191–200 of 273 posts
That's why so many people were taking pictures of Mars back in January, when it was actually possible to take see detail. Right now it just looks like a red orb.
If the moon were only 1 pixel - https://news.ycombinator.com/item?id=39686916 - March 2024 (1 comment)
If the Moon Were Only 1 Pixel (2014) - https://news.ycombinator.com/item?id=32936581 - Sept 2022 (108 comments)
If the Moon Were Only 1 Pixel (2014) - https://news.ycombinator.com/item?id=27573172 - June 2021 (69 comments)
If the Moon Were Only 1 Pixel (2014) - https://news.ycombinator.com/item?id=21735528 - Dec 2019 (82 comments)
If the Moon Were Only 1 Pixel – A tediously accurate map of the solar system - https://news.ycombinator.com/item?id=13790954 - March 2017 (81 comments)
If the Moon Were Only 1 Pixel – A tediously accurate map of the solar system - https://news.ycombinator.com/item?id=13217129 - Dec 2016 (11 comments)
If the Moon Was Only 1 Pixel - https://news.ycombinator.com/item?id=12038584 - July 2016 (4 comments)
A Ridiculously large accurate scale model of the Solar System - https://news.ycombinator.com/item?id=10330303 - Oct 2015 (1 comment)
If the moon were only 1 pixel: a scale model of the solar system - https://news.ycombinator.com/item?id=7551423 - April 2014 (17 comments)
If The Moon Was Only 1 Pixel - https://news.ycombinator.com/item?id=7341690 - March 2014 (178 comments)
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https://en.m.wikipedia.org/wiki/Generation_ship
To make a generation ship work you have to build a self-contained ecology that is stable and self-repairing, inside mechanical and software systems that are fault tolerant and either extremely redundant or self-repairing, run by a political and social system that is also fault-tolerant and self-repairing. We know how to do exactly zero of those things.
Of course, even if we stopped doing that, we'd need to figure out how to visit another place if our ship is passing close by. That also seems to pose a problem: both Voyagers are barely out of the exhaust fumes of our ship's motor, and getting so far took ~40 years.
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What are the chances of hitting a small meteorite or part of it, traveling now at relativistic speeds wrt you?
There's about one particle of dust per million cubic metres. c is about 300 million metres/second. So even at 0.5c that's still a lot of particle collisions per second, each having significant kinetic energy. Basically it would be like flying through explosive sandpaper. Each dust particle would be reduced to plasma, which creates problems of its own. If you're accelerating there's also the Unruh Effect, which will r…
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It makes me wonder what kind of "life" could perform interstellar travel? I used to imagine a spaceship being alive, with people inside being analogous to "cells" in a multicellular organism. Perhaps this is really how AI achieves consciousness?
> It makes me wonder what kind of "life" could perform interstellar travel? That’s essentially the premise of Project Hail Mary. Good book.
He basically just has it work because the fuel difficulties are solved and bam, the main character can zip around nearby start systems at close to perfect C on a ship built with little more than our current 21st century technology. Fun, but not even in the most basic way an attempt at presenting any science seriously.
What makes it more amusing is that for many other parts of the main drama, he puts a lot of effort into making the descriptions and scenarios seem as realistic and science-rich as you could like. I suspect a lot of entertaining word salad there too though.
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> "A photon instantly travels to the end of time" Please explain this. TIA
First set gamma as being 1/sqrt(1-v^2/c^2), with "c" being the speed of light. The factor for time dilation and distance contraction in special relativity is gamma and 1/gamma respectively. That means that when you get to speeds equal to c, your time runs infinitely slower and the distances are infinitely shorter. So if your clock is infinitely slower, so every travel at "c" speeds means that no time passes for you.…
Make sure you press the "c" button in the bottom right. Light is incredibly slow, and everything seems out of reach. I think we'll have a holodeck before we reach another star. And maybe that'll be enough.
It only seems incredibly slow in this model because it doesn't take special relativity into account. If it did, then as you approached the speed of light the Lorentz contraction would make wherever you are heading appear less far away. You can in theory get anywhere in the universe in an arbitrarily short amount of proper time your own reference frame. Of course, you might not survive the G-forces, but that's another…
Make sure you press the "c" button in the bottom right. Light is incredibly slow, and everything seems out of reach. I think we'll have a holodeck before we reach another star. And maybe that'll be enough.
Earlier quoted context omitted.
We’re barely even using our first solar system, it’s way too early to be worried about reaching other stars.
Exactly, there is free fuel and aluminium just floating by, and we are unable to use them to upgrade our ships or refuel them. Until we make full use of robotics and 3D printing, there is no point of heading far. And we have all the tools. Distant stars will not be settled by a fast small ship travelling from earth. They will be settled by a city sized monolith produced by harvesting and smelting an entire small moon
I don’t even think you’d need a whole moon unless it was a tiny one. Nonetheless, by the time we send a ship to another star, building these kinds of large self-contained habitats will be old hat.