Didn't know a rocky planet in the habitable zone of a red dwarf could retain atmosphere against intense stellar stripping.<p>Red dwarfs are known to be cooler (the habitable zone is therefore closer) and unstable.<p>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.<p>Edit: JWST emission spectroscopy of LHS 1140b as it passes behind its star rules out a mini-Neptune. <a href="https://arxiv.org/abs/2406.15136" rel="nofollow">https://arxiv.org/abs/2406.15136</a>
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 <i>has</i> water, just water would be liquid under some circumstances if it were there.<p>So:<p><pre><code> - no atmosphere? no problem
- no water? no problem
- average temperature 40c? fine
- 4c? Yup
</code></pre>
I think both Venus and Mars qualify (barely).<p>All to say, when someone says a planet is "Earth-like" that doesn't mean we should get out our picnic baskets.
The host star is described as very inactive, which probably accounts for the retention of atmosphere.
A really powerful magnetic field could help, also.<p>Without our field, we would be in trouble, too.
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.
I’m not 100% sure I follow what you mean, but here is a link from NASA saying our magnetosphere protects the atmosphere from erosion <a href="https://science.nasa.gov/science-research/earth-science/earths-magnetosphere-protecting-our-planet-from-harmful-space-energy/#:~:text=our%20atmosphere%20by%20the%20solar%20wind" rel="nofollow">https://science.nasa.gov/science-research/earth-science/eart...</a>
He's right the magnetosphere doesn't <i>significantly</i> protect our atmosphere. It probably reduces helium loss on earth and other lighter elements.<p>In addition to his Venus example, Mars lost its atmosphere because it's gravity was too small. Not because it lacks a magnetic field.
Venus has lots all her lighter elements in the atmosphere. Basically no hydrogen left (not even in the form of water).
Atmosphere E != Atmosphere V
Pithy rejoinder, thanks! If this were /. in 1999, I'd call this +1 Insightful.
I went through almost exactly the same thought process reading this :)
We should build a solar lens telescope. By the time we're ready to use it, we'll have a bunch of candidates to point it at.
<a href="https://en.wikipedia.org/wiki/TOLIMAN" rel="nofollow">https://en.wikipedia.org/wiki/TOLIMAN</a><p><a href="https://toliman.space/" rel="nofollow">https://toliman.space/</a><p>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
There's a project that's going well from NASA for this. Still a moonshot but they've progressed through the early stages well so far.<p><a href="https://www.nasa.gov/general/direct-multipixel-imaging-and-spectroscopy-of-an-exoplanet-with-a-solar-gravitational-lens-mission/" rel="nofollow">https://www.nasa.gov/general/direct-multipixel-imaging-and-s...</a>
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.<p>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.
Great in depth youtube video on this project: <a href="https://www.youtube.com/watch?v=go-50Dpzs20" rel="nofollow">https://www.youtube.com/watch?v=go-50Dpzs20</a>
What would a 25km resolution of earth look like
This is the Earth last Wednesday at 0.25º resolution (roughly 28 km per pixel at the equator): <a href="https://neo.gsfc.nasa.gov/servlet/RenderData?si=2050444&cs=rgb&format=JPEG&width=1440&height=720" rel="nofollow">https://neo.gsfc.nasa.gov/servlet/RenderData?si=2050444&cs=r...</a>
It's dead.
What a shame. I had expected the Earth to last a bit longer.
Yeah, it seems it's not permanent. You can go here: <a href="https://neo.gsfc.nasa.gov/view.php?datasetId=VIIRS_543D&date=2026-06-30" rel="nofollow">https://neo.gsfc.nasa.gov/view.php?datasetId=VIIRS_543D&date...</a> and then click on the right side "0.25 degrees 1440 x 720".
Uploaded for the lazy: <a href="https://imgur.com/a/0I8f8DG" rel="nofollow">https://imgur.com/a/0I8f8DG</a>
<a href="https://neo.gsfc.nasa.gov/servlet/RenderData?si=2050444&cs=rgb&format=JPEG&width=1440&height=720" rel="nofollow">https://neo.gsfc.nasa.gov/servlet/RenderData?si=2050444&cs=r...</a><p>Direct link
Earth is 12700 km in diameter, so such an image would be 688 pixels across.<p>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.
