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Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

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Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#141

Post by oneoff786 »

Buttons840 wrote: post #105
fritzo wrote: post #26

> 30,000 times more initial energy than any recorded events As a statistician: this is why heavy-tailed modeling matters. Schools teach the finite-variance version of the Central Limit Theorem and students believe they live in a normal world. The real Central Limit Theorem [1] predicts large rare events following Lévy α-stable distributions. [1] https://en.wikipedia.org/wiki/Stable_distribution#A_generali...

I'm no expert on stats, this discussion is a bit over my head, but it reminds me that not all distributions have a mean. A Cauchy distribution has no mean; as you average successive samples, it never settles down to a consistent average. I was surprised when I first encountered Cauchy distributions and up until then had considered that all distributions would have a mean. I suppose it is one of those "heavy-tailed" d…

There’s no need to get mathy tbh. Distributions are not real, and the ones we create only describe parts of what actually happens. This is obvious and always has been.

How much water does your faucet leak per day? That might be a good case for a normal distribution. But today I smack it with a hammer and it can’t stop flowing. We now have a ton of water far more than should ever appear on that original normal distribution. Is that because the model is wrong? No. It’s because the model is not designed for these circumstances.

We can’t build a model that estimates flow distribution including the possibility that I smack it with a hammer. That doesn’t mean we don’t believe it won’t ever happen or even that we think it is unlikely to happen. It’s just a weird edge case.

A lot of people (taleb) imply statisticians are idiots because they insist the distributions are comprehensive. But statisticians don’t insist this. Black swan, fat tails, and all that are just terms for things outside modeled conditions. And yeah. They happen.

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#143

Post by echelon »

qikInNdOutReply wrote: post #103
echelon wrote: post #46

Earlier quoted context omitted.

> Research at Imperial College, London, shows that far from being rare events, rogue waves can emerge frequently, and may be responsible for some of the 200 supertankers and container ships longer than 200m that have sunk in poor weather conditions in the past two decades. The loss of ten ships a year seems incredible to me. Surely "weather", if it were to blame, could be avoided. This amount of loss is steep. Is it…

There are also source of loss, nothing can be done against. One can not even predict them. Ocean floor methanhydrate and a volcanic shift, results in tremendous bubble columns, which just open up a shaft that can carry nothing. Water begins to boil, ship falls in, breaks apart... End of story.

Surely the gas-producing seafloor distribution can also be studied and modeled.

How many incidents of this have there been? I've heard of the theory, but no actual losses attributed to it.

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#144

Post by hanche »

SnowHill9902 wrote: post #114
Buttons840 wrote: post #105

Earlier quoted context omitted.

I'm no expert on stats, this discussion is a bit over my head, but it reminds me that not all distributions have a mean. A Cauchy distribution has no mean; as you average successive samples, it never settles down to a consistent average. I was surprised when I first encountered Cauchy distributions and up until then had considered that all distributions would have a mean. I suppose it is one of those "heavy-tailed" d…

It’s an example but long tailed distributions can have a mean, and short tailed distributions can have no mean. It’s not indicative.

> short tailed distributions can have no mean

That’s a surprise to me. Now I’m curious: With what definition of “short tailed” can that be true?

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#145

Post by antisthenes »

m_mueller wrote: post #59
gl-prod wrote: post #54

Earlier quoted context omitted.

Is it closer to Interstellar's wave planet?

more like Deep Impact's wave I'd imagine. Though the wavefront there probably looks too sharp?

Deep Impact's wave was barely taller than the WTC towers.

4.5km would dwarf that.

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#146

Post by antisthenes »

Tepix wrote: post #142
nunobrito wrote: post #66

Earlier quoted context omitted.

but... why..?!

Always nice to have a second habitable planet.

Nuking it wouldn't make it any more habitable.

At best you'd make the surface slightly warmer and maybe melt some leftover CO2 on the poles.

To actually terraform it to anything resembling even an Earth desert, you'd need incomprehensible amounts of energy.

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#147

Post by lamontcg »

ekanes wrote: post #128
Idiot_in_Vain wrote: post #73

Earlier quoted context omitted.

