Close enough that we could probably develop a probe to get there in the next few centuries and check it out. What are the current popular candidates for propulsion systems capable of accelerating to near the speed of light?
laser propelled solar sails are the only plausible solution at the moment and it is not a given that even that is possible. Lots of engineering challenges there that may not have solutions.
other ideas:
1. be way more patient
2. anti matter based propulsion (more out there than solar sails)
3. nuclear bomb based propulsion
One issue is as you get to these speed little bits of dust will anhillate the probe, so you need some kind of shielding, raising the mass budget, making it all the harder. A solar sail has to be able to survive holes getting poked it in it and still working, etc.
I wouldn't bet on and as I understand theory allows a shorter routes. Major caveat is weve never observed them and their existence doesn't guarantee they're traversible.
What's exciting to me is that the existence of such a planet provides fuel for more research into the field.
Interstellar travel is probably not ever going to happen. Even if we have antimatter propulsion (which is still probably not practical even under ideal circumstances), we’re still talking hundreds of years of travel time to get to somewhere like this star.
This also goes for aliens visiting Earth. Interstellar travel is just so impractical that I don’t think anyone has come on safari to Earth.
A generation ship is probably doable with some level of conceivable technology. We just have to figure out how to be self sufficient out there then we have all the time in the world, or universe. That's a big "just", I know.
The political challenge of funding a laser program just for research for centuries seems just as daunting - lacking the capability for some self repairing, self healing devices, the automated or (lobster-ai) probe going to stars is just as far away as when Charles Stross first wrote about it in Accelerando some twenty years ago. Given the collapse of political norms, looking back, the decades long research projects of the US space program appear to be soon relics of the past.
One of the Voyager probes measured the density of the interstellar vacuum at 80,000 protons (and the same number of electrons) per cubic meter. A proton going through a piece of aluminum foil delivers a roughly constant amount of energy regardless of speed; a relativistic proton will pinch through and carry most of its energy with it.
(No punchline; I just think that's cool. I understand that the real problem is the rare dust grain, not the ubiquitous gas.)
Back yard meaning we can see it but never touch it. If the ship to get there was ready today, it would get there in the year one-million? Back yard is Mars, Venus, moon. And I'm being generous with Mars and Venus.
Yeah, if your username is any indication of your age, you've possibly taken much the same trajectory of pessimism that I have. As a youth, I assumed we'd be hitting multiple Cs or bending space time when I was an adult; As an adult I thought we might get a percentage of C and conquer the solar system; Now I realise Just How Much Effort it would be to accomplish much of any value on our own Moon, never mind Mars.
I still hold on to the idea that very long term we might make strides in our own solar system, but it is a depressingly-longer timescale than I always used to believe.
Unless we have some magic-level shift in our understanding of physics, we're never getting anything beyond Von Neumann probes to other stars, and even then we're talking thousands of years.
why, so they can watch corporate news from earth to get depressed? /s
Actually, it's a great question. Even if we have single photon sensitivity detectors, just what kind of power would a laser need? Or would it be some other area of the emf spectrum? Or some other kind of communication? Sci fi ventures into gravitational waves sometimes
Small fusion reactors don't really solve any of the key challenges. You need reaction mass to accelerate, you run out of reaction mass way too quickly even with a magical energy source on board to throw it out the back of the ship really fast.
Probably more likely that we work out how to fold spacetime than we get there in anything like a high enough percentage of the speed of light - the fastest object we ever made travelled at something like ~0.064% * C so we are looking at ~750 years with current technology and presumably we'd need to switch on the probe in 3/4 of a millennium and figure out how to slow it down and get it into some sort of orbit around the planet.
750 years is hard for me to get excited about even as a vampire.
Yep. We haven't really figured out how to do a good government that lasts more than 200 years. Maybe unless you think monarchy is good, in which case I still don't want to share a spaceship with you.
How much of that time did it spend fully sovereign over its territory? I'd love to learn otherwise, but my impression is that it has mostly been under the shadow of England, and the pressures of a government under those circumstances are not comparable to those for, frankly, one that's more responsible for its destiny as a starship crew would be. I bet you can find lots of long-running tiny local governments with very little power, both dominated and protected by a string of larger, more powerful, but more volatile governments.
The Tynwald evolved from a jury into a legislature, didn't admit its first elected member until 1866, its first few hundred years of existence are assumed rather than documented, and actual power resided with a mixture of kings (most of whom were also kings of other places or answered to kings in other places) for most of its existence. So not an ideal example :)
I have no doubt that even the most republican of cultures launched from Earth would end up thoroughly monarchistic by the time the generation ships arrived at their destination. At best monarchistic - who knows what savage new forms of society could evolve in that sort of context?
There is a lot of precedent for this. Even on Earth, in 2026, international maritime law states that there is no such thing as a vessel with "democracy" and that a captain always has supreme command. Ships, airplanes, etc are all in a category that operate as strict autocracies.
More optimistically, you might see some kind of "choosing a chief by consensus" type of situations that you see in some small hunter-gatherer societies (being careful with the word "savage", which is... usually misleading). It'll depend a lot on the size of the crew.
> Perhaps, but it is horrifically long in terms of human stuff.
Not really, unless you're obsessed with the idea that great works need to happen within your lifetime. Europe is chock full of cathedrals that took 400-600 years to build, worked on by countless generations who would never live to see them completed.
The difference there being that at the end of your day, having spent it masoning, you could leave the cathedral and go back to your family and have a walk in the fields and drink and be merry with people loved and new. The project wasn't the entiriety of your existence, it was merely the means to pay for it.
Unless we have generational ships the size of small countries, I'm not sure the human brain - unaided and non-forcedly evolved to do so - would be able to handle essential incarceration in a series of metal tubes for its own and its descendents existences.
Maybe I'm over-thinking things. It seems like a lot of people's existences essentially revolve around a pocket-sized glowing rectangle.
Future AI and a database of all of humanity's experience before launch might be enough to keep the generational populace amused and distracted for the entiriety of their meagre, trapped existence... .
Generational ships would of course need to be very large, but I doubt it would need to be as large as you think. And it doesn't need to look like metal tubes. Many northern cities have extensive underground or between-building pedestrian bridges and large shopping malls, etc that can provide quite a lot of variety and the feeling of open and green spaces that is pretty attractive during long cold winters. Whether that's 'enough' to avoid mental health issues in a permanent setting is of course a different story, but that's just one of thousands of problems that would need to be solved before that ever comes close to reality :)
Yeah, this is the problem though - ironically highlighted by my still-maintained love and hope for Starship: Beyond Earth orbit, the energy requirement to move even small tens of tons of useful life-sustaining mass is incredibly expensive.
Like, to get a useful amount of people to Mars would be... the wealth of a first world nation for tens of years. Even using nuclear engines.
A generational megaship travelling at some small percentage of c to a nearby useful star (not even the nearest ones, which are all a bit shit)?
There's just nothing within our current projected reality that could even begin to accomodate that possibility.
Never mind the fact you'd need redunancy, and at least a few hundred years of testing to ensure that whatever mega project you could ultimately send wouldn't simply get vaporised halfway through, from realities unknown.
With variations on nuclear propulsion we could plausibly get to up to around 12% the speed of light. At least that's the number quoted for Project Daedalus [1], which is using nuclear fusion for the first stage and nuclear-powered ion engines for the second stage. With the cruder but more realistically achievable right now Project Orion design (riding the shockwaves of nuclear bombs) you could still get to ~3% the speed of light
But even at 0.12c, we are looking at 400 years to get there. And we'd be zooming by at 12% the speed of light. If we want to slow down a bit that'd add hundreds of billions to the cost.
It might be worth waiting another century to see if we can come up with a faster design in that time. Not like closer targets like Alpha Centauri, where the thing stopping us is mostly just the absurd cost
I think the only way political will can fund nasa to realize these 1960 design ideas is an infinite capacity arch rival that threatens/render irrelavent either the dollar's supremacy or american power (and just those two, because apparently these days there is no "threat"/need to defend a higher cause, like the neo-liberal rules based system or democratic or human right values). Also that arch-rival that is probably/likely not china(practically speaking)
> But even at 0.12c, we are looking at 400 years to get there. And we'd be zooming by at 12% the speed of light. If we want to slow down a bit that'd add hundreds of billions to the cost.
That’s the really hard part. If it’s almost science fiction to accelerate to 0.12c, it’s certainly much more difficult to slow down. At that speed we’d travel and pass this small system in mere minutes.
You just turn around halfway and use your main drive to decelerate. Yes, that does double the travel time, but it's the only way to do it. The hard part is then finding ways to get to a faster speed at turnaround time.
In most realistic settings it's even easier. For example a Project Daedalus probe only accelerates for four years before running out of fuel. So you could decelerate in just four years. Maybe a bit more, since you only have the smaller second stage engines. But essentially you are accelerating for four years, coasting for 392 years and decelerating for another four years. Accelerating for the whole time and turning around in the middle would be faster, but we don't have the fuel for that
The issue is that in the original architecture without breaking you burn 50k tonnes of fuel to get 1k tonnes of payload up to 12% lightspeed. If you want to break all the way back to zero, you need to 50k tonnes of fuel to break. But that means you need to accelerate another 50k tonnes of fuel up to speed.
