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Show HN: Physically accurate black hole you can put in your room

blackhole.plav.in

191–200 of 204 posts

Re: Show HN: Physically accurate black hole you can put in your room

#191
The web-based real-time rendering is insanely smooth, and the visual quality is stunning!

Quick question: How close is this visualization to what a real black hole actually looks like in real life? I’m planning to show this to my daughter, so I'd love to tell her a bit of the science behind it! Super cool project!

Re: Show HN: Physically accurate black hole you can put in your room

#192
post #158

Earlier quoted context omitted.

Running a simulation in a browser is not going to be a complete representation of reality. To think that is possible is really weird. So really, what is happening, we are arguing over the 'Title'?

I've done this as have many other people, its absolutely possible and there are good sims floating around. The OPs simulation is just presenting itself as more than what it is

From your other answers, you know what you are talking about. So wont argue the point.

Because I think we would really be arguing about, what level of reality can be calculated in a browser. Sure, a simulation can be done in a browser. But that could be anything from a thermostat with a single simple equation, to modeling all of the air flow thermo-fluid dynamics in a house down to millimeters volumes. There are limits. And I guess if using WASM browsers have gotten a lot more capable. It would come down to what fidelity we are saying is 'reality'.

Re: Show HN: Physically accurate black hole you can put in your room

#193

Earlier quoted context omitted.

>I don't see "simplified" as being opposite to "accurate". Is it accurate to model a cow as a sphere?

To describe cow's gravity? Pretty much so. Then, for visualization and even for many biological purposes, it's accurate enough to mode the cow as a bunch of organs with known processes happening in them. But that's still far from atoms and quarks that constitute the cow.

For an object with the mass of a cow, the gravitational effects are minute, and thus if we study small gravitational interactions we would surely want to model the distribution of mass of the cow.

Either way, no layperson (to whom this black hole sim is targeted) would consider a simplified spherical cow to be accurate. That's why the spherical cow is a meme.

Perhaps you're getting the pushback you're getting, because you have a different idea of what accuracy in physical simulations means.

Re: Show HN: Physically accurate black hole you can put in your room

#194

> https://blackhole.plav.in/ The lines in the demo look upscaled and aliased for some reason.

Could you please share a screenshot so that I investigate what actually happens? I tested on a few different devices, but far from anything extensive.

This is on Chrome/Win11:

https://snipboard.io/W8SXYm.jpg

Re: Show HN: Physically accurate black hole you can put in your room

#195

Earlier quoted context omitted.

I clicked on this because I worked on the infra that simulated the famous blackhole sim in interstella. I thought "oooh this is interesting I wonder how they are going to do physically accurate on an end device" Recalling how the original particle sim was something like 100TB, took 2 weeks to generate and seemed to write in a way that killed disks. but that was >10 years ago, so what clever stuff has been done to mod…

> why the stars surrounding the black hole are just points, and more over why the lines are straight to the centre of the hole Sorry for confusion! Points + lines are just other users looking at the black hole right now, their camera locations and lines of sight. Nothing more! In the first hours of HN frontpage, there were a lot – and I can see how one can understand them as parts of actual scene :) I decided not to…

Aha! understood

Yeah I couldnt work out what they were in relation too

Re: Show HN: Physically accurate black hole you can put in your room

#196
post #162

Earlier quoted context omitted.

it's common to use a colormap, but not using a perceptually uniform colormap in the year 2026 is quite a blunder

> not using a perceptually uniform colormap in the year 2026 is quite a blunder Then you are up for a big surprise if you browse through modern published papers :)

it is indeed a very commonplace blunder. I'm trying to evangelize as much as I can!

Re: Show HN: Physically accurate black hole you can put in your room

#198
post #59
post #56

Earlier quoted context omitted.

Helio- is actually "sun", not "hole", and it's Greek, not Latin, but I 100% agree with you: it's pointless technical vocabulary that only serves to obfuscate. I think in this particular case, it's just some internet neologism (which is a good word, since coinage can mean a couple different things), made based on analogies with older phobias. For those of us who know Latin and Greek, though, all we can really do is sh…

What would be the correct latin/greek word for it?

Melanastrophobia, perhaps? "Black star phobia". I don't think a modern term has been coined for black holes from ancient Greek vocabulary.

Re: Show HN: Physically accurate black hole you can put in your room

#199
post #34

If anyone's interested in the accuracy, this is very 'visualisation grade' software. Its a bit of a pet peeve of mine that people present these sims as being very physically accurate, when they contain major inaccuracies, some of which are very obvious and/or deliberate. This one has some serious physical limitations I wouldn't mind at all if it didn't say that this was a *physically accurate* black hole specifically…

but why was the picture taken of black hole have accretion disk yellow?

The vast majority of scientific images, be it in papers on press releases, are using an arbitrarily-chosen colormap to map whatever numeric values are there to actual visible pixels. For the Event Horizon Telescope speficially – it is a radio telescope, so what it sees has no intrinsic "color" as perceived by a human eye at all. Same with this simulation here.

Re: Show HN: Physically accurate black hole you can put in your room

#200

Earlier quoted context omitted.

Could you please share a screenshot so that I investigate what actually happens? I tested on a few different devices, but far from anything extensive.

This is on Chrome/Win11: https://snipboard.io/W8SXYm.jpg

Hmmm I think I see what's happening here. Basically, all devices I tested (laptops/phones/tablets) seem to have small pixel size, and to save on compute power for weaker devices I decided to render with half as many pixels as the screen has, letting the browser upscale the result. In your case, pixels are probably quite a bit larger, and half-res rendering has these prominent artifacts.

Can you try if increasing "render scale" in params->display helps?

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