Say, some alien just wanted to mess with us, but doesn’t invade, or even care enough to want to kill us, but seeing how everyone is on their phone all the time, they decided to just jam all our radios to watch us suffer. Their transmitting power they use is so powerful, its jamming signals are 1000 times stronger than the strongest radios we have, so there’s no way we can overpower the jamming.
What does the immediate aftermath look like?
What does it look like in the long term?
(Please don’t say “kill the aliens” they have tech so advanced, its impossible to do it)
My phones/tablets would be dead in the water, but I avoid wifi for almost everything not actively mobile. So all my iron - even the laptops - are hardlined.
Unless they’re looking to employ Carrington-event-class interference, my networks are fine.
Their transmitting power they use is so powerful, its jamming signals are 1000 times stronger than the strongest radios we have
Strongest (declassified) radio transmitter is (likely) the Eglin AFB Site C-6. https://en.wikipedia.org/wiki/Eglin_AFB_Site_C-6. Peak radiated power is 32 megawatts, it operates at a bandwidth of 10MHz.
32MW is about 105dBm. Times 1000 will add 30 dB, so the alien transmitter will be at least 135dBm, which corresponds to 32GW.
Given the Friis Transmission Equation, 135dBm with a transmit antenna gain of 1dBi, at a distance of 12,756km (diameter of earth), a receive antenna with a gain of 1dBi, will receive a signal of: 22.44dBm at 1MHz, 2.44dBm at 10MHz, -17.56dBm at 100MHz, -37.56dBm at 1GHz, -57.56dBm at 10GHz, adding an additional 20dB of loss per decade. This is completely ignoring all effects like atmosphere and ionosphere, signal traveling through or around the earth, reflections, any funky propagation, or constructive/deconstructive interference patterns that may occur. Also ignoring antenna gain.
A rule of thumb is that the signal-to-noise ratio (SNR) should be at least 5x (or about 7dB) in general and some digital modes will tolerate it. 20dB is usually the minimum recommended in general, with 25dB or more being recommended for voice.
AM radio at about 1.5MHz will still work- but only for about 1km from the tower. At this point the AM signal from a 100kW transmitter would be about 46.03dBm for a specially designed antenna and receiver, but the noise level would be about 22.44dBm. Realistically, AM will not work and may even blow out a receiver front-end. Television at about 88MHz will be usable for only about 1km using a specially designed receiver, normal TV likely won’t work at all.
GPS is around 1.5GHz and the typical levels received are about -130dBm. Our noise is about 90dB or 1,000,000,000 times stronger than the received signal. No chance of GPS working at all. Wifi is around 2.4GHz or 5GHz and a “perfect” signal is about -30dBm. The received noise at 2.4GHz would be about -45.17dBm, and at 5.6GHz this would be -52.53dBm, so feasible that wifi could still work if you are close to your router/antennas.
Cell Phones have an extremely wide range of frequencies. On the lower frequency end, they likely won’t work. For something like K band at 10GHz, the phone itself would be transmitting about 33dBm. At a distance of 2 km, the cell tower will be seeing about -83dBm from your phone, while the the noise received will be far higher at about -57dBm.
Lastly, Submarine communication is typically done at ELF (3-30kHz). They typically need about a whole power station dedicated to powering it, and the effective transmitted power will be something like 5 watts or less. A submarine at 100km might pick up a signal of -2.99dB on the surface (realistically, far far less when submerged due to sea-water attenuation). The noise level on the surface from noise would be 52.9dBm.
This is all assuming that somehow, the aliens have a perfectly efficient wide-band transmit antenna. And have landed on earth with their super transmitter. And all of these numbers assume that max transmit power takes up the same bandwidth as the signal of interest.
In practice, the aliens would want to be far away from us. No closer than the moon, let’s say. And they probably will want an array surrounding the earth to maximize line-of-sight. To maintain the previous numbers, they would need an additional 25dB of transmit power. And probably an additional antenna on a ship, opposite to earth from where the moon is. So that’s an additional 3dB of power required (x2 for 2 antennas).
They could probably knock off about 20dB if they used high-gain antennas. But let’s say they use that power to further overwhelm earth’s ability to use radios, even for edge-cases.
They would require 163dBm- about 20TW of power. To jam a single frequency listed above.
Let’s say to jam the TV station, they were broadcasting over a bandwidth of 6MHz. That gives a power-spectral-density of 3.4MW/Hz. To cover the entire spectrum at the same time, say 10kHz to 300GHz, they would need just over 1 exawatts. 10^18 watts. That’s a lot of power! They could use a partial dyson sphere with the sun, but we could say the aliens are nice enough to still allow the sun to illuminate the earth and other planets to keep everything else the same.
I think you’re being intentionally obtuse here and betraying the spirit of the question?
Your meta analyzing the question instead of just taking the questions as it is, and in the process failed to actually address the core question. It’s a hypothetical scenario where most of our radio communication is jammed and unusable.