Which means you need 50 times for fuel to get from 0.11c to 0.12c, and you need to accelerate that fuel to 0.11c, so you need more than 50 times the fuel for the step from 0.10c to 0.11c, and an even larger factor more to accelerate from 0.09c to 0.10c, etc. So you don't just require another 50*50k = 2M tonnes of fuel, but an exponentially larger amount. The tyranny of the rocket equation
Those 190km/s of the Parker solar probe were, crucially, periapsis speed.
This is a bit like bouncing a rubber ball from a building, measuring its speed at ground level and then going: "Given our fastest achieved speed, we expect to hit the cloud level in <10s".
~200km/s sustained speed is already insanely optimistic for anything we could realistically build in the next half century, so your position is even more ironclad than it looks at first glance.
It’s highly unlikely we’re ever getting FTL. We should become comfortable with that and let go our fantasies. Let theoretical physicists chug away at this, we should get underway with projects that are possible with known science.
It would help if our science wasn’t distracted by things like global warming and nazi governments though. There are definitely ways we can help the process * right now *
Scientists and engineers with an interest in such things would have an easier time working on it, if the broader economic and civic context they work in wasn't being messed with by demagogues.
They shouldn't be drafted to resolve the rise of petty tyrants. It's a waste of their time.
Was it my comment you really wanted to reply to? My point is that there are things we can do right now/today in order to heal our society from the sort of malignancies that distract us from advancing as a race.
Even if FTL is achievable (which I agree, highly unlikely), it's still extraordinarily slow on cosmic scales. The closest star is a little over 4 ly away!
And probing the universe outside the Milky Way? Forget about it.
1. if FTL is achievable, then presumably it isn't limited to 1.00000000001 x C
2. I like to think about the size of the universe by always remembering that with the naked eye, on a good night, there's only a single object in the entire night sky that isn't in our galaxy (M3, the Andromeda Galaxy).
I think you mean M31 instead of M3, and assuming northern hemisphere viewing only. I think the Magellanic Clouds are visible in the southern hemisphere.
The entire universe seems to be inside a giant black hole, anyway, and the more it goes, the more evidence is found to support that. Might as well find a black hole and visit other universes than explore our own.
Depends on who you mean as "we". The speed of light isn't a speed limit. If you can create a ship that is capable of 1g acceleration, it doesn't just stop accelerating as it reaches the speed of light relative to some stationary object, like Earth. Instead you start getting relativistic effects and things start getting very weird with time and distance doing some funky stuff. You keep zooming along just fine from your perspective, but an at-rest observer on Earth would see your ship asymptotically approach the speed of light, but never exceed it. The universe is very weird. In any case you could viably travel billions of light years in a single human lifetime, but for an observer at rest billions of their years would genuinely pass. In other words, traveling into the future is very much a real thing, so far as our current understanding of the universe goes.
The search term on this is 'relativistic starship.' Here's [1] a calculator to see what the math works out to for a ship capable of accelerating at 1g indefinitely. So for instance you could travel to Andromeda, some 2 million light years away, in about 28 years. But 2 million years would really pass for those at relative rest, such as those on Earth. So if you came back, the humanity you found (if any) would be unimaginably different.
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 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.
Relativistic starships are impossible because they require impossible amounts of fuel. "If you can create a ship that is capable of 1g acceleration" is doing a lot of heavy lifting. The rocket equation means you need to take along exponentially increasing amounts of fuel
Even antimatter rockets top out at 50% of light speed. Laser boost like with Dyson Swarm could get similar speeds because time dilation slows down the acceleration.
This isn’t gonna work, space isn’t truly empty. Even with antimatter propulsion the interstellar medium will start to vaporize your ship at speed above 0.2c.
If we design a probe that travels at speed of light it would reach there in 48 years and it would send back what it's seen after another 48 years. It would take multiple generations of scientists to work on this project. The longest we have worked on, are Voyager projects. Can we expect that level of commitments from our governments or corporations? Voyager became successful because people could see distant futures. We can barely plan few years ahead.
This is where English’s defective subjunctive makes life harder: The point wasn’t about the practicality of the probe from a scientific position, but rather pointing out that even in a best-case scientific scenario, the political-economic-cultural forces are against us.
> Can we expect that level of commitments from our governments or corporations?
Clearly, right now we cannot. This is one of the worst obstacles to progress in these areas that I see, and I don't see any obvious way to fix it.
The situation we're currently in would've been utterly unfathomable to me 30 years ago. I have lost a great deal of the hope and optimism I held in the past. Interstellar exploration is but one of many fields where we are suffering due to short term thinking.
If you could solve propulsion enough to accelerate and decelerate a spaceship at just 1G, you could forget the probe and just send people there. While it would take ~50 years of earth time, it would only take ~7.5 years for the astronauts. They could reach the planet with most of their lives free to go to work studying or even colonizing it.
This is indeed an interesting perspective, but "constant 1g rocket acceleration" is not even an engineering pipedream, it's strictly fantasy territory.
I had this realization in high school. At the time I did not appreciate how impossible it is to accelerate at 1G for that long. Absent some entirely new physics becoming available. All signs point to it not being possible, so not even likely new physics could exist.
Just going to recycle this comment I made in reply to an almost identical comment as yours. I don't think you folks realize how big space actually is.
The speed of light is 1079 252 848 km/h, the fastest space craft ever made was the Parker Solar probe (using a sling shot) clocking in at 692 000 km/h. So at that speed it would take, 1559 years to travel one light year.
This planet sits at a distance of 48 light years, so it would 74 832 years to get there. Just for good measure, when it gets there it would also take 48 years for us to know that since radio travels at the speed of light.
Note, that the speed of the spacecraft I mentioned was the peak speed. Space is big, really big.
Science fiction has entertained and inspired millions of people and we should all be grateful for that but it has also distorted what people think space really is.
When you consider the scale of space it becomes pretty understandable why the Milky Way isn't teeming with civilizations sending large amounts of mass all over the galaxy. A realization one comes to despite the facts that it has taken humans a blink of an eye (on a galactic timescale) to go from tools to rockets and the Milky way is billions of years older than the entire history of the Earth.
I blame Star Wars, kinda. Watching it with my kid, I can't help but notice that everywhere they travel in space -- even by accident -- they end up by a planet that can support human life in terms of temperature, atmosphere, and gravity. Mandalore (the Mandalorian home planet, natch) has a moon that doesn't only support life; it also has the exact same gravity as Mandalore!
Sentient life in hospitable environments is as unavoidable in the Star Wars universe as it is absent in ours.
Project Hail Mary does a pretty good job, although probably doesn't come across in the film. SF that doesn't even bother using wormholes or some other FTL travel (e.g. warp speed) is quite annoying, though.
I mean, even there they pretty use the Astrophage as a plot device to fill in the huge gap in technology needed to cover those distances. They make it clear that they would have no chance to cover those distances without the Astrophage, but it is very convenient.
On a scale of probable -> less probable, you have:
Self-organizing chemicals -> replication -> evolution -> multi-cellular life -> creatures that move around -> intelligent life -> use of tools -> basic technology like wheels, steam engine -> industrialization -> advanced tech -> automation -> space faring -> capable of interstellar travel -> capable of intergalactic travel. Powered by energy sources of increasing complexity/sophistication & scale.
This whole evolution requires a stable environment. Dinosaur-killing asteroid & it's back to square 1. Also (for example) how would intelligent life on a waterworld (which basically excludes electronics as we know it) become space-faring?
So it's not unlogical to expect that microbial life could be 'everywhere', tool-using intelligent creatures are rare, and interstellar-capable civilizations are so few & far between that (on average) they're just too distant in space or time.
Doesn't matter who visits who if neither party can cross the ocean in between.
If we’re talking about human technology available in a few hundred years, don’t discount far more exotic options. I’ve heard people talk of theoretical terrestrial lasers pushing on tiny probes. With an absolutely gigantic laser and magical material at the back of the probe that won’t instantly vaporize there’s enough energy to get something the size of a smartphone up to a reasonable proportion of the speed of light.
I can’t prescribe this theoretical technology to the problem. But I also think it’s unreasonable to set the limit using known technology and then discount the idea altogether. We have no idea what will be possible in 300 years.
Exactly. Imagine what would be possible after a billion year of technological evolution, heck even just 100'000 years. We already know that space time metric engineering is theoretically possible within our current understanding of physics, we don't have either the technology or access to energy density necessary to do it. And that's only within our limited understanding of how the universe works.
If you have a billion year long civilization, it would probably be easier to genetically/medically engineer humans to live forever, so that a 75,000 year space voyage doesn’t seem so long. Easier than near-lightspeed space travel at any rate.
Note that you can't use these lasers to slow down the probe, which will dramatically limit the things the probe can do at the destination. I'm not even sure what kind of interesting things a probe the size of a smartphone could do, let alone phone home.
send an unending chain of them and you solve the transmission problem _and_ they don't have to slow down as you'll always have another on the way past whatever you're targeting
How many times the Earth's materials would we consume doing that? And wouldn't it block ma lazor from reaching the previous probes and accelerating them?
> you can't use these lasers to slow down the probe
You can, but you need a couple of solar sails. You beam the laser at the sails to accelerate, then at the halfway point one of the sails detaches and becomes a reflector, which lights up the now flipped probe and remaining sail to decelerate them.
