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Project Hail Mary – Stellar Navigation Chart (valhovey.github.io)
1110 points by speleo 1 day ago | hide | past | favorite | 227 comments
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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

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.


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.

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


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.

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.


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.

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

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

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 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 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.

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

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?

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.

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!

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?

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.

Not if you play roguelikes.

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

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.

Apple 2 was often az/,. .

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


Just FYI the sizes of the planets, stars, and their orbits are not to scale at all. To get an idea of how empty space is, there are 63,360 inches in a mile, and 63,239 astronomical units in a light-year. So if you scaled everything down such that Earth was 1 inch from the Sun, Neptune would be 30 inches away and Alpha Centauri would be 4 miles away.

If you were using a 4k display and had the Sun and Alpha Centauri visible at opposite sides of the display, the orbit of Neptune would be in the same pixel as the Sun.


FYI we have a up to scale model of the solar system in Sweden https://en.wikipedia.org/wiki/Sweden_Solar_System

Come visit!


Here in Australia we have earths largest scale model of our solar system.

https://www.nsw.gov.au/visiting-and-exploring-nsw/locations-...



There is a Wikipedia List (German) [1] of quite a few of those (in Germany and in other countries). I stumbled upon it, while trying to find a link to the one in my home town I have wandered quite a few times, as I lived between Neptun and Pluto (it was built before Pluto was demoted), very close to Pluto. It ran the street I grew up in and was built to scale (1:4 bln scale) by a teacher who was a full blown astro nerd and in his free time taught quite a few of the local youth about space, planets, the science behind it, but also built rockets with us and let them fly.

I so fondly remember him, as he was one of those people being a massive inspiration to my life.

[1] https://de.wikipedia.org/wiki/Planetenweg

Edit: Added scale.


That looks really cool! I've visited scale models of the solar system in Eugene, Oregon[1] and Norwich, Vermont[2], but neither one is anywhere near that size.

[1] https://eugenesciencecenter.org/exhibits/eugene-solar-system...

[2] https://montshire.org/exhibit/exhibits/outdoor-discovery-tra...


There is also one in Palo Alto, California! https://www.paloaltozoo.org/Exhibits/Solar-System-Model

We have one in Munich as well. Quite nice walk along the river

https://www.deutsches-museum.de/museumsinsel/programm/progra...

It is old, hence Pluto is still part of it


There is one in Corpus Christi (Texas) that I've seen.

https://www.visitcorpuschristi.com/blog/post/things-to-do-on...


Traverse City, MI has one on their bike trail system: https://traversetrails.org/solar-system/

There is also one in Zagreb, Croatia https://en.wikipedia.org/wiki/Nine_Views

That is awesome!

Wow. Such an awesome idea! Thank you, you made my day

You are technically correct, the best kind of correct. However! That would be a terrible UX/UI experience. While showing distances on a linear scale is accurate, it fails to capture all the information a person in an interstellar ship may wish to see.

Something like logarithmic distances would better capture information like "Am I about to crash into the star or enter a nice orbit" while still showing the full picture of where you are in relation to where you're going and where you came from.

No idea of that's what happened here, just a thought, I'm not an expert in starship computer interface design.


Mercury is orbiting partially inside the Sun, and Jupiter is nearly as wide as the Sun when it should be 1/10 as much, so the planet nodes should be scaled down 10x relative to the Sun.

Also, I did a top-down pixel measurement, where I could see the distance to Tau Ceti as well as the orbit of Neptune. The radius of Neptune's orbit was 32px, while the distance to Tau Ceti was 1152px, for a ratio of 36, when in reality, Tau Ceti is 11.9 ly away, while Neptune has an orbit radius of 30 AU, which means Tau Ceti is around 25,000 Neptune orbits away, so the planet orbit scale is too big (or distance to other stars too small) by a factor of ~694 (25000/36)

Edit: Since this was top-down, the vertical displacement didn't factor into the distance, which also contributed to Tau Ceti appearing too close on screen, so the error is slightly better than that, maybe a factor of 600.

Edit 2: Tau Ceti is rendered at 3.652 pc × 3 world units/pc = 10.956 world units

Neptune’s orbit radius is rendered as 30.05 AU × 0.0065 world units/AU = 0.195325 world units

The rendered ratio is 10.956 / 0.195325 = 56.09 Neptune-orbit radii

The real ratio should be 25,067.5 Neptune-orbit radii

The scale error = 25,067.5 / 56.09 = 446.9×


Also, since we're nit-picking, the positions of the planets are not being updated in real time. For example, I know that Venus and Jupiter are currently approaching conjunction: there are spectacular views of them both at sunset right now here in the Southern Hemisphere!

Thanks: All your math checks out.

Sure, but why does this need to be to scale. Isn't the point more to get the humans a way of understanding where things are relatively? Navigating the map makes it interesting in being able to interactively see where some of the stars are relative to each other. Seeing Regulus and Castor/Pollux from this perspective is much different than on terra firma.

