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Comment by wongarsu | Hacker News Reader

Within in the next ~100 years we will advance to a state where nuclear weapons taking out one planet won't kill our civilization outright anymore, and within the next 200-500 years we might reach a point where even war across an entire solar system won't be enough.

There's the risk that we will develop stronger weapons to match our increasing resilience, but on the other hand in the last 100 years we've made good progress on either outlawing many weapons of mass destruction or at least making their development much harder, so there's hope.

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> we will ... we will ... we will

Not much more substantiated than what people believe will be the return of Christ, it's all sci-fi

Not much fundamentally changed in the last 100 years, even a nuclear reactor is just a fancy steam engine. We're closer to horse carriages than a solar system wide civilization

The problem is that planetary civilization is inherantly fragile to those living up outside the gravity well. Every depressed belter asteroid-trucker with a balistics computer, can throw a garbage can at earth or mars at speed and end planetary civilization.

I think you're confusing reality with science fiction.

Rods from god are roughly as powerful as nukes, which is bad but a single nuke wouldn't end planetary civilization. If the belters were able to throw things at relativistic speeds you'd have a problem, but there's also no stealth in space so it's feasible to monitor space traffic around a large planet and deflect anything incoming, be it a projectile launched from longer range or an untrusted, uninspected, shady-looking belter ship.

I think rods from gods is oversold. The classic version of this is a "telephone pole of tungsten", or something along the lines of a 6 meter long cylinder, 0.3 meters across, which works out to 0.42 cubic meters of tungsten, which would be just over 8000 kilograms. If you do the math, rods coming in at orbit speeds are barely worth talking about; the actual rods from god USAF proposal had these tungsten telephone poles starting in orbit and impacting the ground at merely 3 km/s, equivalent to 11 tons of TNT.

Faster then: the kinetic energy of such a mass moving at 12 km/s, faster than escape velocity, would be 'only' 137 tons of TNT, approximately 1/15th of the 2020 Beirut explosion. Even if you throw the rods into the ground at a blistering 50 km/s, that only gives you the equivalent kinetic energy of 2.4 kilotons of TNT, or 1/6th of the Little Boy nuclear bomb.

Then there are the terminal effects; such a tungsten rod is basically an oversized armor piercing dart like tanks shoot at each other. It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose.

> It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose.

Wonder if it could be precision enough for non-military applications? eg possibly faster for deep geothermal drilling than using the existing surface based borehole drilling approach.

For military applications though, it'd wonder if such a rod (or small sequence of them) could be effective when striking geological fault lines. eg the San Andreas Fault line

Aka the old "use the terrain" approach.

Anything small enough will just burn up in the atmosphere and big stuff will be easy to detect, even at the boost stage as the initial orbit change might take weeks or months possibly.

Orbitals at predictable orbits and surfaceinstallations on airless bodies might be more in danger though. There even a well targeted fast crowbar might do quite some damage.

The "rod from space" just need to deflect the orbit of an already existing large asteroid doesn't it?

Which would hopefully be detected in time to "solve" the problem, but still... ;)

"just" is doing a lot of work there. It's a pretty serious engineering effort to move rocks around the solar system and unless you have unlimited-energy future tech, you're probably stuck with the current paradigm of nudging things slightly to take advantage of convoluted gravity assists and small time windows to move things about. It'd be a very slow and predictable weapon that we already watch for.

Iran is getting closer to nuclear weapons, and they sure seem to be dead set on using them.

(OT: I do not understand the U.S. policy in this, but surely they are doing everything in their power to prevent that, since this will affect, like, everything. Right?!)

And, the tension between the U.S. / NATO vs. Russia / China / Iran / (Brazil ?) has lessened, but it certainly it isn't gone. How optimistic are you?

We went from 4-5 countries getting nuclear weapons in the first 15 years, and an era of about 60 nuclear tests each year in the 30 years after that, to the current era where it's about one country every 10-20 years gaining nuclear weapons and basically no tests happening. I'd say that's a massive improvement.

We've also mostly stopped with firebombing, and have seriously dialed back the chemical and biological weapons that were much more popular in the WWI/WWII era.

> one country every 10-20 years gaining nuclear weapons and basically no tests happening

This past week had a test in both N. Korea and Iran, so I don't think that is accurate.

> I'd say that's a massive improvement.

Oh, yes sure it's an improvement. But if we only have two countries intent on starting a nuclear war, thats already enough to hose the whole planet. And I am far from confident that we can safely say we aren't there.

> This past week had a test in both N. Korea and Iran

Neither of these happened.

North Korea tested a missile which could be used to deliver a nuke, they haven't tested any nukes since 2017. I don't know what Iran tested, but it certainly wasn't a nuke. The only news of a missile test from Iran this week that I can find is them testing an anti-tank missile, which obviously isn't even meant to deliver nukes.

Reading the news, my gut feeling is that US and China are preparing the ground for war between each other, though it makes no sense from an economical point of view, so perhaps I'm reading it wrong.

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