If we are receiving the FRBs, the focused beam must be pointed towards earth. So the spaceships with light sails must be headed in the direction of earth. Get ready for the invasion!
Only if they were aiming at where we are now, which doesn't make sense. They would have to aim the craft at where we are going to be in X years. X being the duration of the voyage.
Come to think of it, even if they were aiming directly at where we are now I would assume the light source would still be occulted regularly by everything between us and them.
Gotta remember, if we are seeing light intentionally or unintentionally, they pointed these sails to our current position, almost X years in the past. Where X is the distance in light-years.
You have two sails in concentric rings that are connected, with your craft attached to the outer ring. When you want to decelerate you disconnect the two rings and and tweak the reflection of the inner ring to be somewhat outward focused and give the inner ring a little push. As it moves forward the energy bouncing off the inner ring is directed backwards to the outer ring, which slows. As long as the inner ring reflect more energy backwards (and to the outer ring) than the outer ring is getting from your source the outer ring slows down. Really hard to describe, but easy to draw. First proposed by Robert L. Forward.
If you project a large magnetic field the extra-solar ionized gas (intergalatic, between stars) can exert a fair amount of drag.
A lot of people talk about bussard collector (magnetic scope for hydrogen/helium) to power fusion. But instead of collecting gas use it as a drag chute.
Well, it'll take them awhile to get here. There's still time to start putting rail-guns on asteroids for purely mining purposes, or giant laser arrays on Mercury - just for moving ships around of course.
Maybe I'm just crazy but there are a list of things I hope we figure out in my lifetime, and extraterrestrial intelligence is right up there in the top ten.
Maybe we have figured it out, and just don't like the answer.
(Short answer: we're alone, or at best among the very first tech civilizations in our galaxy. Longer version: given sufficient time and space, even the most unlikely possibility will take place with probability near 1. If there have been technical civilizations in galactic history at a level slightly above our own or better, it's near certain that somebody would have launched a self-replicating interstellar "Bracewell - von Neumann" probe, and they'd saturate the galaxy for the rest of time. We don't see them, though.)
There's also the Three-body problem (https://en.wikipedia.org/wiki/Three-body_problem) answer: anyone who knows what's good for them is hiding. Any interstellar-civilization which reveals its presence is destroyed in a first strike by another civilization in hiding. Any self-replicating probes are also hiding (because there's no meaningful distinction between a self-replicating probe and an interstellar civilization anyway).
I think that's one of those things that's better to have been born well after (assuming a good outcome) or born well before (assuming a bad outcome). It's really hard imaging the transition as anything other than misery and chaos.
You're right, I'm sure the billions of deeply religious people would cope with literal proof that we're not a privileged and special "creation". Even worse, they might not accept that.
Plus new tech, new perspectives, old power structures being overthrown, etc... etc...
Things would change, and change is good for the future, but dangerous to those living through it.
> I'm sure the billions of deeply religious people would cope with literal proof that we're not a privileged and special "creation".
Muslim scholars have considered the possibility of life in the heavens as far back as the Middle Ages. Companions of the Prophet openly considered the possibility of religious beings in the heavens. It was recorded of Ibn-e-Abbas that "He even went so far as to say that they may have a Prophet like Muhammad (pbuh), a Adam like our Adam, a Noah, like our Noah, an Ibrahim like our Ibrahim, and a Jesus like our Jesus."
The Roman Catholic Church has also officially accepted that there may be intelligent aliens. So that covers a pretty large chunk of the world's religious believers already explicitly ok with it.
Generally people ignore changes that don't directly affect their life within a short timespan. Global warming will cause far more disturbance in the near future than anything else will and people seem to be mostly oblivious to it. Extraterrestrials would provide a brief philosophical shift and when people realize they are not coming to visit us and we really can't say anything concrete about them they would continue their life mostly unaffected. Says I.
What is it with tech/science forums and the belief that religious people are crazy, backwards, zealots who would go crazy causing enormous destruction when faced with compelling new scientific revelation. . . this despite the fact that theologians from nearly every religion, including Christianity, Islam, Hinduism have considered extraterrestrial life and claim it does not contradict with their religious beliefs.
