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Can I hijack this thread for an almost completely unrelated question that I have observed in nearly every simulation of movement in space, even from sources like NASA and SpaceX which “should know better”?

And I’m mostly asking this out of scientific curiosity, not as a criticism.

Why do they always portray movement in space by showing stars moving past the view at variable rates, or even at all?

The opening screen of this video while you’re waiting for the feed to start shows stars moving that seem to be only feet away, and only a few inches in diameter. Like little orbs of light just passing outside the window.

Isn’t this highly unrealistic, for even extremely fast travel in space?

I would imagine at most you would see very slow movement of a very static field of stars. But every depiction in sci-fi, video games, and other simulations like in this video insist on making it seem like space is full of tiny 6-12” stars floating only feet away from each other.

Is there any explanation where this could actually be considered realistic that I’m not thinking of?

I’m just a lowly software engineer, so my expertise in this area is null. But from a basic understanding of stars and physics, this seems unrealistic.

Admittedly, I guess it wouldn’t be very exciting to view movement in space in a way that I’m imagining would be realistic, and maybe that’s the only explanation there is/needs to be.

But I guess I’m thinking that there would be enough people at SpaceX (for example) to scream “this is not even close to realistic!” for something like that to not make it to production, even if it is more exciting to watch.

6 comments

As others have said, you're correct. But one reason for doing this, beyond just looking cool, is to give a visual cue for motion. The aim isn't primarily to look realistic, but to make it as easy as possible to interpret the outputs. Motion cues help with this.

As an example, if you're watching an airshow against a clear blue sky, especially filmed with a long lens where you can't see the ground, it is very hard to understand what's actually happening because you can only see attitude changes, but not the velocity vector. Add just a few clouds in the background and the impression is very different.

I’m guessing when making an artistic depiction of something going very fast in space, that sort of parallax helps? The goal of consumer content (including the ones by spacex) isn’t to be realistic, it’s to entertain

That said, “the expanse” is an exception here - they make it look as realistic as possible, including the battles where ships don’t even see each other. Stars barely move on it too

You're correct, it's hilariously unrealistic (IIRC requires actual superluminal speed), but people have been conditioned to accept it by various scifi media.

Imitating science fiction is great marketing for a space company.

Brand association with familiar depictions of “the future” is the goal, not realism.

> Is there any explanation where this could actually be considered realistic that I’m not thinking of?

You could record the full trip, and then speed the record up. What the point to watch at thousand years of the record with slowly changing picture, if you can watch it in a few minutes.

That’s what I was wondering — even if you sped up a realistic capture from space, wouldn’t it still just look like stars moving at about the same speed?

There might be small variances in velocity, but it seems like not near to the extent we see in these simulations.

Again, this was mostly a theoretical/scientific curiosity — I understand why they do it like this, I’m mostly trying to figure out what real movement might look like, even at nX speed.

If they were truthful, you'd think the picture was frozen, signal issues etc.