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.
johnnyjeans · 19m ago
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. It becomes much more apparent how alive plants are when we observe them in a time-lapse. Now realize that plants are still relatively short-lived. The absolute oldest ones only go back to the early neolithic, that's only 14000 years or so. 1000 years is a long time for humans, but probably not for the trees where a single one can live 10x that.
From the hypothetical perspective of a star, with a lifespan measured in billions upon billions of years, the entire ecoscape of the world changes in a blink. From the sun's perspective, MENA was green just a very short while ago. Hell, Pangea wasn't that long ago. At this timescale, continental drift would be as apparent as the movement of boats are to humans. Anything that's working at the cosmic scale where the seemingly low speed of light sounds exhausting is most definitely working at this stellar perspective at the minimum. 14000 years of travel might as well be the equivalent of a 10 minute commute to the store.
Philosophically speaking, of course.
davidee · 6m ago
Thanks for this.
In addition to the insight, it reminded me to water a plant at a desk I no longer use. The plant's been with me through quite a bit and I have been neglecting it recently as I no longer see it regularly.
eddd-ddde · 16m ago
I always think of those motor proteins moving along slowly inside our bodies, and wonder if maybe we are just the motor proteins of the cosmic scale.
M95D · 4m ago
We have a long way to go before we learn to move a star (or a rosette).
> Light is incredibly slow, and everything seems out of reach.
Yes, agreed. I find it a little depressing. An unimaginably huge universe, tantalisingly there, but completely out of reach.
raxxorraxor · 2h ago
Not out of reach if you get very close to light speed. Time would advance very slowly for you, so counterintuitively it is possible to travel 5000ly in your life time.
Although for everyone else at least 5000 years will pass, so better say goodbye to family and friend.
Hm, not sure if that is really less depressing...
Also light isn't slow. A photon instantly travels to the end of time and yet it still takes a few minutes from the surface of the sun to us. Or about 100000 years from the center of the sun to its surface.
danudey · 12m ago
It depends on acceleration though. If acceleration and deceleration take long enough, it could take an entire generation to get up to a fast enough speed that relativistic effects make any difference, and another generation to slow down enough to interact with anything you might see.
Plus if you're traveling at near light speed, running into any matter at all would be pretty devastating for whatever craft you're in.
Edit: someone further down claimed that the math says that accelerating at 1G would get you to 0.1c in a month, so that's actually not that bad all in all. I still maintain that hitting any matter at those speeds might be unpleasant.
causal · 1h ago
Yeah if you have a body that can tolerate sudden jumps between reference frames you could pretty much explore the entire galaxy trivially, so long as you don't mind that few places will stay the same long enough to visit twice.
ryandrake · 52m ago
You wouldn't need a sudden jump. If you had a rocket that accelerated at a pleasant 1G forever, you could reach and stop at the center of the milky way in about 20 (your time) years, and you could reach and stop at the Andromeda galaxy in about 28 years. Play around with some of the online space travel relativity calculators--it's wild!
Of course building and fueling such a rocket is what's totally out of reach.
amne · 2h ago
How would that feel as a traveler? Does all motion slow down to a crawl, all sub-atomic particles just "freeze" and essentially your thoughts and body aging too? So it would seem like you got there in an instant?
For sure you're not just sitting there watching people get born, live and die in second and shrugging your shoulders.
Sharlin · 1h ago
You’d feel nothing out of the ordinary whatsoever. The starscape outside the ship would look strange though, shrinking into a small, blueshifted patch of sky straight ahead, while stars behind you would redshift out of the visible range. Everything moving at very low speeds relative to you would indeed appear to happen really fast.
seanw444 · 46m ago
If the light behind you redshifts out of the visible spectrum, would the light in front of you blueshift into dangerous territory? X-rays, gamma rays, etc?
amelius · 1h ago
What are the chances of hitting a small meteorite or part of it, traveling now at relativistic speeds wrt you?
TheOtherHobbes · 1h ago
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 raise the perceived temperature. By a lot.