The mechanics of how the question got there don’t really matter, that’s not part of the question, it’s pointlessly pedantic to pick it apart. Just imagine the scenario with the mechanics you can consider plausible for such a scenario, and roll with it 🤦
“Aliens have technology beyond our means and largely render radio communication impossible by way of jamming”
What I like about these kind of questions is how different people take things in a totally different direction. I find it absolutely fascinating to see detailed replies about connotations I never thought of. It’s the whole reason why I love xkcd’s What If. If you’re unfamiliar, do yourself a favour and have a read. I particularly enjoy his answer to the question of everyone standing in one spot and jumping at the same time. He more or less ignores the core question and focuses on the societal & environmental impact of a mass human migration to one point, resulting in a fantastic read.
Let people enjoy thought experiments as a tangent.
Chill out. I was interested in the “how” and thought I would share.
I really appreciate your comment- Do you work with RF day to day?
I appreciated your post.
This is an underpinning of the plot of Final Fantasy VIII, where a sorceress with incredible power is entombed and sent to space, and her screaming drowns out all the radio frequencies on the planet.
Pulls out my big box of old CAT5 cables… Who’s the packrat now?!
The volunteer firefighter effect leads me to suspect you were behind the jamming all along!
we use wired communications until the issue is solved.
Wired communications would take over immediately and it would be a massive pain in the ass, but we’d ultimately adapt.
If the EM jamming is enough to also degrade the signal in copper lines, which at 1000x the strongest signal, might happen, then basically all modern society would collapse within 48 hours
If the jamming was spread spectrum and affected wired signals, it would also be strong enough to cook every living thing on the planet.
“Dang it, I’m being cooked AND the internet isn’t working!”
Dude, the internet is cooked!
WE’RE being cooked!
That too.
Yummy fried human meat! 😋
I guess if the aliens were carbon-based, it would let them cook planets and then sample the biological products at leisure.
The oceans and lakes would boil off, of course.
We better not run out of whales then
To serve men.
At what point does an EM jamming signal just become electricity running through the wires? That’s what would happen in a so called Harrington event, right?
Interestingly in Ukraine they are beginning to use drones with huge spools of fibre optic cable to transmit control and video signals. They’re doing this because of the jamming.
They also did that in Dr Stone
Not nessasarilly. U can reletivly easily block signal jamming for a confined area with a Faraday cage and most long distance is fibre optic nowdays.
You can also buy shielded Ethernet cables (especially for installation parallel to power lines) which would be much, much harder to jam.
In addition to wired you’d probably also see an uptick in line of sight optical transmissions via laser. Both of those options would really be the only two ways around it.
For me, since my entire house is wired, I’d just lose use of my cell phone. Most all internet infrastructure is wired too, so all that would continue to operate.
I wonder if there’d be enough fiber communications to get by.
If the signal is too strong, it’d certainly interfere with the circuitry inside everything electronic, even optical network modems within PCI adapters (computers).
Radio waves cause induction.
For urban areas probably. Ohh and the stock market would be fine.
Yeah, the dedicated cables for international market coordination and HFC would be unaffected except in the most dire situation.
What does it look like in the long term?
If they don’t stop, we’ll start using their jamming as a source of power for small mobile devices. It’s free energy at that point.
In the three body problem books one of the main plot points is a very similar scenario (although not identical). No spoilers but it might be worth a read / watch.
Which version, aren’t there a couple ones you can watch?
I haven’t read the books, but I did watch both versions, and they’re both decent, but I would recommend the Chinese version. Not only is it obviously more faithful to the books (you can just tell as it is so much more detailed than the Netflix version), but I found it fascinating to watch a high budget series from China, as I’ve never seen any Chinese art/media at that level. Interesting to see how they are and aren’t influenced by Western media.
I wouldn’t say the Netflix version was bad (much much shorter, and not the full story yet) though. I wonder if the portrayals of the Cultural Revolution in the Chinese version were white washed a bit (though I will say that, surprisingly, it was slightly critical of the CCP at times).
I’ve read the English books. The Netflix series was kinda faithful to the books but it’s only season 1 so far. It’s not finished yet. There’s a Chinese tv series as well which is a lot harder to find but I’ve watched a bit of it and it seems much more like a direct adaptation of the books.
Is the chinese show caught up on the booksnor still unfinished?
I am sure someone will use it as a pretence for invasion. I loosely remember reading somewhere that jamming can be classified as an act of war but I don’t recall where I heard it.
“A communications disruption can mean only one thing. Invasion!”
Jamming isn’t so trivial because it’s not really the volume but the signal to noise ratio that really matters no matter how much energy the aliens use. Therefore, I propose that this question doesn’t make technical sense.
Take for example GPS. The signal strength is way below the noise and you can’t really hear it at all because it’s so weak. The background noise is overwhelmingly loud already. You have to process the signal out of the noise using special techniques to collect the energy you care about using statistical correlation. While can still jam the signal in general, jamming requires that you understand how the signal is being used to impact that signal to noise ratio and stop the information flow. Simply screaming into all frequencies might not have all that much impact unless you understand what a signal means for each use case. Many wireless applications are even point to point links that are great at rejecting inputs outside of the intended direction and even the wrong polarization. There are physical limitations that preclude a general all signal jammer.
