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

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

#162
post #145

Earlier quoted context omitted.

Sadly there is no realistic approach to get there (even assuming fantasy-levels of technology). Chemical rockets are currently the only thing that allow sustaining such accelerations briefly for human-size payloads, but the low exhaust velocity and exponential reaction mass requirement make sustaining it for days/months/years completely impossible. You'd have to supply the energy externally (i.e. some sort of beam pr…

> You'd have to supply the energy externally (i.e. some sort of beam propulsion), but getting any significant fraction of g out of such a system (with human-sized payloads) seems unlikely within the next centuries, especially as the distance increases. Or some form of ram scope, plenty of H everywhere, but those also have the issue of you collecting things while going at relativistic speeds.

You need ablative ships cruising ahead of you..

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

#163

Earlier quoted context omitted.

Yeah, it is and the math get's really counterintuitive to grasp since humans (at least me) have trouble thinking in exponential terms. If you accelerate at 1g constantly for 1y you travel 0.5 light years. You do that for 10.5 years and you reach the center of the milky way. You do that for another 4 (~14 total) years and you are in the Andromeda galaxy, and you do that for another 10 years (~24 years total) and you r…

> If you accelerate at 1g constantly for 1y you travel 0.5 light years Can't we accelerate past 1G constantly? Or do we expend so much energy doing it that we can't realistically do it with today's technology?

Not with current technology. That was kind of the physics “trick” in the book ‘Project Hail Mary’, where the astrophage provided enough energy and propulsion to be able to sustain 1G of acceleration.

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

#166

Earlier quoted context omitted.

Of course it is logical, we are not discussing the math. But it isn't intuitive, you're not used to numbers that big or that grow that fast. Few things go from a million to a billion, especially when related to time.

Going from a million to a billion isn't some special relationship. It's just * 1000. It's the same as going 1 1000 or 10 1000. I find it frustrating that people seem to think that someone going from 1M to 1B is somehow different to other numerical operations. It's not. It's 1000 times bigger, it's not a huge deal.

And any exponential growth is also a multiplication, it's not a big deal, just giving example on what they asked before.

Somehow people are interpreting this as some kind of math trick.

It's not a trick, our brains are not wire to deal with numbers growing quickly, but we do understand the math.

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

#167

Earlier quoted context omitted.

Yeah, it is and the math get's really counterintuitive to grasp since humans (at least me) have trouble thinking in exponential terms. If you accelerate at 1g constantly for 1y you travel 0.5 light years. You do that for 10.5 years and you reach the center of the milky way. You do that for another 4 (~14 total) years and you are in the Andromeda galaxy, and you do that for another 10 years (~24 years total) and you r…

> math get's really counterintuitive to grasp People always say that about speed of light stuff, but I don’t get it. Do you have any more examples of counterintuitive math? Because what you’re describing is basically the equivalent to compound interest in finance. (e.g. investing $100 at 10% interest over 10 years results in $260)

[dead]

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

#168

Earlier quoted context omitted.

Of course it is logical, we are not discussing the math. But it isn't intuitive, you're not used to numbers that big or that grow that fast. Few things go from a million to a billion, especially when related to time.

Going from a million to a billion isn't some special relationship. It's just * 1000. It's the same as going 1 1000 or 10 1000. I find it frustrating that people seem to think that someone going from 1M to 1B is somehow different to other numerical operations. It's not. It's 1000 times bigger, it's not a huge deal.

Only abstractly. If you are living in the process, it is hard and very few people live that.

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

#169

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,…

On YT there is a video of a flight through the solar system at the speed of light starting at the Sun. It's a pretty boring video. You see very little movement and change over time. After 8 minutes Earth slowly passes by. After 44 minutes you reach Jupiter and the video ends.
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