Avi Loeb, a Harvard astrophysicist, writes about interstellar objects like 3I/Atlas and whether they could be alien technology.
HN commenters see his alien-technology claims as speculation, though some find them fun thought experiments and note he also does real science.
> It also means that
No, it doesn't mean that. What makes 'Oumuamua special is not the fact that we didn't see interstellar objects before. It's rather the fact that 'Oumuamua has highly unusual and hard to explain properties. Avi Loeb:
> ‘Oumuamua exhibited a non-gravitational acceleration of 4.92 ± 0.16 × 10^⁻6 m/s² that decreased proportionally to 1/r², where r represents the heliocentric distance, corresponding to a formal ~30 σ detection of non-gravitational acceleration (Micheli et al., 2018). The inverse-square relationship typically indicates radiation pressure or outgassing forces. However, despite extensive observations by the Spitzer Space Telescope, no carbon-based molecules, dust, or thermal emission indicative of cometary outgassing were detected (Trilling et al., 2018). Such a paradox — acceleration without observable mass loss — violates fundamental assumptions about how small bodies behave in the solar system.
> The object’s extreme geometry presented another unprecedented observation. ‘Oumuamua’s brightness varied by a factor of 10 during its 8-hour rotation period, indicating an extreme geometry with an aspect ratio exceeding 10:1 (Drahus et al., 2018; Meech et al., 2017). Such extreme elongation is unprecedented among known Solar System objects, leading to competing interpretations of either a cigar-shaped or pancake-like geometry (Belton et al., 2018; Luu et al., 2020; Mashchenko, 2019; Moro-Martín, 2019a,b; Zhang & Lin, 2020).
> More significantly,…
Avi Loeb is an interesting scientist. I read a longer article about him that gave some more background about his work [1]. While he is famous for going on podcasts and making wild claims about objects being signs of alien intelligence, the actual hard science that he's doing is interesting. E.g, this expedition he managed to get funding to recover these extrasolar particles. The clickbaity pop media says that this is "alien tech" but reading his blog [2] shows some hard science about how his team isolated the extrasolar candidates and launched an expedition. He's also trying to fund another project to watch the skies for more UFOs/extraterrestiral technology [3]. Even though the clickbaity aspect is that this is for hunting aliens, the likely worst case scenario is that he managed to raise a bunch of funds using the current UFO hype to gather more evidence about meteors entering Earth's atmosphere. I think it's unlikely that any of the unknown sightings are aliens, but I fully support Loeb because the science he is doing will have interesting results even without the discovery of aliens.
[1]…
This article is late to the party. I would hardly call SETI leading edge alien detection tech today. Our best bet would be to look at our recent interstellar visitor 3I/Atlas and to use other modern instruments to detect remnants or signatures of past intelligent activity.
It's very likely given the age of the universe and the number of known habitable zone planets that other life forms did evolve and live there (or come by here) at one time. It would be unscientific to deny that.
This is exactly what Avi Loeb[0] is complaining about with the way the scientific community is approaching Atlas (and how it approached 'Oumuramura before it). These are not farmers in a field who saw a UFO. They're not even pilots who reported UAPs. These are real, observed objects in our solar system which did not come from our solar system. They're worthy of serious attention.
[0] https://avi-loeb.medium.com/
Fun link dump:
* harvard & aliens & crackpots: a disambiguation of Avi Loeb by acollierastro (2022) https://www.youtube.com/watch?v=aY985qzn7oI&t=5s
* Critique of arXiv submission 2308.15623, "Discovery of Spherules of Likely Extrasolar Composition in the Pacific Ocean Site of the CNEOS 2014-01-08 (IM1) Bolide", by A. Loeb et al by Steve Desch, Alan Jackson https://arxiv.org/abs/2311.07699
* The IM1 Spherules from the Pacific Ocean Have Extrasolar Composition by Avi Loeb (August 2023) https://avi-loeb.medium.com/the-im1-spherules-from-the-pacific-ocean-have-extrasolar-composition-f025cb03dec6
* Reconstructing the First Interstellar Meteor, IM1 by Avi Loeb (September 2023) https://avi-loeb.medium.com/reconstructing-the-first-interstellar-meteor-im1-923c1bb37c2a
This guy completely lost his marbles [1]. Sean Carroll interviewed him [2] a few years ago for his podcast and I don't recall hearing any extremely outlandish claims in that episode. After that, however...
[1] https://avi-loeb.medium.com/starting-the-analysis-of-spherules-from-the-interstellar-expedition-2bc608d2d7ce
[2] https://www.preposterousuniverse.com/podcast/2021/01/25/131-avi-loeb-on-taking-aliens-seriously/
Here is the paper linked in the piece
https://lweb.cfa.harvard.edu/~loeb/Interstellar_Expedition.pdf
Note: That is not the Avi Loeb paper, but it is reported to have been submitted about his work.
A diary of that research trip is here
https://avi-loeb.medium.com/the-im1-spherules-from-the-pacific-ocean-have-extrasolar-composition-f025cb03dec6
Related Wikipedia
https://en.wikipedia.org/wiki/CNEOS_2014-01-08