It can't do that if it's not to scale! And who knows where the errors are? Neptune's orbit is way too big compared to Alpha Centauri. Are other stars also way too close compared to that? I can't stand these intentionally misleading education images of stuff. You have to work at undoing the artistic license of the author before it's useful.

We seem to be conflating the actual navigation computer with a display to show the humans information. If it were to scale, it would effectively be useless to the human as the scale of space is just too damn big to fit in some sort of navigation display. However, the actual navigation computer can be as accurate as necessary to not become Lost in Space. That's an entirely different franchise

I suspect this lack of scale on the planets was intentional from a usability perspective, because otherwise the planets be bits of dark dust that would be really hard to find. Jupiter has 11x more diameter than Earth and the Sun is 109x larger. When you consider the size of the solar system (including the Oort cloud) the Sun itself is bit a spec of tiny dust.

Another comparison: if you count the "solar system" as ending at Neptune's orbit (obviously it extends much further, but just for the sake of comparison), then you could fit ~4465 "solar systems" in between our sun and the closest star, Proxima Centauri.

As I understand it, there is no consensus on the size of our solar system. We can measure the orbits of the planets, but it is much harder to measure where the Kuiper Belt or the Oort cloud ends. Estimates on both of those vary greatly.

Even sci-fi writers that try to get this right have a hard time wrapping their heads around it.

"It's called space for a reason."

When I saw the series adaptation of The Expanse, it was really obvious they played a lot of artistic license to make it exciting. A real space battle would be dots firing invisible dots at each other. "Close quarter battle" would be within something like 2000 kilometers, maybe more. That is close.


That’s quite true. But even leaving that aside, most space battles are poorly written too. One of the best that I know of is the battle for Proxima from Babylon 5 (<https://www.youtube.com/watch?v=bE7lZv6LmrM>). This one is really good because we know why the battle is important, why the battle is going to happen here and not somewhere else, but most importantly we learn who the _people_ are (or at least the captains). They become characters, not just anonymous chits on a map.

Although the Expanse did well in some areas, it had no battles that were as well written or as memorable as this one.


All of those authors usually have to resort to the idea of "shipping lanes" so if the heroes are stranded between two planets eventually someone else will pass close to them on the way from one of those planets to the other one. This is wrong in a number of ways (first of all, they keep going anyway) but without that and without magically powerful fuels plots would be "they launched from Mars to Neptune, forget about them for the next three seasons, they'll be there at the beginning of the fourth one".

I thought orbital mechanics would still create those "shipping lanes" as the most efficient way to go from A to B. Of course with enough fuel you can go anywhere, but shipping specifically will love those reduced costs.

The problem is that the planets aren't standing still.

You want to do an optimum burn for Earth -> Mars? Compute an ellipse such that one end touches Earth's orbit, one end touches Mars' orbit. Oops, Mars isn't going to be there, you wait. Once every 26 months you will find that half an orbit later Mars will be there, then you burn. We call this a launch window.

26 months later they will line up again, but neither Earth nor Mars are where they were before. A spacecraft in this second window will never pass anywhere near a crippled spacecraft that flew in the first window. Nor could they do anything but send a report if it did happen--if you're doing efficient burns you don't have the fuel to go to somebody's aid.


Hitchhiker's Guide to the Galaxy:

   “Space ... is big. Really big. You just won’t believe how vastly hugely mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist, but that’s just peanuts to space."

> When I saw the series adaptation of The Expanse, it was really obvious they played a lot of artistic license to make it exciting. A real space battle would be dots firing invisible dots at each other. "Close quarter battle" would be within something like 2000 kilometers, maybe more. That is close.

This is noteworthy because The Expanse tried to get this better than other scifi, say Star Trek, Battlestar Galactica, or Star Wars (ok, space opera), where engagements take place at absurdly short ranges. In The Expanse you see the spaceships are really far apart, mostly dots to each other, and the engagements are (mostly) at really long torpedo ranges, with the exception of those cool scenes using PDCs. You get all those awesome shots where one spaceship sees the other as a tiny dot, then the camera zooms in dramatically to the other point of view. Cool!

And still, engagements are far too close range. But they "feel" long range in The Expanse, I think they got that visually right. I cannot blame them because I haven't seen anything any space combat in shows or movies that is even half as exciting and well done.


The Expanse also was (for me) the first to introduce the concept of a braking burn. Star Wars ships just stop without turning around - can’t unsee it. I think the way X-wing fighters “fly” also wouldn’t work at all, I don’t see any reaction mass coming out the sides.

Lucas wanted to make a swords and sorcery epic in space, and that’s what he did. And he wanted to make space battles look like WWII dogfights, so he did that too. There’s no point trying to compare Star Wars with any sort of realism.

Babylon 5 was the only show in the 90s that actually had any sort of physics based space combat (as opposed to Star Wars-style "they're really just airplanes but we're pretending it's space").

