moon/sun that *causes* the tides.-- I'd wager he acknowledged the incompleteness of it. Which would still be mostly accurate. It's hard to imagine him knowing about the complicated tides in England and saying definitively he had a full model of the tides.

Your clock was off. Tides advance ~30 minutes per day. But not exactly 30 minutes. Sometimes more. Sometimes less. Sometimes it doesn’t follow a semi diurnal pattern.

Water can’t pass through landmasses, and that is a huge factor. If the earth had no landmasses, the tides would be entirely as you expect. However, if you look at a global visualization of tidal heights, you will see that a small landmass, NZ is a great example, can have highs and lows just miles apart. Same in Panama, what happens on the pacific coast is wildly different to what happens on the Caribbean.

In addition, the gravity of the sun comes to factor as well. Where I am, north of the 50th parallel, we simply don’t get very low tides during the day when we are near the winter solstice. The opposite happens in the summer.

The timing of the tides for any given spot tend to be predictable (where it is semi diurnal anyway, other places are a mess). But heights are extremely variable.

The SE answer gave you a nice map. The points where the white lines coalesce experience no change in height. The blue regions experience low tidal amplitude, whereas the red regions experience high tidal amplitudes. The white lines are the lines of equal phase: if a point on the line is experiencing its high tide, so is every other point on the line, and likewise for low tide.

As is clear from the map, the tidal response is profoundly affected by land mass and ocean depth, which have complex shapes; so too the tidal response is as complex as it is, which is simple in comparison.

From reading the accepted StackExchange answer, I think the answer to your last questions is that this model might still be too simplified.

In your simplified model of the Earth, you would also need to make the ocean deep enough that the water could travel fast enough to keep up with the Earth's rotation (~22 km).

Nicely spotted!

earth is 3D not 2D ;) "bulges" same. that is where confusion comes from. also tesseract is nonsense.

No, don't! Use the simplest model that applies in your context!

If it makes you feel better, the crust of the earth does bulge more in line with the classic answer due to the flow of the underlying magma being effectively uninterrupted by solid obstructions. Which then means the classic tidal answer is technically correct, except what we observe as tides is a delta between land and ocean.

Most kind way of saying Newton was a simple man.

What are the others?

The Bernoulli principle is one.

Turns out teachers are people and general understanding evolves over time and not all at once.

Who would have guessed. Well, Laplace maybe.