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

rivendell.dmitrybrant.com

91–100 of 216 posts

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

#91

Fun 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.

If we realized tomorrow we had the speed of light slightly wrong, we wouldn't change the length of a meter, we would change the definition of the meter. We've redefined the meter thrice already.

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

#92

I 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.

The third volume of « Three body problem » and its fan-written and author-approved sequel deal with those local physical constants changes !

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

#96

I 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.

"A Fire Upon the Deep" and "a Deepness in the Sky" by Vernor Vinge

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

#97
post #96

I 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.

"A Fire Upon the Deep" and "a Deepness in the Sky" by Vernor Vinge

Deepness in the Sky "programmer-archaeologist" will never come to pass because of LLMs :(

The Forever War series changes the speed of light at the end to mess with the mortals, not to prevent any calamity however.

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

#98
post #63

Feels like W goes back (instead of forwards like in an FPS), and S goes forward. Is that intended or just my keyboard being weird? EDIT: ah, by setting 'Speed of light' parameter to 40km/hr I find it a bit more intuitive

I think it is an illusion because as you approach the speed of light everything in your wide view contracts to the front of where you are going, so it would seem like you are moving back. Stop, and you now appear closer. It's probably why you do not see this effect on sci fi films, instead they show the ship moving forward by streaking the stars showing through the window, which is more intuitive for our brains to understand.

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

#99

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,…

> At 99.999% C, the traveler would take ~11,000 years

if we add more 9s, is it possible to reduce that number to within a human lifespan?

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

#100
post #99

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,…

> At 99.999% C, the traveler would take ~11,000 years if we add more 9s, is it possible to reduce that number to within a human lifespan?

Yes. Time dilation (with respect of the stationary observed) is calculated using the Lorentz factor.

At 99.999% of C, the Lorentz factor is ~223.6.

It grows pretty quickly as you add more 9s to the fraction. Every two additional 9s multiply the Lorentz factor by ~10.

So at 0.99999999999 c, it'd be ~223,607x.

2.5M years / 223,607 is: ~11 years

Of course this is all highly theoretical.

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

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