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Comment by speleo | Hacker News Reader

Hi there! This is Val, I made the star chart. There's a little "about" blurb you can open in a modal on the site, but I wanted to mention that this demo uses the amazing GAIA DR3 dataset from ESA. I have a Python script that renders all 1.8+ billion stars into custom images, which is what I used for the skybox. The star positions and colors all use the GAIA data (save for a few bright stars not in the set). The data is amazing, and if you have any interest in doing some fun projects with open data I recommend checking it out: https://www.cosmos.esa.int/web/gaia/dr3

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Cool! One question: what do the planes represent? I thought it was the galactic plane and planes parallel to it, but then I saw that the "band" of the galaxy is (almost?) perpendicular to it, which doesn't fit somehow?

EDIT: TIL that the ecliptic plane of the Solar System is at an 60.2° angle to the galactic plane (https://en.wikipedia.org/wiki/Galactic_plane#/media/File:Mot...) - until now I somehow assumed that they were more or less parallel and never questioned that assumption. So it looks like the "main" plane is the ecliptic plane (which is of course very anthropocentric, after all the ecliptic plane doesn't really matter anymore once you leave the Solar System? But I guess that was they way it was shown in the movie?). Would be interesting to be able to switch to showing the galactic plane instead...

Thank you for posting this. I wonder if anyone has made a physical galactic orrery. It seems that the concept is used in the video game Warhammer.

Something implicit in the diagrams of the galactic plane but not explicitly stated is that the solar system travels clockwise (retrograde) around the galaxy [0]. I find this unexpected as I thought the same "right hand rules" of planetary motion [1] were somehow connected to those of electromagnetism [2] and would apply upwards in scale.

  The Sun follows the solar circle (eccentricity e < 0.1) at a speed of about 
  255 km/s in a clockwise direction when viewed from the galactic north pole at 
  a radius of ≈ 8.34 kpc about the center of the galaxy near Sgr A*, and has 
  only a slight motion, towards the solar apex, relative to the LSR.

0. https://en.wikipedia.org/wiki/Local_standard_of_rest

1. https://en.wikipedia.org/wiki/Poles_of_astronomical_bodies

2. https://www.arborsci.com/blogs/cool/three-right-hand-rules-o...

I wonder if anyone has made a physical galactic orrery.

Maybe it's harder than it seems. Does a definite galactic plane even exist? The ecliptic is defined by Earth's orbit, not a mean of all the planets. IIRC Sun's rotation plane is not aligned, not should it matter.

If there's a way to measure galactic plane, independently of Sun's orbit around the galaxy center (that also seems difficult to determine) it would involve measuring positions and trajectories of many very distant objects.

Yes, an example is "Local stellar kinematics from Hipparcos data" [0]. Afaict: stars have color (red or blue shift) which represents relative motion; Hipparcos is a large large dataset from an eponymous satellite; fancy math determines relative motion based on position and inferred distance.

0. https://arxiv.org/abs/astro-ph/9710077

I believe such data exists--examine the movement of all galactic objects you can. That will give you a center of mass, the galactic plane is the plane such as to minimize the total distance from objects to the plane.

Go outside on a dark night and look at the Milky Way: you'll see (at the right time of the year) that it's tilted at a large angle to the celestial equator. (There's also the fact that the Earth's axis is tilted relative to the Ecliptic, of course.)

This is awesome!! I made a map of the events in the Martian many years ago (https://www.cannonade.net/mars.php) and when I read Hail Mary I wondered if something could be created for the new book.

You completely nailed it!! :)

That's an awesome website! I had never heard of Patrick O'Brian before looking at your maps, I'll give The Mauritius Command a read.

Recommend the whole series of books! Starting with Master and Commander. The books are also available in audiobook, read by Simon Vance. An awesome series of books. Beware, when you start... There are over 20 volumes in the series, and it's hard to stop.