What is it with tech/science forums and the belief that religious people are crazy, backwards, zealots who would go crazy causing enormous destruction when faced with compelling new scientific revelation. . .
You're right that lots of theologians are frankly much more impressive than the average adherent. What a pity that we're not surrounded by billions of theologians.
When you talk about biblical flat Earthers you are talking about a very small subset of Christians, to claim that all Christians are like them is akin to claiming that all Muslims are like ISIS.
Similarly Zionism is not really a religious view as much as it is a political one. This can most clearly be seen in the fact that orthodox Jews oppose the state of Israel. They correctly interpret the Torah as saying that Jews have had the holy land taken away from them by God and it can only be re-established by God, not by the the act of men. Similarly the Koran says outright that Allah had given the holy land to the Jews, and groups like the Muslim brotherhood and Hamas that seek take Israel are motivated by political, not religious goals.
If anyone is going to create violence and chaos at first contact, it's not religious people but rather politicians that have a stake in a system that exposure to other, more equal or efficient systems may upend and industrialists that have a stake in the technologies that first contact will replace. There are so many other, historically consistent places to look for potential sources of revolt than mere ordinary people (in fact the majority of the human population) who are merely in search of the divine and greater meaning.
It's always a "small subset". A "small subset" is rabidly anti-abortion. A "small subset" thinks women should be subservient to men, wear burkas, or stay at home and have lots of kids. A "small subset" thinks the Earth is 6000 years old. A "small subset" thinks that it's just a matter of time before the End Times. A "small subset" thinks that Shia/Sunni is apostasy. A "small subset" thinks gay people are evil, thinks that people shouldn't use contraception, etc... etc...
It's always these little small subsets hiding the allegedly "vast silent majority", but unfortunately they add up, they fight, and they ruin it all for the rest of us. I don't worry about the physicists with faith, I worry about the other 99.9999%.
Thinking that Israeli politics has anything to do with religion or that the Israeli Arab conflict has any religious basis is a common but a very big mistake people make.
Have you been to Israel lately? I have. Putting aside the Arab-Israeli conflict, just looking at internal social issues, education, politics... it's the ultra-orthodoxy running the show.
I never thought I'd live to see the day Netanyahu was "moderate".
The use of the term "Ultra-Orthodox" is again problematic, it's not used correctly, it should be used to describe the "Haredi" Jews which aren't really controlling anything, in fact I would go as far as say that even "Haredi" aren't a good fit for the "Ultra-Orthodox" moniker, as there are more hardcore groups than they are including those who want nothing to do with the state of Israel as they believe that the state of Israel cannot be established until the messiah comes the dead have risen and all that fun end of days stuff happens.
And when people use that term to describe the "settlers" that's even beyond, they are nationalist not ultra-orthodox.
Just a random thought, your reality is made up of your environment. Ever imagine being taken out of the Earth and being in space. Suddenly, no bills, no kids, no debt, no whatever. Also nothing else either. You'd probably be dead haha. Still, if there are aliens, it's kind of dumbfounding like "Huh... am I free now?" Is there something greater than this government that controls me? Not saying the government does, I make my own dumb decisions that create my own misery.
It would be a slap to the face though, look at these aliens that can choose to anihilate us or enslave us. (bad case). Just my thoughts, I'm nobody, no credentials, this is purely opinion/current mental maturity haha.
I don't know it's always depressing to me how massive space is, 40 years traveling at 50-150,000mph and the voyager just leaves our solar system hahaha. Crazy. (my numbers might be off depending on reference but that idea of 4 years of 9,000,000 feet per second) to get to the nearest start (dot in the sky) holy christ.
edit: haha holy crap it's approximately 984 million feet per second for like 4.6 years
edit: voyager speed ~36,000 mph, not sure how long that took to build up to that speed.
