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?
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.
What's exciting to me is that the existence of such a planet provides fuel for more research into the field.
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.
(No punchline; I just think that's cool. I understand that the real problem is the rare dust grain, not the ubiquitous gas.)
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.
You might want to look up what the unix epoch is based on ;)
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
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
assuming we can make it another few centuries, which seems increasingly unlikely.
750 years is hard for me to get excited about even as a vampire.
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.
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.
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.
Provided the Earthlings that were sent along don't let their incarceration induced insanity infect the youngin's.
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... .
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.
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
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.
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.
They shouldn't be drafted to resolve the rise of petty tyrants. It's a waste of their time.
And probing the universe outside the Milky Way? Forget about it.
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).
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...
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.
For any object with nonzero rest mass, reaching exactly the speed of light in vacuum would require infinite energy.
I love it.
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 think of one, bring it up.
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.
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.
Sentient life in hospitable environments is as unavoidable in the Star Wars universe as it is absent in ours.
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.
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.
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.
What kinds of scientific breakthroughs would be required? Could those breakthroughs be achieved in the next 2 or 3 centuries?
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.
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).
That is a pretty big missing part. Not as big as the galaxy, but still huge.
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.
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 ...?
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?Nonsense. You mean not able to support terrestrial life.
>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.
So the question becomes: How much of that atmosphere is helium?
The era of ridiculous sounding last words came to an end
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.
If all your reactive chemistry comes from water/minerals, you’re also a heck of a lot more tethered, as both these cycle slower than the atmosphere.
A dynamic atmosphere is a huge component of the energetic efficiency of life on earth. And while it’s totally plausible other chemistries can match this, what’s implausible is for no chemistry to match it.
And when it comes to complex life on earth, it literally didn’t happen till oxygen percentages got sufficiently high in the atmosphere, a two billion year long process set off by Cyanobacteria. You can’t get big bodies if you can’t get this kind of energy.
Don't be so open-minded about extra-terrestrial life that your brain falls out.
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.
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.
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.
But what is the actual source?
…would you? The lensing would occur right at the apparent surface of the sun.
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.
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).
For all intents and purposes, you'll be in the interstellar space.
Of course, the rocket equation often makes "just add a few percent more delta V" pretty hard ;)
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".
https://ntrs.nasa.gov/api/citations/20140013260/downloads/20...
You have to be so far because that's the minimal distance where the Einstein ring becomes larger than the Sun's apparent diameter.
https://www.nasa.gov/general/direct-multipixel-imaging-and-s...
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.
They may be planted by alien AI to lull us into false sense of security.
In fairness, this very often helps us understand the unknown thing more.
Currently we don't know a lot of things - but without trying out new ideas how are you ever going to know?
"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.
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.
> all the extraterrestrial AI swarms
Of course, getting the telescope into place, steering it, etc. - that's the hard part.
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.
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.
But first-- the price to get that circular orbit is steep, you end up imaging empty space for a lot of the time (no real way to "skip ahead") and your orbital speed vector makes you leave the observation cone for any interesting target pretty quickly.
In conclusion: You probably really want to stick with "one telescope probe per target system", and to give them one-shot orbits because those are cheap, reasonably fast and inside the observation cone (for your single target) for longer.
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.
I hope they did that eons ago so that I have a chance to see those images in my lifetime!
But that got me thinking, if an intelligence goes around collecting species, how would they keep their specimen populations from evolving? How could they possibly keep so many specimens alive over the eons?
Perhaps their strategy would be to take a vast amount of genetic samples and preserve those species as data. Rather than abduct dozens of T-Rexes for some zoo exhibit, they take the genomes from tens of thousands of T-Rexes and make a population snapshot. After they depart from Earth they could clone or create as many as they want, as needed.
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
https://www.snexplores.org/article/idea-would-turn-earth-gia...
I started a new thread for further discussion:
and blaming Canada.
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.
Yeah, but not that much.
* 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
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.
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.
I was answering to someone saying that they would dream of seeing animals from another planet. Pretty sure that they (like everybody else) cannot list 0.01% of the insects out there.
If one is interested in animals, there is more to discover on Earth than what they can realistically do in their whole life. Being interested in alien animals feels like "I don't actually care about animals, but I find the idea cool".
I get the point, but it sounds like you just don't care about football in the first place.
The above can be repeated for every other sport. I know someone not interested in the soccer world cup despite it being the most talked about event in the US now - but they are at the local kids lacrosse games (not a common sport in the US). I'm like that, I'm very interested in another cat if one is found, but I don't care about another insect. I'm not against you caring, it just isn't me.
add in a bunch of complication for "oh wait, you need to stop too"
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.
[0] https://www.science.org/content/article/astronomers-spot-fir...
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 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.
The second is likely easier than the first
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.
When I say it like that, it sounds pathetic. And in fact, it is. Yet, here we are.
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.
You don't think exploring a problem/possibility space (heh) that is probably unobtainable is an effort in creativity?
I don't know, it feels like you can't process the output of human creativity.
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.
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
Without our field, we would be in trouble, too.
In addition to his Venus example, Mars lost its atmosphere because it's gravity was too small. Not because it lacks a magnetic field.
There should be a decent amount left as sulfuric acid.
So:
- no atmosphere? no problem
- no water? no problem
- average temperature 40c? fine
- 4c? Yup
All to say, when someone says a planet is "Earth-like" that doesn't mean we should get out our picnic baskets.
based on what
>but it's also so large that we'll never sense them let alone communicate with or see them.
unfalsifiable.
The planet must have an enormous escape velocity to contain helium in its atmosphere. If there is life there they are stuck.
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.
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.