North Korea ramps up preparations for war with US

Lee Duna@lemmy.nz to World News@beehaw.org – 52 points –
North Korea ramps up preparations for war with US
newsweek.com
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“Nuclear powered” has no reference to their weapons capabilities, but instead how it generates electricity to run the ship.

Back in the old days, subs had diesel generators that required air to run the generators (like any fossil fuel powered engine) that recharged the batteries that powered the ship while submerged. That means that if the batteries were running low, the sub would need to surface to use the diesel engines to recharge the batteries so they could dive again. With the invention of nuclear powered subs, surfacing wasn’t needed except for replenishing breathing air. Which I think is like a few days or maybe a week or two. Or whatever, I’m not an expert on this.

Now, that’s not saying that a lot of nuclear powered subs don’t also carry nukes (like tridents, for example). But “nuclear powered sub” doesn’t have any bearing on that. It’s purely describing how the sub generates electricity.

I hope that any submariners that read this will correct me if I’m wrong. This is all based on info I read years ago.

There are ways of creating oxygen onboard submarines. The only real limits to time submerged is the amount of food the boat can carry.

Here is a video by Destin from the Smarter Every Day youtube channel explaining oxygen generation onboard submarines. https://youtu.be/g3Ud6mHdhlQ

I think it downplayed the importance of CO2 scrubbing, because we can tolerate low O2 a lot easier than high CO2. High CO2 is also what gives us that suffocating feeling.

It briefly touches on rebreathers near the end. The theory behind them is that the difference between the %O2 on the inhale and exhale of our breathing cycle is very little. So if you can get rid of the CO2, you can re-breathe that same air for a "long" time before it starts to get too low in O2 content and it starts to impact your survivability.

High CO2 may be what leads to that suffocating feeling, but low O2 is what makes us literally die

CO2 is literally toxic. As in, if you're stuck in a hermetically sealed chamber, you'll suffocate to death due to CO2 toxicity, not lack of O2.

I just re-watched all the first 14 Bond movies, and there are apparently satellites that can track all the subs, so we're good 😊👌 Also, you can just reprogram the missiles to blow up the other subs — just steal the launch codes, easy peasy 👍 Check mate, Kim! 💥🚀

Side note: many (or, indeed, most) of the films did not age well 😣 I'm not proud of how little of the misogyny, borderline rape-y, no-consent, belittling of women stuff I failed to notice as a kid (patents' fault) and adolescent (my fault); it starts to get a bit better around the end of the Moore era, and I'm now getting ready for the Dalton era. It will be interesting to see the newer films with this fresh context of the old ones, and I've never seen the two newest ones, which I think were supposed to address all of these issues.

Secondary side note: so far, the best ones (IMHO, YMMV) have been For Your Eyes Only, Octopussy, A View To A Kill.

I don't know if this is done in practice, but if you have a nuclear powered sub, implementing a water electrolyzer that makes oxygen is fairly trivial. Then you have air as long as you have power, so they could in principle stay submerged for ≈ 20 years, or however long the nuclear reactors can go without refill.

Technically a Sub can stay underwater forever, it is the crew that is the problem there. If they had Star Trek replicators to make them food with that reactor then boredom becomes the limiting factor.