At the distances involved even the beam from a gigantic laser will be spread out enough not to vaporise anything — you won't need a magic material, just a very large, thin, and highly reflective solar sail.
> I want to know what future technologies could accelerate an object to a significant fraction of the speed of light.
With all due respect, this has been extensively debated online and is extremely easy to look up.
> Could those breakthroughs be achieved in the next 2 or 3 centuries?
Any predictions on future scientific breakthroughs are wishful thinking. Even directions that seem promising at some point can end up being dead ends and we simply don't know what we will or will not achieve.
With current technologies, even hypothetical ones we can't get there in a time period that is under a few centuries at best and over a millennium at worse. Even for the centuries figure we'd require technologies we haven't been able to crack yet.
> the fastest space craft ever made was the Parker Solar probe (using a sling shot) clocking in at 692 000 km/h…
After 44 days of acceleration. On a multi-millennia mission we’re talking a velocity likely 300x what the Parker Solar Probe achieved (while falling into the Sun).
The comment you replied to doesn't appear to be misunderstanding the size of the galaxy, they mention acceleration to near the speed of light so they're probably thinking 100 years to get there and another 48 to receive signals back. The missing part is the propulsion system capable of doing that.
If I understand correctly, time spent within this interstellar ship reference frame would be significantly less than 75k years. And at 1c speed, 48 years on Earth would be ~2 years of "flight" for the passengers, correct me if I'm wrong.
You are not wrong, but it still wouldn't make a whole lot of difference. First of all with any technology we currently have, including hypothetical proposals, we can't even get close to 1c. The best we can do, and this assumes purely hypothetical unproven ideas, is accelerate to a fraction of the speed of light. Acceleration itself will take up a significant amount of time and even then we are nowhere near the speed of light. Project Orion would in theory be able to do 3% to 10% of the speed of light. That's about the only proposed propulsion we actually have the technology for in the sense that we might be able to build it this decade.
So let's be optimistic and assume we can reach 10% of c (unlikely), that is 10 years for one light year, meaning that it takes about five centuries. Practically speaking 10% of c is unlikely, it takes about a month to accelerate to those speeds you'd need an insane amount of mass in the form of bombs to explode to just get up to speed. Which is why 3% is more "realistic". Oh, did I mention that there is no realistic way to slow down either? In theory it is just detonating the same amount of bombs in front of the craft, but in order to take that mass on your journey you'd need a lot more mass to get up to speed and the numbers get silly rather quickly.
So "realistically" at 3% of c we are talking about roughly 1500 years to just speed past our target.
Also, the original remark was about sending probes, not humans. But at 3% or 10% of c time dilation isn't much of a factor either so you'd need a generational craft if you want to send people.
Man, that’s not how intelligence works. Eventually if a civilization doesn’t blow itself up, it will achieve anything, and it’s not incremental steps. Speed has never been incremental steps. in 1810 you would’ve been thinking about faster horses or some shit like that. Def not rockets. OP said hundreds of years. In hundreds of years from now our rulers will definitely have that kind of tech, whatever tech it is.
We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far. The sciences, each straining in its own direction, have hitherto harmed us little; but some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new dark age.
I was skeptical about that as well so I googled it and:
>Helium cannot support life because it is a chemically inert noble gas. It does not form the complex, stable molecular structures (like carbon chains) required for biology. Unlike oxygen, it cannot be used by living organisms for cellular respiration to generate energy, making it an asphyxiant.
However, maybe we are projecting our current understanding of biology and shouldn't rule it out. I'm not a scientist so I have no idea.
Well, some years ago helium was a preferred way for suicide. This reflected very bad on the producers of party balloon helium tanks, so they added an amount of oxygen and it was no longer an effective way.
So the question becomes: How much of that atmosphere is helium?
Hmm, really? That's interesting.... [time passes] ... I found more information than I really needed on how to kill one's self with helium, and I saw some places making suggestions that helium be cut with oxygen, seemingly starting with a New Zealand coroner in 2011, but nothing suggesting this had been implemented at any sort of scale. The links I found on Amazon for party balloon helium tanks all mostly proudly state they are 99%+ helium.
Note: terrestrial chemistry is no different from chemistry that can occur anywhere, given the right molecules and conditions, and even then it’s a matter of degree.
Nitrogen being replaced by helium would actually be fine but for the niggling issue that we need nitrates. There are no heliates (?) to compensate. The name doesn’t even make sense… helium is the sole gas to have an ium end like metals- chemically it’s that meaningless what you call it as an ion…it shines elsewhere though.
For biology, it’s a necessary condition that the environment react with it and it reacts to the environment. Over time the two become deeply intertwined through the process of evolution.
It’s hard to see how that kind of evolution will occur if a lot of the environment is nonreactive.
Survival may be plausible though. There’s been some research showing some bacteria can survive in high helium environments. That’s a far cry from proving something like a bacterium can evolve in a helium environment that’s non-reactive though.
Why would it be necessary for life to depend on breathing atmosphere? The atmosphere could just help in keeping the temperature even and provide some nice pressure, maybe that’s favorable over vacuum.
Life needs energy to be moving around, without energy exchanges, by very definition, nothing interesting happens.
An inert element, for that reason is just not suitable for life. It's not a reasoning based on anthropocentricity it's just basic chemistry and mathematics. If things can't assemble together, and combine, and form more complex structures, you can't get life.
If you could get life out of simple basic atoms, we would see life everywhere, and we would be creating it everyday in labs. We don't.
Doesnt mean life can't exist there by using other elements, but detecting helium is not increasing the likelihood of finding life there at the very least.
When you think about it honestly, we really don't know anything about anything. We don't know how many planets there are in the galaxy (nor in the universe, nor in the multiverse, nor if there is a multiverse). We don't know what the chances are of a given planet being habitable (nor what "habitable (for all possible life)" means, nor what "all possible life" means). And we don't know what the chances are of life existing on a given habitable planet. So apart from the fact that all of the above probabilities may well be at or near zero, we're barely even capable of articulating the necessary questions, let alone searching for answers.
According to AI, an equivalent would be roughly when Google maps shows you 10mi/20km reference scale.
Turning off the labels, aliens would probably assume that the world is naturally full of green stuff that is dealing with some strange grey infestation.
Heh, your flip remark leads to an interesting observation: I think the most obvious signature of "abstract intelligence" is suboptimality. An alien would look at an agricultural grid and wonder, what possible natural process would divide something into squares rather than hexagons? Even without knowing what they are or how they form, it's hard to imagine anything that would prefer such a high energy configuration. Such stupidity implies a system oddly bounded in its ability to optimize, which implies a feeble biological brain trying to do something "on purpose" rather than a natural process.
I wonder if there are conscious ants and similar small infrastructure-builders running around on the ground with the exact same ideas. "Of course the big-beings-in-the-sky recognize our tracks here are major roads and agricultural areas, they must understand we're intelligent"
> aliens would probably assume that the world is naturally full of green stuff that is dealing with some strange grey infestation.
I think they would draw the correct conclusion, actually. I know it's popular to compare humans to mold or cancer or whatever these days, but this kind of thing is both unrealistic and insulting to the aliens, who by the definition of the scenario are at least as smart as we are, quite probably more.
Our nighttime view of the planet has dramatically changed in the past 100 years and is increasing. They would instantly see us using electricity and could possibly see our satellites.
The wild thing is that, if I understand it correctly, if you were floating in a spacesuit at the same spot you'd also see that resolution (likely highly distorted) with the naked eye.
I'm genuinely curious for someone less lazy than I to do the trigonometry. My gut feeling is these would be tiny apparitions on the edge of the disc. Not visible to the naked eye, even with a shield.
Similar to using everyday objects as pinhole cameras. At certain specific distances and angles my blinds offer magnification of small bits of the trees outside.
There is no "building" such a thing. All we could do right now is send the "telescope probe" >500AU away, on the opposite side of the sun from the observation target, then hope it still works 80 years later or so when it gets there.
Edit: My point is that you can't "build" such a thing and later point it somewhere-- you have to fly the camera part of the "telescope" about 3 times as far as voyager 1 went, exactly opposite of your observation target, and it is not gonna stay there for too long either.
As long as we improve rapidly at both drone-building and exoplanet target selection, it is not really gonna be worthwhile because both the drone hardware and the target will be hopelessly obsolete before we even get halfway to the observation point.
Well, there is a way to do it slowly, the probe(s) just need to be in a 500AU circular orbit. At that distance power and thrust are an issue, and RTGs seem like a better choice than solar. Certainly, takes longer to get to orbit than fly through a point for a pic, but you would get a lot more pics.
First: Orbital period out there is over 10000 years.
And if you circularize (which is expensive to do in delta-v), you minimize the time window you have for observation (because you're basically pointing your speed vector straight to outside of your observation cone).
The orbital velocity at this distance is around 1 km/s, so you can fairly trivially (compared to anything else) zero it out. Then you can just hover in place, the solar gravity acceleration at this range is in _microns_ per second squared.
For all intents and purposes, you'll be in the interstellar space.
In order to get something there fast enough it would be traveling out very fast. Getting something there to orbit I think is not realistic for us any time soon.
> so it's not too different to "get there" and "orbit there".
