Posted 21 January 2021 - 05:06 AM
Very interesting, thanks for sharing!
There're many explanations at Fermi's paradox, for me the most important is that we belive that an alien civilization want to contact us, that's the same old story of our culture, we still belive to be the center of the universe
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Posted 21 January 2021 - 08:08 AM
Just happened to have read that article yesterday. Unfortunately, Ave Loeb has probably injured his reputation as a 'serious' scientist by engaging in speculation as to the identity of the object. Nothing worse than group think in academia. I have a friend whose son works for government contractors installing and maintaining satellite communication systems world wide. He claims that extraterrestrials are not coming here - they are already here. He seems like a pretty level-headed engineer but, of course, that is just one person's claim. He won't say how he knows, or what the evidence is, he just smiles and says, "that would get me in trouble." To me, the entire claim of extraterrestrial visitors to earth demands, as Othello put it, on "ocular proof."* In some respects, claims of extraterrestrial visitors begin to take on the characteristics of religion, which requires a leap of faith to believe in the unseen (and that is not meant to demean or criticize people of faith).
*Interestingly enough, this phrase appears again in Washington Irving's classic, The Alhambra.
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Posted 21 January 2021 - 08:29 AM
Moving to Astro Art, Books, Websites & Other Media.
Posted 21 January 2021 - 07:36 PM
Hey, that was a really good article! Thanks for posting. I read the whole thing.
Posted 21 January 2021 - 11:16 PM
Article quoted... "It might be the alien equivalent of an abandoned car, “floating in interstellar space” as “debris.”
Maybe a Tesla!
Posted 22 January 2021 - 05:56 PM
Thanks for sharing this interesting article. Speculation is fun; this particular subject has been talked about in my family since I can remember. (Since the 50’s at least.) But, alas, speculation is all it is. And yet folks will hang on to their beliefs....
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Posted 01 February 2021 - 12:17 AM
Great article. I particularly like this line: "Loeb, though, explicitly rejects the Sagan standard—'It is not obvious to me why extraordinary claims require extraordinary evidence,' he observes—and flips its logic on its head: 'Extraordinary conservatism keeps us extraordinarily ignorant.' "
I also find it interesting how suggesting it possibly being alien is scoffed while suggesting (with absolutely no evidence) that the acceleration was likely caused by an out-gassing that had gone undetected because of its “unusual chemical composition” is somehow scientifically acceptable Whether it was caused due to the object being "manufactured" or from undetected gasses due to their “unusual chemical composition”, either are speculation. Never good when a scientist cannot keep an open mind and instead biases their thinking toward expecting the conventional. Always best to wrestle with the full range of speculations, regardless of their conservative or extremist points of view, so one can find the full subset where testable hypotheses are feasible.
Edited by BillP, 01 February 2021 - 12:18 AM.
Posted 01 February 2021 - 06:13 AM
I would think if they were Aliens
they would have slowed down to get a good look at us,
or maybe they just saw enough and kept going
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Posted 18 February 2021 - 11:56 AM
All I can say is that in over 50years of Amateur astronomy experience and thousands of hours observing with various optical instruments and amateurs I have not ever seen anything that I could not explain. I have watched many intriguing, thought provoking documentaries where many intelligent people of different professions have seen some extraordinary phenomena.
If someone were to ask me "is there any intelligent life out there?" I would have to give the only answer that I can. I don't know. Any other answer from me would be a lie.
Untill I have actual, physical and tangible evidence, I can only give the only answer that I currently have.
Posted 18 February 2021 - 12:33 PM
Regarding the 2018 paper by Bialy and Loeb "Could Solar Radiation Pressure Explain 'Oumuamua's Peculiar Acceleration?
This is my opinion, review, and critique of that paper (the bulk of which I wrote to an astronomer friend at the time that paper came out).
A. My personal opinion is that it would be very nice if what they were speculating were to turn out to be true, however, in a modest attempt at applying critical analysis to the paper, the following come to mind:
1. Quoting them "Based on the survey properties and the single detection, Do et. a (2018) estimated that interstellar density..."
For the purposes of this Bialy/Loeb paper, in statistical analysis, we cannot imply a population or derive statistics from a sample of one. This is the same problem as in the SETI.
2. "...if outgassing was responsible for acceleration (as originally proposed by Micheli et al. 2018), then the associated outgassing torques would have driven a rapid evolution in "Oumoumua's spin, incompatible with observations."
Considering the short observation period of this object, combined with the already rapid rotation, odd shape of at least 5:1, and albedo variability indicating a complex aperiodic presentation of specific surface features, I suspect that there's a good chance that we could not detect changes due to torque imposed vector variation due to it's chaos-like tumbling presentation (the animation and light curves of which can currently be seen in the bottom right of the Wikipedia article https://en.wikipedia.../wiki/ʻOumuamua .)
3. "This work was supported in part by a grant from the Breakthrough Prize Foundation".