There's no way to make this work with any kind of engineering we know about today.
kqr · 1h ago
Extremely low. Space is very empty.
brazzy · 1h ago
But it's also very big, and GP doesn't even specify how far of a trip they're asking about nor how small a meteorite.
"Extremely" and "very" don't cut it here. This is beyond the human ability to guess. You'd actually do at least some back-of-the-napkin math to give a real answer, and with a far enough trip, the answer may well become "Almost 100%".
wat10000 · 24m ago
And at a high enough speed, the impacts from the ~1 hydrogen atom per cm^3 in interstellar space become a major problem.
thombat · 2h ago
But unless you have a way of slowing down again you'll never see anything of your destination, just the briefest of flares of light as you sail past. And if you do have a way that involves anything like physics that we recognise, you've brought along a huge rest mass that then got accelerated to near light speed. Probably your civilization needs to be approaching Kardashev Level 2 to pull this off.
mock-possum · 48m ago
That doesn’t make sense - if you were traveling at the speed of light, it would take you 5000 years to travel 5000ly - longer if you were just ‘very close’ to C. Time wouldn’t advance slowly for you, it wouldn’t advance perceptively different at all - you’d still live every second of those 5000 years.
ghosty141 · 35m ago
I dont think you are right. Light for example doesnt perceive time at all. From the photons point of view it never aged even a microsecond while it traveled lightyears. Time is relative too so from our POV 1 year passed when a photon traveled 1 ly, but for the photon no time passed.
zwily · 21m ago
Read up on time dilation and special relativity. Time absolutely does pass slower for you as you accelerate.
sheepscreek · 3h ago
It’s not the destination, it’s the journey :)
ant6n · 3h ago
10,000 years of empty space to get to the next solar system. Exciting.
sheepscreek · 2h ago
Not with light speed travel. At even 1% the speed of light, the travel time diminishes significantly:
- Titan, Io and Ganymede are only 2.5 days away
- Pluto is about 23 days
Edit: Even at such speeds, we still can’t visit a nearby star system in a reasonable time-frame. Oh well.
Reubachi · 2h ago
As time passes, the universe is expanding infinitely in every direction from every point.
Even if we could travel at 1 percent the speed of light, the "destination" would be inflating away from us at much greater relatavistic speed.
To your point, this is less an issue with solar or extra solar objects.
Sharlin · 1h ago
Traveling at .1c within the solar system wouldn’t really be feasible due to the need to accelerate and decelerate. Not for meatbag ships anyway.
ryandrake · 43m ago
There's nothing about 0.1c or even 0.999c travel that's detrimental to meatbags. They would both feel exactly the same to the traveler. If your (for now) imaginary rocket could accelerate at a constant, gentle 1G, you could reach 0.1c in about a month (traveler's time), and you could reach 0.999c in about 44 months. Building and fueling such a rocket is the hard part.
dylan604 · 2h ago
Plenty of time for reflection on one’s choices in life that put them in that situation.
ant6n · 2h ago
Especially generation 143 of 330, they can definitely spend their whole life on that reflection.
literalAardvark · 4m ago
Speaking of which, Peter Watts' Sunflower Series has a great and short enough hard-ish scifi story about just such a ship.
gwbas1c · 2h ago
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?
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.
danudey · 5m ago
There's a CRPG I've been meaning to play where this is basically the plot; there was a generation ship, it was heading towards some planet or another, but the social and political structure on the ship broke down at some point and now there's no one actually in charge, the ship is getting run down, and they probably blew past their destination a hundred years ago if they were even still on course at all.
