To follow up on the end of my last post, what if by optimizing for photon communication, we’re just making a giant planet-sized wheat triangle that’s primitive, quaint, and functionally useless because no ETI in their right mind uses wheat triangles anymore?
The readings for this week, especially Hippke’s 2017 paper about other information carriers for SETI, actually settled my mind on this score.
To skip to the punchline, Hippke finds that everything that we know of so far is inferior to photon transmission (specifically 1 nm X-rays, based on the argument in his previous paper), except perhaps physical artifacts (which might be preferable if you don’t care about speed). This is exciting, and puts my mind at ease about the wheat field thing.
He looks at the following methods, and generally finds the following flaws:
You will notice a lot of ???s in the Pros categories, and I think that’s interesting. Hippke does a good job of going through a lot of messaging options that seem ridiculous at face-value (and not excluding them for that), working out some actual physics behind them, and doesn’t jump onto being a proponent of any “new thing!”. I appreciate this.
The assumptions that he makes with regards to point-to-point communication are interesting. He assumes that more information transmitted is preferable to less, information arriving earlier is preferable to later, and more efficiency is preferable to less. He then discusses, at the very end of the paper, how the landscape would change if any of these assumptions were incorrect (which is very cool!), or incorrect and stacking.
I would like to point out that Hart’s sociological argument probably stops any of this assumption-fiddling from mattering too much. Just because one ETI actually doesn’t care how fast information arrives (Because they’re very long-lived? Because they’re post-biological?) doesn’t mean that another won’t. Just because one ETI is naturally incurious and doesn’t care about actually transmitting their entire “encyclopedia” (if you will), doesn’t mean that another is.
If anything, I think that the “more efficiency / less efficiency” might be the easiest one to break without running afoul of this sociological argument. If you have access to enough energy, you won’t care whether a big METI project takes 10^-100 or 10^-95 of your energy budget. And, with the assumption that virtually all ETIs should have been around for far longer than we are (and that they care about energy/resources in the first place!), they’ll all probably have a much larger energy budget, and might not care too much about efficiency. Just a thought!