Effects of EMP (For Sci-Fi Book)

[Mr Ask]

This is a sister to my first topic: http://www.scienceforums.net/topic/108036-moon-explosion-and-radiation-for-sci-fi-book/

 

In my story, a major explosion sets humanity back in technology, and there is a major explosion on the moon.

It could be the moon explosion that generated an EMP, or it could be a major solar flare that generated the EMP on earth and also caused the moon explosion. I'd prefer to have it all caused by the moon explosion (NEMP). If the explosion has to be nuclear, that fits my current idea as to why it happened at all.

 

 

But here I want to ask another question. For my story it is important that the EMP bursts continue several times each day, providing a major technological hurdle for mankind, but I also need (crucially) some electronics to work, and I am having trouble squaring this hole.

 

#1: I am planning to say that the EMP bursts don't necessarily fry all electronics (aside from the first major one), but more complex machines with more circuits are more likely to encounter failures. So cell phones and computers will mostly be fine, but electric cars and (importantly) space shuttles will not.

How plausible is this scenario? Is there a "magnitude" of EMP bursts that just causes interference rather than full shut-down, or should I instead find an alternate explanation such as, "The larger they are, the more likely a part of them gets hit"?

Or if EMP's travel through the ground, would phones be safe as long as the person is wearing rubber boots or such? And cars could be fine if their tires are designed properly?

I'm not really sure of the physics behind EMP's. They travel through the ground, but they would still zap a space shuttle in space coming close to the source on the moon, right?

 

#2: The EMP aftershocks are coming from the moon. If there is a magnitude of bursts that does what I want by the time it reaches Earth, how large would it have been at the source on the moon? Things will definitely fry close to the moon, which is why a space shuttle to go there and fix the problem is impossible.

 

#3: The first explosion takes a gigantic chunk out of the moon (between 20 and 25%), so an NEMP suits that situation fine, but the following aftershocks will continue for hundreds of years and can't be violently destroying the moon each time.

Violent aftershocks would also destroy the source of the aftershocks.

So I need the following EMP bursts to be strong enough to hit Earth from the moon, but not generated through violent reactions such as nuclear explosions. Is this possible? How can I set up repeated EMP bursts strong enough to reach Earth but not trough violent explosions?

 

#4: This question may be fun to answer as you can use your imaginations.

My story takes place around 70 years after the initial explosion (the sequel will revolve around the events of the explosion), which happens around the year 2110.

After the initial NEMP sets humanity back and continues to send smaller EMP aftershocks daily, what are your ideas for how humanity has dealt with this during the next 70 years?

Here are a few of my example ideas:

- A: Some elevators have been restored with shielding.

- B: Satellites have all been destroyed and there is no way to put any back up, and the previous underwater cables connecting countries today aren't shielded. Communications have only been restored between a few countries (Japan and America as one example) by laying down new cables with shielding.

- C: Rubber boots designed to prevent pulses from traveling through the ground up into people?

- D: Cars tend not to fry people when hit by lightning do to their tires. Any changes needed to protect from EMP bursts?

- E: Are my ideas stupid? How would daily global EMP attacks change our world over 70 years? Changes to the home, changes to attire, changes to anything.

 

 

Thank you,

Mr. Ask

 

 

[NOTE: I had just read about EMP's traveling along the ground, but I had never heard that before and wasn't originally thinking that way. I am fairly sure they do not.]

Edited July 21, 2017 by Mr Ask

[MigL]

An EMP ( electro-magnetic pulse ) is strong enough to 'ionize' ( blow away ) electrons out of the conduction band and semi-conduction band of most electronic and electrical equipment.

Semiconductors would be more easily affected with today's small design rules.

 

There is no 'after-shocks' unless there are 'after-explosions'.

 

If one quarter of the Moon were blown away, I'd be more concerned with WHERE these chunks of moon were going to land, as at lest some would come crashing down on Earth. Global annihilation would be more of a concern than cell phones not working

[Mr Ask]

Keeping things simple, are you trying to say that any pulse at all will either do all or nothing?

It should be a gradient. Strong pulses can permanently fry equipment, weak pulses temporarily disable them, and weaker pulses can just mess with them.