Thanks very much :) Glad you like it. These books are awesome I really recommend starting at Master and Commander and working your way through all 20 :P

How many 3D bodies are there? I'm curious because it renders really fast even on a relatively old mobile phone.

If I counted things correctly, 53,836.

I wanted to hook into the THREE object and explore the scene, but I wasn't able to figure out how to bring it back into scope after it's been optimized out of the js context, so instead I searched through the bundle to find where it unpacks the data and did that manually.

It just boggles the mind how you can simply write a 3D program with a ready-made library today, instantiate tens of thousands of objects in 3D space, and the whole thing will render in real time on a phone without you ever having to worry about how that incredible performance is possible.

The power of computers comes at least partly from the fact that for many practical problems, they let you effectively pretend that resource constraints don’t exist at all.

It does, it helps to stop and smell the roses occasionally and remember how far we’ve come.

My first proper computer (defined by programming on it) was a 3.5MHz single core processor with 48KB of RAM.

My current one is 16C/32T that can boost to 5.7GHz and has 64GB of RAM.

Considerably more than a million times the RAM and about a million times the processing power (if you factor clock speeds, core count, OOE, branch prediction, memory width and depending on workload etc).

I have more RAM in my house than every ZX Spectrum ever sold (about 5 million which comes out to ~240GB).

Adjusted for inflation a million spectrums (175 at 1982 prices) comes out to about 640 million quid.

My PC cost ~4000 in late 2022.

A million times faster for 0.000625% of the price, it’s been a hell of a ride.

My pet realization: most of the power increase has been spent on graphics at an ever growing resolution, including in resolution not only the number of pixels, that's a squared number, but also color depth and FPS.

Dealing with graphics has shadowed how hugely powerful the modern computers are. We're noticing now because of AI.

For a general user I suspect that is true.

That said I think programmers do notice the performance outside of AI when they use software that surfaces how fast modern machines are which we do more than most.

I can remember when compiling a Linux kernel was “start it and go watch star gate” now I barely have time to boil the kettle for a cup of tea.

Definitely agree with the sentiment (also a Speccy 48K guy), but at the risk of being pedantic, I think you're double-counting: "million times faster" is for one Spectrum, the "0.000625% price" is for a million...

Great map. Wish the star map in Starfield was this nice!

Very cool! With a few additions (and with part 5 a lot perhaps) you can also have one for the Bobbiverse! (I recognize some names)

I've had making something like this for the Bobbiverse in the back of my mind for years. Maybe this is what finally will make me start.

Since you built it, I am curious about the scientific accuracy of the movie, book and while taking the information GAIA DR3. I wanted to assume at least the stars part is science, but I think, there is a lot of fiction in that setting. Is this map the reality of what we know as science, since it came from GAIA DR3 dataset?

And, thank you very much. This is super cool and exciting. I wish such a one exists for Asimov's foundation universe (fiction).

The stars featured in the movie and in this chart (and in the book) are real, and reflect their real-world locations.

The planets around the stars, aside from our own solar system (obviously), are fictional-- both Tau Ceti and 40 Eridani are stars where we're looking for exoplanets, but we don't have strong evidence for either yet.

IIRC at the time the book was written, there was some data suggesting a planet detection around 40 Eridani, but has been ruled out since then.

The book does a significantly better job explaining the science behind the mission than the movie (which I found insulting, but I'm clearly in the minority of holding that opinion).

The book was certainly better than the movie, but I'll take every damned example of 'humans working collectively to solve an existential crisis' I can get.

As 'on the nose' as 'Don't look up' was, we clearly need more content that inspires action than pits us to despair.

This was exactly one of the reasons why I hated the movie.

Andy did a fantastic job describing how nation-states might put aside their differences and work together to solve an existential crisis. Some of the events he imagined were just as awesome as they were unlikely in today's political climate.

ALL of that was distilled away in the movie. Like, LITERALLY ALL of it.

Lord Miller reduced the book to "Hot Homer in space and telepathic rock alien thing work together to save their planets." It was a beautifully crafted movie, but SO much dumber than it had to be.

