6 ms·

I doubt SETI could detect even our own signals, when it’s encrypted digital data. I mean it’s just noise like any background signal.. Then, we people are very

by miika 3y ago

I doubt SETI could detect even our own signals, when it’s encrypted digital data. I mean it’s just noise like any background signal.. Then, we people are very soon capable of communicating using quantum entanglement, which means it’s beyond wireless and you simply couldn’t tap into it with some antenna. For these reasons I suspect that SETI is waste of money.

bnralt 3y ago
Yeah, the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1]: > If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth? > In general, no. Most earthly transmissions are too weak to be found by equipment similar to ours at the distance of even the nearest star. But there are some important exceptions. High-powered radars and the Arecibo broadcast of 1974 (which lasted for only three minutes) could be detected at distances of tens to hundreds of light-years with a setup similar to our best SETI experiments. It's not really a surprise why we aren't finding things. It's a surprise that we're still acting like this is a good way to look. [1] https://www.seti.org/faq#obs12 https://www.seti.org/faq#obs12
- andyjohnson0 3y ago
  > the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1] TO be clear, the signals it is referring to are those that would be similar the unintended leakage of normal broadcast and military radar systems used on earth. So detecting ETIs from their passive emissions is certainly unfeasible that the moment. Signals broadcast by a hypothetical extraterrestrial civilisation as part of an intentional seti signalling effort would (presumably) use much higher power, narrower bandwidth, and frequencies chosen to reduce attenuation by the interstellar medium. These would be detectable using our current technology, and is largely what seti is looking for.
- cgriswald 3y ago
  I don’t see that as being much of a problem. Although we would not be able to detect regular Earth signals, we are relatively near the point where we would be able to detect Earth, including its atmospheric composition. Given we’ve already sent the Arecibo message, we might be likely to send such a signal to Earth. If so, other beings may as well. I think the real problem is the timing. It seems unlikely that anyone will be looking at the same time anyone else is sending a message.
nradov 3y ago
Quantum entanglement communication is science fiction. There are strong theoretical reasons to think that it could never work.
deleted 3y ago
[deleted]
pmoriarty 3y ago
"I doubt SETI could detect even our own signals, when it’s encrypted digital data. I mean it’s just noise like any background signal" Just because it's "noise" (ie. random/unpredictable looking) doesn't mean it's indistinguishable from other "noise". Not all "noise" is created equal. "noise" can have properties that make it distinguishable from other "noise". You may have heard of "white noise", "brown noise", "pink noise", "gaussian noise", etc... A sequence that appears random or unpredictable may nevertheless fall in to certain distributions. I am not an astronomer, statistician or cryptographer, but would not be in the least surprised if encrypted communication could be clearly distinguishable from the cosmic microwave background radiation -- not only based on its distribution, but other properties such as intensity of the signal, how frequently the signal appears, and other much more advanced signal analysis techniques which are way beyond my expertise to analyze but not beyond the experts at SETI.
- xcv123 3y ago
  Encrypted communication would be detectable. The underlying content may appear to be random, but the transfer protocol and encoding itself is structured, not random. It still needs to be encoded then transported with error correction, etc.
nwallin 3y ago
> I doubt SETI could detect even our own signals, This is true. The signals we communicate with amongst ourselves would be too weak to detect using present equipment at any distance. > when it’s encrypted digital data. I mean it’s just noise like any background signal.. This part is not true. A simple spectrum analyzer will show what radio bands are being communicated on and it's clear as day. > we people are very soon capable of communicating using quantum entanglement, This is very much not true. This is theoretically impossible. Unless we are very--very--wrong about quantum mechanics, we cannot use effects related to quantum entanglement to communicate.
- TechBro8615 3y ago
  > we cannot use effects related to quantum entanglement to communicate ELI5 to a non-physicist why not? I thought this was possible, if Alice and Bob share an entangled pair of a set of particles (i.e. each has a clique of particles entangled with the other), and they pre-arrange an algorithm for determining the meaning of different states of their particles. IIRC wasn't this the gist of the "wormhole" paper that went viral last year (which was criticized for being improperly named, but nonetheless demonstrated a method of "communication" between two locations given a prearranged algorithm for assigning meanings to different states of entanglement)?
  - nwallin 3y ago
    Quantum entanglement is like two dice that "agree" with each other to always roll the same number. If Alice and Bob shake their dice in their hands, and roll it on the table, they'll always roll the same number. It does not allow Alice or Bob the place a die on the table on a specific number and have the other die roll over to that number. If Alice or Bob try to influence the number that the die rolls, it will break the connection between the two dice.
    - TechBro8615 3y ago
      But why can't Alice keep rolling the die until it gets to a state that she and Bob agree is a part of an encoding scheme? Is it because she needs to read the number on the die to know whether to stop rolling it, but by reading (measuring) the number, she is effectively re-rolling (collapsing) it, so she could never know when to stop rolling it? In other words, she could stop after she measures a state, but the current state of the system is N, she'd be stopping after N-1, and there is no way to coordinate with Bob to know the difference? The link I posted downthread seemed to suggest that the No Cloning Theorem is the constraint that makes this impossible. Any chance you can try to explain that within the context of the dice analogy?
bastawhiz 3y ago
> I mean it’s just noise like any background signal.. My microwave produces noise but I'd like to think scientists could pick it up with their sensors and say "huh, sounds like a microwave". You might be sending encrypted noise over the wire, but the things like error correction codes are not encrypted. It might be white noise, but you've got to make sure it's the correct white noise when it arrives at its intended destination. > Then, we people are very soon capable of communicating using quantum entanglement How many years from now do you think it'll be before we simply stop using radio waves entirely?
MagicMoonlight 3y ago
Yeah but they’ve wasted their lives doing it so they’re going to keep up the act.
- p-e-w 3y ago
  That's a very unpleasant and cynical way to put it, but the underlying idea is true. Admitting that you spent a big portion of your life on something that has no realistic chance of success is a herculean task, and most people understandably find it much easier to just continue in the pretense that it was, and still is, worth their time.
jojobas 3y ago
They are not trying to eavesdrop on aliens, they hope to detect their attempts to contact us (or anyone).
gnulinux 3y ago
> we people are very soon capable of communicating using quantum entanglement This is nothing other than sci-fi. I don't understand how you can be so sure of something like this.
- burnished 3y ago
  Its old sci fi that seemed plausible at one point - hell I thought an ansible was still possible even a few years ago.
drmpeg 3y ago
Depends on the signal. There is lots of complexity in a 4G LTE or 5G signal. Take a look at the waterfall of this 4G base station. https://www.w6rz.net/attlte.png https://www.w6rz.net/attlte.png
NavinF 3y ago
> we people are very soon capable of communicating using quantum entanglement How much do you wanna bet? Do you have a specific bitrate and year in mind?
f6v 3y ago
> I doubt SETI could detect even our own signals, when it’s encrypted digital data. I guess you haven’t heard of the military monitoring the activity even of encrypted enemy channels. You don’t even need to know how to decrypt it, you can detect peaks in communication.