You have the comfort and leisure to comment on HN, the education to do so coherently, and you've never lived in chaos, but you think you have more to gain than to lose.
extragalactic travel seems to be a really dangerous and difficult prospect. The journey will take millions of years (assuming no FTL travel), and there's basically nothing in between. Even if your species is immortal or something, there's serious risks. You need to bring everything to need for the journey, including energy, because there aren't any stars you can stop at along the way to gather solar energy. You'd have to be very careful planning things so you don't wind up stranded partway.
If you're effectively immortal why would you want to hang around the same place forever? You wouldn't. In fact, you might hope for "something to happen" along a 100,000-year trip just to shake things up a bit!
Also, don't assume that alien life is like ours. It could be many orders of magnitude more efficient and in all likelihood isn't even biological in nature if they've reached the point where a million-year journey is feasible. It could just be a bunch of AIs constantly re-making themselves from resources they pass by as they coast through the universe.
They might not even have a destination! They could literally just be a bunch of machines that "live" in space. Floating around from place to place, grabbing resources from asteroids as they go by.
Lastly, in regards to energy: Why assume solar? Once you've reached speed you're not going to slow down much. Just leave the sails open to protect your craft from debris. I'd also expect a nuclear battery in such a craft to power on-board components. There's plenty of radioactive material in space to draw from for renewal as well. You also don't have to worry about disposal! Just toss it towards the nearest star system or asteroid belt and get a bit of thrust out of the action :)
I was talking about traveling between galaxies, my understanding is there's essentially nothing between them: no asteroids to mine. So you'd need to bring everything you might need in advance. But maybe I'm wrong, maybe there is a decent amount of debris floating between galaxies?
> They could literally just be a bunch of machines that "live" in space. Floating around from place to place, grabbing resources from asteroids as they go by.
Whenever I think of what an advanced civilization would look like, I picture something like this (though not necessarily just machines). Something semi-nomadic, an entire civilization of ships in a big fleet, wandering together through the galaxy, stopping at various systems to gather some resources or explore the planets. Maybe the fleet breaks up and goes in different directions for a time, and rendezvous later.
>I was talking about traveling between galaxies, my understanding is there's essentially nothing between them: no asteroids to mine. So you'd need to bring everything you might need in advance. But maybe I'm wrong, maybe there is a decent amount of debris floating between galaxies?
The current thought now is that there's likely quite a few "rogue planets" out there, and other asteroids that haven't gotten captured by a star. However, the density of such things is likely to be so low, and you won't know until you get there what they're composed of, so it seems like a bad idea to plan a trip assuming you're going to stop at a bunch of asteroids and rogue planets to pick up supplies; you'll easily make your trip far, far longer. Don't forget also the big problem in long-distance space travel is speed. If you want to get to a particular star system, you need to get up to speed and stay there until you're ready to decelerate. You can't afford to slow down and stop at a bunch of rocks along the way, and you'll be going far too fast to capture the small ones. Most of your fuel will be used in acceleration and deceleration, so you can really only do that once most likely.
>Whenever I think of what an advanced civilization would look like, I picture something like this (though not necessarily just machines). Something semi-nomadic, an entire civilization of ships in a big fleet, wandering together through the galaxy, stopping at various systems to gather some resources or explore the planets. Maybe the fleet breaks up and goes in different directions for a time, and rendezvous later.
That doesn't sound like an "advanced civilization" at all, that sounds like a nomadic gang. An advanced civilization will value stability, and stay on their home planet(s) where all their infrastructure is located. They may very well send out exploratory missions, but those nomadic wanderers will not be the civilization itself, just one small part of it.
> An advanced civilization will value stability, and stay on their home planet(s) where all their infrastructure is located
My thoughts were that a sufficiently advanced civilization would desire exploration, both for resources and scientific advancement. And you don't want your people spread out too far (for some definition of far), for a variety of reasons, the biggest being the consequences of the delay in communication and travel. For instance, scientists in different solar systems would find in next to impossible to collaborate: it could take years for news of one group's findings to reach the other, at which point they may very well have independently discovered the same thing, which is inefficient. Also, if one of the systems is attacked, or has some sort of crisis that requires assistance (plague, natural disaster, etc), the rest of the civilization would be unable to react in a timely manner. In short, it's safer to stick together.
