US Military's Microwave Weapon Can Fry North Korean Missile Electronics • Hacker News Board

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#31

Post by leggomylibro » Tue, Dec 05, 2017, 5:32 PM UTC

lisper wrote: post #21

This story has been all over the news in the last 24 hours, but it's sending my bogometer well into the yellow because Faraday cages are a simple and effective defense against any electromagnetic interference. (That's why you can safely peer into your microwave oven while it's pouting 1500 watts into your leftover lasagna.) So this feels like a Saddam-has-WMDs-style disinformation campaign to me. It also has a whiff…

I love the explanation I got from my high school physics teacher for why microwaves aren't dangerous to be near; anyone comment on whether it's actually accurate? Or whether I may be misremembering it?

'You can look into the microwave safely because the holes in the grate are smaller than the amplitude and thicker than the frequency of the microwave.'

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#32

Post by digi_owl » Tue, Dec 05, 2017, 5:36 PM UTC

clort wrote: post #25

klodolph wrote: post #18

Earlier quoted context omitted.

Not arguing about the propaganda point, but there are legitimate reasons for not shooting down test missiles. If you always shoot down test missiles, then NK just has to keep firing test missiles until they build one that doesn't get shot down.

or until they run out of money

The place is an autocracy. The only way they will run out, is if nobody, and i mean absolutely nobody, wants to trade with them, officially or under the table.

And with NK slaves showing up in Polish shipyards, that is highly unlikely.

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#33

Post by digi_owl » Tue, Dec 05, 2017, 5:38 PM UTC

riku_iki wrote: post #16

sandworm101 wrote: post #14

Earlier quoted context omitted.

This isn't about shooting down a rocket. This is about disrupting the launch complex. It's about sending enough energy into a complex that computers, the ones in the offices, stop working reliably enough to launch. It is possible, but imho would require a dish far to large to fit on an aircraft. So I agree that it doesn't exist, that this is propaganda. EM interference is why launch complexes use fiber. You don't wan…

And after reading this news, North Koreans likely in rush to use some dead simple and reliable knob for launching, instead of computers.

Vacuum tube radar, anyone?

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#34

Post by dboreham » Tue, Dec 05, 2017, 5:39 PM UTC

richardfeynman wrote: post #10

Most of North Korea's ICBMs are deep underground in elaborate fortified tunnel systems. Can this technology really pierce deep into mountains?

Is this true? Everything I've read says they use mobile launchers (that they bought from China on the basis they had been de-militarized and converted for "logging").

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#35

Post by whatshisface » Tue, Dec 05, 2017, 5:40 PM UTC

leggomylibro wrote: post #31

lisper wrote: post #21

This story has been all over the news in the last 24 hours, but it's sending my bogometer well into the yellow because Faraday cages are a simple and effective defense against any electromagnetic interference. (That's why you can safely peer into your microwave oven while it's pouting 1500 watts into your leftover lasagna.) So this feels like a Saddam-has-WMDs-style disinformation campaign to me. It also has a whiff…

I love the explanation I got from my high school physics teacher for why microwaves aren't dangerous to be near; anyone comment on whether it's actually accurate? Or whether I may be misremembering it? 'You can look into the microwave safely because the holes in the grate are smaller than the amplitude and thicker than the frequency of the microwave.'

That can't be right because the amplitude of EM waves has nothing to do with spatial displacements (unlike guitar strings). The way it works is that every point in space has an E (electric) and B (magnetic) field vector which can oscillate around a 3D space. The vectors point towards other places in space, but their meaning is a field strength and direction at a single point. So this diagram[1] is actually describing the EM fields along a single line, not in the volume of space that the (purely illustrative) arrows are drawn in.

The correct understanding of Faraday cages is that their holes must be small relative to the wavelength: this is easy to remember because on a very large wavelength scale you would expect the tiny holes to not be very noticeable, and on a very short wavelength scale you're essentially talking about the light that you can see your food with.

https://en.wikipedia.org/wiki/Light#/media/File:Light-wave.s...

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#36

Post by maxxxxx » Tue, Dec 05, 2017, 5:42 PM UTC

LeifCarrotson wrote: post #28

maxxxxx wrote: post #17

Earlier quoted context omitted.

Not doing this was a really bad mistake. I think most of his successors would have tried to find a peace agreement quickly.