That's phenomenal. This would bring us so much fascinating information.
Enough to see cities
Donald Trump's ego would show up as just one pixel.
Wow. 25km resolution of the exoplanet's surface.<p>Of course, getting the telescope into place, steering it, etc. - that's the hard part.
I wonder about all the extraterrestrial AI swarms that have already imaged earth.<p>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.<p>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.<p>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: <a href="https://www.youtube.com/watch?v=PqEmYU8Y_rI" rel="nofollow">https://www.youtube.com/watch?v=PqEmYU8Y_rI</a><p>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.<p>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.
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.
"dunno" is just a really unsatisfying answer to anything<p>Currently we don't know a lot of things - but without trying out new ideas how are you ever going to know?
> and create a narrative like we know anything about the unknown thing. It helps us feel like we understand it more.<p>In fairness, this very often helps us understand the unknown thing more.
I'd argue that it's this same pattern-seeking drive that undergirds science.<p>"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.<p>That urge to explain the surprising, to find the pattern, leads directly to our understanding of the cosmos.
It’s how science and discoveries are done too…
who made you the Pope of deciding what can and cannot be known?
That would be me.
Abdication syndrome.
<p><pre><code> > all the extraterrestrial AI swarms
</code></pre>
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.
>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<p>They may be planted by alien AI to lull us into false sense of security.
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.
I'd be impressed if those microbes or butterflies visited the moon and came back to tell about it.
Maybe visiting moon is overrated. We can't know, we have very narrow tube vision centered around our rather primitive lives.<p>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...
> But compare it with to photosynthesis<p>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.<p>> or butterfly metamorphosis<p>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: <a href="https://www.pnas.org/doi/10.1073/pnas.0707873105" rel="nofollow">https://www.pnas.org/doi/10.1073/pnas.0707873105</a>)<p>> or the fact that microbes can double their population in a few hours<p>Wow, we humans surely do not have cells that double. Oh wait ... nevermind. Humans consist of cells. Who would have thought...<p>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.<p>> about a rose or a redwood tree than all the random and superficial activity the chimp brain produces<p>That comparison is weird. A rose is thinking as much as a chimp brain?<p>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.
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If they let me watch the videos of our dinosaurs, I would happily let them use my hemes for their calculations.
I do not really believe the wormholes or computronium scenario, but letting my mind run through those possibilities resets my sense of scale
I doubt any new physics will be needed, just computational imaging, meta-optics, very long baselines (multi AU, or even light years).
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.<p>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, <i>exactly</i> opposite of your observation target, and it is not gonna stay there for too long either.<p>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 <i>and</i> 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.
an ort cloud of eye peices comes to mind
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.
> I hope that aliens build a similarly amazing telescope<p>I hope they did that eons ago so that I have a chance to see those images in my lifetime!
I hope they picked up dinosaurs and bred them. And maybe bring them back home! Even though our atmosphere is no longer oxygen dense enough.
In theory we can then get 100 meter resolution on alien worlds. That would be insane.
According to AI, an equivalent would be roughly when Google maps shows you 10mi/20km reference scale.<p>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.
> aliens would probably assume that the world is naturally full of green stuff that is dealing with some strange grey infestation.<p>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.
Even on that scale, major roads and agricultural grids are clearly visible. The mark of abstract intelligence is unmistakeable.
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"
This reminds of me <i>canali</i> : <a href="https://en.wikipedia.org/wiki/Martian_canals#Interpretation_as_engineering_works" rel="nofollow">https://en.wikipedia.org/wiki/Martian_canals#Interpretation_...</a>
Well, they would see the I-35 out of Houston, but that would show them no sign of intelligence. Just signs of corruption
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 <i>squares</i> 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.
The most powerful observational tool in the universe would not show 35 anywhere near Houston.
Yup, mixed it up with the I-10. That's the widest road/band on earth. Much easier to see than the Chinese wall. <a href="https://supercarblondie.com/widest-highway-in-the-world-houston-texas-26-lanes-katy-freeway/" rel="nofollow">https://supercarblondie.com/widest-highway-in-the-world-hous...</a>
Spectral analysis at that resolution would be much more telling.