I remember someone pointing out that a generation ship could be problematic because you have one generation who decides to launch this expedition but will never see the end, multiple generations who didn't choose this life and won't get to see the benefits, and then one generation who actually gets to the planet but might not even want to be there. Without some kind of cryogenic sleep or relativistic speeds the whole thing might fall apart just because most of the people involved "didn't sign up for this" but they have to toil away anyway for someone else to benefit from it.
once_inc · 3h ago
Assuming our models of the universe are correct, and faster than light travel is impossible. There are very strong reasons to believe this, but perhaps we can cheat by stretching and compressing space around us.
nurettin · 3h ago
Meh, most of it is just more of the same thing. I'd rather play with a paper plane than float in space.
beklein · 4h ago
Maybe light’s insanely fast and space is just huge. It’s all relative ;)
isolli · 3h ago
I would say they're two sides of the same coin. The time it takes for light to travel the universe (which makes communication even with nearby stars essentially impossible) is what makes the universe huge.
neuroelectron · 2h ago
Luckily FTL communication isn't actually impossible and special relativity only applies to energy and mass.
jordigh · 2h ago
I can't tell if you're joking or if you know something nobody else does.
As far as I know, anything going faster than the speed of causality violates causality. So what are you talking about?
neuroelectron · 2h ago
Don't conflate causality and special relativity.
SR breaks down at both ends of the spectrum, at the event horizon of black holes and in Bose Einstein condensates. That proves that it is an emergent property of observations, statistical behavior of decoherent systems, and not a universal law.
ClumsyPilot · 2h ago
> violates causality
But we don’t know that casualty is a law of physics, do we?
krapp · 2h ago
FTL communication is actually impossible, what are you talking about?
uncircle · 3h ago
True but doesn’t matter how slow light is. The closest to c your speed is, the shortest the time you experience on board of the space ship. At light speed, space and time cease to exist. You reach destination instantly.
So the goal is to create engines that can take us close to light speed. Then the issue is braking (spacetime expands as you slow down…)
baxtr · 3h ago
Me scrolling is faster than the speed of light!
Nice.
schaefer · 2h ago
Dude, chill.
We’ve got to preserve causality. :P
clocker · 3h ago
> Lightly is incredibly slow
Its relative! Sitting on a couch and watching the pixel move from the sun to the earth for 8 minutes feels incredibly slow but if you are actually traveling in a light speed aircraft then it won’t feel that slow.
orobus · 2h ago
If you were actually traveling at the speed of light it wouldn't feel like anything at all! Photons don't 'experience' time—any length trip would be instantaneous from the traveler's point of view.
quchen · 3h ago
Quite the opposite, much like when skydiving, going really fast without any close reference point makes everything stand still. And in space, there wouldn’t even be (very loud) atmospheric drag to physically remind you about what speed you’re actually going.
jjbinx007 · 2h ago
I believe the OP was referring to relativity - the closer to the speed of light you get the slower time appears to tick. So if you could travel at light speed you'd arrive at your destination immediately from your reference frame, but much slower from another person's.
dylan604 · 2h ago
Then what’s up with all of those sci-fi chows where using FTL still takes some amount of time to arrive?
krapp · 2h ago
1) it's better for the plot and drama to have travel time. FTL in fiction is always analagous to some known terrestrial form of travel (usually ships and boats) and the limitations and parameters of FTL in a fictional universe shape the narrative in necessary ways.
2) it's assumed within the framework of the fictional universe that time dilation isn't taking place because the actual travel is occurring within an external frame of reference like "hyperspace" or a "warp field."
thrance · 3h ago
If you travel at relativistic speeds, your trip will appear far shorter to you than to those that stayed on Earth.
With a ship able to accelerate at 1G continuously, you can be at the edge of the observable universe in <50 subjective years [1].
Naive question: is accelerating at 1G continuously within the range of what we consider possible?
Reubachi · 2h ago
Amazingly, yes, in a few ways (the mechanics are possible). But no in as many ways. (Fuel, sustainability, tracking)
The greater barrier is that the nature of the expansion of the universe prevents any real interstellar travel that has a "destination" in mind. Of course we might have some "FTL" or "near light speed" travel in futre, but if the universe is expanding infintely from every point in space at light speed, how could we ever "catch up" to objects we see even now?
brazzy · 54m ago
This is not true. Expansion does not affect gravitationally bound structures. Our galaxy, and even the other galaxies in our local cluster, will stay in reach.
