Very related Scott Manley video that discusses and simulates the same effects https://www.youtube.com/watch?v=R_g9EeT233Q
Show HN: What if the speed of light was 5 km/h?
81–90 of 263 posts
Re: Show HN: What if the speed of light was 5 km/h?
#82The Schwarzschild radius is proportional to c^-2, so this would mean the Schwarzschild radius of the Earth would be about 400 billion km, and the Earth would be a black hole.
Re: Show HN: What if the speed of light was 5 km/h?
#83The book Redshift Rendezvous from 1990 explores this idea. (TBH the story is a little clunky, but if you like to see someone look at the physics in depth, it's pretty interesting.) https://www.goodreads.com/en/book/show/1382560.Redshift_Rend...
I'm reading the clockwork rocket at the moment. It's a little different but it's set in a universe where the laws of physics / behaviour of light seems to be different to our own.
Re: Show HN: What if the speed of light was 5 km/h?
#84Earlier quoted context omitted.
Not just that but your average russian or ukrainian used expendable munition UAV that uses a singlemode fiber spool uses the cheapest and most mundane of fiber transceivers. There's no requirement for data rates above 1 Gbps, so ordinary SFP optics (not SFP+ or anything) are used, and the distances involved means it works fine with a extended range 1550nm to 1610nm reach thing that can nominally handle 40 to 80 km of…
You can get a pretty good 1080p60 video at only 6mbps. Depends on how well the sender is encoding I guess, but it shouldn't be too much more than that.
I think the drones don't use a complex encoder because latency.
Re: Show HN: What if the speed of light was 5 km/h?
#85Fun fact: given that the meter is defined in terms of speed of light (and cesium frequency), "changing the speed of light" is a counterfactual impossibility, what is actually changing are some other fundamental constants.
Re: Show HN: What if the speed of light was 5 km/h?
#86One oddity of Lorentz invariance is that two non-parallel boosts decompose into a boost and spatial rotation.
I've never quite wrapped my head around this and was hoping to get some insight from this simulation. But afaict, I'm not seeing this effect (press W for a bit, the A for a bit and it's not obvious I'm at a different orientation - if I look down at the ground the gridlines are still axial).
I don't know if I'm misinterpreting the math, or the simulation, or maybe the simulation is doing something to 'correct' for this behavior so things are more natural, or something else. Does anyone have any insight?
Re: Show HN: What if the speed of light was 5 km/h?
#87Whenever I think about light speed being fast, I imagine myself standing at the edge of the solar system and watching a hypothetical photon travel from the Sun to the Earth and taking 8 minutes. Suddenly it doesn't feel like light is really all that fast except at human scales. 5 km/h would be fascinating though.
But light is not really even light except at human inference level. Like yes if you were a god like being looking at this and understanding light in a proton level way, it wouldn't be very impressive but I would say that is not the right way to think about physcial phenomena. How can you even be sure time has any definite meaning outside human's concept of it? In that sense what do words faster or slower or minutes even mean
Re: Show HN: What if the speed of light was 5 km/h?
#88I think the old SciFi classic "Zone of Thought" and the other book which name escapes me now explorer this idea, although not 5Km/h.
To stop a 'blight' in the universe, some natural laws have to be changed wherever it starts to spread, is the story premise if memory serves me.
Re: Show HN: What if the speed of light was 5 km/h?
#89The first few Discworld books explore this a little bit too. I think pterry dropped the concept after that, I don't really remember it later in the series.
Darkness travels even faster than light on Discworld, because it has to be fast enough to get out of the way when light arrives.
Re: Show HN: What if the speed of light was 5 km/h?
#90Some time ago I had the following shower thought: "the Speed of Light is pretty slow"
How i got there:
The closest major galaxy to the Milky Way is Andromeda, and is 2.5 million! light-years away. And this is the CLOSEST galaxy, the universe is extremely big.
Of course that as you get closer to C, the traveling object will experience time dilation (relative to observer), so the time passed will be less. At 99.999% C, the traveler would take ~11,000 years to arrive to Andromeda.
So again, even at 99.999% C, 11K years seems like a LONG time to reach even the closest galaxy.
My reasoning was: the speed of light is pretty damn slow.
But then I realized: no, it's not the speed of light that is slow, is my frame of reference.
For us humans, 11,000 years seems like A LONG time, but for the universe is not that long.
The universe's age is estimated to be 13.8 billion years. 11,000 years is 0.0000007971 of the age of the universe.
An average human lives 70 years, 0.0000007971 of that lifespan is approximately ~0.4 hours, or 29 minutes, so it's not that bad.
So yeah, frame of reference matters.