This reminds me of clinical drug trials sponsored by pharmaceutical companies, smoking studies by cigarette companies, or environmental studies by petrochemical companies; there's reason to suspect biased thinking in the paper. Breakthrough Iniatives, https://en.wikipedia...ugh_Initiatives is a multi-pronged effort, but what's interesting here is that this paper brings together two areas of investigation (SETI and Starshot) into one contemplation. Regarding the objectivity of the investigators, one has to ask, do any of the authors have other works in progress or that they've previously written that would cause them to want to validate their prior or current works? At the time of the writing of that paper, the answer in my opinion would have been (and is) yes, based on prior to Nov. 2018 light sail-related writings by paper author not related to Oumuamua. Not that that's necessarily a bad thing; people looking at a specific series of questions/problems will tend to be the first to observe characteristics of objects that fit with patterns they've observed previously, but the human tendency to super-impose perspectives based on past experience, or fill in the dots if you will, can be a myopic experiential bias that could perhaps cause a misperception of reality, or perhaps inhibit objectivity (if the object is to be unbiased). More specifically, they see things in terms of light sails because that's what they do every day (and worked on prior to this paper), not necessarily wrong, but suspect in the least that there could be some significant bias here. Why would E.T.'s use a form of propulsion that is consistent with the prior work of the authors? In the least it's highly coincidental, at worst it seems coincidentally self-serving (in my opinion).
4. "Although 'Oumamua has a red surface color, similar to organic-rich surfaces of Solar-System comets and D-type asteroids (Meech et al. 2017) this does not contradict the artificial scenario, since irrespective of the object's composition, as it travels through the ISM its surface will be covered by a layer of interstellar dust, which itself is composed of organic-rich materials (Draine 2003.)"
IMO this is highly contradictory! If it's covered in ISM dust, and it looks like a D type asteroid https://en.wikipedia...D-type_asteroid , maybe it is one? If one follows this reference they made to the Draine 2003 paper, one sees that there is absolutely no indication in that paper of how long it would take for ISM dust deposition to occur in sufficient amounts to alter the presentation of a light sail to appear to be comet/asteroid like. Indeed this seems deleterious to their argument that this could be a purposefully directed probe; why would a purposely directed probe be coated in ISM dust-like coating that perhaps would to impair the light sail performance? (indeed, perhaps it might actively seek to clean/remove it over time?) And if E.T.'s were trying to use a camouflaged probe, I would not think it stealthful to present an asteroid-like object with unnatural/non-keplerian motion while still within easy imaging range. It seems like they want it multiple ways, is it technological detritus (aimlessly floating space garbage), or is it intelligently steered? (aimed at the Sun). It spectrally looks like a rock/comet from a Kuiper-belt-like zone of a different solar system, but we're to instead infer that this is actually an intelligently driven solar sail that looks like a rock/comet?
In my opinion Sagan (and most scientists) would have required more in the way of empirical evidence to support this intelligent craft claim, no wonder Loeb seems as the article stated "explicitly rejects the Sagan standard"; how convenient, reminds me of all the other times people went wrong: Astrology, Aristotle's Earth-centered Universe, belief in gods associated with specific stars, comet cults... Things appear to some people/adherents to be one way, even build temples to them, or find a reason to continue pursuing something, but over time I think it will become evident to most that there isn't enough evidence here to ever make this conjecture into a fact (and in item 6 below you can see why), no matter how much they wish it to be true.
5. If it's technological detritus, this seems antithetical to its behaviors of being a directed probe (i.e. the close solar passage.) It seems to me that that finding (by others) that this writing
Kinematics of the Interstellar Vagabond 1I/'Oumuamua (A/2017 U1)
"...In the Local Standard of Rest frame (circular Galactic motion), 'Oumuamua is remarkable for showing both negligible radial (U) and vertical (W) motion, while having a slightly sub-Keplerian circular velocity (V; by ~11 km/s). These calculations strengthen the interpretation that A/2017 U1 has a distant extrasolar origin, but not among the very nearest stars. Any formation mechanism for this interstellar asteroid should account for the coincidence of 'Oumuamua's velocity being so close to the LSR."
I think this argues against the probe actively accelerating with a purpose, and is more like being drifting galactic sea foam that our Sun has overtaken.
6. And last but certainly not least is
"Since it is too late to image 'Oumuamua with existing telescopes or chase it with chemical rockets (Seligman & Laughlin 2018), its likely origin and mechanical properties could only be deciphered by searching for other objects of its type in the future."
They might as well have said, since our paper is not scientifically provable, we can say whatever we want. Being unable to test their any of their suppositions puts their speculation into a highly anti-scientific realm IMO (even SETI seeks repeatability/testability).
(but I hope they are right :^)
Edited by Jason H., 18 February 2021 - 04:48 PM.
Posted 20 February 2021 - 02:34 PM
There're many explanations at Fermi's paradox, for me the most important is that we believe that an alien civilization want to contact us, that's the same old story of our culture, we still believe to be the center of the universe
It's funny, because it's true.
One explanation that always made sense to me is that any intelligent life would probably be very far away. The universe is BIG and the distances are hard to wrap your head around. It's possible that all intelligent life would be so spread out that two civilizations ever discovering each other is practically impossible.
Also, the amount of time humans have been around is so incredibly short, especially on a cosmic scale. Even shorter is the amount of time we've been sending radio transmissions and had radio telescopes.
It's like a newborn baby opening it's eyes for the first time and expecting to see a penguin.
-"Why don't I see a penguin? I know they must exist, but I can't see any of them. Where are all the penguins?"
Mom: "Um, That's a pretty specific thing to want. They live pretty far away, and they're not aware of you. They're kind of doing their own thing."
-"Yea, but why wasn't a penguin awaiting my arrival and making eye contact the instant I opened my eyes?"
Edited by Bushdoc42, 20 February 2021 - 02:50 PM.
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