But to "get there" within any reasonable timespan requires going really fast - which is currently highly impractical. And then once you get there, you have to them cancel pretty much all of that velocity which is not just a "few percent more delta V".
We can do 7-8 AU per year right now using tech we have. Voy 1 and Voy 2 are moving at 3.59 and 3.25. A starship sized rocket could also possibly get a small payload that separates to 15 AU. This is all using conventual propellent. If you consider using nuclear explosive as a prepulsion technique the math starts to change substantially and you can achieve even 25 AU / year.
I wonder about all the extraterrestrial AI swarms that have already imaged earth.
Surely it has happened. They must have all spotted our planet millions of years ago and must be watching us with a continuous high-resolution feed. They've seen our dinosaurs. Their interest will really be piqued when they finally see us invent electricity, though that might be some time in the future for them.
Perhaps even gravitational lensing is primitive to them. Perhaps they're able to break and manipulate physics and peer directly into our light cone, breaking the speed of light. Perhaps through direct wormholes they're already here - computronium in the very oxygen atoms that surround us. In rock silicates, in the air you breathe, in your hemes, in your brain. Calculating.
But perhaps we're the only intelligent species in the entire universe. That is also a possibility. Some big names in astrophysics, such as David Kipping, suggest strongly that we should not rule out that hypothesis. I find his suggestions haunting and beautiful at the same time. You need to watch his videos, and this is a good start: https://www.youtube.com/watch?v=PqEmYU8Y_rI
And finally, it may be that we're all just a historical simulation. Or maybe that's ascribing too much importance to ourselves. Maybe we're just a slop simulation on some AI's plaything, existing for no reason at all. Background NPCs with self-importance, ephemeral existences. But procedural generation at scale isn't really all too different from the laws of the physical universe itself.
The scale of the universe fills me with awe. Every time I think about it, my worries about random algo-rage and clickbait fades away to nothing. It deeply contextualizes our short time here.
>But perhaps we're the only intelligent species in the entire universe. That is also a possibility. Some big names in astrophysics, such as David Kipping, suggest strongly that we should not rule out that hypothesis
They may be planted by alien AI to lull us into false sense of security.
This comment encapsulates how poorly we humans are at accepting unknowns. For me, that explains a lot of our belief systems. The fact we can’t just take the unknown but instead have to fill in the blanks with what ifs. and create a narrative like we know anything about the unknown thing. It helps us feel like we understand it more. That’s literally how religions and a lot of other things get created, it’s a pattern, then the logical person sees the patterns and say it’s a simulation. A quite predictable filling of another blank.
I'd argue that it's this same pattern-seeking drive that undergirds science.
"Zeus sends the lightning, his wrath darkening the very sky," is an understandable model that connects "dark storm clouds" to a likely prediction of lightning.
That urge to explain the surprising, to find the pattern, leads directly to our understanding of the cosmos.
As Lynn Margulis reminded us we are not the main show. Our individual intelligence is highly over rated. The brain itself is kludge upon kludge accumulating over thousands of years, to solve problems that keep changing with time and environmental changes. Its quite a piece of crap actually if you tabulate all the accumulated junk. We arent as interesting as we think we are.
Some of the tech and knowledge generated might be interesting. But compare it with to photosynthesis or butterfly metamorphosis or the fact that microbes can double their population in a few hours, all of which is happening without needing any human intelligence. So they may very well be watching but are more curious about a rose or a redwood tree than all the random and superficial activity the chimp brain produces.
Maybe visiting moon is overrated. We can't know, we have very narrow tube vision centered around our rather primitive lives.
Effectively immortal organisms may be more impressive. Or those surviving in anaerobis boiling water conditions. Or fixing radiation defects like its nothing. Or vacuum. Or...
Artifical solar capture systems exist. Synthetic biology also bridges that gap as well and the genetic basis is known and has been manipulated. Granted, coming up with more efficient photosynthesis is very hard, but I don't share your "we humans are stupid" opinion here at all whatsoever.
> or butterfly metamorphosis
Nothing fascinating here. It is just a genetic program. Viruses have similar programs too - yes, no metamorphosis, but take retroviruses and the syncytium. Mammals only reproduce thanks to retroviruses (not 100% correct, but look at this here: https://www.pnas.org/doi/10.1073/pnas.0707873105)
> or the fact that microbes can double their population in a few hours
Wow, we humans surely do not have cells that double. Oh wait ... nevermind. Humans consist of cells. Who would have thought...
Yes, microbes are much faster, but they don't have to coordinate as much as humans do in 3D, not even in a bacterial biofilm. And we have to double a lot more DNA than bacteria do, so of course they are faster.
> about a rose or a redwood tree than all the random and superficial activity the chimp brain produces
That comparison is weird. A rose is thinking as much as a chimp brain?
The human brain is special. Chimps are very clever too but humans have very solid abstract thinking. Animals have this too, to some extent (predator hunting prey, chimps have hunting strategies) but e. g. look at mathematics - animals don't waste their time coming up with higher order theorems.
It's expected that a human would associate life with intelligence, but it's also a bit of a contradiction because it does not seem very intelligent to do so given all we know about the history of life on our planet.
Earth is 12700 km in diameter, so such an image would be 688 pixels across.
Basically you won't be reading license plates but you'd see enough to identify evidence of very large scale construction, and with multiple images over time I bet you could draw even more conclusions.
This requires sending something to at least about 548 AU and then effect falls off from there but anything you send that far will be going at a velocity that would keep it going. You would be in effective range for some time but basically you'd need to keep sending satellites to that distance in order to keep using the technique. You'd also want to send them into different directions in order to image different parts of the sky.
It’s basically imaging one exoplanet per satellite. Would be good to figure out a way to slow down at 500 AU. In order to maximize the time for observation.
With a Jupiter/solar oberth boost we can at best do around 20 AU per year, so best case scenario it would take atleast 25 years to get there, which honestly isn’t bad at all. For comparison voyager does around 3.6 AU/year.
A series of permanent stations near the vicinity of the oberth burns at Jupiter and the sun could add a lot of Delta V by firing a laser at the probe and the probe could fire one back. Even more so if it was a series of laser boosters strategically placed around the solar system. The numbers start to get really crazy.
It would be most likely a whole solar system. Consider that new horizons only had hours during its flyby to collect all the telemetry that it did. Imagine having 600 pixels of resolution for an exo planet for up to 15 years. Plus all the other telemetry you'll be collecting about the galactic space near us.
Couldn't you do something like a Hohmann transfer orbit ? As I understand it, adjusting the orbits far out there isn't as demanding as one might think (you don't have to spend the same energy you took to get out there to get into an orbit. Of course, this also means you will not be able to stay in one place and continuously map the same area, but you can map all the space within a disc?
It takes decades however to finish Hohmann transfers that far out apparently.
Rabbithole: Some calculations that may be entirely wrong would suggest that a <10000lbs spacecraft might be held "in place" for 100 yrs with a small fission reactor and an indium-based FEEP drive with about 15lbs propellant.
Nuclear-powered ion thrusters could solve this issue. They provide low acceleration for a long time consuming very little consumable. This would allow the telescope to stay at the right position for observation.
It's just a funny little thing but I love how in a world of "megapixel" and even "gigapixel" space images we have here a "multipixel" imaging of planets, due to achieving a resolution of several pixels.
Though the 25km resolution mentioned actually sounds far, far better than the very pixellated planet in the "artist’s depiction". I suppose it depends how small and far away the planet is.
A kilometer scale telescope contract would exercise all the right pipelines for massive orbital buildout like in-situ assembly, multi-lift cadences, and big-old infra. And it'd look cool as hell in the night sky during assembly.
An even more ridiculous dream of mine: I hope that aliens build a similarly amazing telescope, point it at Earth, and share the images with us, so that we can _see_ our Earth in the distant past.
No, they detected helium, which would be in the upper reaches of the planet's atmosphere (as on Earth); they believe there are other gasses lower down, but the helium is what's confirmed.
They detected helium escaping from the upper atmosphere which they believe to be evidence of a retained atmosphere, but haven't been able to fully identify the elements present in the lower atmosphere.
Due to the density of the planet they believe it could be a water world, or a mostly-icy world due to the lack of hydrogen found, and the lower atmosphere could consist of nitrogen, water vapor, and carbon dioxide. Since the host star is very inactive, there's little atmospheric erosion that would strip away a heavier atmosphere.
Super-Earths are interesting but not technically habitable, at least not by humanoids, the gravity would be insane
There are new telescopes and techniques coming online really soon that can potentially find closer to Earth-sized planets but they probably won't be within 50 light years
adding: hmm maybe gravity not too horrible on 1140b but still INTENSE
You can downvote me as much as you want, but that's a genuine question: there are more species on Earth than any of us know. Before hoping to find new animals on new planets, why not caring about what's on ours?
No downvote from me, but - Aren't the undiscovered ones just different colored insects or jellyfish? I mean, it's a cool job if you get paid for it to discover new things that can kill us fast in the Amazon. I think we can leave them alone to do their thing and concentrate on team Human. Money better spent.
I'd be terrified to meet an alien. Very much doubt they'd be attractive purple skinned humanoids like in the STNG. But they are welcome to discover us if they are so advanced, why do we need to sweat, we aren 't done with this rock yet? Thank the universe and light years it's never gonna happen.
