4 ms·

Good grief, did anyone read the paper, or are you all just sprouting your own personal Fermi paradox theories? > The basic assumption of this work is the hypot

Good grief, did anyone read the paper, or are you all just sprouting your own personal Fermi paradox theories? > The basic assumption of this work is the hypothesis that alien civilizations do not bother to explore merely biotic planets, so that the radiosphere criterion becomes the main trigger for alien civilizations to send interstellar probes The tldr; in this work is that they assume there’s a finite (short) duration during which civilisation are “noisy” and given that our “noise” is currently at most ~100 light years from us, no one has noticed us and bothered to send a probe or direct a signal at us. I mean, it’s an interesting (not, in my view, novel) take, in that it posits that every civilisation has a finite spherical band in which they are “detectable” by radio emission before they go to “quiet” technology like fibre optic; and you’d have to be specifically looking at just the right time while you were in that (supposedly) brief band. …but, it really doesn’t to give any thought to spectral analysis / why a “quiet” civilisation would be undetectable on the basis of generating complex / unusual chemical signatures in their atmospheres, and why we don’t see anything like that out there. It’s really, just restricted to the consideration of radio broadcast and, unsurprisingly, given the restrictions, makes it implausible anyone would notice us / we would happen to be looking while anyone was “noisy” and visible in the radio spectrum. Eh. Did I miss anything interesting in there? It doesn’t seem particularly novel.

denton-scratch 4y ago
Well, I didn't notice the bit about a "noisy period" - I took the sphere to be the surface of a volume, not a shell. I think the idea was that once you start emitting detectable information, you don't stop. It's all hypothetical. All the stuff about probes: it doesn't matter whether the aliens are interested in talking to us. It doesn't matter whether they are interested in space and stuff. The authors define this sphere as the space wherein a hypothetical alien civilization COULD have detected our existence, and COULD have signalled or sent a probe in response. Also, they choose to define their sphere in terms of the beginning of the radio era. That's arbitrary. There might be other signals that planets carrying life emit, that we don't know about. SETI searches for radio signals like a drunk searches for his keys under the street-light. Note: I only read the abstract.
m4rtink 4y ago
Even a very efficient and radio quiet civilization would still have to release obscene amounts of heat if they do any serious stuff in space. Unless they somehow hack thermodynamics there is really no way around that.

denton-scratch 4y ago

Well, I didn't notice the bit about a "noisy period" - I took the sphere to be the surface of a volume, not a shell. I think the idea was that once you start emitting detectable information, you don't stop. It's all hypothetical. All the stuff about probes: it doesn't matter whether the aliens are interested in talking to us. It doesn't matter whether they are interested in space and stuff. The authors define this sphere as the space wherein a hypothetical alien civilization COULD have detected our existence, and COULD have signalled or sent a probe in response. Also, they choose to define their sphere in terms of the beginning of the radio era. That's arbitrary. There might be other signals that planets carrying life emit, that we don't know about. SETI searches for radio signals like a drunk searches for his keys under the street-light. Note: I only read the abstract.

m4rtink 4y ago

Even a very efficient and radio quiet civilization would still have to release obscene amounts of heat if they do any serious stuff in space. Unless they somehow hack thermodynamics there is really no way around that.