Because a few ships a year are expendable for the global economy. Not worth it to try to make every ship less sinkable - e.g. it may decrease the number of annual losses by 50% at the cost of making an average ship 10% more expensive - obviously a bad trade. Some ships will still sink, because of stuff like human errors.

This trade-off is everywhere. As a society, we choose to have some people die due to speeding instead of making speed limits 15mph, which would absolutely make roads safer. Human life just doesn't trump all else - we factor in other things.

And a company would go broke trying to secure itself against every conceivably IT security threat, so IT security aims to keep breaches out of the headlines rather than eliminate them completely.

Your own skeletal system is a trade-off of different factors.

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#148

Post by lamontcg »

Someone wrote: post #68
echelon wrote: post #46

Earlier quoted context omitted.

> Research at Imperial College, London, shows that far from being rare events, rogue waves can emerge frequently, and may be responsible for some of the 200 supertankers and container ships longer than 200m that have sunk in poor weather conditions in the past two decades. The loss of ten ships a year seems incredible to me. Surely "weather", if it were to blame, could be avoided. This amount of loss is steep. Is it…

https://www.statista.com/statistics/1326758/number-of-oil-ta... : There were 8,883 oil tankers worldwide in 2021. If those are all ocean-going, ten a year is about 1.1%. Depending on how expensive it would be to prevent this, that may not be bad for ship owners, but it is very bad for those seeking a career in working on those ships.

plus 5,589 containerships

https://www.statista.com/statistics/198227/forecast-for-glob...

although the parent comment mentioned "longer than 200m" but its difficult to find containership stats by length rather than by TEU.

ignoring that though it would be 0.07% lost per year or 1 out of every 1447.

probably not too surprising, since if you pick 1447 oil tankers/containerships and audit them consider what the worst looking one is going to look like after decades of salt damage and abuse and poor maintenance.

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#149

Post by cosmojg »

nextos wrote: post #35
fritzo wrote: post #26

> 30,000 times more initial energy than any recorded events As a statistician: this is why heavy-tailed modeling matters. Schools teach the finite-variance version of the Central Limit Theorem and students believe they live in a normal world. The real Central Limit Theorem [1] predicts large rare events following Lévy α-stable distributions. [1] https://en.wikipedia.org/wiki/Stable_distribution#A_generali...

This is so true. Heavy-tailed distributions and extreme value theory [1,2] should be taught more widely. The normal distribution is just a very particular case of the generalized CLT. For example, some drug effects are heavy-tailed, but safety trials are often ignoring this. [1] https://adamwierman.com/wp-content/uploads/2020/09/2013-SIGM... [2] https://adamwierman.com/wp-content/uploads/2021/05/book-05-1...

Got any sources which discuss the heavy-tailed effects of drugs and how they're ignored by safety trials? I'd love to read more!

Re: Simulation of tsunami from dinosaur-killing asteroid that brought 2.5 mile waves

#150

Post by vba616 »

baq wrote: post #85
Idiot_in_Vain wrote: post #76

Earlier quoted context omitted.

Heavy-tailed modeling doesn't reallly matter. There are very few enterprices where preparing for extremely rare events is worth the effort - nuclear power plants, weapons of mass destruction, bio labs working with dangerous organisms, big chemical plants, maybe AI research and big particle accelerators.

the most important of all - your 401k

If you tuned out of current events, financial and otherwise, five years ago - in early 2018 - and your 401k was entirely on autopilot in an S&P 500 fund, it looks like your average annual return would've been about 11.5%, annual US inflation was 3.7%, and return after inflation 7.5%. Per year. You can't reasonably expect better.

And practically speaking, the tax avoidance means that's considerably better than 11% in a non-retirement account, but it was too much effort to do the math.

Despite all the pestilence, war, earthquakes, and stuff like that, doing nothing was the smart move again, with $1 or $1 million.

I don't think it makes sense to prepare for a global collapse of civilization because in the event whatever you will reap won't make hardly any difference in how much things suck. You can't eat money, much less use it as a shelter from a global rain of molten rock.

So on principle, regardless of the probability of Armageddon, I don't think one should give up much to try to hedge the end of the world.

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