I really missed on watching Babylon 5 (it was during my time, but I unfortunately dismissed it as just another Star Trek wannabe, and only learned later this was unfair). I wish I had given it a chance. I cannot watch it now because of several reasons, and I'm not sure it would stand the test of time anyway, after having watched The Expanse.

Babylon 5 is at the beginning of the uncanny valley of computer graphics so it looks funny (I think they used Amigas) but if you pretend that those effects are of current cinema quality, everything else is good. They travel with hyperspace portals (maybe you saw Cowboy Bebop) so they don't have to perform many unphysical motions in normal space. It's still a great show. Less of a space opera compared to the Expanse, more like a Star Trek DS9 with ETs way more powerful than earthlings.

I was in a kind of similar situation. Didn't watch it when it was originally airing, though I could have. I eventually watched it decades later and absolutely loved it. That said, it was pre-The Expanse. But I still think it holds up pretty well, even if the special effects aren't as good.

I personally think B5 is a better show than The Expanse, but I don't mind the dated visuals or the occasional bit of campy acting or whatever. The storytelling is absolutely first-rate.

Biggest thing they all still get wrong for reasons of drama is showing humans wrestling with controls and flying like a fighter pilot. Real spaceships do not and will not have humans in the control loop except to specify a destination or target.

>Real spaceships do not and will not have humans in the control loop except to specify a destination or target.

Jim Lovell would like a word.


After the accident, Apollo 13 had 4 burns.

The DPS-1 burn which restored the free return trajectory was done using the Apollo guidance computer.

The PC+2 burn which sped up the return from earth was done using the Apollo guidance computer.

The MCC-5 mid-course correction burn was done by hand.

The MCC-7 mid-course correction burn was done by hand, but used the Apollo guidance computer to integrate the accelerometer to let everyone know when the burn was done.

(All the burns on Apollo 8 were computer controlled. I'd assume Gemini 7 and 12 were hand flown, though I don't know for sure.)


Present and future tense, not past tense.

As would Neil Armstrong.

That’s actually how the cons work in Star Trek (and many other SciFi shows too).

What officers do at the con once the ship is in motion is monitor ships systems and check for any external changes to the environment (such as other ships coming in for interception).


Yes sure I'd say that's the exception, can't think of many others.

Would dead-reckoning work or using some galactic sextant?

Maybe?

Ultima (Proxima Book 2) by Stephen Baxter:

    “Oh, come on. This is just great. An imperial Roman starship! . . . We know they lack sophisticated electronics, computers. I wonder how the hell they navigate that thing.”

    “The drive isn’t always on,” said Titus.

    Stef realized that a more precise translation of his words might have been, *The vulcans do not always vomit fire.*

    “Every month they shut it down, and turn the ship.” He mimed this with his one good hand, like aligning a cannon. “The surveyors take sightings from the stars. Then they swivel the ship to make sure we’re on the right track, and fire up the drive again. It’s like laying a road, on the march. You lay a stretch, and at the end of the day the surveyors take their sightings to make sure you’re heading straight and true where you’re supposed to go, and the next day off you go. Works like a dream. Why, I remember once on campaign—”

    “Navigation by dead reckoning,” said the ColU. “Taking sightings from the stars—simply pointing the craft at the destination. They have no computers here, Colonel Kalinski, nothing more complex than an abacus. And they have astrolabes, planispheres, orreries, sextants, and very fine clocks—all mechanical, mechanical, and remarkably sophisticated. But, Colonel, this starship is piloted using clockwork! However, if you have the brute energy of the kernels available, you don’t need subtlety, you don’t need fine control. You need only aim and fire.”


Yeah. Though they do have some nods towards realism, like how most combat systems are fully automated. PDCs fire automatically (at most they need a designated target, and for point defense they just fire), and even torpedos are assigned to targets using some touch screen and that's it, they are not fired using a joystick or similar nonsense.

Star Trek (TNG onwards) gets this right.

That's how The Expanse generally worked, except when they needed to do things outside of normal circumstances.

I seem to remember there was a scene where a human piloted Rocinante through a space station, using what looks like joystick controls and a large viewscreen in front of him.

https://www.youtube.com/watch?v=_c9W-icdTmg&list=PL66J-Gd5vt...


Yeah, exceptional circumstance.

Yes, even today it’s rare. Docking with the ISS or initiating the trans lunar burn on the most recent mission were all completely automated. The pilot arms the engine and authorizes it to proceed. I can imagine it being possible to grab the controls but it’s only done in exceptional or unusual cases.

Of course astronauts are trained for it in simulators in case computers fail.

If there are ever real space battles, that’s actually the most ridiculous time to have humans flying. Human reflexes and ability to mentally model 3D space under microgravity and orbital mechanics are just categorically inferior to what any machine can do. We are too slow and too imprecise.

If there are pilots at all it’ll be at a higher level, like the piloting equivalent of a programmer commanding AI bots. The computer will present the pilot with a digested real time tactical and strategic abstraction and the pilot would make decisions at that level.