Not naive at all. With chemical rockets we can only sustain 1G for a few minutes, so it won't do at all for interstellar flights.
There is a known way to achieve 100% fuel efficiency: antimatter. By storing equal parts matter and antimatter, you can fuse them to propel your spacecraft. It's unknown wether or not this kind of engine can actually be made.
Alternatively, and even more far-fetched, you could onboard a small singularity. Dumping anything into it will result in it being turned to pure energy at 100% efficiency, through Hawking's radiations. The smallest the singularity, the fastest it radiates, meaning you can sort of control the output. You can create singularities with very large particle colliders.
With 100% fuel efficiency you can probably sustain 1G for long enough to reach the nearest stars. You would need a very large spacecraft (on the order of kilometers) for a comparatively very small payload. And it would arrive completely empty at its destination, meaning no turning back. I think I saw someone do the math, but can't find it anymore.
Anyway, there are other difficulties. Travelling at .99c means tiny space dust now becomes very dangerous. So does radiations, all made extremely energetic by the Doppler effect.
On the plus side, continous 1G means you have artifical gravity for the whole trip.
barrenko · 4h ago
I really thought hitting "light speed" would just zoom it all in a minute, but nope... So much for my physics preconceptions.
pdpi · 3h ago
> would just zoom it all in a minute,
The Earth is about 8 light-minutes away from the Sun :)
barrenko · 3h ago
I am not liking this fact.
justusthane · 40m ago
The sun could have exploded seven and a half minutes ago and we’d have no idea! Enjoy the next 30 seconds of your life.
scraft · 3h ago
Well, if you were traveling at light speed you could move anywhere in the universe instantly. If you are an observer on earth, watching an object move away from you at the speed of light, then it will take a very long time to traverse the tiniest regions of the universe.
Reubachi · 2h ago
Er, "instant" here is "relativistic instant."
even in a vaccum, light speed travel from the travelers POV still takes time, and said traveler would perceive time passing exactly as occurring in that local space.
But yes you're totally correct, the observer on earth would in this time see only the briefest part of my journey's trail due to light from my journey taking "exponentially" longer to travel back to the observer.
ck2 · 57m ago
Alternate view:
be thankful things are far apart
a gamma-ray burst from a collapsing star closer than 200 light years away would destroy ALL life on earth
philwelch · 2h ago
We’re barely even using our first solar system, it’s way too early to be worried about reaching other stars.
ClumsyPilot · 2h ago
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
ClumsyPilot · 2h ago
All of fiction and discourse fails to consider that the Solar System is actually a huge place and just the period of settling and industrialising it will take hundreds of years.
Everyone things that a game breaker technology is better engines, or fusion, or FTL, but they are wrong, the game breaker technology has already happened: 3D printing.
If we can manufacture things with minimal infrastructure using local resources, we can that is all we need.
And all of it reachable with simple nuclear power and technology we have today.
amiga386 · 2h ago
I love how simple the HTML/CSS is. Absolute positioning with really large left: values.
Caused Brave in iOS to crash. I have a newer iPad mini with 12GB ram too. But luckily It didn't crash until I tried to close the tab.
pc86 · 2h ago
This seems like a browser issue more than anything else. Yes it's "weird" to have millions of pixels horizontally on a page that is only a few thousand pixels tall, but it seems like an absolutely reasonable edge case that the browser should support.
Sharlin · 2h ago
“Why not save space by storing dimensions as uint16 internally?”
technothrasher · 3h ago
I remember back in elementary school, way before we had such things on computer, we had a vinyl roll for the age of the planet. You'd roll it out in the hallway, starting with present day and watch as the different time periods came into view. You were just a few feet at the origin of man, at the end of the hallway by the time you got to the beginning of Cambrian era, and out the door and across the huge athletic field before you got to the formation of the planet.
andersco · 7h ago
Still an extraordinary experience after all these years and possibly the best use of horizontal scrolling I’ve seen. Lots of previous discussions and posts on HN:
https://hn.algolia.com/?q=if+moon+only+1+pixel
IggleSniggle · 4h ago
It's very very good! I thought this one hit hard though, I assume inspired by the moon = 1-pixel viz.
that's a great share, I feel like it would also benefit from setting the "speed of light", as something like median average yearly income.
susam · 3h ago
When I was dabbling with POV-Ray many moons ago, I drew the planets of our solar system to scale with it. You can see it here: https://github.com/susam/pov25#planets
A friend once asked if I couldn't show the planets in orbit rather than lying flat on a plane. I could, of course, but this is ray tracing. What do planets actually look like to human eyes from Earth? Just tiny dots.
