
The Grand Unified Theory of Rogue Waves - theafh
https://www.quantamagazine.org/the-grand-unified-theory-of-rogue-waves-20200205/
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Ono-Sendai
If anyone wants to see a clear video of a rogue wave in the wild:
[https://www.youtube.com/watch?v=uK_4V3zqAvg](https://www.youtube.com/watch?v=uK_4V3zqAvg)

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killjoywashere
I wish people walking around with personal video cameras in their pockets were
a thing at the turn of the millennium. I was on the bridge of an aircraft
carrier going around Cape Horn, taking green water over the bow. Not once, but
many, many times.

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gshubert17
> [a better model] paving the way for machinery that could, for instance, scan
> the ocean and notify ship captains that they face a 13% chance of running
> into a 30-meter wave in the next 15 minutes.

What sorts of actions would captains take under these circumstances? Rogue
waves are so large and powerful--would any action be enough to prevent losing
a ship?

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eloff
You'd want to orient the ship to hit it bow first probably, rather than on the
side where it could roll or punch a hole in the ship. But what Captain in a
serious storm is not going bow first through the waves anyway? I don't know
much about the industry, so that's an honest question - maybe deadlines and
route optimization still plays a role and they will often sail at an angle to
the waves, I doubt they would ever sail near 90 degrees in any case, but maybe
you could change a 30 degree angle to closer to 0 if you had warning.

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slavik81
If the wave is big enough, bow-first won't save you.

If you go over the wave, half your ship ends up cantilevered over the peak. A
ship isn't built to hold half its weight in the air like that. It will break.

If you go through the wave, the upper decks get hit by a wall of water. The
windows blow out, the bridge is destroyed, the computers are toast and the
ship is swamped.

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echelon
Why don't we design submersible container ships? Are the energy costs of
displacement while moving entirely underwater too expensive?

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eloff
It would definitely use more energy, and container shipping is all about
efficiency. It's a non-starter.

~~~
usrusr
Many military subs are actually faster submerged than surfaced.

The wave drag (or wave resistance, to disambiguate from the shock wave drag of
supersonic aerodynamics) referenced in sibling comment is the energy contained
in the waves created by a surface vessel. The details that you'd have to
understand to optimize a hill shape are quite complicated, but for a simple
surface vs sub comparison it's enough to know that surface waves exist and
that they contain energy that is projected away. A sufficiently submerged
vessel does not create those.

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ishtanbul
this seems like an insurance problem, rather than a technical one. rogue waves
appear to be rare enough that spending money on prediction or detection might
outweigh the cost of simply insuring against catastrophic loss

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HeyLaughingBoy
Tell that to the people on the ship that it happens to!

Granted, it's usually survivable. Decades ago a friend of mine on a
containership experienced a rogue wave with no more harm than being terrified
by "either the last thing I was ever going to see or the most majestic thing
I'd ever see" but it doesn't always end that way.

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jschwartzi
Does this have anything to do with Markov Chains? Because it's smelling like
that type of problem.

The verbiage in the article is a little too "wanky" for me to tell.

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mturmon
If you had to reach into your bag of probability concepts to pick the most
closely related one, it would be "Large Deviations", which comes up for
engineers in the context of information theory.

Basically, as explained in the article, many kinds of rare events (like,
averages attaining values far from the population mean) can be characterized
without knowing a lot of problem-specific details.

For instance, if the typical value for an average of 1000 positive numbers is
10, and you want to know the chance of an outcome greater than 100 (a "large
deviation"), you can pretty much just calculate the chance of the outcomes
very near 100, without caring about 120 or greater. That is, it turns out that
the larger outliers carry very little probability, although that's not
obvious.

This phenomenon comes up a lot and goes by several names. It was known to
Laplace and there's an approximation used commonly in that area bearing his
name. It's also related to the notion in information theory of the "typical
set".

Similarly, you can, in some ways, characterize the _realizations_ that cause
these extreme values. (As opposed to just computing their probabilities.)

For instance, if I remember right, the typical realization that gives rise to
a large average has just a few larger-than-expected values and a vast majority
of about-average values, rather than every value being slightly too large.
This is a highly general property.

