Depends on the surrounding terrain and if you are on street level. This video here has moments that if you are on street level it crashes all around 4:30 https://youtu.be/EPjliKVtmUA?si=5ELV7bnxkQBa_xZt

For example last year's Greenland Tsunami that was in a fjord reached 200m height and a top speed of 150km per hour.

Yes, Fukushima looked a lot like a flash flood compared to the kind of wave portrayed in apocalypse themed movies.

> water moving

The complexity comes from the fact that water moves mostly up-down in a wave, not horizontally. It's _wave_ front that moves horizontally towards a beach.

Missing the point a little, tsunami's are not comparable to ocean waves. They ARE more like a huge, very fast, rising tide, modelling is not the same as a breaking ocean wave. This research impacts the modelling for ocean or coastal structures which have relied on the breaking wave dynamics for a particular depth and topology. The research shows that the maximum breaking wave height can be much greater than previously thought. So, the off-shore wind turbine which was believed safe because the expected max wave height will never manifest as a breaking wave in the depth of water it's sitting in may actually be in jeopardy.

Or, and that's the most important one you missed, "just air". If there's enough air movement to offer an opposing force, that wave gets broken.

"The science is way behind the engineering" - it has been my experience that this is the case for most fields with commercial or hobbiest applications.

Wave science has been tightly tied to lab models and computer models of lab conditions for as long as I can remember. It seems like an inherently calculatable environment, and the messiness of nature a distraction. This bias, I think, is what has caused it to lag behind the empirical reality of wave engineering. Observation is hard and often unfruitful. Simulation often fails to imagine the complex interactions that create extreme observations.

It’s just a hard slog any way you look at it.

I think what was meant were the direction of travel of the wave as one axis and the height as the second axis. The third axis would then be the direction along the length of the wavefront, as seen from above.

The assumption was that this third axis was irrelevant with respect to the wave's breaking behavior and max height - so simulating waves in a narrow channel of water would be the same as simulating waves in an ocean (as far as max height is concerned).

This paper now showed the assumption is wrong, and interactions parallel to the wave front (or coming from yet other directions) also influence the max height.

At least, that's my understanding.

from the side; the assumption is that the wave is propagating in a single direction so the two dimensions are the vertical and the axis of propagation

I've gotten into surfing over the last few years (started during covid) and it's made me really appreciate how elaborate wave patterns are.

If you know the directions of the incoming swells and you're out in the water judging each wave to decide if you can ride it, you start to get a feel for how swells that have different frequencies and are coming from different directions can merge together.

There are times when a certain combination of swell forms a great peak—maybe the long period south swell and short period southwest swell are merging—and you realize it's happening on a regular basis, like once every three or four sets. This kind of thing can actually be very useful for getting waves when it's crowded. People will tend to concentrate where the peaks are showing up most consistently, but if you can identify a "weird" peak that reoccurs on a regular basis, you can get it to yourself each time it appears even if there are like 30 other surfers nearby.

Rogue waves/sneaker waves are the same kind of thing. In surfing there's the term "cleanup set" for a set of waves that are way larger than the typical pattern and break much further out. I tend to see at least one of these per session in northern CA, though it depends on the day—while you can get cleanup sets in relatively small conditions, they seem to show up more frequently as the swell gets larger and more powerful.

And then every once in awhile there are waves that are on a whole other level. I used to play poker a lot and statistically it reminds of something like getting a straight flush. It's quite rare obviously but if you spend a lot of time playing poker you'll eventually get some. I was surfing in Linda Mar on a fairly calm shoulder high day (3-4f) and then out of nowhere I got to experience what I'm pretty sure was a double overhead wave (10-12ft) during a cleanup set. Linda Mar is a beginner spot so you can imagine the carnage that it left behind :)

How does it work from an energy point of view. If a wave weighs ten tonnes per meter width per meter high, say, each collision needs to move increasingly large amounts of water up like a hanoi tower (although some of the energy may come from vacating space going down). Is that energy coming from currents or the waves? Can you really get 100x bar a tsunami or similar?

I don't think that such scenarios would fall under any sort of long-tail thinking, since the chance of having N waves converge at a point decays exponentially in terms of N, whereas the height/energy/damages/etc. increase polynomially at most. This means we can place finite (and not very large) 50th, 90th, 99th, etc. percentiles on the heights of combined waves, assuming we can accurately predict the height distribution of a single wave.