by miika 3y ago

bnralt 3y ago

Yeah, the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1]: > If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth? > In general, no. Most earthly transmissions are too weak to be found by equipment similar to ours at the distance of even the nearest star. But there are some important exceptions. High-powered radars and the Arecibo broadcast of 1974 (which lasted for only three minutes) could be detected at distances of tens to hundreds of light-years with a setup similar to our best SETI experiments. It's not really a surprise why we aren't finding things. It's a surprise that we're still acting like this is a good way to look. [1] https://www.seti.org/faq#obs12 https://www.seti.org/faq#obs12

andyjohnson0 3y ago
> the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1] TO be clear, the signals it is referring to are those that would be similar the unintended leakage of normal broadcast and military radar systems used on earth. So detecting ETIs from their passive emissions is certainly unfeasible that the moment. Signals broadcast by a hypothetical extraterrestrial civilisation as part of an intentional seti signalling effort would (presumably) use much higher power, narrower bandwidth, and frequencies chosen to reduce attenuation by the interstellar medium. These would be detectable using our current technology, and is largely what seti is looking for.
cgriswald 3y ago
I don’t see that as being much of a problem. Although we would not be able to detect regular Earth signals, we are relatively near the point where we would be able to detect Earth, including its atmospheric composition. Given we’ve already sent the Arecibo message, we might be likely to send such a signal to Earth. If so, other beings may as well. I think the real problem is the timing. It seems unlikely that anyone will be looking at the same time anyone else is sending a message.

nradov 3y ago

Quantum entanglement communication is science fiction. There are strong theoretical reasons to think that it could never work.

deleted 3y ago

[deleted]

pmoriarty 3y ago

"I doubt SETI could detect even our own signals, when it’s encrypted digital data. I mean it’s just noise like any background signal" Just because it's "noise" (ie. random/unpredictable looking) doesn't mean it's indistinguishable from other "noise". Not all "noise" is created equal. "noise" can have properties that make it distinguishable from other "noise". You may have heard of "white noise", "brown noise", "pink noise", "gaussian noise", etc... A sequence that appears random or unpredictable may nevertheless fall in to certain distributions. I am not an astronomer, statistician or cryptographer, but would not be in the least surprised if encrypted communication could be clearly distinguishable from the cosmic microwave background radiation -- not only based on its distribution, but other properties such as intensity of the signal, how frequently the signal appears, and other much more advanced signal analysis techniques which are way beyond my expertise to analyze but not beyond the experts at SETI.