If I were to show them in their proper orbits at scale using perspective projection, I'd only be able to render one planet large enough to be visually interesting. The rest would appear as small dots. I didn't want to use an orthographic projection, as it wouldn't reflect how we actually see the universe.
Those were, of course, limitations of a still image. An interactive page like the one in the original post does a fantastic job of conveying the vast scale of our solar system, both in terms of the sizes of the planets and the immense distances between them.
dahart · 1h ago
Would you have to use double precision to ray trace the planets in their proper orbits at scale using either perspective or orthographic projection? With the ratio of Neptune’s distance from the sun to its radius being almost 2M, I’m guessing fp32 rounding would turn Neptune into a couple of squares if the sun was at the origin. What other challenges would there be? Maybe I’ll try it today just for fun.
j_m_b · 1h ago
One of my favorite visualizations of the scale of the solar system is from Stephen Hawking's Genius.
It's a hands-on, practical example of how far things are away that we can easily visualize. I highly recommend the rest of the series as well. It's one of the best science shows ever produced. It shows the practical path of scientific discovery. You can watch is on the PBS app, which requires a $60 a year pass. Highly worth it. (I have no affiliation with PBS)
tomxor · 2h ago
Shameless plug: Accurate solar system in 192 Bytes:
The red bit is the sun. 1000 kilometers per pixel, and 1000 seconds per second.
They all fit onto the screen by looking through the orbital plane, as if through a telescope from a distant world, i.e effectively an orthographic projection. The orbits are accurate in terms of mean orbital distance (in reality there is slight perturbance) and sidereal periods.
darajava · 2h ago
Incredible - how does this work?
tomxor · 2h ago
You mean technically? I should have posted the beta dwitter link which has the "compress" toggle, because most dweets are unicode packed. https://beta.dwitter.net/d/26521
This one is actually relatively simple to explain, it loops over the 10 planets (i), and draws a circle for each, with the position and size all being defined in the x.arc method. Planets are differentiated by the arrays of values selected by [i]. The X position is calculated as the orbital distance multiplied by the sine of time / orbital period... d x sin(t/p). But d and p are substituted for the value for each planet using the arrays [1,2,3][i].
Surprisingly the precision used in those encoded values is enough at 1000km per pixel (I checked).
botverse · 38m ago
I’ve been thinking about how to teach the size and proportions of the solar system to my kids, I’ve bought a couple of packs of blank RFID cards on which I intend to paint the planets over a starred background. And then walk with my kids the meters necessary to cover the distances before displaying them. What I don’t know is if there is a clever way to use the RFID tech, this website kinda offers an idea.
ge96 · 36m ago
space engine is neat
robin_reala · 4h ago
The light speed toggle really hammers home the emptiness. Like, I know that the Earth is ~8 light minutes out, but sitting and waiting 8 minutes for a few pixels to appear when scrolling away from the sun…
jstummbillig · 3h ago
and even this is not making it super tangible, because the speed of light to monkey brains is basically infinite.
Symmetry · 1h ago
One thing to notice is how small Mercury is, only 1 pixel like the moons that show up. Here's a good photo size comparison. Mercury is smaller that two of the solar system's moon!
EDIT: And Pluto is smaller than all the moons almost anyone has heard of.
CapsAdmin · 4h ago
I've seen countless analogies that explain the size of space, but this was really something else. Especially how frustratingly slow the speed of light felt.
