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I think the authors do not understand how planetary resonances work and how precise (or imprecise) the orbits need to be for the resonance to hold. Resonances

I think the authors do not understand how planetary resonances work and how precise (or imprecise) the orbits need to be for the resonance to hold. Resonances are very common. We have lots of resonances in our Solar system in all different places between bodies. For the resonance to be stable, two bodies do not need to have mathematically precise orbits in relation to each other. There is quite a wide margin for error. Once two planets are close enough to the resonance, the resonance may become stable due to feedback. What happens is planets will exchange energy back and forth on each orbit in a way, that preserves the resonance. A substantial input needs to be provided to break up the resonance. What is actually interesting about this particular system is the long chain of resonances. But that is also nothing super special -- once you know how resonances form you can see how all of the planets, when they are close enough to the resonance, will transfer energy between themselves to snap into it and then continue on their resonant orbits. There is absolutely no reason to suggest that a resonance like this must have come from unnatural origin. It would be like saying that because the period of our Moons rotation is so precisely the same as period of its orbit around Earth that it always faces Earth with one side, that somebody must have put the Moon on the orbit. That's obviously false, these resonances form easily and naturally.

foofie 3y ago
[flagged]
bilekas 3y ago
> It would be like saying that because the period of our Moons rotation is so precisely the same as period of its orbit around Earth that it always faces Earth with one side, that somebody must have put the Moon on the orbit I don't think that's the implication though. Life on earth would not be the same without the moon's orbit to provide stable ocean current rides. I would imagine not having that would add extra complexities to establish long term growth of "life"?
- darkmarmot 3y ago
  He's saying that tidally locked bodies are products of simple physics and you can't extrapolate deeper meanings from them.
  - bilekas 3y ago
    Ah okay and I agree. I was just saying that they do seem to promote the growth of life easier from what we can study at least.
aptwebapps 3y ago
The article does not claim anything like that even though the headline could be interpreted that way, and maybe that was not accidental. Scientists are investigating the system simply because it has properties that might make it easier to detect signals from.
rendall 3y ago
What is the mechanism by which orbiting bodies exchange energy?
- empath-nirvana 3y ago
  Gravitational waves.
  - jerf 3y ago
    Gravitational waves from planets are undetectably small. They do it through gravity directly, as sandworm101 says. You can model it with pure Newtonian gravity and get resonance effects just fine. See for instance: https://www.youtube.com/watch?v=Qyn64b4LNJ0 https://www.youtube.com/watch?v=Qyn64b4LNJ0
- sandworm101 3y ago
  Gravity. Same as how space probes gain energy from a planet when they "slingshot" past. But this is two planets closer in mass/speed so the energy transfer is less profound.
deleted 3y ago
[deleted]
empath-nirvana 3y ago
The reason they're _actually_ looking at that system is that we're looking directly down on it so we can see the orbits of all the planets at once. It has nothing to do with thinking the orbits are unnatural.
- usefulcat 3y ago
  Are you sure? TFA states "HD 110067 is viewed edge on from Earth", which doesn't sound like what you're describing. Of course they could have made a mistake; I don't know either way.
deleted 3y ago
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bunabhucan 3y ago
>HD 110067 (TIC 347332255) is a bright K0-type star with a mass about 80% that of the Sun, located at 12h39m21fs50, 20°01'40farcs0 (J2000). Breakthrough Listen (BL) is observing additional targets selected from the Exoplanet Follow-up Observing Program for TESS (ExoFOP-TESS) in addition to the nearby star sample described by Isaacson et al. (2017). HD 110067 is valuable as a technosignature target not only because of its interest for biosignature searches. First, Earth views the system edge-on, which increases the likelihood of detecting radiation from any transmitters present whether intentional (Traas et al. 2021) or resulting from planet-to-planet transmissions which could be observed by their "spillover" during planet–planet occultations (Ashtari 2023); second, the large number of planets regardless of their position in the star's habitable zone increases the likelihood that an advanced civilization could have spread technology to neighboring planets, as has happened in our own solar system (Wright et al. 2022). https://iopscience.iop.org/article/10.3847/2515-5172/ad235f https://iopscience.iop.org/article/10.3847/2515-5172/ad235f Nobody is suggesting the resonances are unnatural. The edge on aspect helps the search in other ways.
wolverine876 3y ago
> I think the authors do not understand ... The authors are scientists from SETI, Berkeley, Oxford, and NASA. Probably they understand anything you (or I) understand about the topic, and quite a bit more. (A funny phenomenon is that if they posted here, starting their comment with 'SETI researcher here ...', we would all listen to them and ask questions. If they 'post' a paper to a journal, a paper they spent years researching and revising, alongside other scientists, we disregard them.) Like many similar HN comments, I think there's a valid question in there. IMHO it's a mistake to immediately conclude that, perceiving some inconsistency, the other person must be wrong, obviously ridiculous, etc. That doesn't make sense unless I am omniscient: the inconsistency between my idea and theirs could just as easily be a problem on my end - much more easily when comparing my ideas of orbital physics with those authors. Here is how I have learned to think of it (using this example): To me, it seems clear that planetary resonances explain the observed phenomenon. Obviously the authors thought of that; how did they address that issue? Humility is truth, unless you are a god.
- wolverine876 3y ago
  And here is the apparent answer to the mystery: https://news.ycombinator.com/item?id=39543532 https://news.ycombinator.com/item?id=39543532