A computer or avionics failure in a space battle would probably just be fatal. Which would mean EMP weapons against computers might factor in heavily.


> Star Trek, Battlestar Galactica, or Star Wars (ok, space opera), where engagements take place at absurdly short ranges.

I think that is we could maneuver spaceships like cars and get from place to place in seconds then we would engage at close distance. The only reason for keeping far away would be to have time to react to missile launches and attempt to intercept them. But that's not different than what ships do at sea.


Everything in space is so big, spaceships have to be so fast to get anywhere in a TV-friendly amount of time. I feel like spending an appreciable amount of time inside visual range would be like 2 enemy fighter jets pulling up next to each other so the pilots could sword fight. It really needs the deliberate cooperation of both parties. If anybody even breathes on their control stick they'll drop out of range instantaneously. Not that I'm complaining lol, I like to be able to see things in my TV shows.

Assuming identical weapons.

But if your weapons outrange your enemy you will want to keep the range long. And if your weapons suffer less range penalty than theirs do you will want to keep the range long. The flip side being that if you're on the other side of either of these scenarios you want to keep the range short. And that's before you consider the effects of shielding--most universes with shields make them more effective against weaker attacks. This would mean that if you're facing lighter weapons than your own you keep the range open, if you're facing heavier ones you close.


>The only reason for keeping far away would be to have time to react to missile launches and attempt to intercept them. But that's not different than what ships do at sea.

Yes, that's why you would do it in space, too. The only reason sci-fi media doesn't do it is that it would look boring onscreen. You're just sitting there in the dark then all of a sudden a tungsten rod moving at some fraction of c vaporizes your hull, or a cloud of goo attaches to your hull and you bake to death slowly because you can't evaporate heat well enough. And of course actual lasers in a vaccuum are invisible.


Hitting debris at these velocities would be instant death. Debris comes from other vehicles (generally). You’d never want to be going where other people are, for safety.

There was one particularly egregious scene in The Mandalorian. The protagonist had to fly from Planet A to Planet B without hyperspace for reasons, and he was waylaid by some kind of space patrol, and then he just "turns the steering wheel sideways," and bam, he's landing on a different planet!

Even by Star Wars standard that was absurd. What is this, a highway chase scene?


The books are more realistic than the show. The show takes liberties to look cool, I think, which is okay. Not only does it mess with scale a lot but it also adds a lot of sound and visual effects that would not be there.

> also adds a lot of sound and visual effects that would not be there.

Nah, they'll have regulations forcing them to add artificial sound generators like today's EVs


I recently read The Mote in God's Eye and its (much later) sequel The Gripping Hand, which had very interesting long-distance space combat scenes with high powered lasers - which only move at the speed of light. There's a very real "fog of war" element where you might be VERY out of date with what's happening just due to radio transmission speeds / direct observation.

I don't think the Expanse authors were going for "hard sci-fi." There's, you know, fiction elements -- gates, aliens, magic. And the TV series is itself an adaptation of the books for a visual medium. Showing almost nothing would make for kind of boring TV combat.

> There's, you know, fiction elements -- gates, aliens, magic.

Setting aside magic, fictional science and technology aren't incompatible with hard sci-fi; in fact I'd argue that exploring those on "serious" terms is the entire point of the genre.

At some point I started seeing people advance this weird idea online that hard sci-fi means essentially nonfiction but that's not correct (or even sensible if you stop and think about it since at that point you're just writing a traditional character or political drama or whatever). It simply means taking a simulation style approach to various technological elements of the story. The deeper the simulation goes (ie the more nested levels of "okay and why does that work that way and what are the practical impacts on society") the "harder" the work is.

Magic is an interesting case. In theory it could be compatible with science but in practice the sort of phenomena that people usually mean by that term necessarily imply the intervention of some higher power.


Agreed. It's not "rock-hard sci-fi." It's "medium-hard sci-fi."

The background world building was pretty good from a hard SF point of view. Fusion rockets are possible and the high performance ones in the series are at the edge of physical plausibility but possible. Some of the details, like spinning up asteroids, don't work, but the basic physics of humanity's solar system build-out is mostly sound.

The rest of it gets increasingly soft and fantastic. Which is fine, it's fun space opera.


The issue is, and I believe the authors talk about this, is that the fusion torches they use are absolutely plausible, the problem is that theres no way those ships hold enough fuel for those trips, ripping the engines back out of plausibility again.

Right, they hand-wave this away with the "Epstein Drive"[0] (a name which I suppose has not aged well), which appears to somehow run on orders of magnitude less propellent than seems realistically possible.

[0] https://expanse.fandom.com/wiki/Epstein_Drive


The biggest issue is that with the energy economy of the drives as shown, none of the actual conflicts would ever happen.

Earth, the belt, etc. would have infinite clean water, for example, and plenty of energy to grow food via hydroponics.

No one would have any issues refining metals or other materals, due to all the available energy. Etc. etc.


