Hacker News Reader

Comment by peonicles | Hacker News Reader

There's a comment [1] in the other reddit thread that somewhat rules this out.

> That doesn't even make sense when you're flying within the Solar System. Stuff moves, so you have to fly towards where it's going to be, not where it is.

> The star is far enough away to be treated as a point source, with its light forming an apparent cone with the Earth's diameter. It doesn't intuitively make sense, at least to me, that the ship would stay within that cone as it corrects for the motion of our Solar System (and its own) within our galaxy. Remember that this dimming effect has been observable for several decades.

Then again, aliens don't have any obligation to make sense to us.

[1] : https://www.reddit.com/r/Astronomy/comments/4waozn/new_paper...

View on HN

You just need a big enough ship.

A while back I had a plan for a science fiction setting: an intergalactic ship is approach Earth. The people who sent it thought big, and as a result the ship has at its core an enclosed star (a miniature Dyson Sphere) as a gravitational anchor and power source, and round it is orbiting a vast swarm of asteroids and habitats with a few million times the living space of Earth, inside which civilisations endlessly rise and fall.

The plot centred around this thing going to make a class pass by Sol in a few years at 0.01c, with the gravitational effects pretty much dooming the Earth; so the current lead civilisation sends some ships on ahead to evacuate the Earth. (Big ships. I did the maths.)

The story never gelled, but I think it's plausible that my ship would produce these effects.

BTW, if this turns out to be true, I want credit.

You might enjoy some of Liu Cixin's stories, which are often similar to that: https://www.amazon.com/Wandering-Earth-Classic-Science-Colle...

https://en.wikipedia.org/wiki/Nemesis_(Asimov_novel)

is kinda similar

Yet another book recommendation:

Terre en fuite (Fleeing Earth) (1960) by François Bordes (pen name Francis Carsac), though, there is still no translation in english of that gem, where Earth and Venus was converted to spaceships for running away from exploding Sun!

Yet another book recommendation: Marrow by Robert Reed. Some similarities to your story :)

Wouldn't the ship collapse under it's own gravity?

Or maybe we are the ones traveling to the star.

Keep it up! I'd read that.

> if this turns out to be true, I want credit

You cool if we blame you too? :)

Maybe they are taking the long about route on purpose to let us know about their arrival!

Unless military tactics dictate that they try to "hide" in the cone since they first picked up our radio signals... Even If they're on a "civilian" mission, they might have navigators/a captain with military training...

Not plausible because:

a) Tabby's Star is roughly 1500 light years away from us; we only began emitting radio signals ~150 years ago (at most -- assuming propagation from early telegraph wires; not actually very likely) and it'd take ~3000 years for our signals to reach the vicinity of Tabby's Star and indications of a reaction getting back to us,

b) "Military" is a category error on this scale; the energy budget required to generate the sort of luminosity changes we're seeing around Tabby's Star by deliberately occulting it are mind-blowing compared to anything we've ever achieved. Might as well speculate about an ant-hill (us) wondering about the military intentions of an M1 Abrams tank driving across the Iraqi desert (hypothetical alien actors at Tabby's star) -- either they aren't going to drive over us, or we just encountered an Outside Context Problem.

A) but if the ship is only 2 ly away, they could've changed maneuvering a hundred years ago.

B) sure.

It could be a way to announce their arrival passively.

That would assume they know we're scanning the skies for short-lived and easy-to-miss flux variations.

The corollary: if there are aliens around KIC 8462852 they don't care that what they're doing is visible for 1500 light years around them.

Reply on news.ycombinator.com