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Even with EM, they could have a highly advanced encoding format which is barely detectable about the random noise floor (spread spectrum like). US army uses the
by 21 8y ago
Even with EM, they could have a highly advanced encoding format which is barely detectable about the random noise floor (spread spectrum like). US army uses these kind of techniques to make the signal both hard to detect and hard to jam.
Who knows how far you can push this, maybe to the point where it's essentially impossible to detect the signal if you are not the intended target.
- wongarsu 8y agoMost signals would presumably also be highly targeted. The narrower the beam you are sending, the less energy is required to send the information. Unless aliens cheap out on antennas or prefer to waste lots of energy on broadcasting in all directions, we are very unlikely to be in the path of their communication beams.
- gm-conspiracy 8y agoI thought we could Van Eck phreak the aliens.
- joering2 8y agoWouldnt heavily advanced civilization wanted to remain silent? If they know they are less sophisticated aliens out there like us humans, then for sure there are civilizations more advance than they are. I suspect they are not interested of sending their own signal to someone who could anihilate them with a push of a button (even higher civ.)
- ASalazarMX 8y agoThe only civilizations we have known definitely show that contact involving a great technological difference is usually a disaster for the less advanced people. https://en.wikipedia.org/wiki/Fermi_paradox#It_is_dangerous_to_communicate https://en.wikipedia.org/wiki/Fermi_paradox#It_is_dangerous_...
- rrival 8y agoThe Dark Forest (Three Body Problem) explores this
- barrow-rider 8y agoVia video game, no less. Well, simulation-y video game. Sort of.
- losteric 8y agoScarcity is an important factor. Today, primitive societies (mostly) safe from Western conquest because they simply don't have anything we want.
- azernik 8y agoThat's more about selection bias than about anything that's inherently different about advanced societies today. There were primitive societies that did have valuable things [1], and they were all destroyed or conquered very soon after contact with more powerful societies, and they remain vulnerable to outsiders as soon as they come into possession of something of value. When gold was discovered on the land of uncontacted Amazonian tribes, for example, this happened: https://www.theguardian.com/global-development/2018/aug/22/alleged-massacre-of-amazon-tribespeople-javari-valley-brazil https://www.theguardian.com/global-development/2018/aug/22/a...
- martincmartin 8y agoEnergy is very abundant by E = mc^2, so what we consider "wasting energy" they may not even consider. The average web page is bigger than the original DOOM download, about 2/3 the size of War and Peace. In an era before Gutenberg, when monks copied books my hand, I wonder if anybody mused that nobody would "waste" the equivalent of 750 pages to communicate "please log in using your email and password."
- saagarjha 8y agoYou need to consider that you're sending a message over millions of light years. You'd need a a power output comparable to a star to be visible across that distance if you didn't focus your message (because, obviously, stars themselves do it!)
- dogma1138 8y agoIf you want to do it you might as well use the star itself it won’t be that hard to encode a message into the light emanating from the star itself you only need a sufficiently large polarizer or anything else capable of modulating the light coming form the star. Any civilization that would need to communicate even across a few 100 light years would be capable of doing so.
- bardworx 8y agoI’m totally ignorant in this so my question could be half baked but what exactly are you saying? By polarizing light, do you mean that a device would intercept the photons escaping from the sun and then changing their wavelength to encode a message similar to Morse code? Or do you mean something else entirely? Edit: a word
- dogma1138 8y agoA polarizer only allows light of certain polarity (the "direction" the waveform oscillates, think sunglasses or 3D glasses, or the polariser in your LCD screen) to pass through. https://en.wikipedia.org/wiki/Polarization_(waves) https://en.wikipedia.org/wiki/Polarization_(waves) But it doesn't have to be polarization just any easy modulation of the light, polarization is just easy to do since all you need is a huge polarizer and a few reaction wheels. Think about planetary transitions; we can detect those quite easily this is how we find exoplanets these days, in fact we can fairly accurately identify the composition of the planet's atmosphere and the atmosphere is a fairly thin slice of the entire planet's silhouette. So the only thing you need to do is to position a sufficiently big object it doesn't have to be even that big (still huge in our scale but something in the range of 100's or even 1000's of kilometers across would likely be sufficient the radius of the earth is only 6300KM~ and we can detect planets smaller than the earth AFAIK, and it can be as thin as a solar sail and considering we already build satellites with antenna that unfold to the size of a few football fields it might be possible even with our current level of technology or something not that far off) because you take advantage of the distance between planetary systems that object needs to be able to modulate the light it can be polarization, abstraction, color filtering. To put it simply make a huge ass thin TFT LCD let the sun act as a backlight and put it in a stelar synchronous orbit from the vantage point of the star system you want to communicate with so it would always appear in line between it and your local star and blink your messages away. If you want to go for the golden star then build a huge ring which also is capable of acting like lense this can allow you to have a communication array which can also direct the signal in a relative narrow beam.