xcv123 3y ago
Encrypted communication would be detectable. The underlying content may appear to be random, but the transfer protocol and encoding itself is structured, not random. It still needs to be encoded then transported with error correction, etc.

nwallin 3y ago

> I doubt SETI could detect even our own signals, This is true. The signals we communicate with amongst ourselves would be too weak to detect using present equipment at any distance. > when it’s encrypted digital data. I mean it’s just noise like any background signal.. This part is not true. A simple spectrum analyzer will show what radio bands are being communicated on and it's clear as day. > we people are very soon capable of communicating using quantum entanglement, This is very much not true. This is theoretically impossible. Unless we are very--very--wrong about quantum mechanics, we cannot use effects related to quantum entanglement to communicate.

TechBro8615 3y ago
> we cannot use effects related to quantum entanglement to communicate ELI5 to a non-physicist why not? I thought this was possible, if Alice and Bob share an entangled pair of a set of particles (i.e. each has a clique of particles entangled with the other), and they pre-arrange an algorithm for determining the meaning of different states of their particles. IIRC wasn't this the gist of the "wormhole" paper that went viral last year (which was criticized for being improperly named, but nonetheless demonstrated a method of "communication" between two locations given a prearranged algorithm for assigning meanings to different states of entanglement)?
- nwallin 3y ago
  Quantum entanglement is like two dice that "agree" with each other to always roll the same number. If Alice and Bob shake their dice in their hands, and roll it on the table, they'll always roll the same number. It does not allow Alice or Bob the place a die on the table on a specific number and have the other die roll over to that number. If Alice or Bob try to influence the number that the die rolls, it will break the connection between the two dice.
  - TechBro8615 3y ago
    But why can't Alice keep rolling the die until it gets to a state that she and Bob agree is a part of an encoding scheme? Is it because she needs to read the number on the die to know whether to stop rolling it, but by reading (measuring) the number, she is effectively re-rolling (collapsing) it, so she could never know when to stop rolling it? In other words, she could stop after she measures a state, but the current state of the system is N, she'd be stopping after N-1, and there is no way to coordinate with Bob to know the difference? The link I posted downthread seemed to suggest that the No Cloning Theorem is the constraint that makes this impossible. Any chance you can try to explain that within the context of the dice analogy?

bastawhiz 3y ago

> I mean it’s just noise like any background signal.. My microwave produces noise but I'd like to think scientists could pick it up with their sensors and say "huh, sounds like a microwave". You might be sending encrypted noise over the wire, but the things like error correction codes are not encrypted. It might be white noise, but you've got to make sure it's the correct white noise when it arrives at its intended destination. > Then, we people are very soon capable of communicating using quantum entanglement How many years from now do you think it'll be before we simply stop using radio waves entirely?

MagicMoonlight 3y ago

Yeah but they’ve wasted their lives doing it so they’re going to keep up the act.

p-e-w 3y ago
That's a very unpleasant and cynical way to put it, but the underlying idea is true. Admitting that you spent a big portion of your life on something that has no realistic chance of success is a herculean task, and most people understandably find it much easier to just continue in the pretense that it was, and still is, worth their time.

jojobas 3y ago

They are not trying to eavesdrop on aliens, they hope to detect their attempts to contact us (or anyone).

gnulinux 3y ago

> we people are very soon capable of communicating using quantum entanglement This is nothing other than sci-fi. I don't understand how you can be so sure of something like this.

burnished 3y ago
Its old sci fi that seemed plausible at one point - hell I thought an ansible was still possible even a few years ago.

drmpeg 3y ago

Depends on the signal. There is lots of complexity in a 4G LTE or 5G signal. Take a look at the waterfall of this 4G base station. https://www.w6rz.net/attlte.png https://www.w6rz.net/attlte.png

NavinF 3y ago

> we people are very soon capable of communicating using quantum entanglement How much do you wanna bet? Do you have a specific bitrate and year in mind?

f6v 3y ago

> I doubt SETI could detect even our own signals, when it’s encrypted digital data. I guess you haven’t heard of the military monitoring the activity even of encrypted enemy channels. You don’t even need to know how to decrypt it, you can detect peaks in communication.