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Comment by onenukecourse | Hacker News Reader

We can, and have, shut off large portions of the grid in seconds.

Take the 2003 blackout. Yes, the whole shut down took 15 minutes (?). But thats because it was a cascading effect that had to travel down the lines. Once the fault was detected by a particular segment of the grid, the relays responded in milliseconds. They have since the 1920s? Add in an "incoming solar flare" fault condition and we can trip the whole grid in seconds and send a start signal to the diesel generators to warm up to bring her back up.

Pretty nifty trick.

Question is why would we? The grid has been undergoing a lot of strengthening against EMPs and flares for decades. Its not obvious to me that a flare can take it out, especially if we shed dumb loads (partial blackout, say data centers) before it hits to give the conductors and transformers head space.

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If we had done enough to mitigate EMPs, the nuclear powers of the world wouldn't have space-based nuclear EMPs as the first step of their attack plan. We still do, and so does Russia.

Geomagnetically-induced current is different from the plain-vanilla EMPs anyway—GIC can last for hours.

We might easily be unprepared, but that the military tries things that might not work. Military attack is all about trying things that might cripple the enemy and/or increase the cost of an effective defence. So an EMP isn't necessarily because it is expected to do horrific damage. It is just part of a thorough test of an adversaries preparations, making it harder to protect their infrastructure.

I fail to understand why we don't do more to make equipment robust to this kind of thing. There's a whole range of problems that this solves looong before we get to general nuclear exchange.

If stuff was shielded, isolated, and grounded better, everything from your phone to your WiFi would work a lot better and have longer range. Wind slapping power lines together wouldn't destroy everything plugged in inside your house and solar flares wouldn't be more than a passing concern. The design changes to affect all of this aren't remotely expensive or difficult, we just don't.

There is no need to shield electronics. The induced currents only cause damage to long conductors, to the electrical grid and to long fiber optic cables.

That's a complicated one, it's still the electronics but they need a particular circuit that can stop short rise time transients. Also, any larger devices probably want to have shielding and ethernet devices will need some extra hardening, we're talking 25+kv/m events here so unless your computer can handle the monitor being at a 25kv differential from the tower you're gonna have a bad time.

How does it compare with static electricity at that voltage? Which I assume is harmless enough.

Would this also affect m mammals, including us then?

It's not very different in terms of amplitude, though rise times for an E1 EMP impulse can supposedly be single digit nanoseconds so equivalent to a >400 MHz impulse. I know from experience that modern electronics can't handle that because I've fried USB ports by operating radio systems in that band, though there are some obvious differences there.

I don't think there are any space-based EMPs, at least no publicly known ones. There have been and perhaps still are plans to detonate high-yield nuclear weapons at high altitude above enemy territory to cause an EMP, but that is a very different situation from a CME solar storm. We're able to spot a CME hours in advance vs mere minutes for submarine-launched ICBMs, and the latter would only ever be deployed in the opening minutes of an all-out nuclear war, in which the electric grid and all grid-level precautions against solar flares are likely to be irrelevant, because most of its critical components would be vaporized or torn to shreds by attacks on ground targets anyway. Even just forcing the other side to keep burning money on military countermeasures that do work might be worth a few launchers and warheads.

Google starfish prime.

I don't think anything published about that test contradicts what I've written?

Ish. There seems to be some vocabulary fuckery going on around the term "orbital", most likely due to a poor choice of wording upstream. "Orbital" in the shit-blew-up-outside-the-atmosphere sense EMP strikes are absolutely phase 1A of any large scale nuclear attack and such capabilities are trivially executed by ICBMs with appropriate warhead selection and detonation altitude parameters. "Orbital" in the EMP-weapons-literally-orbiting-the-planet sense violates several international treaties. Given the levels of secrecy required to pull that off for any length of time it seems unlikely but is impossible to rule out entirely.

the conclusion from starfish prime is that the approach they tried was a really bad idea.

Which is in keeping with all other applications of nuclear weapons attempted to date, so there is that.

> We can, and have, shut off large portions of the grid in seconds.

Speaking from personal experience, this is BS. During a bad wind event, a bunch of lines came down, started a huge forest fire around 10 or 11pm which was heading for a small town with 50-70mph winds. First responders couldn't get in to warn anyone because the downed lines were energized, so they called up the power plant. The whole process to de-energize took hours. There is a kill-switch now, but most power plants apparently can't shut off the juice in a matter of seconds, and they may not even have a plan to do so in an emergency.

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