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

rivendell.dmitrybrant.com

241–250 of 269 posts

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

#241
post #202

Earlier quoted context omitted.

You can adjust the speed of light and hold the fine structure constant (and all other dimensionless parameters) fixed by adjusting some of the other dimensionful parameters.

Found Q's alt account.

Simple. Change the gravitational constant of the universe.

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

#242

At first sight, this is remarkably more accurate that the "slower speed of light" game from MIT that was made available all those years ago (~2012). Many issues with the MIT game were discussed here: https://physics.stackexchange.com/questions/43695/how-realis... While the thread lists multiple issues, the issue that I found was with modeling temporal aspects of relativistic doppler (I also reported it on the github…

Thanks! Yes, I'm trying to pay extra close attention to modelling every perceivable effect as closely as possible. The remarkable thing is that none of the mathematics is particularly complicated, so if you get the math right, then all of the predicted effects emerge automatically.

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

#243
post #209

Earlier quoted context omitted.

Can you explain for dummies how... a normal person with a normal web browser should access this?

Enable ipv6

Not an option for me. I have a residential ISP that gives me symmetrical gigabit fiber, but has no support for IPv6.

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

#244

I assume someone has considered whether the apparent expansion of the universe is spaghettification as we enter an event horizon?

Spaghettification is directional / linear, and is in the form of a tidal acceleration. Expansion of the universe is uniform in all directions. Urban legends about cosmic sized black holes are in conflict with what cosmologists can actually see.

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

#245
post #140

Some 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,…

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.

That's the premise of Tau Zero, a very good novel:

https://en.wikipedia.org/wiki/Tau_Zero

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

#246

Some 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,…

There’s sci fi novels that deal with it in just these terms. Like some folks with head out on a .99c acceleration ship and be like “okay we’ll be there in fifteen thousand years (original reference frame time)” and that’s just the scale at which the story unfolds. You just accept that when you leave on these trips that if you ever come back now it’s tens of thousands of years in the future there. Nbd

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

#247
post #140

Some 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,…

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.

I’m confused. Is it 11k years to the closest galaxy at the speed of light, or somehow accessible in a human lifetime?

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

#248
post #82

The 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.

If you're allowed to change the speed of light, you can also change the gravitational constant G to compensate since the Schwarzschild radius is r = 2GM/c^2, where M is the mass of the object.

Sure, you could change all sorts of things. Doing it likely means changing so much that things end up looking just like they do now, just scaled somehow.

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

#249

Earlier quoted context omitted.

Links seem to be broken?

No, but IPv6 only these days. I never set up dynamic DNS.

ftfy

pic: http://numpad0.com/imgs/home.davidgoffredo.com/proper-time-o...

plot: http://numpad0.com/imgs/home.davidgoffredo.com/proper-time-o...

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

#250
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.

I’m confused. Is it 11k years to the closest galaxy at the speed of light, or somehow accessible in a human lifetime?

Relativity is weird. If you keep accelerating, at some point the objects stop accelerating toward you faster but the distances get shorter.

To an outside observer, the trip might have taken you millions or billions of years while to you it was only ten or twenty.

It’s helpful to think about the limit. To light, which travels at the speed of light, it arrives at your retina the exact moment it was created in the core of the sun. From our perspective, it took almost a million years (about a million years to make it from the core to the convective region, then another few minutes to travel from there to Earth).

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