Therefore, it would make a lot of sense to put your whole civilization into a fleet of ships with all your infrastructure (or maybe a single giant ship, Death Star sized), and move around. You could stay in a single solar system for a few millennia mining resources, or hop around looking for life.
Sticking to one place or a few nearby places is also an option, but I think it lacks certain advantages a fleet civilization would have.
For instance, scientists in different solar systems would find in next to impossible to collaborate: it could take years for news of one group's findings to reach the other, at which point they may very well have independently discovered the same thing
Even on Earth, where the latency between devices on opposites sides of the planet is measured in hundreds of milliseconds, this is true.
The ten closest stars to Earth are within about 10 light years distance. While two way communication would be impractically slow, sending a continuous stream, UDP-style, to another colony would probably do the job sufficiently well.
>Also, if one of the systems is attacked, or has some sort of crisis that requires assistance (plague, natural disaster, etc), the rest of the civilization would be unable to react in a timely manner. In short, it's safer to stick together.
This is incorrect. This is the "all your eggs in one basket" problem: if you have a big crisis in your civilization, you don't want everyone in one place, because your whole civilization could get wiped out. A civilization this advanced is likely also a very large civilization, so it makes more sense for it to have different parts in different places, just in case.
As for communications, as the other responder pointed out, a continuous transmission, assuming the data rate is high enough, will help keep the different locations in sync. Who cares if scientists independently discover things? Hopefully a civilization that advanced won't be so worried about patent rights.
As for "hopping around" looking for life, you'll do a whole lot better keeping your civilization in one place (or a few permanent locations better yet) and sending probes or exploration teams to a bunch of different places at once. Moving your entire civilization to only one star system at a time would be horribly slow, and sticking everyone in a giant death star means your energy requirements for transporting your civilization between stars would be ridiculous.
A fleet civilization wouldn't have any advantages besides mobility. You only need that if you have something you're trying to get away from, or have a well-founded concern that staying in one particular place could be dangerous. For Battlestar Galactica, it made sense because they were constantly being chased by the Cylons, and even then, the show did a pretty good job, at least at first, of showing what a PITA it is constantly being on the move. For a large, highly advanced civilization that doesn't have a bunch of genocidal robots chasing it, I just don't see how there's any advantage to remaining highly mobile. Mobility requires a lot of energy and greatly limits you in other ways. For a modern analogy, look at people today who live in RVs. Sure, they can drive their whole home away quickly and don't have to worry much about packing up to move, but they don't have much space, their home is easily damaged compared to normal dwellings, and it costs a lot to move it (because of the poor fuel economy). The only way living in starships makes any sense is if energy is basically free for you, which includes having a way to store immense quantities of it, because you'll need a lot when you're between stars.
Hmm your arguments make sense. I think I was overvaluing mobility, because I figured once reaching a post-scarcity society exploration would become the top priority.
My only other point is that the continuous transmission idea only works up to a point. Two populations that sufficiently far (I'd say hundreds of light years, but it could be thousands or millions of light years) apart are essentially different civilizations, because their societies would drift out of sync. Think about how much our culture, our language have changed in the past few centuries, and the rate of change in our society in only increasing. Extreme longevity or immortality might slow down the rate of change, but I'd argue that it wouldn't stop completely.
I guess my point is that civilizations have a maximum radius over which they can function, otherwise societies will drift apart until they are essentially distinct.
That's something I don't see much on these forums! Thanks!
>I think I was overvaluing mobility, because I figured once reaching a post-scarcity society exploration would become the top priority.
I know Star Trek isn't the most realistic TV show in the world, but I do think it (esp. TNG, esp. seasons 3+ because 1-2 sucked!) did a pretty fair job of showing what a post-scarcity society would look like, though to be fair energy was somewhat limited, but not that much.