From the linked article: > Thornley also argued that Germany was almost defeated and, if Hitler were assassinated, he would become a martyr to some Germans, and possibly give rise to a myth that Germany might have won if Hitler had survived. Since the idea was not only to defeat Germany but to destroy Nazism in general, that would have been a highly undesirable development. Hitler was an eloquent and persuasive perso…

From what I know by 1944 pretty much everybody around Hitler knew that their cause was lost. I doubt anybody else would have had the power to continue. And yes, he had a spell over the people around him when you read biographies.

Obviously we will never know but I think at the present taking out Kim Jong Un should be worth consideration.

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#37

Post by schemathings » Tue, Dec 05, 2017, 5:43 PM UTC

leggomylibro wrote: post #31

lisper wrote: post #21

This story has been all over the news in the last 24 hours, but it's sending my bogometer well into the yellow because Faraday cages are a simple and effective defense against any electromagnetic interference. (That's why you can safely peer into your microwave oven while it's pouting 1500 watts into your leftover lasagna.) So this feels like a Saddam-has-WMDs-style disinformation campaign to me. It also has a whiff…

I love the explanation I got from my high school physics teacher for why microwaves aren't dangerous to be near; anyone comment on whether it's actually accurate? Or whether I may be misremembering it? 'You can look into the microwave safely because the holes in the grate are smaller than the amplitude and thicker than the frequency of the microwave.'

Was curious .. google turned up this http://rabi.phys.virginia.edu/1060/1999/final_answers.html

A satellite dish is actually a mirror telescope for microwaves, with its receiving antenna located at the real image of the distant satellite. But unlike the smooth, shiny mirror of a light telescope, a typical satellite dish is made of dull metallic mesh. Microwaves reflect almost perfectly from this mesh because

Answer: (A) its holes are much smaller than the wavelength of the microwaves.

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#38

Post by njarboe » Tue, Dec 05, 2017, 5:43 PM UTC

Maybe the world should support any country with nuclear weapons in their efforts to build domestic ICBMs. If a nuclear power attacks a country, having it arrive on the tip of an ICBM leaves no doubt where it came from and who is responsible. Using a submarine, shielded shipping container, 4x4 across the Mexican border, etc. to plant and explode a nuclear weapon in the USA or other country would cause much greater long term harm to global political and social systems.

On the other hand, one does not want North Korea armed with hundreds of atomic weapons and the ability to end civilization single-handedly. How about this as an opening offer to North Korea? We will accept you with 10 warheads and end the embargo. You allow full inspections of any location at any time, so the number of warheads can be verified. Seems like new approaches to the North Korea problem are needed as they now have detonated a ~100kT device.

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#39

Post by wrs » Tue, Dec 05, 2017, 5:44 PM UTC

leggomylibro wrote: post #31

lisper wrote: post #21

This story has been all over the news in the last 24 hours, but it's sending my bogometer well into the yellow because Faraday cages are a simple and effective defense against any electromagnetic interference. (That's why you can safely peer into your microwave oven while it's pouting 1500 watts into your leftover lasagna.) So this feels like a Saddam-has-WMDs-style disinformation campaign to me. It also has a whiff…

I love the explanation I got from my high school physics teacher for why microwaves aren't dangerous to be near; anyone comment on whether it's actually accurate? Or whether I may be misremembering it? 'You can look into the microwave safely because the holes in the grate are smaller than the amplitude and thicker than the frequency of the microwave.'

Not sure what "thicker than the frequency" means, but it's because they're much smaller than the wavelength, which is a few inches, as you can demonstrate with some marshmallows. (Google "measure speed of light with microwave oven".)

Re: US Military's Microwave Weapon Can Fry North Korean Missile Electronics

#40

Post by lisper » Tue, Dec 05, 2017, 5:45 PM UTC

leggomylibro wrote: post #31

lisper wrote: post #21

This story has been all over the news in the last 24 hours, but it's sending my bogometer well into the yellow because Faraday cages are a simple and effective defense against any electromagnetic interference. (That's why you can safely peer into your microwave oven while it's pouting 1500 watts into your leftover lasagna.) So this feels like a Saddam-has-WMDs-style disinformation campaign to me. It also has a whiff…

I love the explanation I got from my high school physics teacher for why microwaves aren't dangerous to be near; anyone comment on whether it's actually accurate? Or whether I may be misremembering it? 'You can look into the microwave safely because the holes in the grate are smaller than the amplitude and thicker than the frequency of the microwave.'

You've got it backwards: the holes are smaller than the wavelength of the microwaves, and the material is thick enough that the eddy currents induced by the microwaves don't generate enough heat to melt the grating.