The speed of light is 1079 252 848 km/h, the fastest space craft ever made was the Parker Solar probe (using a sling shot) clocking in at 692 000 km/h. So at that speed it would take, 1559 years to travel one light year.
This planet sits at a distance of 48 light years, so it would 74 832 years to get there. Just for good measure, when it gets there it would also take 48 years for us to know that since radio travels at the speed of light.
Note, that the speed of the spacecraft I mentioned was the peak speed. Space is big, really big.
This whole search for life outside planet Earth is ... stupid.
Life is already on this planet. Why would it matter whether
life exists outside of this planet or not? I mean, this is
pointless. I understand that some have a financial motife
to drive this narrative, but it is not logical. The counter
argument is quite simple: IF there is no divine being, then
ALL of life's complexity is logical and natural. So, it really
does not matter WHERE it originates nor how many times. Why
would it matter if it originated 10000x or only once? Now,
I do not doubt that it has originated several times rather
than once, but my point is that this extra-terrestrial
search MAKES ABSOLUTELY NO SENSE AT ALL. That is not to say
that research and exploration in space are pointless, but
that it IS pointless to "search" for extraterrestrial life.
Yet none in the media point that out. It's all as if it were
some magical, mythical quest here.
I'm always so alienated (sorry) by the excitement around things like this. People start fantasizing about FTL and space arks and there is just no evidence that any of that is possible, desirable, effective, anything really.
I know I'm a killjoy, but I do think there's something negative about the impact of science fiction on engineers. Like, the people who tend (no offense) to be the most literal, black and white thinkers get exposed to art and instead of processing it as the output of human creativity, they start to imagine that it's desirable or even real.
There is too much fantasy about distant habitable planet and not enough about making a planet in solar system habitable or building artificial habitats
Or even before that, fixing the habitat of the planet we are living on. A lot of the current cultural fantasy of colonizing space feels less like expanding the human frontier and more like escapism.
> Like, the people who tend (no offense) to be the most literal, black and white thinkers get exposed to art and instead of processing it as the output of human creativity, they start to imagine that it's desirable or even real.
Why can't you process their fantasizing about it as an output of human creativity?
I don't think I've ever sounded so cynical in my life, but something about the way sci-fi fandom bleeds into real science really makes me deeply uncomfortable.
cynicism and critique are comfortable positions imo. i appreciate the relatively newfound cultural shift back towards earnestness (although i can already feel the pendulum starting to swing back)
skimming your comment history, to me you seem very comfortable occupying the sociocultural critic position which is to some degree inherently cynical imo. i say that because i also recognize it in myself
FWIW I don't think it's pathetic at all, and I have the same reaction as you to a lot of things on HN. There are a wide variety of topics that bring out various biases and other cognitive blind spots in people, and bots.
Space travel seems to be one of the more harmless ones, but I agree it's frustrating to see people implicitly or explicitly skip over things like near-light-speed travel as solved problem, then reject arguments from others as "not thinking big enough", etc.
In general, divorce from reality doesn't seem to be related to intelligence at all in my experience. I'm sure there are plenty of times when my wishful thinking gets in the way too.
Well I'll give you that most of the stuff about accessing other star systems is deeply unrealistic now. But pretty much all of the awesome stuff that we've actually created in the last 150+ years started out with someone's imagination running away on something that didn't seem very realistic at the time. The idea of having artificial satellites was once a pipe dream, and now we have so many of them we have to redo our numbering scheme to track them all properly.
I'm not gonna hold my breath for the other star system stuff, but if they manage to get the kinks worked out of Starship and it delivers full reusability as promised, it seems like off-world colonies might actually be possible in our lifetimes. If that gets up and running, we might plausibly develop enough space infrastructure that some of the ideas don't seem too crazy anymore.
This is false. Earth's magnetic field does not significantly impact atmospheric loss. For comparison, Venus is closer to the sun and has no magnetic field, but has a substantially thicker atmosphere than earth.
The definition of "earth-like" in this context is almost absurdly broad: roughly it means: a rocky-metallic planet, around Earth mass (maybe 0.5 to 1.5 or so?), and in an orbit that might support liquid water -- not has water, just water would be liquid under some circumstances if it were there.
So:
- no atmosphere? no problem
- no water? no problem
- average temperature 40c? fine
- 4c? Yup
I think both Venus and Mars qualify (barely).
All to say, when someone says a planet is "Earth-like" that doesn't mean we should get out our picnic baskets.
The universe is bigger than the part of it we can see. The part we can see is large enough that there statistically has to be life out there, but it's also so large that we'll never sense them let alone communicate with or see them.
it's reportedly tidaly locked, which means that it's surface is frozen solid on the far side and the only gas that isn't frozen out on the dark side, is the detected helium, with the ultra low boiling point to keep it gasious
so if truely tidaly locked, it's a dead world in a very hard vacume
I think we should focus at the solution of Fermi paradox, especially the short time window factor. Life on earth evolved for billions of years, while one of it's creatures is capable to receive/send messages to space for only 50. That leads to a factor of billions/50 reduction at the calculated probability of alien life discovery. Multiply that with another billions/xxx at the receiver side, if they are similarly able to communicate for only a few centuries at best. I assume you agree that our and their evolution are independent.
So the new probability becomes quite low, which fits with our (non-)observation of alien life. We might not be alone, but we are far away and very short lived.
Considering we started our search for extra terrestrial intelligence 67 years ago, and we likely didn't go extinct in 2009, 50 years seems a rather pessimistic estimate.
I'm a bit upset with Science for their current wording of some things. "Super Earth"? Really, what will ever be found out there that's more super than what we have here? Earth absolutely has sisters out there, but what could possibly be better than Her?
I get that super is more a reference to their size, but really? Science, please respect our Earth and don't label large rocks rotating around some distant star more super than what we have right here! I hate that term, it's offensive.
I also feel science has it totally wrong with "looking for life on other planets". Let start acknowledging that it's the planet ITSELF that is alive, not what's living on it's outer skin.
Science will never find life on a dead planet, OBVIOUSLY.
Science should be looking for "Planets that are alive".
Sorry OP, this has nothing to do with your post, the wording it used was appropriate. I do wonder, how can an atmosphere of He form? Helium commets? Must have been.
jimbokun | a day ago
Close enough that we could probably develop a probe to get there in the next few centuries and check it out. What are the current popular candidates for propulsion systems capable of accelerating to near the speed of light?
JMKH42 | a day ago
other ideas: 1. be way more patient 2. anti matter based propulsion (more out there than solar sails) 3. nuclear bomb based propulsion
One issue is as you get to these speed little bits of dust will anhillate the probe, so you need some kind of shielding, raising the mass budget, making it all the harder. A solar sail has to be able to survive holes getting poked it in it and still working, etc.
WarmWash | a day ago
sebastianconcpt | a day ago
0x59 | a day ago
What's exciting to me is that the existence of such a planet provides fuel for more research into the field.
baron816 | a day ago
This also goes for aliens visiting Earth. Interstellar travel is just so impractical that I don’t think anyone has come on safari to Earth.
jfyi | a day ago
stevenwoo | a day ago
Jeff_Brown | a day ago
(No punchline; I just think that's cool. I understand that the real problem is the rare dust grain, not the ubiquitous gas.)
jonathaneunice | a day ago
Erenay09 | a day ago
1970-01-01 | a day ago
detritus | a day ago
I still hold on to the idea that very long term we might make strides in our own solar system, but it is a depressingly-longer timescale than I always used to believe.
Unless we have some magic-level shift in our understanding of physics, we're never getting anything beyond Von Neumann probes to other stars, and even then we're talking thousands of years.
creesch | a day ago
You might want to look up what the unix epoch is based on ;)
DaveZale | a day ago
And work out safe systems for hibernation, maybe rotate the crew in shifts
Oh yeah this is the stuff of science fiction coming to life
criddell | a day ago
gibybo | a day ago
DaveZale | a day ago
Actually, it's a great question. Even if we have single photon sensitivity detectors, just what kind of power would a laser need? Or would it be some other area of the emf spectrum? Or some other kind of communication? Sci fi ventures into gravitational waves sometimes
JMKH42 | a day ago
dijksterhuis | a day ago
assuming we can make it another few centuries, which seems increasingly unlikely.
andy_ppp | a day ago
750 years is hard for me to get excited about even as a vampire.
buildbot | a day ago
detritus | a day ago
andrewflnr | a day ago
dingaling | a day ago
cadamsdotcom | a day ago
andrewflnr | a day ago
notahacker | a day ago
detritus | a day ago
oceanplexian | a day ago
detritus | a day ago
How long's the longest voyage these days?
Mutinies aren't so common nowadays, but they were when ocean voyages were measured in months and years.
andrewflnr | a day ago
dopidopHN2 | 12 hours ago
oceanplexian | a day ago
Not really, unless you're obsessed with the idea that great works need to happen within your lifetime. Europe is chock full of cathedrals that took 400-600 years to build, worked on by countless generations who would never live to see them completed.
detritus | a day ago
Unless we have generational ships the size of small countries, I'm not sure the human brain - unaided and non-forcedly evolved to do so - would be able to handle essential incarceration in a series of metal tubes for its own and its descendents existences.
forgotaccount3 | a day ago
Provided the Earthlings that were sent along don't let their incarceration induced insanity infect the youngin's.
detritus | a day ago
Future AI and a database of all of humanity's experience before launch might be enough to keep the generational populace amused and distracted for the entiriety of their meagre, trapped existence... .
allannienhuis | a day ago
detritus | a day ago
Like, to get a useful amount of people to Mars would be... the wealth of a first world nation for tens of years. Even using nuclear engines.
