3 ms·

I haven't read enough on the subject to know the answer to that question, so here's another one. How do we know that ET uses radio for communication? They might

by tjpnz 5y ago

I haven't read enough on the subject to know the answer to that question, so here's another one. How do we know that ET uses radio for communication? They might've moved onto something else. Tachyons or gravitational waves might make good candidates but those are just the ones we know about. For those two we do have instruments sensitive enough to detect potential WOW signals, just not a lot of will for them to be used for that purpose.

joe__f 5y ago
It may be possible to use gravitational waves to transmit signals, although gravity is hugely more challenging to manipulate than electromagnetism because it's purely attractive and interacts much less strongly with matter, making this very unlikely in my opinion. Another theoretically plausible but very unlikely signal carrier could be neutrinos. 'Tachyon' is a name used to refer to any theoretical particle which travels faster than the speed of light; as far as I'm aware all current experimental evidence rules out the existence of tachyons.
PeterisP 5y ago
Out of all the physical phenomena we know about, EM (various aspects of it, radio or lasers or whatever) is the best way to transmit information across space. Tachyons are fictional, there's no reason to assume they exist. Gravitational waves require exceptionally large amounts of energy to generate; we can't transmit with them, and for a more advanced civilization which does have that capability, using the same amount of energy for a focused/directional EM transmission would be much easier to detect; because gravitational waves (unlike EM) radiate equally in all directions but EM can be directed to a particular recipient. Neutrinos are similar to EM but worse, as their transmission/power characteristics are pretty much the same but it's very difficult to detect them.
tjpnz 5y ago
Too late to edit my comment but regarding tachyons what I really meant was neutrinos. Clearly I've been watching too much Star Trek.
analog31 5y ago
A massive object flying at a substantial fraction of the speed of light would be better for communication over very long range. Sure, the overall latency would be greater, but a massive object doesn't suffer from the inverse-square law if you know where you want to send it, and doesn't need a larger antenna to make it more directional. If it's some kind of programmable or even intelligent machine, then it could adapt to the evolution of conditions at its destination upon arrival, and engage in many iterations of short distance communications before sending data homeward. It's like why we sent human envoys during the era when communication speeds were limited by horses and ships. ET has probably given up on long range radio for their local comms, just as we have. The bulk of our comms go through waveguides (electrical cables and optical fibers). Even our radio comms have relatively short range, and are designed to be virtually indistinguishable from noise. It's as if we've wrapped ourselves in a primitive Dyson sphere.

by tjpnz 5y ago

joe__f 5y ago

It may be possible to use gravitational waves to transmit signals, although gravity is hugely more challenging to manipulate than electromagnetism because it's purely attractive and interacts much less strongly with matter, making this very unlikely in my opinion. Another theoretically plausible but very unlikely signal carrier could be neutrinos. 'Tachyon' is a name used to refer to any theoretical particle which travels faster than the speed of light; as far as I'm aware all current experimental evidence rules out the existence of tachyons.

PeterisP 5y ago

Out of all the physical phenomena we know about, EM (various aspects of it, radio or lasers or whatever) is the best way to transmit information across space. Tachyons are fictional, there's no reason to assume they exist. Gravitational waves require exceptionally large amounts of energy to generate; we can't transmit with them, and for a more advanced civilization which does have that capability, using the same amount of energy for a focused/directional EM transmission would be much easier to detect; because gravitational waves (unlike EM) radiate equally in all directions but EM can be directed to a particular recipient. Neutrinos are similar to EM but worse, as their transmission/power characteristics are pretty much the same but it's very difficult to detect them.

tjpnz 5y ago

Too late to edit my comment but regarding tachyons what I really meant was neutrinos. Clearly I've been watching too much Star Trek.

analog31 5y ago

A massive object flying at a substantial fraction of the speed of light would be better for communication over very long range. Sure, the overall latency would be greater, but a massive object doesn't suffer from the inverse-square law if you know where you want to send it, and doesn't need a larger antenna to make it more directional. If it's some kind of programmable or even intelligent machine, then it could adapt to the evolution of conditions at its destination upon arrival, and engage in many iterations of short distance communications before sending data homeward. It's like why we sent human envoys during the era when communication speeds were limited by horses and ships. ET has probably given up on long range radio for their local comms, just as we have. The bulk of our comms go through waveguides (electrical cables and optical fibers). Even our radio comms have relatively short range, and are designed to be virtually indistinguishable from noise. It's as if we've wrapped ourselves in a primitive Dyson sphere.