MIT Game Lab made a take on this back in 2012. https://gamelab.mit.edu/games/a-slower-speed-of-light/
Loved that game!! Blew my mind in my 1st year physics classes
Show HN: What if the speed of light was 5 km/h?
21–30 of 213 posts
Re: Show HN: What if the speed of light was 5 km/h?
#22In the Three Body Problem Trilogy by Liu Cixin some of the more advanced civilisations have the ability to change the speed of light locally with very interesting consequences for the that local space
Pedantic note: The speed of light in glass, optical fiber and water is different from vacuum (much lower). On a certain scale, humanity also knows how to locally alter the speed of light though not to this extent.
It's not actually that the speed of light in a singlemode fiber optic cable is slower, but that the photons aren't travelling in a direct path down the fiber like water down a pipe. They're bouncing off the interior walls of it at like a 45 degree angle billions/trillions of times before it reaches the other end of the cable.
Basically imagine like if you wanted to walk in a straight line between two points at both ends of a empty, long, narrow rectangular warehouse, and instead of walking in a straight line from A to B, you bounced off each wall at an angle (like a pool ball ricocheting off the bumpers) to get from one end to the other. Making your cumulative distance travelled on foot much greater.
Re: Show HN: What if the speed of light was 5 km/h?
#23In the Three Body Problem Trilogy by Liu Cixin some of the more advanced civilisations have the ability to change the speed of light locally with very interesting consequences for the that local space
I'm being vague to avoid spoilers, but I'll just say that it serves for a very interesting meditation on the concept of loss, and has stuck with me for the 5+ years since I read the trilogy.
Re: Show HN: What if the speed of light was 5 km/h?
#24Earlier quoted context omitted.
Pedantic note: The speed of light in glass, optical fiber and water is different from vacuum (much lower). On a certain scale, humanity also knows how to locally alter the speed of light though not to this extent.
It's not actually that the speed of light in a singlemode fiber optic cable is slower, but that the photons aren't travelling in a direct path down the fiber like water down a pipe. They're bouncing off the interior walls of it at like a 45 degree angle billions/trillions of times before it reaches the other end of the cable. Basically imagine like if you wanted to walk in a straight line between two points at both e…
Light’s still slower in glass than in a vacuum, though, or it wouldn’t refract at the transition between the two.
Re: Show HN: What if the speed of light was 5 km/h?
#25MIT Game Lab made a take on this back in 2012. https://gamelab.mit.edu/games/a-slower-speed-of-light/
Played around with this one before. Very interesting. Thanks for linking it.
Re: Show HN: What if the speed of light was 5 km/h?
#26Earlier quoted context omitted.
It's not actually that the speed of light in a singlemode fiber optic cable is slower, but that the photons aren't travelling in a direct path down the fiber like water down a pipe. They're bouncing off the interior walls of it at like a 45 degree angle billions/trillions of times before it reaches the other end of the cable. Basically imagine like if you wanted to walk in a straight line between two points at both e…
Light’s still slower in glass than in a vacuum, though, or it wouldn’t refract at the transition between the two.
Right, and it varies with what type of glass, google "refractive index of glass".
If you google image search "refraction fiber optics" you'll get some decent pictorial examples of what I meant by photons bouncing off the interior walls of a 9/125 SM fiber optic strand billions/trillions of times on its path, I guess I was trying to write an extremely simplified explanation of refraction in something like a typical SMF-28e / G.652.D fiber.
Re: Show HN: What if the speed of light was 5 km/h?
#27Velocity raptor is a free game that accurately simulates the effects of special relativity. It slows down the speed of light to 3m/s and you solve puzzles as a cute dinosaur. https://www.testtubegames.com/velocityraptor.html There is also a helpful FAQ which explains all the strange things happening, such as length contraction, time dilation, and color shifting: https://testtubegames.com/srel101.html My favorite leve…
From further back, https://gamelab.mit.edu/games/a-slower-speed-of-light/ and https://theandelope.itch.io/a-slower-speed-of-light (https://news.ycombinator.com/item?id=4731749 284 points by po on Nov 2, 2012 with 106 comments and in 2024 https://news.ycombinator.com/item?id=40332586 with 60 comments)
> A Slower Speed of Light is a first-person game prototype in which players navigate a 3D space while picking up orbs that reduce the speed of light in increments. Custom-built, open-source relativistic graphics code allows the speed of light in the game to approach the player’s own maximum walking speed. Visual effects of special relativity gradually become apparent to the player, increasing the challenge of gameplay. These effects, rendered in realtime to vertex accuracy, include the Doppler effect (red- and blue-shifting of visible light, and the shifting of infrared and ultraviolet light into the visible spectrum); the searchlight effect (increased brightness in the direction of travel); time dilation (differences in the perceived passage of time from the player and the outside world); Lorentz transformation (warping of space at near-light speeds); and the runtime effect (the ability to see objects as they were in the past, due to the travel time of light). Players can choose to share their mastery and experience of the game through Twitter. A Slower Speed of Light combines accessible gameplay and a fantasy setting with theoretical and computational physics research to deliver an engaging and pedagogically rich experience.
Re: Show HN: What if the speed of light was 5 km/h?
#28In the Three Body Problem Trilogy by Liu Cixin some of the more advanced civilisations have the ability to change the speed of light locally with very interesting consequences for the that local space
I'm being vague to avoid spoilers, but I'll just say that it serves for a very interesting meditation on the concept of loss, and has stuck with me for the 5+ years since I read the trilogy.
Same here, the quote on time passing stuck with me quite a bit.
Re: Show HN: What if the speed of light was 5 km/h?
#29It would be nice to add controls for mobile.
Re: Show HN: What if the speed of light was 5 km/h?
#30Earlier quoted context omitted.
>it doesn't make sense to talk about a speed through time Only if you're talking about other people's clocks and not your own. Your own clock is one second per second, but someone else's may be slower or faster relative.
Are you trying to tell me time is relative?
As understood by general relativity, it actually is. There is no absolute time.
You can say the age of the universe is 14 billion years, but that's in our reference frame.
In another reference frame it may be a different number.