I am so happy this movie did great, the book was great

Similar to me books: Bobiverse, Long Way To A Small Angry Planet

I'm not a heavy reader

This site is cool, I want to get to know stellar navigation stuff for astrophotography watching a video like this where they pull up star charts to point the telescope at it pretty cool https://www.youtube.com/live/TexqPMQMyZg?si=oEnvrxW21-D0VXGV...

Tangent I'll throw in here, I never get the fabric folding gravity well diagrams as it seems to have a "down" direction, I guess it looks like it's down since it's a slice but the effect is an inward sphere?


> I guess it looks like it's down since it's a slice but the effect is an inward sphere?

Yes, gravity is a vector field: every point in space near a heavy body has a vector pointed at the center of the body with a magnitude of the field strength. https://en.wikipedia.org/wiki/Gravitational_field

Whenever someone uses fabric sheet analogy, they need to shout that the X-Y of the sheet is a 2 dimensional analog of X-Y-Z space, and the Z direction of the sheet is the field magnitude, with the slope indicating direction.

All models are wrong, but some are useful (for understanding).


Other thing is I believe they say gravity is strongest at the center of the sphere/core but I would think the mass is split evenly away from the core eg. maybe 2/3 radius from the center where it's equal mass on each side. But probably doesn't make sense wouldn't be a ball.

Since the strength is represented by the slope of the sheet (not the depth), it should still line up. Underneath the ball at the very center the sheet will be level, to match as you say, that the field strength is 0 there. The exact shape will probably be wrong though since it's mostly determined by the shape of the bottom of the object.

Inside a solid uniform sphere, gravity is exactly equal to the gravity of the sphere of material under your feet, as though any mass at any "altitude" higher than you did not exist. It's a pretty standard calculus problem. (the opposite is true, inside a solid hollow shell gravity is exactly zero everywhere)

The next thing they do after showing you the sheet is to roll a ball around the stretched part to demonstrate an orbit. Explaining how that analogy works starts to take more math than the actual field you’re trying to explain!

Just a question - why do you classify Long Way with PHM - because there are aliens working with humans? I don’t see any other similarities. The technology IIRC (haven’t read in years) in the Becky Chambers book is closer to Star Trek than reality, and there’s not that much of an overarching plot - which is not to say a book cannot be good without one but it’s a big difference.

True less technical and space themed so maybe not fitting just a fun easy read

Oh yeah another series would be Nick Webb Constitution (Legacy Fleet), I think I got farther into that series but didn't finish it unlike Bobiverse, maybe I did finish this trilogy, I haven't read books in a while honestly. That was a good series though I remember the depiction of the space battles.

Trying to be better at being in the moment vs. watching youtube/scrolling a website at the same time kind of thing


If you like sci fi in general you might ask on /r/printsf on Reddit for recommendations based on what you like. The Libby and Hoopla app also gives recommendations based on what I have already read. I, too, completed Bobiverse but gave up after one Chambers book, YMMV.

In the vein of popcorn scifi, expeditionary force books are fun.

Added to my kindle list, funny I tried to read Gravity's Rainbow as I heard it in a song, I did not get far, on the topic of reading, it is related to rockets but yeah

it's like an inverse gas bubble underwater, or a liquid blob in gas in microgravity, but without phase border.

see, it's not that easy to explain or visualise.


Yeah I watched this video recently about slingshotting I can see how it works but yeah https://youtu.be/-CqBP-CtM0c?si=BdCiZwWgpAp07mgs&t=15

It's not like there is a "down" it's just you're looking at it from a top view?


There is no down, yes. There is no looking at it from a top view either, since there is no bottom. 3d models like this video are helpful, but one must keep in mind that they are but a slice.

I doubt my opinion will be well-received by all, but I hope that creators like the author of the Bobiverse will be able to, affordably and within their own capabilities, create new forms of content, such as AI-generated long-form content, like entire TV seasons, as the technology matures. That series is fantastic.

According to the author, it's been optioned to Lord Miller Productions, the same group that adapted Project Hail Mary.

I can also recommend https://www.youtube.com/watch?v=8FT-oz9aZU4 Time Dilation Visualized (by The Overview Effekt).

It talks about the distances and times involved and how time compression and astrophage infection rates work out. As a fan of the book and the movie it was nice to see the actual 3D star chart of everything. (warning: there may be spoilers there)


The time dilation aspect of it is cool, but doesn’t discuss how far we are from a propulsion system that could credibly pull this off. Even if we solved fusion it wouldn’t get us remotely close. Maybe if you could somehow produce 50 tonnes of antimatter you could do it. But we have no idea how to produce antimatter efficiently or at scale, and even if we could do it with 100% efficiency, it would take many years of humanity’s current energy budget just to make the antimatter fuel for a single manned trip.

To me it seems like we’d need new physics (not just new technology) to have any chance of pulling this stuff off.