I've seen several, Planet Trek in Wisconsin is a good bikeable one with high quality signage. The sun is downtown, the moon is the size of a peach pit, Pluto is ~20 miles away.
gary17the · 2h ago
How does all that space out there make you feel about the 30 years of paying off your mortgage for all that 0.25 acres of land you own? ;) J/K
ge96 · 36m ago
I like the other one where you can zoom in/out to planck level or to the unobserved universe
kennu · 4h ago
Scrolling with mouse scroll wheel a few hundred thousand kilometers at a time is so much work that I gave up :-(
blueflow · 4h ago
Repetitive strain injury any% speedrun
werdnapk · 3h ago
Click on the planet symbols at the top to fast track.
tacker2000 · 4h ago
Its quite cool on the phone
jadbox · 1h ago
Unrelated, but the Elon dream of getting a human colony on Mars seems beyond imagination. Ignoring safety of such a long travel, the radiation issue of Mar's surface, and the massive infrastructure to have a self-sustainable biosphere (also somehow protected from radiation) to recycle enough oxygen, we still have to deal with the immense number of failures that could happen with no way to send help.
Like, building a fully self-sustainable underwater city or moon base would be far more in reach. It feels that SpaceX should start with prototyping these safer alternatively before overreaching to something 100x more challenging and dangerous.
brazzy · 49m ago
It's very clearly not "beyond imagination". It doesn't require any fundamentally new technology.
It may well be beyond our ability to practically apply those technologies at the required scales and reliability levels, but that's hardly unimaginable.
drewchew · 51m ago
I've probably thought about this website daily or weekly since it originally came out. Glad to know it still exists.
NKosmatos · 2h ago
We’re never going to leave this planet/solar system if we don’t discover FTL (Faster Than Light) travel. Pretty scary if you think about how ridiculously empty is space.
Andrex · 2h ago
We can leave it pretty easily. :p Only took Voyager 1 about 40 years.
If ~1.0C is the fastest man can travel, that's still pretty good. Alpha Centauri is in reach (less than five light-years).
stevage · 3h ago
I just love that this is still online after all these years.
bradley13 · 3h ago
I've seen models like this before. We live in a universe with many, many orders of magnitude. In both directions. Living creatures to small to see, space too big to comprehend.
Mining asteroids for space resources sounds great, right up until you consider the distances involved. Living on Mars - yes, we really should - but you sure aren't going to support a colony long-term from anywhere but local resources.
whoisthemachine · 2h ago
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.
1over137 · 3h ago
How does this website work? I feel like I'm stuck on the first screen maybe? It says 'scroll to explore' but there are no scrollbars. Does it only work with a mouse with a scroll wheel?
This is truly marvelous! Not only is the horizontal scroll really extra awesome for making me feel the distances...but as others stated, the moment you toggle on the light speed....wow, it really is quite profound! Amazingly done!
mg · 3h ago
The way I often visualize the solar system is:
If the sun would be the size of a coin, then earth would be around 2m away from it and so small you could barely see it.
eric-p7 · 2h ago
You may think this page is big. But that's just peanuts to space.
zengineer · 2h ago
Love it! Are there stats on how many people scrolled to the end? :)
raindev · 2h ago
The planets are just grains of sand in a vast empty space.
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.
From the hypothetical perspective of a star, with a lifespan measured in billions upon billions of years, the entire ecoscape of the world changes in a blink. From the sun's perspective, MENA was green just a very short while ago. Hell, Pangea wasn't that long ago. At this timescale, continental drift would be as apparent as the movement of boats are to humans. Anything that's working at the cosmic scale where the seemingly low speed of light sounds exhausting is most definitely working at this stellar perspective at the minimum. 14000 years of travel might as well be the equivalent of a 10 minute commute to the store.
Philosophically speaking, of course.
In addition to the insight, it reminded me to water a plant at a desk I no longer use. The plant's been with me through quite a bit and I have been neglecting it recently as I no longer see it regularly.
https://en.wikipedia.org/wiki/Stellar_engine
https://en.wikipedia.org/wiki/Klemperer_rosette
Yes, agreed. I find it a little depressing. An unimaginably huge universe, tantalisingly there, but completely out of reach.
