Recovery from Alien Invasion

[Grey_Fox]

Heya fellow GURPSateers,

Context: I am looking to re-start an older game of GURPS that i was running about a year ago. In this Game the players played a group of special forces soldiers during an alien invasion. The aliens that were invading earth hold the belief that life is more sacred than free will and will invade and enslave sentient races who they believe will either destroy themselves or that are causing irreparable damage to their planet, as such when they invade planets they try to cause minimal planetary damage. So the invasion broke down into two main steps, first EMP weapons were deployed against the most technologically advance areas of the planet, second ground forces were sent in to strike military targets and begin population control. Not important to the question but worth mentioning for context, the entire invasion fleet is robotic.

I would like to move the story line forward once the aliens are defeated. which raises the following

Questions:
1. How long would it take for the world to recover from what is essentially a planet wide EMP?
2. What would be the death toll around the world from such an EMP in the months that followed?
3. How quickly could a modern air force recover from such an EMP in order to get planes back in the air?

Thanks in advance!

[Nereidalbel]

1. Depends on the intensity of the EMP. If it just shorts things out, a few years. However, if it completely burns out components, it'll take over a decade, at minimum.

2. Every single person on life support is toast, and major cities will have starvation issues. Isolated tribes probably won't even notice a difference, though.

3. Very quickly, once the refineries start working again.

[malloyd]

Originally Posted by Nereidalbel

1. Depends on the intensity of the EMP. If it just shorts things out, a few years. However, if it completely burns out components, it'll take over a decade, at minimum.

Also, depends on what counts as "recovered" and how much stuff is sitting around in storage somewhere. Not much from before about 1970 that's not a radio or television is going to be badly hurt by EMP that isn't intense enough the currents generated start killing people and starting fires, so old stuff might be put back into service pretty fast if it is still around. And even modern technology that isn't actually powered up is hard to kill, especially given that there's no way to detect it and warehousing tends to be outside of urban centers where land is cheaper. If nothing happened but an EMP pulse over the major cities, less than a year might be perfectly reasonable. For a more serious war, recovering from a major war than involved leveling big chunks of your national infrastructure has lately taken a decade or two, but that's with trade with less damaged areas. Rebuilding civilization from scratch everywhere might take two or three generations. At the far end its hard to make a post-apocalyptic situation last more than a couple centuries - very little stuff more than two centuries old is still in use after all, so it didn't take longer than that to build it the *first* time. If you smash the population down to a handful of families and give up on all institutional continuities you can do longer of course, just don't try to convince anybody the recovered future shares any ethnic groups, languages or religions with the pre-apocalypse.

2. Every single person on life support is toast, and major cities will have starvation issues. Isolated tribes probably won't even notice a difference, though.

Actually many sorts of "life support" can run without electricity - oxygen bottles for example, and offline backup generators are hard to kill anyway. Even operating generating capacity is pretty tough - it is after all designed for big currents, since making them is what it is *for*. Not that many people are on life support anyway. But yeah, I think starvation is the big issue, though some city water systems are pretty dependent on powered pumps. How compromised is the food transport network? Again, if it's just an EMP hit on the cities, things might not be so bad - get the grain elevators and trains running again and deploy your army to keep order and you can probably prevent mass starvation. With ongoing hits on your transport network and your army busy doing other stuff losing a quarter or a third of your population to hunger and the accompanying unrest and disease seems pretty reasonable.

3. Very quickly, once the refineries start working again.

Or faster, there's lots of fuel sitting in tanks all over the place. I suspect you can get a lot of stuff into the air in a couple hours, you don't need electronics to fly, and a modern air force will have plans in place for nuclear attack. Though it will be less capable and if there's somebody shooting it down it may not stay up long. Building something that will fly with a small machine shop you can run on local power is a few man-years project tops, so once the war is over you can have something flying again in weeks even if nothing airworthy survived. Rebuilding to pre-pulse standards means waiting for new construction of high tech stuff, so roughly as long as it takes to reconstruct everything else.

[starslayer]

An emp would be a wicked effective first strike because it will short or everything with an antenna and ADC based sensor. However basically everything not in that category is fine unless the emp was created with such intensity that it also kills people. Your average computer case makes an adequate Faraday cage for protecting the sift electronics inside. Laptops with plastic cases would be destroyed.

Most servers are inside a Faraday cafe to reduces interference and outside noise so the internet would likely survive though a lot of new network cards will be required... but the cell phone network would not.