The book dodges these inconvenient numbers with a bit of a deus ex machina plot device that I won’t spoil here :)


Definitely, the amounts of energy needed are is beyond anything realistic today or anytime soon. It’s still clarified the principle for me that we could in theory at least reach those points in a human lifetime.

For other software engineers thinking of following in Andy Weir's footsteps and writing a novel, I put together my guide to self-publishing using software tools and techniques here: https://frequal.com/forwriters/

Didn’t know he was a programmer!

For anyone who enjoys this, exploration in "Elite: Dangerous" (for which you need to be neither elite nor dangerous, exploration is peaceful) might be enjoyable for you as well.

From the wiki: Elite Dangerous has a 1:1 scale simulation of the Milky Way galaxy based on real-life scientific principles, scientific data and theories. It includes around 400 billion star systems, modeled on actual galactic charts. Planets and moons rotate and orbit with 1:1 scale in real-time, thus constantly changing a system's environment

https://elite-dangerous.fandom.com/wiki/Galaxy


It's been a long time since I played, but I don't recall the motion of the planets mattering much. Supercruise lets you move fast enough that planets and moons that move enough to be noticeable are very easy to get to regardless.

It watching the starscape change around me as I jumped from system to system, actually seeing formations and nebulae in the distance and being able to move toward, around, into them, which made it feel alive to me. I agree the planets moving doesn't really matter on a gameplay timescale.

I was completely immersed - it was a good way to spend a few days during lockdowns :)


Ah yeah, the starscape changing was very cool, being able to actually go to the Pleiades or to various nebulae also caused me to better understand where different things are relative to each other in the night sky.

Elite would be a great game if it wasn't for the frustrating and terrible game design.

I had sudden memories of playing Frontier: Elite 2.

I wanted to go to Sol, buy luxury goods...and take them to Barnards Star


I have memories of using a hex editor to edit the save file to get enough money to buy a docking computer because even as a kid my technical abilities were much better than my hand eye coordination.

I have a dim memory that one of my A-Level physics teachers (David Massey) was credited as a consultant on the Newtonian physics in F:E2.

The game came out at the start of my upper-sixth year so it often came up during his classes.


Yep, quick trip in your panther clipper to ross 154, park up and buy everything on the planet.

Coming to this thread late but this makes me want to do a star trek one! Going to be way more difficult to parse through all the competing references to location and distance but I guess we’ll see how big of a trekky I am

This is pretty cool. Has anyone ever seen a diy star projector for the home? Most of these toy star projectors like the Sega Homestar require placing the projector at the center of the room to point up. At the same time most of the small active projectors (like for movies) require a screen for the image to be better seen (they aren’t very bright). Ideally I would like something that could autocorrect the dimensions of things on the surface, so it would project distorted in a way that it would visually look non-distorted and also I would be looking for the cheapest projector that still manage a good bright for stars during the night, without requiring to put a screen on the home ceiling.

I’ve seen proper star projectors from Zeiss but my ceiling is not a dome - plus expensive and requires infinite amounts of power..


Those interested in this might also like my "Project Hail Mary Stellar Map" at:

https://dwheeler.com/essays/project-hail-mary-map.html

My page shows a stellar map (from the viewpoint of Polaris) and a sky chart showing the key stars from Earth's viewpoint.

Source code (MIT license for my stuff) is at: https://github.com/david-a-wheeler/plot-stars


Thank you so much for the blog post! I credited you in the about page, I used your charts as reference for the Astrophage infection graph view with the Petrova mode. I shared your blog with my friends, it was a great read.

Thanks for the credit, I appreciate it! Glad it was helpful.

I wouldn't call it a "blog post" though, it's simply an essay. I update my essay whenever I decide it needs updating, and "blog posts" are usually chronological and fixed in time once posted.

Take care!


Thank you for making this whoever you are. There is a wonderful video at https://www.youtube.com/watch?v=8FT-oz9aZU4 that visualizes space travel and time dilation in Hail Mary. What I wished I had immediately after watching it was an interactive stellar chart.

You're welcome! I love that channel so much. Their videos and the blog post I link in the about section/citations on the starmap were inspirations for making this.

Very cool. On Voyager 2 we placed a map on the side of the probe that places the position of our sun based on an array of Pulsar stars (the map was designed by Carl Sagan). I noted in the PHM movie Rocky and Dr Grace made similar 3D maps (I think they were pulsars(?)). I guess pulsars form natural beacons that can be detected at large distances.

Cosmos : The Shores of the Cosmic Ocean - https://youtu.be/x-bJLG9_sUg?si=1K96fMX2T9iXu0zA&t=783

For the "how far?" https://www.aanda.org/articles/aa/full_html/2011/04/aa16141-...

We can get timing (rather than imaging) parallax...

> We find that with the first method a parallax with an accuracy of 20% or less can be measured up to a maximum distance of 13 kpc, which would include 9000 pulsars. By timing pulsars with the most stable arrival times for the radio emission, parallaxes can be measured for about 3600 ms pulsars up to a distance of 9 kpc with an accuracy of 20%.