As a related thought experiment, suppose I jump down from a 5-foot ledge and land on the ground, sending a wave of pressure through it. In principle, I could be walking down the street, when a similar wave of pressure comes up through the ground and launches me 5 feet in the air. Yet the vibrations in the ground are normally so dispersed that such a ground wave will never occur in anyone's lifetime (outside of an earthquake, of course).

A 20 foot wave is likely to have approx 4 times the volume of a 10 foot wave. So combining 2 x 10 foot waves won't give you a 20 foot wave. More like a 14 foot wave.

I think the chances of three of anything colliding in a single place are extremely low

I think (but definitely could be wrong) that this is more about how open-water waves can form great heights (i.e. what I've often heard referred to as "rogue waves" in the past). I do know these rogue waves were a bit of a mystery in the past because mathematical modeling said waves shouldn't get that big.

Near shorelines/sea floors is a whole other ball of wax, though, because the terrain can essentially "funnel" waves into giant monstrosities like what happens at Nazare. Depending on the shape of the shoreline I don't believe there is a single "max wave" height, i.e. I believe you can have situations like the Bay of Fundy (that is tides though, not waves) where you can get massive difference in high vs. low tide due to resonance.

This caught my eye. After checking it seems that the correct height is 100 feet, or ~30 meters.

Meters or feet?

The surfing records from Nazare are all under 30 meters, i.e. under 100 feet.

100 meters seems much too high for any non-tsunami wave.

Hello, I recently read in the comment section on HN that the waves at Nazare are more like 30 meters high. Maybe you mixed up meters and feet ? Just to let you know, in case you didn't notice the other comments. Cheers, mate.

Nazare is around 28m max. Been there, and I know the world record holder.

You mixed up feet with meter.

The Portuguese town of Nazaré can deliver 100-foot (30.4 meters) waves.

What they've done here is a specific model of a specific physical phenomenon, that predicts higher extremes than the previous models predicted (and better agrees with certain observations that contradicted the previous models). Specifically, they are modeling certain aspects of how waves that oscillate both along and across the main direction of motion behave.

You can't apply this research itself to finance, because it's about the movement of water, not money. You might be able to take inspiration from some of the math, or take heed that even well established models can turn out to be wrong in significant ways.

> Most financial software uses known worst case scenarios while doing retirement planning, such as a 30% drop in equities.

... yes, and of course in retrospect of 2008, COVID, land war in Europe, "totally not a war in the Middle East" ... who knows what's the right "worst case" scenario.

But. But. There are clear difference between business as usual and blatant charlatanism masquerading as BAU. (See the snippet below, highlighting the bad deals between 2006 and 2008.[1])

And rating agencies just issued AAA or whatever. This of course points to problems with the industry not with science. (See also the linked reddit thread.[2])

"""

D. Fallen Angels

Next we examine structured finance securities that suffered the most severe downgrades. From 1983 to 2008, 11% of the tranches were eventually downgraded 8 or more notches (fallen angels). Table 7 decomposes these fallen angel tranches by their original credit rating. Tranches rated below Ba3 cannot fall more than 8 notches by definition (the lowest rating, C, is precisely 8 notches below Ba3). Surprisingly, we find that most fallen angels were originally rated AAA (19%). Tranches originally rated Baa2 or A2 make up the next largest portions of fallen angels at 12% and 10%, respectively. Clearly, some of this is supply driven (every CDO has a AAA tranche, but not every CDO has a Aa1 tranche). Table 7 also shows that nearly all of the fallen angel tranches (86%) were issued between 2006 and 2008, underlining the poor quality of recent deals.

"""

[1] https://www.journals.uchicago.edu/doi/full/10.1086/648293

[2] https://www.reddit.com/r/AskEconomics/comments/13812y2/what_...

I doubt this is relevant for EM waves. Water waves are much more complicated because the wave speed in water is highly frequency dependent. That makes things much harder to model. Whilst in optics (and thus EM) people have been reasoning in terms of wavefronts in 3d for about half a century. Look at a YouTube channel like Huygens optics to see what a former professional can easily do in his shed.

> superfluid quantum gravity with Bernoulli's and Navier-Stokes, and vortices of curl

And Gross-Pitaevskii

Not as scary as Gyp Rosetti

https://m.youtube.com/shorts/AoUy5ZuK0F8

No, it's acknowledging that for decades, the people doing mathematical modeling of waves dismissed lived experiences and reports of waves that didn't fit their models as "anecdotal", "folklore", and "insufficiently evidenced".