The most major hit would actually be currency. With so much of currency being virtual and reliant on intercommunication losing telecom means noon physical currency losses value. Which means that the global currency does not balance.

Rebuild time for replacing network cards for the internet day a few months and millions of dollars. Replacing every cell phone antenna.. Tens of billions and will likely take a lot longer. Strife fom the loss of interindustry banking.. I don't know

[kachobo]

deep stuff

I think you need a good excuse but no more, the aliens technology is unknow, so you need focus in the result for the people in the planet

[johndallman]

Originally Posted by malloyd

you don't need electronics to fly, and a modern air force will have plans in place for nuclear attack.

Their plans consist largely of "be dispersed and inside shelters that are screened against EMP, having predicted when the attack will take place." The prediction is important, because the peacetime occupations of an air force are much harder in that dispersed posture. Will they have any warning? How good are those EMP weapons? One presumes at least TL9?

Modern fighters - in the USAF from the F-16 onwards - are deliberately designed to be unstable, because that makes them more manoeuvrable and require software control in the fly-by-wire system to be able to stay in the air. The controls are inputs to the computer, and don't operate control surfaces directly. If the computer's out, the plane can't fly, only crash. The ejection seat still works.

More generally, if the EMP attacker takes care to EMP the factories that build computer chips, you have a serious problem. Because the production machinery is largely automated, and you need the right chips to repair it.

[PTTG]

Take a look at the book "One Second After" for a well-researched if slightly fatalistic example. Life support without a national power is an inevitable death; sooner or later, you're going to run out of bottled oxygen.

We probably wouldn't rebuild the same way we built initially. It would take more than a decade for the US to rebuild all the destroyed electrical transformers, and that's assuming that all the factories that make transformers were ready to go right off the bat. I'm assuming we'd use very localized electricity with hydro, tidal, and wind (they don't need any fancy minerals, only a motor that runs backwards). Some places could get those set up in a few months, but it'd be survival electricity.

I imagine that Hoover Dam would remain a useful site... after one or two years of concerted repair efforts.

Thermal focusing solar would also be useful in a lot of places, because it's just mirrors and boiling water. Photovoltaics, useful as they are in the real world, would require high-precision engineering that might be hard to replicate.

Submerged nuclear submarines would be kingmakers. The onboard computers alone would be incredibly valuable, and the weapons would have new meaning if they're the only long-ranged fighting implements and there's no way to accurately determine where it came from.

[johndallman]

Originally Posted by starslayer

Rebuild time for replacing network cards for the internet a few months and millions of dollars.

If your network card factories are still working, along with the factories that make the chips and components they use. They're also mostly in China, and just might be having to give priority to local requirements. Not that one country would ever use an world-wide emergency to gain advantage over another.

[malloyd]

Originally Posted by PTTG

Take a look at the book "One Second After" for a well-researched if slightly fatalistic example. Life support without a national power is an inevitable death; sooner or later, you're going to run out of bottled oxygen.

Only if you don't recover or die before the oxygen runs out - most people on life support are not on it for a really long time.

And frankly, I think the people claiming mass transformer meltdowns are talking nonsense, nor would it take down electricity supplies even if it were true. They are talking about interconnects that route power between sections of the grid, lose them and you chop the grid into lots of smaller pieces, which is means you can't support the former peak loads in high usage areas until you fix them, but it's going to be quite a while until you need too anyway what with all the consumer stuff that isn't working anymore.

I imagine that Hoover Dam would remain a useful site... after one or two years of concerted repair efforts.

Um, what mechanism are you imagining for damaging it? An EMP pulse isn't going to do much, and an actual shot at it that breaches the dam isn't going to be anything as minor as a two year repair. Really, it's not the generators that are a problem anywhere, so postulating going to alternate energy sources is rather strange - fossil burning plants are still going to be there or easily repaired, its the distribution network, full of long wires that will double as antennas, that is vulnerable at all, not the primary production.

[tantric]

The EMP=> ecological salvation is HIGHLY questionable. Most of our energy comes from oil or fission. If the people live and the energy flow shuts downs, people will hit the surrounding forests like termites with the munchies. Ecological damage is generally slowed in high tech whereas areas that go through economic collapses are very destructive. Consider Haiti vs the Dominican Republic, which is still fairly well forested. No, I recommend biological warfare. Technology becomes the vector. Besides, the nukes are shielded from EMP, and humans will most certainly try to use them.

Actually, the best way might be to give humans fusion and cheap space travel, maybe even a bean stalk.