In the show, most people/beings in the Federation lived on their home planets, or on colonies. There were a LOT of colonies; it seemed they were shown or mentioned every other episode. Most biological beings, assuming they evolve on a planet, and don't upload their minds into androids or something, are probably going to want to continue something like the lifestyle their ancestors had. In addition, there's huge logistical advantages to having stable facilities on planets. Where does the Federation build its starships? On planets, or in orbital construction yards (most likely, the components are largely made planetside, especially small but valuable ones like their computer equipment, and the ships are assembled in orbital shipyards). Where does the Federation mine the resources needed for ships and other stuff? Probably largely on planets and moons, though not necessarily the ones they live on, but the mines are probably very long-term and stable. And where does the Federation get the antimatter it needs to power its ships? According to the technical manual IIRC, they synthesize it from solar energy somehow, since antimatter is not naturally occurring in this universe. So all the infrastructure their society depends on for exploration (which is what many of those starships spend their time doing) is located in relatively fixed locations. Plus, the number of citizens in the Federation is surely enormous (they have thousands of members IIRC, and Earth alone probably has at least 5 or 10B by that time, depending on how many perished in WWIII and how many left the planet for colonization and of course the birthrate). The number of Federation citizens living full-time on starships is surely a tiny, tiny fraction of the total number.
>Two populations that sufficiently far (I'd say hundreds of light years, but it could be thousands or millions of light years) apart are essentially different civilizations, because their societies would drift out of sync.
That's true, but it really depends on the size of the civilization. If our civilization grew to span the nearest 50 star systems, for instance, they'd still all be within 16 light-years [1]. That's a pretty good-sized civilization IMO, and 16 years isn't that long to wait for a news about what's going on the homeworld (though it also means it's about 32ly between the farthest two colonies). A civilization spanning thousands or millions of ly would either be an incomprehensibly enormous civilization, or one which is really picky about which star systems it bothers with.
If you expand that radius to 30ly, now you're looking at probably hundreds of stars. Couple that with the immortality you mention, and assume very stable governments (since a civilization with governments like ours is not going to be spanning multiple star systems, and wouldn't even get far off the planet) and I do believe the rate of change will be much slower so that it's not that big a deal if you don't learn about some interesting news or new music or something from one of the other colonies until it's 50 years old. And don't forget, we consider ourselves (humanity) as having a singular civilization, but how in-sync are we between different nations? Not that much; we don't even speak the same languages much of the time. Most likely, in such a civilization, the different worlds would have different cultures, and there's only be so much interconnection between them, mostly for trade but also probably tourism and such. But I guess now we're getting into an argument over the exact definition of "civilization"; do we have a singular one now, or are the US and China two separate civilizations with trade and cultural exchange? What about centuries ago when communication was all by hand-carried letter or word-of-mouth?
I think that when they say "intergalactic", they're not referring to ships crossing between galaxies - they just mean that the signals we're detecting (which may be light-sail 'engines') come from outside the Milky Way. The ships themselves could just be cruising between stars within those galaxies.
There was this movie called 'Oblivion', one of the concepts suggested in the movie was- Interstellar travel being so hostile for biological life only real and practical way of ever encountering a life form would be in the form a machine/AI.
You don't need to travel in your biological bodies. You can upload your brains to the AI and then have the machine basically run forever. The machine becomes your universe, and it figures out how to best survive in the universe(Mine planets, asteroids, prepare better versions of it self etc etc)
I've often thought to ask whether we'd even come up with technology to pick up fast moving objects in space heading towards us even before we have the capacity to travel at those speeds ourselves.
we've always observe things in nature and then replicated them, if we saw something move faster than light that would advance our technology even if it's just by knowing it exists elsewhere.
More than once I've been in a meeting where someone said "But competitor A spent 1 Billion dollars building that". And I would quip back "And now we know it can be built and it won't take a billion dollars to do it".
I agree, the real value is know something is possible from there all things related make more sense and many decisions can be made based on that one fact.
When I saw this new article start popping up yesterday it reminded me of the book Starfarers by Poul Anderson. Strange radiation signatures are detected in space, scientists figure out it is alien tech, and then figure out how to reverse engineer it.
