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

rivendell.dmitrybrant.com

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

#283

Earlier quoted context omitted.

> “At 99.999% C, the traveler would take ~11,000 years to arrive to Andromeda.” So presumably this means 11k years from an earth point of view? But the traveler would still be alive and a very short time would have passed for him?

Nope! Far, far longer. I don’t know the specifics that the GP used but Andromeda is about 2,500,000ly away. An observer on Earth must perceive you as taking more than 2,500,000 years to get there, as you would have to have exceeded the speed of light to arrive any sooner. At 1g of constant acceleration you can reach Andromeda in just under 15 years of experienced time. An observer on Earth will perceive you as having…

So the question becomes where does the 11k come in? It was just wrong?

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

#284
post #267

Earlier quoted context omitted.

Because the doppler effect shifts all light coming from that direction to infrared, which your eyes can't see.

Would the photochemistry of my eyes stay the same? :-)

Yes, in your reference frame. That's one of the basic tenants of relativity.
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