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Two undersea cables in Baltic Sea disrupted

(www.cnn.com)
577 points mooreds | 17 comments | 18 Nov 24 14:31 UTC | HN request time: 0s | source | bottom
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staplung ◴[18 Nov 24 20:22 UTC] No.42176496[source]▶
It's worth mentioning that cable breakages happen quite often; globally about 200 times per year [1] and the article itself mentions that just last year, two other cables and a gas pipeline were taken out by an anchor. The Gulf of Finland is evidently quite shallow. From what I understand, cable repair ships are likely to use ROVs for parts of repair jobs but only when the water is shallow so hopefully they can figure out whether the damage looks like sabotage before they sever the cable to repair it. Of course, if you're a bad actor and want plausible deniability, maybe you'd make it look like anchor damage or, deliberately drag an anchor right over the cables.

Cable repairs are certainly annoying and for the operator of the cable, expensive. However, they are usually repaired relatively quickly. I'd be more worried if many more cables were severed at the same time. If you're only going to break one or two a year, you might as well not bother.

1: https://www.theverge.com/c/24070570/internet-cables-undersea...

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ValentinA23 ◴[19 Nov 24 00:38 UTC] No.42178949[source]▶
A 1 in 36 million chance for three breaks in one day.

https://mathb.in/80217

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1. CrazyCatDog ◴[19 Nov 24 03:24 UTC] No.42179837[source]▶
“Knowing that 200 undersea cables break every year globally, estimate the probability that 3 cables break in the baltic sea on the same day.”

I’m stealing this to use for grad-student mock-interviews—thank you!

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2. ◴[19 Nov 24 03:42 UTC] No.42179919[source]▶
3. Moru ◴[19 Nov 24 08:43 UTC] No.42181237[source]▶
Hint: The cables are often very close. If one breaks, the otherone also breaks :-)
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4. gitaarik ◴[19 Nov 24 09:21 UTC] No.42181451[source]▶
Why would cables close to each other break?
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5. leovingi ◴[19 Nov 24 09:31 UTC] No.42181533{3}[source]▶
because if it's an accident and someone is dragging an anchor behind them, if the cables are only meters apart then they are going to cut both
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6. CrazyCatDog ◴[19 Nov 24 11:50 UTC] No.42182424[source]▶
Right, if it’s a case interview, then higher accuracy ought to prompt the interviewee to ask: (1) Do the 200 cuts typically occur in clusters? (2) What’s the typical density, eg are they usually collocated? (as an alternative to the above) (3) Are there pathways that avoid the sea but connect Europe and North America (getting at density in the sea in question) Etc.

That’s what makes this one so good—lots of opportunities to extend or roll-back difficulty.

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7. usrusr ◴[19 Nov 24 12:26 UTC] No.42182683[source]▶
What are the chances that they break in close proximity spacially, but not temporarily? (I'm assuming that it would be headline material if the lines had disconnected within minutes)

Tangent: an attacker trying hard to provoke that kind of accident would likely not have a very fast success feedback. "Let's try once more, for good measure"

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8. jeltz ◴[19 Nov 24 13:42 UTC] No.42183316{4}[source]▶
No, because anchors can easily damage several cables close to each other. And that is how it almost certainly happened no matter if it was an accident or sabotage.
9. Cthulhu_ ◴[19 Nov 24 14:14 UTC] No.42183644[source]▶
A clever answer would be "it's a 50/50 chance, either it happens or it doesn't". That's statistics my simple brain can comprehend at least.
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10. ◴[19 Nov 24 15:30 UTC] No.42184537[source]▶
11. ◴[19 Nov 24 15:31 UTC] No.42184557[source]▶
12. kqr ◴[19 Nov 24 15:48 UTC] No.42184772[source]▶
In what way is that clever? It's clearly wrong. If it were true, we'd experience three breakages at least 150 days of the year, every year.
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13. ValentinA23 ◴[19 Nov 24 15:59 UTC] No.42184900{3}[source]▶
I was surprised to see so many upvotes this morning and was disappointed when I realized it wasn't for another comment I made about the Anthropic Principle.

My take is that in face of coincidences supporting the emergence of intelligent life, we should expect to observe coincidences unnecessary for the emergence of life too.

An analogy: imagine you have lost the key to your mansion and try to cut one at random out of a metal sheet. If it can unlock the door, then chances are that you cut unnecessary notches (the analogy only holds for warded locks and the key you crafted is a master key).

See: https://news.ycombinator.com/item?id=42178306

I'm wondering where I'm wrong in my reasoning because the implication is weird.

14. crote ◴[19 Nov 24 20:46 UTC] No.42187910{3}[source]▶
Still pretty decent, given the right circumstances.

For example, the 2011 earthquake in Japan resulted in damage to 7 cables[0]. But it wasn't the quake itself which instantly broke all 7 cables - they were destroyed by underwater avalanches triggered by the earthquake. Avalanches can occur hours after a seismic event, and some underwater avalanches go on for days.

I highly doubt that's the case here, but if you're asking about chances it's not as unlikely as you'd think!

[0]: https://www.theverge.com/c/24070570/internet-cables-undersea...

15. dgfitz ◴[19 Nov 24 21:45 UTC] No.42188435{4}[source]▶
Are they?
16. kqr ◴[20 Nov 24 12:53 UTC] No.42193511{4}[source]▶
I think it is in the spirit of Hacker News to explain rather than just whoosh someone.
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17. rrr_oh_man ◴[20 Nov 24 13:07 UTC] No.42193597{5}[source]▶
You're right, that was not kind. Apologies. It was late at night and I'd read too many depressing news (and many even more depressing, warmongering comments). Not an excuse, just a human factor.

What I should have said:

By clever GP most probably meant funny (with a hint of self-deprecation) rather than smart (or even correct).