Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

If the moon were only 1 pixel: A tediously accurate solar system model (2014)

joshworth.com

Post reply on HN
Print view View original

251–260 of 273 posts

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#251

Post by munchler »

lisper wrote: post #215
dyauspitr wrote: post #197

Earlier quoted context omitted.

You can accelerate continuously at a comfortable 1g and get to 0.5c in about 5 months. G forces are not the issue.

The Lorentz factor at 0.5 c is 0.86 so this only reduces your proper travel time by about 15%. Even at 0.9c the LF is only 0.43, so it would still take you 2 years just to get to Proxima Centauri. And as you approach c, 1G acceleration speeds you less and less. And you also have to slow down at your destination.

Not to mention that you also have to survive any collisions with specks of dust in between.

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#252

Post by PartiallyTyped »

ant6n wrote: post #37
sheepscreek wrote: post #35

Earlier quoted context omitted.

It’s not the destination, it’s the journey :)

10,000 years of empty space to get to the next solar system. Exciting.

We can instead happily drive our solar system in a different direction by nudging the sun.

At this point in humanity's history, I think that's more feasible than high speed traveling.

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#254

Post by api »

johnnyjeans wrote: post #117
amelius wrote: post #3

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.

Is light slow? Or is the human perception of time just scaled down as a result of our rapid metabolism and infinitesimality? People historically mistake plants for being inanimate things with no reactivity, that they are far more simple and stupid than they truly are. Outside of a few exotic examples, plants simply operate on a wider timescale that's basically imperceptible without careful and particular observation.…

That’s one of the answers to how you could go to the stars: go sloooooow as in slow down your cognition and metabolism so the trip doesn’t take long.

Ents could fly to the stars no problem.

Makes me wonder if there might not be a bunch of star faring “slow life” out there that we don’t notice for the same reason a hummingbird doesn’t notice trees growing.

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#255

Post by lukas099 »

lenkite wrote: post #225
ifa_ wrote: post #211

Earlier quoted context omitted.

yeah light _is_ actually pretty slow and we hit that in networking and optics pretty often if iirc. like not even on a human level, universally even on a grand scale the speed of light is almost torturously slow, there’s nothing philosophical about it

Might have been a deliberate rule enforced on the universe to avoid interstellar wars between sapient civilizations.

But that’s making your simulation deliberately less interesting, no?

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#256

Post by somenameforme »

amelius wrote: post #3

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.

Depends on who you mean by we. The universe is weird and it's entirely possible for you or I to travel essentially arbitrarily far in a single human lifetime, easily billions of light years. Relativity doesn't simply work as a speed limit; instead when things approach velocities anywhere near the speed of light, the universe starts contorting itself in really weird ways to maintain the perceived consistency of the speed of light.

From the perspective of somebody in a ship moving at relativistic rates, distances would begin to physically contract, and time itself would begin to speed up relative to an at rest observer. Here [1] is a calculator to see what this all mathematically works out to. For instance, you could travel to Andromeda, some 2 million light years away, in about 28 years in a ship that was capable of sustaining acceleration at 1g for 28 years. Of course for everybody back home 2 million years would pass. So if we ever achieve ships capable of this sort of acceleration, life is going to get really weird and non-linear, so far as time is concerned.

And this isn't some just some weird fringe theoretical/mathematical thing. For instance GPS satellites have to compensate for time dilation because relativistic effects, though small in this case, would otherwise have a substantial effect. Another example is at things like the large hadron collider. As a convenient effect of relativistic effects, emergent unstable particles exist far longer than they 'normally' would before decaying due to the fact they're moving at relativistic rates.

In other words, this is all very real. The only questionable issue is whether we can discover some sort of an energy source capable of accelerating a ship at 1g for tens of years, and develop sufficient shielding for such a vessel. That's still very much in the domain of sci-fi, but simultaneously seems like something that one wouldn't be entirely surprised to see was discovered just a century from now. This was the most tantalizing possibility behind the EMDrive stuff. [2] Well that or infinite energy, but it seems that universe won't be broken quite so easily just yet.

[1] - http://www.convertalot.com/relativistic_star_ship_calculator...

[2] - https://en.wikipedia.org/wiki/EmDrive

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#257

Post by chmod775 »

lukas099 wrote: post #255
lenkite wrote: post #225

Earlier quoted context omitted.

Might have been a deliberate rule enforced on the universe to avoid interstellar wars between sapient civilizations.

But that’s making your simulation deliberately less interesting, no?

Chances are that only a species who, through one way or another, has become very uninterested in warfare could have advanced to the point where they would be able to run such a simulation, otherwise they'd have ended their own existence with their shiny toys before long.

War only occurs if you have in the literal sense retarded elements in your advanced species and is nonsensical from an outside POV. A species this advanced would have fixed such shortcomings in itself long ago.

So no, I don't think they'd necessarily be very interested in watching primitive species go to war with primitive weapons.

For all we know the simulation of this universe is happening in their equivalent of an overengineered snow globe, us being an artifact nobody has noticed and that nobody would find particularly interesting if they did notice.

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#258

Post by svachalek »

dbetteridge wrote: post #224
tridentboy wrote: post #178

Earlier quoted context omitted.

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.…

Follow up question from someone who's mostly forgotten his university physics. Do photons actually exist, in the traditional sense of physical matter. Or are they just a convenient short hand to describe the transfer of energy via waves in the fabric or space time, if they dont experience the universe when passing through it but only when interacting with matter and matters "dents" in space-time.

As a non-physicist, my understanding is that they actually exist, but can't be thought of as flying around like ping pong balls. I think it's one of those things that comes down to interpretation though, where the math is very clear but how you think of what it "means" lies beyond science.

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#259

Post by mdaniel »

kennu wrote: post #10

Scrolling with mouse scroll wheel a few hundred thousand kilometers at a time is so much work that I gave up :-(

I'm thankful that the view-source:https://joshworth.com/dev/pixelspace/pixelspace_solarsystem.... allows one to see the annotations since clicking on the planet jumps scrolls past them. My gratitude for not baking such things into 8MB of JS

Also thanks to the view-source I learned that it offers different units, including busses, Great Wall of China, etc

Re: If the moon were only 1 pixel: A tediously accurate solar system model (2014)

#260

Post by mdaniel »

whoisthemachine wrote: post #63

I love it, I always love these things. Still, given this is a technical site, one small nitpick is that it would be nice on hover to see how many pixels the current object is.

No need to hover, the drop-down next to the measurement at the bottom has Pixels. Clicking on the Pluto quick-nav shows that it is 1,700,530px
Post reply on HN