> According to AI<p>But what is the actual source?
Turning off what labels?
On that scale, we really do look like mold.
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An alternative is to use Earth's atmosphere for imaging exoplanets:<p><a href="https://www.snexplores.org/article/idea-would-turn-earth-giant-space-telescope" rel="nofollow">https://www.snexplores.org/article/idea-would-turn-earth-gia...</a><p>I started a new thread for further discussion:<p><a href="https://news.ycombinator.com/item?id=48953907">https://news.ycombinator.com/item?id=48953907</a>
Yeps. The target-selection problem will likely solve itself long before the engineering does
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>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><p>…would you? The lensing would occur right at the apparent surface of the sun.
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.
<a href="https://www.youtube.com/watch?v=NQFqDKRAROI" rel="nofollow">https://www.youtube.com/watch?v=NQFqDKRAROI</a>
48 light years is in our back yard.<p>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?
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.<p>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.<p>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.<p>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.<p>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.
We simply don't kow.<p>On a scale of probable -> less probable, you have:<p>Self-organizing chemicals -> replication -> evolution -> multi-cellular life -> creatures that move around -> intelligent life -> use of tools -> basic technology like wheels, steam engine -> advanced tech -> automation -> space faring -> capable of interstellar travel -> capable of intergalactic travel. Powered by energy sources of increasing complexity/sophistication & scale.<p>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?<p>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 <i>or time</i>.<p>Doesn't matter who visits who if neither party can cross the ocean in between.
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!<p>Sentient life in hospitable environments is as unavoidable in the Star Wars universe as it is absent in ours.
<i>Project Hail Mary</i> 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.
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.<p>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.<p>So "realistically" at 3% of c we are talking about roughly 1500 years to just speed past our target.<p>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.<p>Again, space is big, really big.
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.
> Def not rockets. OP said hundreds of years.<p>Yeah to reach it with current tech. No shifting goal posts, thank you very much.<p>> In hundreds of years from now our rulers will definitely have that kind of tech, whatever tech it is.<p>Also, I should point out that technological progress isn't linear and guaranteed. Also, "our rulers" what ...?
I think we can't even build a radio transmitter that covers 48 light years.
> the fastest space craft ever made was the Parker Solar probe (using a sling shot) clocking in at 692 000 km/h…<p>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).
Seriously even the nearest star is 6,200+ years at Parker probe speed.
I want to know what future technologies could accelerate an object to a significant fraction of the speed of light.<p>What kinds of scientific breakthroughs would be required? Could those breakthroughs be achieved in the next 2 or 3 centuries?
> I want to know what future technologies could accelerate an object to a significant fraction of the speed of light.<p>With all due respect, this has been extensively debated online and is extremely easy to look up.<p>> Could those breakthroughs be achieved in the next 2 or 3 centuries?<p>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.<p>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 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 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.<p>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.
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.
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.
> you can't use these lasers to slow down the probe<p>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.
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
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.
Could you expand on what “space time metric engineering” is?
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.<p>750 years is hard for me to get excited about even as a vampire.
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.
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.<p>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 <i>really</i> 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.<p>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.<p>[1] - <a href="http://www.convertalot.com/relativistic_star_ship_calculator.html" rel="nofollow">http://www.convertalot.com/relativistic_star_ship_calculator...</a>
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<p>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 you can create a ship that is capable of 1g acceleration, it doesn't just stop accelerating as it reaches the speed of light<p>For any object with nonzero rest mass, reaching exactly the speed of light in vacuum would require infinite energy.
Even if FTL <i>is</i> achievable (which I agree, highly unlikely), it's still extraordinarily slow on cosmic scales. The closest star is a little over 4 ly away!<p>And probing the universe <i>outside</i> the Milky Way? Forget about it.
1. if FTL <i>is</i> achievable, then presumably it isn't limited to 1.00000000001 x C<p>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).
