EMP shield

[fredreload]

Stable EMP field, not a pulse, that would protect a country from missile and EMP pulse attack. Does it exist?

Edited March 26, 2018 by fredreload

[MaximThibodeau]

An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy.

It must, in the current theory, be originated by, an electric field or magnetic field, variation.

At distance, only light is stable form of those quantity variation.

At short distance, you need a capacitor or a magnet(coil), but how to build that over a country.

Answer: No, i don't think, it's possible.

 

[swansont]

2 hours ago, fredreload said:

Stable EMP field, not a pulse, that would protect a country from missile and EMP pulse attack. Does it exist?

No. An EM field does not block another EM field. You use faraday cages to protect things.

[fredreload]

3 hours ago, swansont said:

No. An EM field does not block another EM field. You use faraday cages to protect things.

Quora says it's possible.

https://www.quora.com/Will-two-magnetic-field-of-equal-magnitude-but-opposite-direction-cancel-out-each-other

5 hours ago, MaximThibodeau said:

An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy.

It must, in the current theory, be originated by, an electric field or magnetic field, variation.

At distance, only light is stable form of those quantity variation.

At short distance, you need a capacitor or a magnet(coil), but how to build that over a country.

Answer: No, i don't think, it's possible.

 

I understand your concern, but it seems they can change whether with this thing, as to how they do it. It could be a huge magnetic field or a directed microwave. Either way this is speculative

Edited March 26, 2018 by fredreload

[swansont]

Just now, fredreload said:

Quora says it's possible.

https://www.quora.com/Will-two-magnetic-field-of-equal-magnitude-but-opposite-direction-cancel-out-each-other

A magnetic field is not an EMP. Putting in an equal and opposite magnetic field will cancel the field in the region where that is the case, but you can't match that everywhere.

An EMP is an oscillating field, meaning you would need to match frequency and amplitude of all oscillations, over all space. That's not going to happen.

It might be possible in a small region, if you could anticipate what the signal would look like. You could get destructive interference. Since energy is conserved, in the areas where you don't have destructive interference, you will have constructive interference, so it will be twice as bad there as the original signal.

 

[fredreload]

2 hours ago, swansont said:

A magnetic field is not an EMP. Putting in an equal and opposite magnetic field will cancel the field in the region where that is the case, but you can't match that everywhere.

An EMP is an oscillating field, meaning you would need to match frequency and amplitude of all oscillations, over all space. That's not going to happen.

It might be possible in a small region, if you could anticipate what the signal would look like. You could get destructive interference. Since energy is conserved, in the areas where you don't have destructive interference, you will have constructive interference, so it will be twice as bad there as the original signal.

 

Agreed it needs to be matched in all directions. EM field is a combination of electric field and magnetic field. From my knowledge I would go with some type of jamming device, since radio wave is also an EM field. But I'll have to look into this. And a jamming device would disable anything within this zone instead of a shielding wall effect

[swansont]

15 minutes ago, fredreload said:

Agreed it needs to be matched in all directions. EM field is a combination of electric field and magnetic field. From my knowledge I would go with some type of jamming device, since radio wave is also an EM field. But I'll have to look into this. And a jamming device would disable anything within this zone instead of a shielding wall effect

If you miscalculate (and you will), the jamming will disrupt everything as effectively as the EMP would. If you could trigger the defense, you'd have the same effect as an attack (assuming you could pull off making this defense, which you can't) 

[John Cuthber]

4 hours ago, fredreload said:

Agreed it needs to be matched in all directions. EM field is a combination of electric field and magnetic field. From my knowledge I would go with some type of jamming device, since radio wave is also an EM field. But I'll have to look into this. And a jamming device would disable anything within this zone instead of a shielding wall effect

Well, you could try that.

Or you could use a biscuit tin- which would work (at least for your mobile phone).

[Bender]

Tin foil hats are great for cerebral implant protection. 

[swansont]

12 hours ago, Bender said:

Tin foil hats are great for cerebral implant protection. 

The government has long since found a workaround. Do you realize how many research dollars the US spent on tin foil hat penetration research?