There is zero testing of either the hypothesis that it is technological or that it is hostile. At best, the methodology he employs in the paper could be argued to test the hypothesis that its path through our solar system is synthetic and intentional; but that's it, and that's also not remotely close to what he said.
The ESA has a possibly more promising plan to divert a probe that's on its way to Jupiter right now [2].
So, again: If you're going to write "The feasibility of intercepting 3I/ATLAS depends on the current amount of fuel available from the propulsion system of Juno" one thing a real scientist would do is, idk, try to find out how much fuel it has left, talk to team members, etc. Instead, Loeb just does presumptive math, which ends up being wrong, but that didn't stop a Florida state rep from taking this "idea from a harvard scientist" and turning it into an official request of NASA, which now more real scientists will have to waste their time with [3].
[0] https://arxiv.org/pdf/2507.21402
[1] https://x.com/Astro_Wright/status/1951530225533329789
[2] https://www.newscientist.com/article/2490618-can-we-send-a-s...
Mass distribution in our galaxy is decidedly anisotropic - most mass lies in the galatic plane.
Loeb's estimate of the comet size is strange, when two observatories concur that the maximum size is around 10km.
Look at https://news.ycombinator.com/item?id=44713579 for links to real science.
At some point, however fact-based, every speculation is a form of fiction, so the line is blurry ...
> The title and the abstract suggest they take this possibility seriously, which is ridiculous.
... but I'd say it's I think the idea is to take some serious and very realistic bits that have a vanishingly low probability ...
> We show that 3I/ATLAS approaches surprisingly close to Venus, Mars and Jupiter, with a probability of ≲ 0.005%
... and then walk from there as rigorously as possible.
As they say, "largely a pedagogical exercise".
There's still a line between the hardest hard sci-fi story about a Boltzmann brain and a fact-based thought experiment computing probabilities for a giant marshmallow to spontaneously appear in the vacuum of space.
> We show that 3I/ATLAS approaches surprisingly close to Venus, Mars and Jupiter, with a probability of ≲ 0.005%
a) What does this even mean? If you throw a dart on a dartboard, anywhere it lands will have some probability. 1/200 doesn't seem that low.
b) It's the height of intellectual laziness and chicanery to go from not-that-low-of-probability to 'aliens'
They're free to make these claims. I'm also free to laugh at how ridiculous it is.
Now, if this thing had some précise shape, or rotational speed, or we saw it adding or subtracting delta V, or if it did gravity assists from multiple planets (not just 'flew kinda close to a couple of them'), now that would be interesting.
> > We show that 3I/ATLAS approaches surprisingly close to Venus, Mars and Jupiter, with a probability of ≲ 0.005% > > a) What does this even mean? If you throw a dart on a dartboard, anywhere it lands will have some probability. 1/200 doesn't seem that low.
Not 1 in 200 here. 1 in 20,000.
It’s as ridiculous as proposing that it could naturally be made of up of M&Ms or that monkeys built the ancient Egyptian pyramids.
That's silly. It's made up of Milky Ways.
Also he raised a bunch of funds to dig one up under the ocean and got nothing.
I’m inclined to let those searchers speculate in public. If society’s rule is that you can’t even speculate about X until you have proof, it will hold back science significantly. History has many such examples of forbidden speculation leading to long delays.
String theory has not really made its debut in the conspiracy crowd afaik. I think "Quantum-___" has done so, especially with the "collapse of the wavefunction through the observer" it has so many esoteric people raving.
String theory is so meaningless to the normal person.
So really it's the same thing, he gets a lot of aggressive pushback online for mentioning 'aliens', but generally speaking nothing he says or does is actually that baseless.