- bcaa7f3a8bbc 8y agoSomething like FHSS (https://en.wikipedia.org/wiki/Frequency-hopping_spread_spectrum https://en.wikipedia.org/wiki/Frequency-hopping_spread_spect...), not only a low level of signal is spread throughout a board frequency range, the central frequency is also changing many times per seconds, synchronization and decoding is only possible if the CSPRNG key is known. The signal of interplanetary communication is also highly directional. I guess an alien civilization has much better ideas to avoid detection.
- garmaine 8y agoThere's a difference between successful real-time decoding, and just determining from a full-spectrum recording whether it is the case that a signal exists, even if its behavior is unpredictable.
- pps43 8y agoThe point of spread-spectrum signal is that it's indistinguishable from noise unless you know the key. With frequency-hopping you still have spikes in the spectrum around the frequencies you hop between, but with most modern systems you no longer have anything distinctive to find.
- garmaine 8y agoIt's not indistinguishable from noise, if it is powerful enough to be received at all. If you filter based on the background noise threshold, you will discover a signal that quickly jumps frequencies in a pattern that is unpredictable without knowing the secret key. If frequency hopping is all that is used, you could even recombine the pieces to put the original message back together again. But in any case it will be very plainly obvious that the signal exists. A radio with a hardware limitation of only tuning to a specific frequency at a time would be unable to pick up on it, and would only hear transient blips as the signal enters and leaves the channel, which is what people mean when they say spread spectrum "looks like noise". You could defeat this analysis by actually broadcasting noise on all frequencies, so the transmission frequency is indistinguishable, assuming the encryption used is also indistinguishable from a random oracle. But now you have a noisy point source in the sky, even if you can't decipher the contents of the message. Succinctly put, obfuscation techniques like frequency hopping spread spectrum are tactical techniques that try to hide transmissions from actual radios in widespread use, not hide the existence of the radio signal in some physical sense. FHSS radio transmissions look like noise sources, not silence. Which is basically what SETI is looking for -- sources of radio noise unexplained by our understanding of astronomy.
- reaperducer 8y agoThere's also the possibility that some ET's may want to be known, and are sending out an easily-detected beacon. That might be our best hope.
- dmichulke 8y agoYeah, who in his right mind would broadcast his position to all the possibly much more advanced, resource-hungry and expansive species out there? ;-)
- komali2 8y agoPerhaps someone with a very strong conviction that they are already the most advanced, resource-hungry, and expansive species out there ;)
- ASalazarMX 8y agoThe Borg have become lazy indeed.
- 3rdAccount 8y agoI would make all my planet's tech based off of sewage. Borg Drone 8 of 200: "Nothing to Assimilate here...time to go assimilate Risa".
- jlarocco 8y agoBut how do we know our concept of an easily detected signal isn't merely a product of how our technology evolved? I think it's worth investigating and looking for signals because it does find interesting phenomenon, I'm just very skeptical we'll ever find intelligent life doing so.
- marshray 8y ago> how do we know our concept of an easily detected signal isn't merely a product of how our technology evolved? Because 150 years of investigation very very very strongly implies that electromagnetism is one of the most powerful of a very short list of fundamental forces.
- janekm 8y agoThat's a very good point. When we first started listening for alien signals, we assumed that of course aliens would have TV and radio. In the few decades since then we have mostly switched to digital TV which has much more efficient (looks more like noise) encoding, and a trend of moving away from broadcast to YouTube, Netflix and podcasts is also evident (using both higher efficiency encoding and much lower transmit powers). And developments like 5G are intended to accelerate this development by using even higher coding efficiencies and shorter distances/lower power, as well as beam steering to directly target the receiver. Perhaps civilisations only typically use broadcast communications for <100 years, a mere blip at galactic scales.