(one kpc is 3261 light years)

Not only can they be detected at large distances, but measurements of how far can be done at greater distances than can be done with imaging ( https://www.youtube.com/watch?v=hFMaT9oRbs4&t=608s ).


I thought the maps they made were of the neighborhood of stars around Tau Ceti, marking their respective home stars with the petrova line.

I believe you are correct. Way too close to use pulsars…

Pulsars also have a rotational period that provides a reference point for interpreting arithmetic notation.

Anyone with a gaming rig and an interest in scale of a galaxy should check out elite dangerous.

Space engine too

"Thumbs" down

You mean up. Question.

Amaze!

Fist my bump

Glad to see it includes Wolf 359.

Edit: oh interesting. Apparently it was mentioned in the book as being affected by the astrophage. I forgot that tidbit and thought it was just a Star Trek reference.


Yeah, and it's one of the nearby stars in reality.

It's also sort of the subject - and title! - of this great short story: https://clarkesworldmagazine.com/macleod_12_17_reprint/


This is great. Nice work.

The galaxy explorer/map in Elite: Dangerous is pretty good, I wish they would produce a stand-alone application of just the galaxy map, whether it's even close to correct or not, who knows, but it's enjoyable just to pretend you can move instantly between star systems and go exploringthe galaxy


I'm at the point where if there's a computer display, or 3D model, or any asset in a movie, I want there to be a Kickstarter to pay the producers to open source the original assets. Even if it's a super restrictive license.

I want all of the War Games original graphics. I know people have come a long way. But I want all of them.

The "Hackers" movie. "Sneakers". "The Matrix". These individual assets deserve to be preserved! They're iconic. They're art, in their own rights!


This is so beautiful, this thread doesn't have enough praise! It's not easy to get this "right". Lovely!

Thank you!

Looks nice, but is it finished? I don't see a skybox or any of the more detailed information mentioned in the "about" dialog, and I don't see any effect from clicking the buttons along the top.

I allowed WebGL and disabled Enhanced Tracking Protection and my adblocker, and still only the star labels appear.


Where is the Petrova line?!

I started to watch the film last night but only got a bit into it. Feels basically like a "Sunshine" ripoff to me but I'll watch the rest tonight.

I found it annoying .. but I know lots of people who liked it.

What is this supposed to be about? The link looks like some sort of star-chart, but I don't see where to get an explanation.

Super cool, I'm like 2 hours away from finishing the audiobook and it has been STELLAR (had to).

If you like space visualizers, NASA has a cool one:

https://eyes.nasa.gov/apps/solar-system/


Wow. I knew that astronomers had mapped and measured a large number of stars in our galaxy; but I had no idea that the number was close to 2 billion.

This is amazing and even works on a phone. Controls are intuitive and no bugs or glitches. Incredible.

this is cool. My nit pick- aren't the petrova lines curving along the wrong plane? For example, in our solar system the line should start at the sun and should be pointed at where Venus used to be, but then curve towards where Venus is now (until gets to venus). Since the astrophage will course-correct over their journey and stay in the same plane as Venus' orbit.

It has been a little while since I read the book, but I think you have the cause of the curve wrong. These things are moving at such a high percentage of the speed of light that there isn't much visible curve from the movement of the planet. The curve is instead caused by them leaving the star at the pole (which leads to a different nitpick of the visualization since the curve isn't shaped to represent that). It's theorized that the Astrophage do this to make is easier to find their way as exiting the plane of the solar system reduces the chances of there being any occultation blocking their view of their destination.

oooph, been a while and I don't remember any of those details. Good excuse for me to re-read it!

very cool concept

Movie was awesome & will be watching again.

Why is the path curved at the start?

Cool! How would navigation actually work? Dead reckoning? Inertial? Stellar reference? Pulsar navigation?

Also, the dashed red line is --- SPOILER ALERT! ---- only part of the trajectory in the film, as there is another leg of the voyage not shown.


Oh, that doesn't seem so far

This was so mesmerising! Will show this to my nieces when they come visit. Kudos!

Pretty cool, I would suggest removing the z axis grids. Finding them very distracting

Love it. The grid is cool but I think it needs to be more transparent.

Why does it show the asteroid belt and not the Kuiper belt?

Nice! I love the film

really cool, can we hot-plug in our own map?

Really cool!

That is super cool!

Are the Pfhor still engaged at Tau Ceti? Is there a bus route to Wolf 359? I have so many questions.

Moving up or down relative to the Solar System's plane takes an insane amount of Delta V and with our technology would require getting a gravity assist from the Sun. But with astrophage that problem goes away.

Cool project

If, like me, you have an older android and are running Firefox, do not open this site!

Awesome work!

NICE!

This is a test comment

cool project

It can be summed up as "Ken Meets Jesus", "Ken Goes to Space", "Ken is a bumbling moron", "Ken's first friend". "Ken's White Savior moment"

This appears to be the norm for US based scifi now. Glad I'm watching movies like The Wandering Earth and Alienoid instead.