foofie 3y ago

[flagged]

bilekas 3y ago

> It would be like saying that because the period of our Moons rotation is so precisely the same as period of its orbit around Earth that it always faces Earth with one side, that somebody must have put the Moon on the orbit I don't think that's the implication though. Life on earth would not be the same without the moon's orbit to provide stable ocean current rides. I would imagine not having that would add extra complexities to establish long term growth of "life"?

darkmarmot 3y ago
He's saying that tidally locked bodies are products of simple physics and you can't extrapolate deeper meanings from them.
- bilekas 3y ago
  Ah okay and I agree. I was just saying that they do seem to promote the growth of life easier from what we can study at least.

aptwebapps 3y ago

The article does not claim anything like that even though the headline could be interpreted that way, and maybe that was not accidental. Scientists are investigating the system simply because it has properties that might make it easier to detect signals from.

rendall 3y ago

What is the mechanism by which orbiting bodies exchange energy?

empath-nirvana 3y ago
Gravitational waves.
- jerf 3y ago
  Gravitational waves from planets are undetectably small. They do it through gravity directly, as sandworm101 says. You can model it with pure Newtonian gravity and get resonance effects just fine. See for instance: https://www.youtube.com/watch?v=Qyn64b4LNJ0 https://www.youtube.com/watch?v=Qyn64b4LNJ0
sandworm101 3y ago
Gravity. Same as how space probes gain energy from a planet when they "slingshot" past. But this is two planets closer in mass/speed so the energy transfer is less profound.

deleted 3y ago

[deleted]

empath-nirvana 3y ago

The reason they're _actually_ looking at that system is that we're looking directly down on it so we can see the orbits of all the planets at once. It has nothing to do with thinking the orbits are unnatural.

usefulcat 3y ago
Are you sure? TFA states "HD 110067 is viewed edge on from Earth", which doesn't sound like what you're describing. Of course they could have made a mistake; I don't know either way.

deleted 3y ago

[deleted]

bunabhucan 3y ago

>HD 110067 (TIC 347332255) is a bright K0-type star with a mass about 80% that of the Sun, located at 12h39m21fs50, 20°01'40farcs0 (J2000). Breakthrough Listen (BL) is observing additional targets selected from the Exoplanet Follow-up Observing Program for TESS (ExoFOP-TESS) in addition to the nearby star sample described by Isaacson et al. (2017). HD 110067 is valuable as a technosignature target not only because of its interest for biosignature searches. First, Earth views the system edge-on, which increases the likelihood of detecting radiation from any transmitters present whether intentional (Traas et al. 2021) or resulting from planet-to-planet transmissions which could be observed by their "spillover" during planet–planet occultations (Ashtari 2023); second, the large number of planets regardless of their position in the star's habitable zone increases the likelihood that an advanced civilization could have spread technology to neighboring planets, as has happened in our own solar system (Wright et al. 2022). https://iopscience.iop.org/article/10.3847/2515-5172/ad235f https://iopscience.iop.org/article/10.3847/2515-5172/ad235f Nobody is suggesting the resonances are unnatural. The edge on aspect helps the search in other ways.

wolverine876 3y ago

> I think the authors do not understand ... The authors are scientists from SETI, Berkeley, Oxford, and NASA. Probably they understand anything you (or I) understand about the topic, and quite a bit more. (A funny phenomenon is that if they posted here, starting their comment with 'SETI researcher here ...', we would all listen to them and ask questions. If they 'post' a paper to a journal, a paper they spent years researching and revising, alongside other scientists, we disregard them.) Like many similar HN comments, I think there's a valid question in there. IMHO it's a mistake to immediately conclude that, perceiving some inconsistency, the other person must be wrong, obviously ridiculous, etc. That doesn't make sense unless I am omniscient: the inconsistency between my idea and theirs could just as easily be a problem on my end - much more easily when comparing my ideas of orbital physics with those authors. Here is how I have learned to think of it (using this example): To me, it seems clear that planetary resonances explain the observed phenomenon. Obviously the authors thought of that; how did they address that issue? Humility is truth, unless you are a god.

wolverine876 3y ago
And here is the apparent answer to the mystery: https://news.ycombinator.com/item?id=39543532 https://news.ycombinator.com/item?id=39543532