Although for everyone else at least 5000 years will pass, so better say goodbye to family and friend.
Hm, not sure if that is really less depressing...
Also light isn't slow. A photon instantly travels to the end of time and yet it still takes a few minutes from the surface of the sun to us. Or about 100000 years from the center of the sun to its surface.
Plus if you're traveling at near light speed, running into any matter at all would be pretty devastating for whatever craft you're in.
Edit: someone further down claimed that the math says that accelerating at 1G would get you to 0.1c in a month, so that's actually not that bad all in all. I still maintain that hitting any matter at those speeds might be unpleasant.
Of course building and fueling such a rocket is what's totally out of reach.
For sure you're not just sitting there watching people get born, live and die in second and shrugging your shoulders.
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 raise the perceived temperature. By a lot.
There's no way to make this work with any kind of engineering we know about today.
"Extremely" and "very" don't cut it here. This is beyond the human ability to guess. You'd actually do at least some back-of-the-napkin math to give a real answer, and with a far enough trip, the answer may well become "Almost 100%".
- Titan, Io and Ganymede are only 2.5 days away - Pluto is about 23 days
Edit: Even at such speeds, we still can’t visit a nearby star system in a reasonable time-frame. Oh well.
Even if we could travel at 1 percent the speed of light, the "destination" would be inflating away from us at much greater relatavistic speed.
To your point, this is less an issue with solar or extra solar objects.
Perhaps this is really how AI achieves consciousness?
We know how to do exactly zero of those things.
I remember someone pointing out that a generation ship could be problematic because you have one generation who decides to launch this expedition but will never see the end, multiple generations who didn't choose this life and won't get to see the benefits, and then one generation who actually gets to the planet but might not even want to be there. Without some kind of cryogenic sleep or relativistic speeds the whole thing might fall apart just because most of the people involved "didn't sign up for this" but they have to toil away anyway for someone else to benefit from it.
As far as I know, anything going faster than the speed of causality violates causality. So what are you talking about?
SR breaks down at both ends of the spectrum, at the event horizon of black holes and in Bose Einstein condensates. That proves that it is an emergent property of observations, statistical behavior of decoherent systems, and not a universal law.
But we don’t know that casualty is a law of physics, do we?
So the goal is to create engines that can take us close to light speed. Then the issue is braking (spacetime expands as you slow down…)
Nice.
We’ve got to preserve causality. :P
Its relative! Sitting on a couch and watching the pixel move from the sun to the earth for 8 minutes feels incredibly slow but if you are actually traveling in a light speed aircraft then it won’t feel that slow.
2) it's assumed within the framework of the fictional universe that time dilation isn't taking place because the actual travel is occurring within an external frame of reference like "hyperspace" or a "warp field."
With a ship able to accelerate at 1G continuously, you can be at the edge of the observable universe in <50 subjective years [1].
[1] https://www.reddit.com/r/dataisbeautiful/comments/s4tbry/oc_...
The greater barrier is that the nature of the expansion of the universe prevents any real interstellar travel that has a "destination" in mind. Of course we might have some "FTL" or "near light speed" travel in futre, but if the universe is expanding infintely from every point in space at light speed, how could we ever "catch up" to objects we see even now?
Source: https://www.reddit.com/r/askscience/comments/sr7fuo/is_there...
There is a known way to achieve 100% fuel efficiency: antimatter. By storing equal parts matter and antimatter, you can fuse them to propel your spacecraft. It's unknown wether or not this kind of engine can actually be made.
Alternatively, and even more far-fetched, you could onboard a small singularity. Dumping anything into it will result in it being turned to pure energy at 100% efficiency, through Hawking's radiations. The smallest the singularity, the fastest it radiates, meaning you can sort of control the output. You can create singularities with very large particle colliders.
With 100% fuel efficiency you can probably sustain 1G for long enough to reach the nearest stars. You would need a very large spacecraft (on the order of kilometers) for a comparatively very small payload. And it would arrive completely empty at its destination, meaning no turning back. I think I saw someone do the math, but can't find it anymore.
