Show HN: What if the speed of light was 5 km/h? • Hacker News Board

Re: Show HN: What if the speed of light was 5 km/h?

#261

Post by sh0gg0the » Thu, Sep 10, 2026, 9:25 PM UTC

shagie wrote: post #196

sh0gg0the wrote: post #169

Earlier quoted context omitted.

On YT there is a video of a flight through the solar system at the speed of light starting at the Sun. It's a pretty boring video. You see very little movement and change over time. After 8 minutes Earth slowly passes by. After 44 minutes you reach Jupiter and the video ends.

If The Moon Were Only 1 Pixel (A tediously accurate scale model of the solar system) https://www.joshworth.com/dev/pixelspace/pixelspace_solarsys... has a button at the bottom right for 'C' which scrolls to the right at the speed of light on that scale. https://thinkzone.wlonk.com/SS/SolarSystemModel.php?scale=10... lets you make scale model calculations (useful if you're building one). The default model scale has th…

Does this take relativistic effects into account? The video I mentioned doesn't. Near the speed of light your surrounding looks like sped up and the distance to your target is clinched. Your own time runs slower in comparison and the distance is shorter. So theoretically you're able to reach the destination millions of LY away in your lifetime.

Edit: I now watched the animation. It's exactly the same as the YT video. Speed of light is very, very slow.

Re: Show HN: What if the speed of light was 5 km/h?

#262

Post by MathMonkeyMan » Thu, Sep 10, 2026, 9:31 PM UTC

rrr_oh_man wrote: post #233

chungy wrote: post #213

Earlier quoted context omitted.

Have an IPv6 connection.

So basically "go fuck yourself" if your ISP does not yet support IPv6? I'm not saying that I couldn't fire up Cloudflare Warp, but I think it's a legit issue for average users [0]? [0] https://xkcd.com/2501/

Funnily enough, I use Cloudflare Warp at work, and it breaks my site for what I think are DNS related reasons. Maybe there are some more exotic DNS keys that I need to add.

Or I could go back to IPv4 with dynamic DNS, but that would mean changing domain registrars.

Re: Show HN: What if the speed of light was 5 km/h?

#263

Post by [deleted] » Thu, Sep 10, 2026, 9:39 PM UTC

hebelehubele wrote: post #254

Terr_ wrote: post #140

Earlier quoted context omitted.

In terms of comparisons to human lifespan, I think this one is interesting: If you can somehow accelerate/decelerate at a constant human-acceptable 1G, time dilation means almost anywhere is reachable in a human-lifetime. That coincidence(?) could easily become false if we are accustomed to lower accelerations or lesser lifespans.

There was a bit in the series "The Expanse" about a what's called "Epstein Drive" where some guy invents a propulsion tech based on fusion and he losts control of his aircraft under an ever-increasing acceleration. After some minutes, his body gets crushed under its own weight before he could reach the controls and slow the spaceship down. https://www.youtube.com/watch?v=1lS_WxQ3zeU

[deleted]