We are still so slow and have had space travel for so little time, we are almost certainly on the "wait" side of the wait equation: <a href="https://en.wikipedia.org/wiki/The_Wait_Equation" rel="nofollow">https://en.wikipedia.org/wiki/The_Wait_Equation</a>
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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.
The next known black hole is tens of thousands of light years away. Also, the universe does not seem to be inside a black hole.
What definition of black hole are you using?
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 *
Good luck doing anything on any other planet if you can't even handle your own that's perfectly suited for your kind of life form.
Yeah, let's ignore current issues and instead focus on remote stars.
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.<p>They shouldn't be drafted to resolve the rise of petty tyrants. It's a waste of their time.
the message you replied to implied the exact opposite.
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<p>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.<p>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
> 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.<p>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<p>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.<p>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
There is no drive, it’s all orbital slingshots with current technology. None of the other stuff people are talking about here exists…
Just aim for the desired exoplanet and pack a <i>really beefy</i> shielding system. It would make for a spectacular show.
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)
Adding to this:<p>Those 190km/s of the Parker solar probe were, crucially, periapsis speed.<p>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".<p>~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.
Universe #23: keep solar systems far enough that they can't make war on each other.
We are looking at 75,000 years. You forgot the %.
Honestly a near millennia long expedition would be very cool, and doesn’t seem too long on the scale of space stuff.
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.<p>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.<p>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.
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.
If you could solve propulsion enough to accelerate and decelerate a spaceship at <i>just 1G</i>, 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.
We cannot design a probe that travels at the speed of light.
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?<p>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.<p>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.
Find a way to sell ads on it.
Short term thinking isn't why we are suffering. We are suffering because there are no promising avenues to pursue.<p>If you think of one, bring it up.
We have as much chance as a human stepping inside a bacteria (i.e. physics makes it near impossible)
Astrophage
> in the next few centuries<p>assuming we can make it another few centuries, which seems increasingly unlikely.
This is so exciting.
why don't they check us out first?
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.<p>other ideas:
1. be way more patient
2. anti matter based propulsion (more out there than solar sails)
3. nuclear bomb based propulsion<p>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.
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.<p>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.
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.<p>(No punchline; I just think that's cool. I understand that the real problem is the rare dust grain, not the ubiquitous gas.)
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.
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.<p>What's exciting to me is that the existence of such a planet provides fuel for more research into the field.
If humans can't make the trip, what's the point besides maybe satiating curiosity in a few hundred years from now?
need to get small fusion reactors online, then many options blossom.<p>And work out safe systems for hibernation, maybe rotate the crew in shifts<p>Oh yeah this is the stuff of science fiction coming to life
If we had a probe in orbit around this planet, do we have a way to stream data across 48 light years with any kind of reliability?
Send a lot of them and have them act as relays
why, so they can watch corporate news from earth to get depressed? /s<p>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.
I feel like I've been hearing about atmosphere on Earth-like planets for a while. Or maybe I've missed some nuance.
Related/dupe: <a href="https://news.ycombinator.com/item?id=48939742">https://news.ycombinator.com/item?id=48939742</a> (45 comments)
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.<p>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.
> The gas detected in the atmosphere is helium, which would not be able to support life, but other gasses may also be present.<p>Yeah, but not that much.
Let’s go there and destroy everything! Will be lots of fun and make us a lot of money!
Cool, when can I move there? I'm about done with this planet.
The atmosphere is helium so I don't think you'd be living there long.
Stay here, the psycho billionaires will hopefully move themselves.
Keep in mind that Venus is also an Earth-like planet with an atmosphere in the habitable zone of a sun-like star.
| The gas detected in the atmosphere is helium<p>The planet must have an enormous escape velocity to contain helium in its atmosphere. If there is life there they are stuck.
Even if it was discovered in the beginning, wouldn't it be our distant descendants who could go?
> Researchers have found the first atmosphere surrounding an Earth-like, rocky planet orbiting within the habitable zone of a distant star.<p>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.
Am I understanding right? They detected an atmosphere but don’t know what it’s made of?
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.<p>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.
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.