A generational megaship travelling at some small percentage of c to a nearby useful star (not even the nearest ones, which are all a bit shit)?
There's just nothing within our current projected reality that could even begin to accomodate that possibility.
Never mind the fact you'd need redunancy, and at least a few hundred years of testing to ensure that whatever mega project you could ultimately send wouldn't simply get vaporised halfway through, from realities unknown.
wongarsu | a day ago
But even at 0.12c, we are looking at 400 years to get there. And we'd be zooming by at 12% the speed of light. If we want to slow down a bit that'd add hundreds of billions to the cost.
It might be worth waiting another century to see if we can come up with a faster design in that time. Not like closer targets like Alpha Centauri, where the thing stopping us is mostly just the absurd cost
ghm2199 | a day ago
exitb | a day ago
That’s the really hard part. If it’s almost science fiction to accelerate to 0.12c, it’s certainly much more difficult to slow down. At that speed we’d travel and pass this small system in mere minutes.
NoGravitas | a day ago
wongarsu | a day ago
The issue is that in the original architecture without breaking you burn 50k tonnes of fuel to get 1k tonnes of payload up to 12% lightspeed. If you want to break all the way back to zero, you need to 50k tonnes of fuel to break. But that means you need to accelerate another 50k tonnes of fuel up to speed.
Which means you need 50 times for fuel to get from 0.11c to 0.12c, and you need to accelerate that fuel to 0.11c, so you need more than 50 times the fuel for the step from 0.10c to 0.11c, and an even larger factor more to accelerate from 0.09c to 0.10c, etc. So you don't just require another 50*50k = 2M tonnes of fuel, but an exponentially larger amount. The tyranny of the rocket equation
andy_ppp | a day ago
fc417fc802 | a day ago
myrmidon | a day ago
Those 190km/s of the Parker solar probe were, crucially, periapsis speed.
This is a bit like bouncing a rubber ball from a building, measuring its speed at ground level and then going: "Given our fastest achieved speed, we expect to hit the cloud level in <10s".
~200km/s sustained speed is already insanely optimistic for anything we could realistically build in the next half century, so your position is even more ironclad than it looks at first glance.
fellowmartian | a day ago
isodev | a day ago
tuwtuwtuwtuw | a day ago
panagathon | a day ago
They shouldn't be drafted to resolve the rise of petty tyrants. It's a waste of their time.
luckydata | a day ago
parasti | a day ago
isodev | 13 hours ago
dempedempe | a day ago
And probing the universe outside the Milky Way? Forget about it.
PaulDavisThe1st | a day ago
2. I like to think about the size of the universe by always remembering that with the naked eye, on a good night, there's only a single object in the entire night sky that isn't in our galaxy (M3, the Andromeda Galaxy).
jihadjihad | 20 hours ago
behnamoh | a day ago
poly2it | a day ago
mr_mitm | a day ago
somenameforme | a day ago
The search term on this is 'relativistic starship.' Here's [1] a calculator to see what the math works out to for a ship capable of accelerating at 1g indefinitely. So for instance you could travel to Andromeda, some 2 million light years away, in about 28 years. But 2 million years would really pass for those at relative rest, such as those on Earth. So if you came back, the humanity you found (if any) would be unimaginably different.
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 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.
[1] - http://www.convertalot.com/relativistic_star_ship_calculator...
ianburrell | a day ago
Even antimatter rockets top out at 50% of light speed. Laser boost like with Dyson Swarm could get similar speeds because time dilation slows down the acceleration.
jimbokun | 18 hours ago
fellowmartian | a day ago
lossolo | a day ago
For any object with nonzero rest mass, reaching exactly the speed of light in vacuum would require infinite energy.
somenameforme | 19 hours ago
recursivecaveat | a day ago
jimbokun | 18 hours ago
I love it.
Archelaos | a day ago
forinti | a day ago
quaintdev | a day ago
functionmouse | a day ago
dhosek | a day ago
slfnflctd | a day ago
Clearly, right now we cannot. This is one of the worst obstacles to progress in these areas that I see, and I don't see any obvious way to fix it.
The situation we're currently in would've been utterly unfathomable to me 30 years ago. I have lost a great deal of the hope and optimism I held in the past. Interstellar exploration is but one of many fields where we are suffering due to short term thinking.
SoftTalker | a day ago
JMKH42 | a day ago
If you think of one, bring it up.
ryandrake | a day ago
myrmidon | a day ago
JMKH42 | a day ago
small_model | a day ago
creesch | a day ago
The speed of light is 1079 252 848 km/h, the fastest space craft ever made was the Parker Solar probe (using a sling shot) clocking in at 692 000 km/h. So at that speed it would take, 1559 years to travel one light year.
This planet sits at a distance of 48 light years, so it would 74 832 years to get there. Just for good measure, when it gets there it would also take 48 years for us to know that since radio travels at the speed of light.
Note, that the speed of the spacecraft I mentioned was the peak speed. Space is big, really big.
chrsw | a day ago
When you consider the scale of space it becomes pretty understandable why the Milky Way isn't teeming with civilizations sending large amounts of mass all over the galaxy. A realization one comes to despite the facts that it has taken humans a blink of an eye (on a galactic timescale) to go from tools to rockets and the Milky way is billions of years older than the entire history of the Earth.
teachrdan | a day ago
Sentient life in hospitable environments is as unavoidable in the Star Wars universe as it is absent in ours.
globular-toast | 15 hours ago
creesch | 13 hours ago
RetroTechie | 6 hours ago
On a scale of probable -> less probable, you have:
Self-organizing chemicals -> replication -> evolution -> multi-cellular life -> creatures that move around -> intelligent life -> use of tools -> basic technology like wheels, steam engine -> industrialization -> advanced tech -> automation -> space faring -> capable of interstellar travel -> capable of intergalactic travel. Powered by energy sources of increasing complexity/sophistication & scale.
This whole evolution requires a stable environment. Dinosaur-killing asteroid & it's back to square 1. Also (for example) how would intelligent life on a waterworld (which basically excludes electronics as we know it) become space-faring?
So it's not unlogical to expect that microbial life could be 'everywhere', tool-using intelligent creatures are rare, and interstellar-capable civilizations are so few & far between that (on average) they're just too distant in space or time.
Doesn't matter who visits who if neither party can cross the ocean in between.
ourmandave | a day ago
teaearlgraycold | a day ago
I can’t prescribe this theoretical technology to the problem. But I also think it’s unreasonable to set the limit using known technology and then discount the idea altogether. We have no idea what will be possible in 300 years.
pandoro | a day ago
jl6 | a day ago
jimbokun | 18 hours ago
mr_mitm | a day ago
throwawayben | a day ago
zelphirkalt | 13 hours ago
perilunar | 8 hours ago
You can, but you need a couple of solar sails. You beam the laser at the sails to accelerate, then at the halfway point one of the sails detaches and becomes a reflector, which lights up the now flipped probe and remaining sail to decelerate them.
perilunar | 8 hours ago
jimbokun | 19 hours ago
What kinds of scientific breakthroughs would be required? Could those breakthroughs be achieved in the next 2 or 3 centuries?
creesch | 13 hours ago
With all due respect, this has been extensively debated online and is extremely easy to look up.
> Could those breakthroughs be achieved in the next 2 or 3 centuries?
Any predictions on future scientific breakthroughs are wishful thinking. Even directions that seem promising at some point can end up being dead ends and we simply don't know what we will or will not achieve.
With current technologies, even hypothetical ones we can't get there in a time period that is under a few centuries at best and over a millennium at worse. Even for the centuries figure we'd require technologies we haven't been able to crack yet.
Den_VR | 18 hours ago
After 44 days of acceleration. On a multi-millennia mission we’re talking a velocity likely 300x what the Parker Solar Probe achieved (while falling into the Sun).
globular-toast | 15 hours ago
creesch | 7 hours ago
That is a pretty big missing part. Not as big as the galaxy, but still huge.
leobuskin | 14 hours ago
creesch | 13 hours ago
So let's be optimistic and assume we can reach 10% of c (unlikely), that is 10 years for one light year, meaning that it takes about five centuries. Practically speaking 10% of c is unlikely, it takes about a month to accelerate to those speeds you'd need an insane amount of mass in the form of bombs to explode to just get up to speed. Which is why 3% is more "realistic". Oh, did I mention that there is no realistic way to slow down either? In theory it is just detonating the same amount of bombs in front of the craft, but in order to take that mass on your journey you'd need a lot more mass to get up to speed and the numbers get silly rather quickly.
So "realistically" at 3% of c we are talking about roughly 1500 years to just speed past our target.
Also, the original remark was about sending probes, not humans. But at 3% or 10% of c time dilation isn't much of a factor either so you'd need a generational craft if you want to send people.
Again, space is big, really big.
eaenki | 12 hours ago
creesch | 12 hours ago
Yeah to reach it with current tech. No shifting goal posts, thank you very much.