It had a good premise. But it also fell apart immediately. Like, they only sent 3 people, 2 whom died on this UBER CRITICAL SAVE THE PLANET idea?

And Ryan Gosling's character is a fucking moron. You're supposed to be a molecular biologist, and you're basically a reddit-gag line?

Edit: lol -4 , like seriously, its a pretty bad show. I listed movies I compare it to. But no I get shit like "You must be fun at parties." Personal attacks, sigh.


> And Ryan Gosling's character is a fucking moron. You're supposed to be a molecular biologist, and you're basically a reddit-gag line?

The thing about very smart people is that they can still manage to miss the bus.

And if you have read any of Andy Weirs other books they have a common theme of one person who’s in over their head who basically bumbles through by the skin of their teeth.


> The Wandering Earth

That's a movie you watch while drinking, take a shot every time you see something absurd


I agree with your sentiment but this is not the place to complain about a movie you dislike. OP is showing off a project they made, trying to make them feel bad about liking a movie is tactless and reflects poorly on you.

Did Ken also get his catheter yanked out like in the book? I don't plan on watching the movie but that's the only thing I would even care a tiny bit if they included, because I just felt like it was such an odd highly specific bit and I want to know if they committed for the big screen.

> White Savior moment

???


White people doing anything good is actually bad. Duh.

/s, but I think I'm accurately describing the viewpoint you're responding to.


There is a strain of science fiction where the human protagonist (usually a white male) (possibly a boy from backwoods moisture farm) saves the universe, (including all the other dumb luckless species). A notorious example is Battlefield Earth.

However in this example the contribution of the alien, not just to the whole saving the universe business, but to the actual story, the book, was huge.


Fantasizing about saving the universe is a good thing, actually.

It’s a description of a common Hollywood trope (or used to be), like the ‘magical negro’ [https://en.wikipedia.org/wiki/Magical_Negro].

Hard not to see once you know about them, and they are indeed common.

But what should replace it? Good Nuanced writing? Good luck with that!


Chinese film having 100% chinese cast = good.

American film having a single white male lead = not good.


It’s a troll. Just flag and move on.

You must be fun at parties.

As a european arthouse cinema snob I must say Gosling would have made a nice stand-in for Rocco Siffredi. Maybe.

> Edit: lol -4 , like seriously, its a pretty bad show. [...]

I don't think the downvotes are because you expressed the view that the film is bad.

It's mainstream science fiction using tech we don't have. It will never make a lot of sense. And then you decide to bring skin colour/race into the discussion. What do you expect?


> But it also fell apart immediately. Like, they only sent 3 people, 2 whom died on this UBER CRITICAL SAVE THE PLANET idea?

(I didn't downvote, you have a right to dislike a popular movie or book)

They explain why only 3 people (it's a bit contrived, but there's genetics involved), and why no more ships. It's an emergency, a resource and time-constrained mission on which a few things go wrong even before they depart. The world is on full emergency mode, rushing things and getting things wrong. The crew isn't even the initial pick, but there's an accident involved. The lead director believes she'll probably end up in prison after the mission launches. I don't know, it makes sense to me.

> And Ryan Gosling's character is a fucking moron. You're supposed to be a molecular biologist, and you're basically a reddit-gag line?

I think the meme-speak, which I also found a bit jarring, is simply Andy Weir's less-than-good writing style. I think Weir isn't a particularly good writer, but he managed to write an engrossing adventure which I enjoyed.

In-universe, molecular biologists and scientists in general do have sense of humor, enjoy memes, and are generally capable of doing and saying the dumbest things. So it also kind of works!


I think OP only watched the movie. The book is a bit better at showing the main character actually being competent at times. In the movie they (for obvious reasons, but they could have done perhaps once) skip him going down science rabbit holes.

I think the movie also did a decent enough job of conveying that preparing enough astrophage for just one ship was only barely possible in Earth's environment. It was the entire reason for making it a one-way trip.

I thought the portrayal of scientists was a lot more true to life than most media. Millennial and older Zoomers are old enough to be in these positions now, they aren't going to talk or dress like boomers.

Yes, I think it's a bit annoying (to me, because I dislike meme-speak) but it's not unrealistic for the character.

But, to be frank, I think it's also Andy Weir's style, because memes and pop culture references pop up even when it's not the character's PoV.


Elite Dangerous does it better. Pretty but idk.. get the AI generated feeling.

What specifically about this feels AI generated. It might be, IDK, but I'm not seeing any tells, so wondering if you could expand.

I'm not saying it looks AI generated, but AI made it possible to polish things to a level that very few people took the time to ever do themselves.

This is a great thing, but it's also a tell since we all saw the UIs people were building by hand pre-AI.

That said, I don't think it matters. What matters is whether it's low quality.


The font looks like the same font in every AI-generated visualization like this.

Project Hail India – Restroom Navigation Chart



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