Not about the stars part or the map, but xenonite struck me as rather odd from a scientific standpoint. Apparently it's some organic chemical bonded--somehow--to xenon. But the mystery depended on the mass spectrometer Grace uses to analyze xenonite not being able to detect nuclei of atoms smaller than some atomic number (something like 20?). So he couldn't tell what it was made of, except for xenon. My initial assumption was that it had to do with one of the few xenon-based compounds we know about, XeF4 (xenon tetrafloride), but there must be more to it than that.

The movie makes it clear that it is both an unknown, and unexpected, xenon-based material. Plus, the scientist analyzing it has (presumably) no real background in materials science.

IOW: it's intended to seem odd.

This is cool, can you add a focus on 40 Eridani view please?

I'm also looking to do some personal projects with the Gaia DR3 release! Do you have any general recommendations for working with/trimming down such a huge dataset (e.g. Python libraries that can help)?

but why solar system is so out of scale?

Because it’s more cool and important.

Honestly, I'm biased but I think it's the best one.

The damp rock is pretty and compatible with life. 10/10 would inhabit again.

I'm interested in how you're planning on managing the "again" part.

Oh I have no clue how to do that, but if I can no question this damp rock is top of my list.

Human-centric thinking.

Super cool! how long did it take to generate all those custom images?

Thanks! On my desktop it takes around 20 minutes to generate a full sky render with 1.8 billion stars (down to around 22 magnitude).

So very cool! Have been tooling on some very similar space mapping and smiled as I was looking at this. Love the data recommend have not seen that yet, thanks!

Altair looks closer than Alpha-Centauri on this map, although it's actually 4 times as far (probably Z axis squashing).

I'm writing a novella about a trip to Gliese 581 and I'd love to do a similar visualization -- any advice?

I wonder if it's possible to import this data into blender, for excessively accurate space backgrounds.

This is really cool!

Feature request: can you add WASD navigation? Arrow keys are weird on different keyboards. On mine they're squashed into the corner and not fun to use. WASD is the OG OP way to navigate. (WASDQE, where QE are the vertical plane, if you're into Unreal Engine key bindings.)

I don't know if I'd say it's the OG way. Both HJKL and numpad predate WASD, I think.

Are you comparing game bindings to vim bindings? Isn't that an apples/oranges thing?

Not if you play roguelikes.

Shamelessly stolen from Wikipedia:

  Examples of games that use HJKL are the text-based "graphic" adventures like NetHack, the Rogue series, and Linley's Dungeon Crawl. It is also used by some players of the Dance Dance Revolution clone StepMania, where HJKL corresponds directly to the order of the arrows. Gmail, Google Labs' keyboard shortcuts, and other websites use J and K for "next" and "previous".

https://en.wikipedia.org/wiki/Arrow_keys#HJKL_keys

Considering we're not discussing a game, it seems like a perfectly valid comparison.

"if you're into Unreal Engine key bindings." :shrug:

That phrase was in the parenthetical and as such doesn't seem to directly apply to the claim of "WASD is the OG OP way to navigate." Additionally, I was referring to the PRH Stellar Navigation Chart when I said we're not discussing a game.

I remember lots of old bbc games using zx;/ by default. in retrospect it was interesting how they defaulted to one hand for left/right and the other for up/down

Apple 2 was often az/,. .

Decades later I still have better muscle memory for the Beeb's typical ZX*? ( and ELITE's SX<> ) than I do for WASD or arrow keys.

Claude?

I had claude shit out a site that tracked the recent moon flyby mission and the visual feel of that site is very much like this one, and my first thought when the page loaded was this was an ai project.

Sadly we live in a world where software engineer "stolen valor" now exists, where someone with no or little actual engineering ability will use ai to shit out something and then claim they made it themselves.

Not 100% certain that's happening here, but it can't be a coincidence that this site looks so much like a site I had AI create tracking other things in space, imo

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