> In hundreds of years from now our rulers will definitely have that kind of tech, whatever tech it is.
Also, I should point out that technological progress isn't linear and guaranteed. Also, "our rulers" what ...?
tgv | 8 hours ago
SirHackalot | a day ago
seydor | a day ago
SirHackalot | a day ago
astral_drama | a day ago
an0malous | a day ago
NoGravitas | a day ago
astral_drama | a day ago
singpolyma3 | a day ago
Nonsense. You mean not able to support terrestrial life.
jojogeo | a day ago
Nicholas_C | a day ago
>Helium cannot support life because it is a chemically inert noble gas. It does not form the complex, stable molecular structures (like carbon chains) required for biology. Unlike oxygen, it cannot be used by living organisms for cellular respiration to generate energy, making it an asphyxiant.
However, maybe we are projecting our current understanding of biology and shouldn't rule it out. I'm not a scientist so I have no idea.
chicken-stew | a day ago
So the question becomes: How much of that atmosphere is helium?
o_____________o | a day ago
The era of ridiculous sounding last words came to an end
technothrasher | a day ago
randomImmigrant | a day ago
Nitrogen being replaced by helium would actually be fine but for the niggling issue that we need nitrates. There are no heliates (?) to compensate. The name doesn’t even make sense… helium is the sole gas to have an ium end like metals- chemically it’s that meaningless what you call it as an ion…it shines elsewhere though.
For biology, it’s a necessary condition that the environment react with it and it reacts to the environment. Over time the two become deeply intertwined through the process of evolution.
It’s hard to see how that kind of evolution will occur if a lot of the environment is nonreactive.
Survival may be plausible though. There’s been some research showing some bacteria can survive in high helium environments. That’s a far cry from proving something like a bacterium can evolve in a helium environment that’s non-reactive though.
ant6n | a day ago
hliyan | a day ago
singpolyma3 | a day ago
andrewflnr | a day ago
Don't be so open-minded about extra-terrestrial life that your brain falls out.
sailingparrot | a day ago
An inert element, for that reason is just not suitable for life. It's not a reasoning based on anthropocentricity it's just basic chemistry and mathematics. If things can't assemble together, and combine, and form more complex structures, you can't get life. If you could get life out of simple basic atoms, we would see life everywhere, and we would be creating it everyday in labs. We don't.
Doesnt mean life can't exist there by using other elements, but detecting helium is not increasing the likelihood of finding life there at the very least.
jaza | a day ago
petilon | a day ago
mekdoonggi | a day ago
sgt | a day ago
mekdoonggi | a day ago
Turning off the labels, aliens would probably assume that the world is naturally full of green stuff that is dealing with some strange grey infestation.
HPsquared | a day ago
peddling-brink | a day ago
dTal | a day ago
somenameforme | a day ago
rurban | 20 hours ago
dTal | 20 hours ago
rurban | 17 hours ago
stephenhuey | 17 hours ago
rurban | 16 hours ago
embedding-shape | 13 hours ago
dudinax | 13 hours ago
andrewflnr | a day ago
I think they would draw the correct conclusion, actually. I know it's popular to compare humans to mold or cancer or whatever these days, but this kind of thing is both unrealistic and insulting to the aliens, who by the definition of the scenario are at least as smart as we are, quite probably more.
hparadiz | a day ago
mmooss | a day ago
But what is the actual source?
biggc | a day ago
jcims | a day ago
JumpCrisscross | a day ago
…would you? The lensing would occur right at the apparent surface of the sun.
jcims | a day ago
JumpCrisscross | 16 hours ago
fc417fc802 | a day ago
myrmidon | a day ago
Edit: My point is that you can't "build" such a thing and later point it somewhere-- you have to fly the camera part of the "telescope" about 3 times as far as voyager 1 went, exactly opposite of your observation target, and it is not gonna stay there for too long either.
As long as we improve rapidly at both drone-building and exoplanet target selection, it is not really gonna be worthwhile because both the drone hardware and the target will be hopelessly obsolete before we even get halfway to the observation point.
kurthr | a day ago
myrmidon | a day ago
And if you circularize (which is expensive to do in delta-v), you minimize the time window you have for observation (because you're basically pointing your speed vector straight to outside of your observation cone).
cyberax | a day ago
For all intents and purposes, you'll be in the interstellar space.
hparadiz | a day ago
mlyle | a day ago
Of course, the rocket equation often makes "just add a few percent more delta V" pretty hard ;)
DarmokJalad1701 | a day ago
But to "get there" within any reasonable timespan requires going really fast - which is currently highly impractical. And then once you get there, you have to them cancel pretty much all of that velocity which is not just a "few percent more delta V".
hparadiz | a day ago
https://ntrs.nasa.gov/api/citations/20140013260/downloads/20...
fc417fc802 | a day ago
tejtm | a day ago
PxldLtd | a day ago
https://www.nasa.gov/general/direct-multipixel-imaging-and-s...
echelon | a day ago
Surely it has happened. They must have all spotted our planet millions of years ago and must be watching us with a continuous high-resolution feed. They've seen our dinosaurs. Their interest will really be piqued when they finally see us invent electricity, though that might be some time in the future for them.
Perhaps even gravitational lensing is primitive to them. Perhaps they're able to break and manipulate physics and peer directly into our light cone, breaking the speed of light. Perhaps through direct wormholes they're already here - computronium in the very oxygen atoms that surround us. In rock silicates, in the air you breathe, in your hemes, in your brain. Calculating.
But perhaps we're the only intelligent species in the entire universe. That is also a possibility. Some big names in astrophysics, such as David Kipping, suggest strongly that we should not rule out that hypothesis. I find his suggestions haunting and beautiful at the same time. You need to watch his videos, and this is a good start: https://www.youtube.com/watch?v=PqEmYU8Y_rI
And finally, it may be that we're all just a historical simulation. Or maybe that's ascribing too much importance to ourselves. Maybe we're just a slop simulation on some AI's plaything, existing for no reason at all. Background NPCs with self-importance, ephemeral existences. But procedural generation at scale isn't really all too different from the laws of the physical universe itself.
The scale of the universe fills me with awe. Every time I think about it, my worries about random algo-rage and clickbait fades away to nothing. It deeply contextualizes our short time here.
imjonse | a day ago
They may be planted by alien AI to lull us into false sense of security.
conductr | a day ago
The_Blade | a day ago
ethersteeds | a day ago
adamredwoods | a day ago
mlyle | a day ago
In fairness, this very often helps us understand the unknown thing more.
kelipso | a day ago
jaapz | a day ago
Currently we don't know a lot of things - but without trying out new ideas how are you ever going to know?
conductr | a day ago
fwip | 22 hours ago
"Zeus sends the lightning, his wrath darkening the very sky," is an understandable model that connects "dark storm clouds" to a likely prediction of lightning.
That urge to explain the surprising, to find the pattern, leads directly to our understanding of the cosmos.
awfulneutral | a day ago
jzu48 | a day ago
QuercusMax | a day ago
kakacik | 9 hours ago
Effectively immortal organisms may be more impressive. Or those surviving in anaerobis boiling water conditions. Or fixing radiation defects like its nothing. Or vacuum. Or...
shevy-java | a day ago
Artifical solar capture systems exist. Synthetic biology also bridges that gap as well and the genetic basis is known and has been manipulated. Granted, coming up with more efficient photosynthesis is very hard, but I don't share your "we humans are stupid" opinion here at all whatsoever.
> or butterfly metamorphosis
Nothing fascinating here. It is just a genetic program. Viruses have similar programs too - yes, no metamorphosis, but take retroviruses and the syncytium. Mammals only reproduce thanks to retroviruses (not 100% correct, but look at this here: https://www.pnas.org/doi/10.1073/pnas.0707873105)
> or the fact that microbes can double their population in a few hours
Wow, we humans surely do not have cells that double. Oh wait ... nevermind. Humans consist of cells. Who would have thought...
Yes, microbes are much faster, but they don't have to coordinate as much as humans do in 3D, not even in a bacterial biofilm. And we have to double a lot more DNA than bacteria do, so of course they are faster.
> about a rose or a redwood tree than all the random and superficial activity the chimp brain produces
That comparison is weird. A rose is thinking as much as a chimp brain?
The human brain is special. Chimps are very clever too but humans have very solid abstract thinking. Animals have this too, to some extent (predator hunting prey, chimps have hunting strategies) but e. g. look at mathematics - animals don't waste their time coming up with higher order theorems.
mr_toad | a day ago
ErigmolCt | 14 hours ago
rixed | 8 hours ago
bradley13 | a day ago
Of course, getting the telescope into place, steering it, etc. - that's the hard part.
Something1234 | a day ago
holoduke | a day ago
27183 | a day ago
mikepurvis | a day ago
Basically you won't be reading license plates but you'd see enough to identify evidence of very large scale construction, and with multiple images over time I bet you could draw even more conclusions.
escapecharacter | a day ago
prerok | a day ago
kazinator | 21 hours ago
JorgeGT | a day ago
brcmthrowaway | a day ago
nradov | a day ago
JorgeGT | a day ago
medler | a day ago
abrookewood | 21 hours ago
_puk | 23 hours ago
Direct link
singingtoday | a day ago
deadbabe | 20 hours ago
kazinator | 21 hours ago
neom | a day ago
hparadiz | a day ago
ant6n | a day ago
dyauspitr | a day ago
hparadiz | a day ago
hparadiz | a day ago
golem14 | 21 hours ago
Couldn't you do something like a Hohmann transfer orbit ? As I understand it, adjusting the orbits far out there isn't as demanding as one might think (you don't have to spend the same energy you took to get out there to get into an orbit. Of course, this also means you will not be able to stay in one place and continuously map the same area, but you can map all the space within a disc?