 

This person makes an EMP that requires no explosion and does not fry the iPhone (the first phone might have been fried but the iPhone turns on again): http://hackaday.com/2016/10/12/become-very-unpopular-very-fast-with-this-diy-emp-generator/

 

This follows closely with what I am planning. The pulses from the moon are a result of built-up pressure which, when discharged, creates a strong EMP at the source which is fairly weak by the time it hits Earth. There may be pockets of stronger pulses getting through, so larger unprotected equipment will eventually become disabled.

Any unprotected long-distance digital signals will never be reliable, so underwater Internet cables have to be laid again with shielding.

Handheld devices such as phones will have disruptions similar to in the video before the device died. Screen distortions, but remaining functional. Possibly corrupt data or system states requiring rebooting.

 

I'm looking for plausible ways to scale this up, what's possible, what is impossible, and how civilization may have changed as a result.

 

As for lunar rocks, I am expecting that much of the debris goes into orbit and evaporates when falling into our atmosphere, with only some chunks actually doing damage on the surface, but that will be another topic for another sub-forum.

 

 

Mr. Ask

[Danijel Gorupec]

Just some ideas:

 

- you might 'invent' a new type of battery that is extensively used in electric cars. The new battery has all the benefits (gasoline cars being quickly replaced, even banned for years) but also one drawback - sensitiveness to EMP (military should avoid its use in military vehicles).

 

- you might consider that smaller batteries of that type (cell phones) are less sensitive to EMP. Or maybe, it is still possible to find and use classic-type batteries for replacement in cell phones (no such replacements for electric cars).

 

- There could exist microwave (or whatever) energy links between Moon and Earth (sort of power lines) that actually directed and maybe amplified the effect of the Moon-originated EMP.

 

- Flying a space shuttle becomes a heroic mission due to all the debris (satellite network being all crushed generating lots of space garbage).

[Mr Ask]

Thank you for the input.  There are things to consider there.

I've been planning that the end of the series comes by them finally getting to the moon, with the EMP bursts being the main obstacle, but EMP bursts powerful enough to go from the moon to Earth seem unrealistic.

I may instead have to make the obstacle related to all that debris.

 

 

I have been doing my own research into EMP's as well, and am happy to find out that I think my general impression of the civilization should mostly be accurate.
I want cell phones to work, but larger devices not to, for example.  EMP's come in different frequencies, and cell phones may be subject to disruption from higher frequencies, but solar flares and the types of frequencies I plan to use from the moon will be lower.

So I shouldn't need Faraday cages around phones etc., just around power supplies and certain types of equipment.
(Someone let me know if I am completely off here.)

 

I also understand that only about 15% of big trucks in America (though my story takes place mainly in Japan) would stall, some with permanent damage, 70% would experience some other anomalies, but mostly would keep working.

 

I'm wondering if anyone has any informed ideas as to how civilization may have to adapt to constant EMP attacks (let's say of low frequencies).  Phones may work, but how will the network have to be shielded?

Perhaps the lines will be moved underground with shielded access points that poke above ground.  How deep must something be buried to be free of the EMP influence?


Mr. Ask

[HB of CJ]

Interesting premise for a good book.  About the same answers.  EMP could affect most/all gadgets using chips and having an antennae area greater than about 4-8 inches in total.  This may include the smaller electronical gadgets including most smart phones.  The damage would be proportional to the size of the blast divided by distance.

A moon blast EMP would have to be huge.  Too far from Earth.  Maybe 1000 gigga ton anti matter capital ship warheads accidentally targeting the Moon?   Boom.  A Draconian Empire torpedo barrage gone bad?  This would explain the multiple hits.  Proximity fusing?   Also small enough to not blast BIG chunks off the moon endangering Earth?

A CME is a different animal with different effects.  Solar flare caused.  A big X1000 class solar flare could do us in.  But such probably would only be a one time in 1000 year event.  Probably not repeatable, but naturally occurring rather than from the evil Draconians screwing up.  Be easy to learn up on the effects of a BIG EMP.  Fun also.

Good luck with the book.  Go for it.  Respectfully.