There could be a second one (see at the end if this interview).<p><a href="https://youtu.be/twgsq80PD4o" rel="nofollow">https://youtu.be/twgsq80PD4o</a>
i do hope in my lifetime we find other animals on other planets
Habitable for silicon intelligence may be more common than habitable for carbon intelligence.
What technology currently available combined with the best launch window, gravity assist etc exists? Might as well send a probe.
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.<p>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.<p>Note, that the speed of the spacecraft I mentioned was the peak speed. Space is big, really big.
500+ years, and it would likely need to be inert for most of that trip, space is <i>big</i>
How far will we peer into the unknown? What will we find out there?
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.
It's a good Lovecraft quote,but I was inspired by Collective Soul's Shine when I saw the OP.<p><pre><code> Lay me on the ground
And fly me in the sky
Show me where to look
Tell me, what will I find?
What will I find?</code></pre>
aliems
Underlying paper from <i>Science</i>[0]<p>[0] <a href="https://www.science.org/content/article/astronomers-spot-first-atmosphere-around-potentially-habitable-alien-world" rel="nofollow">https://www.science.org/content/article/astronomers-spot-fir...</a>
Nice
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.<p>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.
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.<p>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.
You can't imagine someone getting excited about difficult problems as an engineer? And you can't imagine why there's creativity involved?<p>I don't know, it feels like you can't process the output of human creativity.
There is too much fantasy about distant habitable planet and not enough about making a planet in solar system habitable or building artificial habitats<p>The second is likely easier than the first
Not just likely easier. Far easier. They're so far apart on any reasonable effort scale that the comparison is basically meaningless.
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.<p>Why can't you process their fantasizing about it as an output of human creativity?
No, it doesn't seem very creative to me.<p>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)
> No, it doesn't seem very creative to me.<p>You don't think exploring a problem/possibility space (heh) that is probably unobtainable is an effort in creativity?
there is clear reason why this would be desirable for many, the others - sure.
nanu nanu
we talked about this in great detail yesterday on HN with some fantastic comments<p>* <a href="https://news.ycombinator.com/item?id=48939742">https://news.ycombinator.com/item?id=48939742</a><p>NASA has a neat exoplanet catalog where you can also switch to its solar system view<p>* <a href="https://science.nasa.gov/exoplanet-catalog/lhs-1140-b/" rel="nofollow">https://science.nasa.gov/exoplanet-catalog/lhs-1140-b/</a><p>Super-Earths are interesting but not technically habitable, at least not by humanoids, the gravity would be insane<p>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<p>adding: hmm maybe gravity not too horrible on 1140b but still INTENSE<p>(assuming Google's "AI" is correct)<p>> <i>Gravity Formula: \frac{Mass}{Radius^2}\)Calculation: \(5.6 \div (1.73)^2 = 5.6 \div 2.9929 \approx 1.87\)</i><p>> <i>if you weigh 150 lbs on Earth, you would weigh roughly 280.5 lbs on 1140b</i>
They found Planet X, Nibiru! :0
> The gas detected in the atmosphere is helium, which would not be able to support life<p>Nonsense. You mean not able to support terrestrial life.
I was skeptical about that as well so I googled it and:<p>>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.<p>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.
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.<p>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.<p>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.<p>It’s hard to see how that kind of evolution will occur if a lot of the environment is nonreactive.<p>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 <i>evolve</i> in a helium environment that’s non-reactive though.
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.<p>So the question becomes: How much of that atmosphere is helium?
> helium was a preferred way for suicide<p>The era of ridiculous sounding last words came to an end
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.
Helium is a noble gas. It forms no bonds and is unable to produce even a simple molecule, let along the complex ones needed for life.
Would be briefly hilarious though as the squeaky response made it back through to mission control.
They didn't say oxygen is not present. 78% of earth's atmosphere is nitrogen and we are doing fine.
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
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This whole search for life outside planet Earth is ... stupid.<p>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.
life does not exist on other planets (not considering contamination). I'll bet on it
Sure, but keep in mind that technically New Jersey is "habitable," so don't get too excited.
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?<p>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.<p>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.<p>Science will never find life on a dead planet, OBVIOUSLY.<p>Science should be looking for "Planets that are alive".<p>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.