That said, let’s say the aliens understand all of our wireless communication protocols. I think people would adapt after a short period of disruption because it wasn’t all that long ago that we were using wires for business and critical functions. Heck, some industry still use fax machines and famously a lot of old government tech still has software stored on floppy disc. I think we’ll be OK. Might even be better for our mental health once the phones stop working.
Might even be better for our mental health once the phones stop working.
Ethernet to USB-C adapter sales go BRRRR
The cheap ones make a lot of noise already. I imagine to a passing alien spaceship we look like a giant EMP.
Why can’t the aliens just use a quantum RNG to set the nanosecond to nanosecond amplitude change on each individual frequency?
Those random numbers have a random distribution. Random uniform or random normal, I can average out those values to zero to remove the noise. This is indeed what GPS does for example. This wouldn’t be effective for blocking those types of radio signals.
If you want to be effective, you need to know the symbol rate and cater your jamming to the application. There’s also other parameters of a radio signal besides amplitudes like polarity and your signal also has to propagate through free space and make it through the front end of my receiver which could be selective in other ways. You don’t typically have the privilege of transmitting directly into the receiving antenna.
There’s an interesting related area called channel coding that you might be interested in that models noise and interference and figures out how to encode radio signals in ways where they are not easily disturbed.
For your specific example, if you’re talking about changing the value randomly on every nanosecond, I would expect to see a one gigahertz main frequency with lower harmonics, which would likely look like pretty much nothing to most GPS devices.
Jamming isn’t so trivial because it’s not really the volume but the signal to noise ratio that really matters no matter how much energy the aliens use. Therefore, I propose that this question doesn’t make technical sense.
Tell that to my microwave and WiFi router.
Wi-Fi is interesting. It’s designed for maximum bandwidth at low power levels. It also has a carrier sense system to prevent interference with other unknown devices on the unlicensed spectrum. Most things are sacrificed for that bandwidth, such as exploiting multipath and spatial propagation differences to squeeze out every last drop of data. Orthogonal carriers are spaced very close together maximize the available spectrum.
Still in this case, Wi-Fi operates at other frequencies that do not get microwave interference, and wireless network might explicitly be trying not to interfere with the microwave because it could be a device trying to share the unlicensed spectrum. The other Wi-Fi frequencies don’t go very far and aren’t good at penetrating walls, so the amount of power that an alien spaceship would have to use to block these signals categorically is crazy high. at some point you don’t have a jammer but a giant space death ray.
I’m not saying they couldn’t degrade it, but jamming them all? That sounds like a very challenging ask. Your microwave shares your living space. Meanwhile your wireless router politely avoids speaking when the microwave appears to be talking.
My whole family is going to start complaining that the WiFi is busted and I need to fix it.
Lol, I’m sure they’ll appreciate those long-ass ethernet cables + the Ethernet to USB-C adaptor.
(Please don’t say “kill the aliens” they have tech so advanced, its impossible to do it)
Usa would send all their nukes in an attempt to kill the aliens anyway, because otherwise some top militarists would feel their whole life meaningless.
No we wouldn’t, there’s a documentary about this kind of thing. We’d send a super-talented pilot and the World’s greatest hacker (who no one listened to). And they would fly into the Alien ship and the hacker would hack it and it would blow up.
there’s a documentary about this
I see.
Is it the one where the world class hero asks the pilot “When we start our attack flight right through the sun, isn’t it going to be rather hot there?” and the talented pilot explains “No, stupid, don’t you know we are going at night?”
I don’t think it’s that one, though that pilot is a pretty smart fella!
It’s this one…
The smart guy: You really think you can fly that thing?
The pilot: You really think you can do all that bullshit you just said?
Lol the alien would just be like: “Rude little creatures, lets turn the frequency into microwaves and amplify it a million times, point them all converging directly at those creatures (referring to Americans)”
All of them? including visible light?
They said every radio frequency not every electromagnetic frequency.
If they did, I’d imagine “jamming” gamma rays is going to have some side effects.
So, EVERY radio on the planet is suddenly overwhelmed by broad-spectrum jamming from orbital sources? Every cell phone, wifi, broadcast TV, satellite, AM/FM?
A bunch of people die,.due to distracted-driving car accidents with no way to call for help. News and government adapt modestly quickly, since the Internet itself runs mostly on already-shielded wires. There is a run on ethernet cables and phone modems for a bit, though, since not everyone has one. Navigation and timekeeping get harder, since no GPS or radio time sync, but humans adapt to those fairly quickly.
Long-term consequences depend on how long the aliens keep it up. It’s definitely a holy crap there are aliens! moment, though, since a bunch of sudden radio transmitters would be detected in the sky and identified as alien tech way before the toilet paper shortage even starts.
“way before the toilet paper shortage even starts.” LMAO.
Kill the aliens.
Srsly tho, it’s not about the tech they have or the 1000x power. Any jamming can be circumvented, and humans would have a much greater motivation to adapt than the aliens would.