Anyway, there are other difficulties. Travelling at .99c means tiny space dust now becomes very dangerous. So does radiations, all made extremely energetic by the Doppler effect.
On the plus side, continous 1G means you have artifical gravity for the whole trip.
The Earth is about 8 light-minutes away from the Sun :)
even in a vaccum, light speed travel from the travelers POV still takes time, and said traveler would perceive time passing exactly as occurring in that local space. But yes you're totally correct, the observer on earth would in this time see only the briefest part of my journey's trail due to light from my journey taking "exponentially" longer to travel back to the observer.
be thankful things are far apart
a gamma-ray burst from a collapsing star closer than 200 light years away would destroy ALL life on earth
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
Everyone things that a game breaker technology is better engines, or fusion, or FTL, but they are wrong, the game breaker technology has already happened: 3D printing.
If we can manufacture things with minimal infrastructure using local resources, we can that is all we need.
And all of it reachable with simple nuclear power and technology we have today.
https://hmijail.github.io/1-pixel-wealth/
E.g. it gives Jeff Bezos's net worth as $139 billion, but today it's $228 billion.
A friend once asked if I couldn't show the planets in orbit rather than lying flat on a plane. I could, of course, but this is ray tracing. What do planets actually look like to human eyes from Earth? Just tiny dots.
If I were to show them in their proper orbits at scale using perspective projection, I'd only be able to render one planet large enough to be visually interesting. The rest would appear as small dots. I didn't want to use an orthographic projection, as it wouldn't reflect how we actually see the universe.
Those were, of course, limitations of a still image. An interactive page like the one in the original post does a fantastic job of conveying the vast scale of our solar system, both in terms of the sizes of the planets and the immense distances between them.
https://mass.pbslearningmedia.org/resource/hawking_genius_ep...
It's a hands-on, practical example of how far things are away that we can easily visualize. I highly recommend the rest of the series as well. It's one of the best science shows ever produced. It shows the practical path of scientific discovery. You can watch is on the PBS app, which requires a $60 a year pass. Highly worth it. (I have no affiliation with PBS)
https://www.dwitter.net/d/26521
The red bit is the sun. 1000 kilometers per pixel, and 1000 seconds per second.
They all fit onto the screen by looking through the orbital plane, as if through a telescope from a distant world, i.e effectively an orthographic projection. The orbits are accurate in terms of mean orbital distance (in reality there is slight perturbance) and sidereal periods.
Here's the js anyway:
This one is actually relatively simple to explain, it loops over the 10 planets (i), and draws a circle for each, with the position and size all being defined in the x.arc method. Planets are differentiated by the arrays of values selected by [i]. The X position is calculated as the orbital distance multiplied by the sine of time / orbital period... d x sin(t/p). But d and p are substituted for the value for each planet using the arrays [1,2,3][i].Surprisingly the precision used in those encoded values is enough at 1000km per pixel (I checked).
https://en.wikipedia.org/wiki/Planetary-mass_object#/media/F...
EDIT: And Pluto is smaller than all the moons almost anyone has heard of.
I've seen several, Planet Trek in Wisconsin is a good bikeable one with high quality signage. The sun is downtown, the moon is the size of a peach pit, Pluto is ~20 miles away.
Like, building a fully self-sustainable underwater city or moon base would be far more in reach. It feels that SpaceX should start with prototyping these safer alternatively before overreaching to something 100x more challenging and dangerous.
It may well be beyond our ability to practically apply those technologies at the required scales and reliability levels, but that's hardly unimaginable.
If ~1.0C is the fastest man can travel, that's still pretty good. Alpha Centauri is in reach (less than five light-years).
Mining asteroids for space resources sounds great, right up until you consider the distances involved. Living on Mars - yes, we really should - but you sure aren't going to support a colony long-term from anywhere but local resources.
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
If the sun would be the size of a coin, then earth would be around 2m away from it and so small you could barely see it.