It takes decades however to finish Hohmann transfers that far out apparently.
Rabbithole: Some calculations that may be entirely wrong would suggest that a <10000lbs spacecraft might be held "in place" for 100 yrs with a small fission reactor and an indium-based FEEP drive with about 15lbs propellant.
duchenne | 13 hours ago
Nition | 15 hours ago
Though the 25km resolution mentioned actually sounds far, far better than the very pixellated planet in the "artist’s depiction". I suppose it depends how small and far away the planet is.
jvanderbot | a day ago
dantillberg | a day ago
stronglikedan | a day ago
I hope they did that eons ago so that I have a chance to see those images in my lifetime!
deadbabe | 20 hours ago
Maxamillion96 | a day ago
https://toliman.space/
They’re building one for stars within 10 parsecs of the sun ( and more specifically for Alpha Centauri) which should launch in the next year
dleeftink | a day ago
thangalin | a day ago
somedude89897 | 22 hours ago
https://www.snexplores.org/article/idea-would-turn-earth-gia...
I started a new thread for further discussion:
https://news.ycombinator.com/item?id=48953907
ErigmolCt | 14 hours ago
MattCruikshank | a day ago
SubiculumCode | a day ago
The_Blade | a day ago
and blaming Canada.
fuzzfactor | 6 hours ago
bilsbie | a day ago
calgarymicro | a day ago
notaustinpowers | a day ago
Due to the density of the planet they believe it could be a water world, or a mostly-icy world due to the lack of hydrogen found, and the lower atmosphere could consist of nitrogen, water vapor, and carbon dioxide. Since the host star is very inactive, there's little atmospheric erosion that would strip away a heavier atmosphere.
kevthecoder | a day ago
lucastamoios | a day ago
Yeah, but not that much.
ck2 | a day ago
* https://news.ycombinator.com/item?id=48939742
NASA has a neat exoplanet catalog where you can also switch to its solar system view
* https://science.nasa.gov/exoplanet-catalog/lhs-1140-b/
Super-Earths are interesting but not technically habitable, at least not by humanoids, the gravity would be insane
There are new telescopes and techniques coming online really soon that can potentially find closer to Earth-sized planets but they probably won't be within 50 light years
adding: hmm maybe gravity not too horrible on 1140b but still INTENSE
(assuming Google's "AI" is correct)
> Gravity Formula: \frac{Mass}{Radius^2}\)Calculation: \(5.6 \div (1.73)^2 = 5.6 \div 2.9929 \approx 1.87\)
> if you weigh 150 lbs on Earth, you would weigh roughly 280.5 lbs on 1140b
dempedempe | a day ago
Well, if they observed not only a planet orbiting the star but also the planet's atmosphere, it must not be a very "distant" star.
danieltk76 | a day ago
palata | a day ago
palata | 8 hours ago
stasomatic | 7 hours ago
I'd be terrified to meet an alien. Very much doubt they'd be attractive purple skinned humanoids like in the STNG. But they are welcome to discover us if they are so advanced, why do we need to sweat, we aren 't done with this rock yet? Thank the universe and light years it's never gonna happen.
techteach00 | a day ago
micromacrofoot | a day ago
creesch | a day ago
creesch | a day ago
This planet sits at a distance of 48 light years, so it would 74 832 years to get there. Just for good measure, when it gets there it would also take 48 years for us to know that since radio travels at the speed of light.
Note, that the speed of the spacecraft I mentioned was the peak speed. Space is big, really big.
nobody9999 | a day ago
[0] https://www.science.org/content/article/astronomers-spot-fir...
quotemstr | a day ago
notahacker | a day ago
shevy-java | a day ago
Life is already on this planet. Why would it matter whether life exists outside of this planet or not? I mean, this is pointless. I understand that some have a financial motife to drive this narrative, but it is not logical. The counter argument is quite simple: IF there is no divine being, then ALL of life's complexity is logical and natural. So, it really does not matter WHERE it originates nor how many times. Why would it matter if it originated 10000x or only once? Now, I do not doubt that it has originated several times rather than once, but my point is that this extra-terrestrial search MAKES ABSOLUTELY NO SENSE AT ALL. That is not to say that research and exploration in space are pointless, but that it IS pointless to "search" for extraterrestrial life. Yet none in the media point that out. It's all as if it were some magical, mythical quest here.
seydor | a day ago
throw4847285 | a day ago
I know I'm a killjoy, but I do think there's something negative about the impact of science fiction on engineers. Like, the people who tend (no offense) to be the most literal, black and white thinkers get exposed to art and instead of processing it as the output of human creativity, they start to imagine that it's desirable or even real.
ClumsyPilot | a day ago
The second is likely easier than the first
chrsw | a day ago
xboxnolifes | a day ago
eightysixfour | a day ago
Why can't you process their fantasizing about it as an output of human creativity?
throw4847285 | a day ago
I don't think I've ever sounded so cynical in my life, but something about the way sci-fi fandom bleeds into real science really makes me deeply uncomfortable.
whimsicalism | a day ago
throw4847285 | a day ago
whimsicalism | a day ago
throw4847285 | a day ago
When I say it like that, it sounds pathetic. And in fact, it is. Yet, here we are.
DavidPiper | 21 hours ago
Space travel seems to be one of the more harmless ones, but I agree it's frustrating to see people implicitly or explicitly skip over things like near-light-speed travel as solved problem, then reject arguments from others as "not thinking big enough", etc.
In general, divorce from reality doesn't seem to be related to intelligence at all in my experience. I'm sure there are plenty of times when my wishful thinking gets in the way too.
eightysixfour | a day ago
You don't think exploring a problem/possibility space (heh) that is probably unobtainable is an effort in creativity?
throw4847285 | a day ago
whimsicalism | a day ago
square_usual | a day ago
I don't know, it feels like you can't process the output of human creativity.
throw4847285 | a day ago
ufmace | 21 hours ago
I'm not gonna hold my breath for the other star system stuff, but if they manage to get the kinks worked out of Starship and it delivers full reusability as promised, it seems like off-world colonies might actually be possible in our lifetimes. If that gets up and running, we might plausibly develop enough space infrastructure that some of the ideas don't seem too crazy anymore.
tulio_ribeiro | a day ago
Red dwarfs are known to be cooler (the habitable zone is therefore closer) and unstable.
I don't think LHS 1140b is "Earth-like" at all. Rather, it's more like a mini-Neptune, being boiled off by its star.
Edit: JWST emission spectroscopy of LHS 1140b as it passes behind its star rules out a mini-Neptune. https://arxiv.org/abs/2406.15136
mr_toad | a day ago
kazinator | 21 hours ago
Without our field, we would be in trouble, too.
jjk166 | 18 hours ago
tonmoy | 18 hours ago
rustyhancock | 10 hours ago
In addition to his Venus example, Mars lost its atmosphere because it's gravity was too small. Not because it lacks a magnetic field.
PeterHolzwarth | 18 hours ago
upelephants | 18 hours ago
eru | 17 hours ago
ErigmolCt | 14 hours ago
gcanyon | 9 hours ago
So:
I think both Venus and Mars qualify (barely).All to say, when someone says a planet is "Earth-like" that doesn't mean we should get out our picnic baskets.
izend | 8 hours ago
OrvalWintermute | a day ago
de6u99er | a day ago
https://youtu.be/twgsq80PD4o
smb06 | a day ago
jdthedisciple | a day ago
peter_stokes | a day ago
timbit42 | 22 hours ago
metalman | a day ago
waynecochran | a day ago
The planet must have an enormous escape velocity to contain helium in its atmosphere. If there is life there they are stuck.
goldlimetea | a day ago
tsoukase | 23 hours ago
So the new probability becomes quite low, which fits with our (non-)observation of alien life. We might not be alone, but we are far away and very short lived.
jjk166 | 18 hours ago
naveen99 | 22 hours ago
ErigmolCt | 14 hours ago
jenova-marie | 22 hours ago
I get that super is more a reference to their size, but really? Science, please respect our Earth and don't label large rocks rotating around some distant star more super than what we have right here! I hate that term, it's offensive.
I also feel science has it totally wrong with "looking for life on other planets". Let start acknowledging that it's the planet ITSELF that is alive, not what's living on it's outer skin.
Science will never find life on a dead planet, OBVIOUSLY.
Science should be looking for "Planets that are alive".
Sorry OP, this has nothing to do with your post, the wording it used was appropriate. I do wonder, how can an atmosphere of He form? Helium commets? Must have been.
thesurlydev | 21 hours ago
Pijuspaul321 | 14 hours ago
BodyCulture | 13 hours ago
shrubby | 13 hours ago
koko443 | 11 hours ago
jimnotgym | 10 hours ago
cedws | 10 hours ago
dbbk | 9 hours ago