Didn't read the article, but it's always fun following these lines of thought. We have no evidence of life outside earth, but darn it...we can't be the only ones here...I mean we can, but that just doesn't sit well with me. I wonder if almost any civilization would end up using lightsails powered by beams or if many skip it in favor of some other technology.
I've always wondered if we're already observing evidence of extraterrestrial civilizations, we just think it's some natural phenomenon. All of astronomy is based on observation, if we mistake alien activity for a natural process it could completely screw up our understanding of what's going on. For instance, maybe Quasars are artificial super-structures, created as a power source, or a beacon to signal other civilizations (similar to the signals SETI broadcast) or something else.
NOTE: I don't know nearly enough about astronomy to speculate which phenomena could be potentially artificial, but I do think it is a distinct possibility.
It will probably be something similar to this [1] that allows humans/aliens to travel to distant worlds. As per my limited understanding, nothing can move faster than light in space-time, but it seems that it may be possible for a space-time wave to move faster than light. We would just ride that wave.
That requires the existence of exotic matter, something that really isn't known to exist at all, and it'd be pretty surprising if it did. Pretty much all FTL schemes require some exotic thing that's unlikely to actually be feasible in our universe.
The bending of space is possible though. We could figure out how to bend space in a different way. Think about it, alchemists were trying to figure out how to turn lead into gold. We now know how to transmute an element into gold, although not economically. Science is till pretty young. I wouldn't rule out something similar to the Alcubierre Drive for space travel.
Remember that any such device allows you to travel backwards in time. Does it still seem so plausible to you when you realize that 'c' isn't some kind of cosmic speed limit, but the speed of causality in the universe?
I'm not sure it matters as long as space-time in one section is independent from another section. Maybe? Of course, I don't really know what I'm talking about since I'm not a Physicist. On a related note: As a kid, when I was still an innocent soul, I tried to build a perpetual motion machine and transmit high rate video-without first encoding it- through a phone line. It wasn't until I learned about conservation of energy and bandwidth that I understood the error of my ways. Point is, my ignorance is probably taking me astray.
I don't think you're that far astray, but you might be missing one key factor. There is a concept in physics called the spacetime interval, which can imply one of three kinds of separation: Timelike (events which can be causally connected, i.e. events which are within each other's light-cones), Null (the worldlines followed by photons), and Spacelike (events which are causally disconnected). For an easy example of "Spacelike", anything within an event horizon has a spacelike separation from anything beyond that horizon (an extreme example).
However
What if you could connect those regions with this "warp drive"? You could create a causal link between regions that would otherwise be causally disconnected. You could carry information from the past to the future, or visa versa. You could essentially ignore the very fabric of spacetime.
Now... maybe that's possible, but I doubt that it's possible in the context of warping gravity. If M-theory is correct in some form, or MWI is correct (basically any multiverse theory) then maybe you could do it. After all, if the universe is a lower dimensional structure embedded in a higher one, you could imagine traversing those spacelike separations in the same way that you could do things in 3D that someone bound to 2D could not. That however, depends on so many "if's" that it's basically magic.
Other than the fact that it seems mind-boggling, is there any reason to believe that time travel is forbidden by the laws of physics, or that causality is an absolute?
Time travel isn't forbidden. At least, there are solutions to the Einstein field equations that allow for the existence of wormholes between two points in space-time. But that doesn't mean there are wormholes in our universe, or that wormholes could be created (that last part is a little tricky, it's not easy to talk about causality when dealing with time travel). There could well be other laws of physics that prevent time travel, but general relativity seems to allow it.
It's a solution that assumes things like a perfectly uniform sphere of gas collapsing from infinity (Schwarzschild geometry), without any angular momentum. Even then, the ERB isn't traversable. A lot of the talk around wormholes and time travel suffers from map-territory issues.
For example, if you look at the maximally extended Schwarzschild geometry (the Kruskal-Szekeres extension) you see two asymptotically flat regions of spacetime connected by a "wormhole". It's probably just an artifact of the model though, and not anything physical.
A lot of the, "Math allows" stuff probably falls into that category, which is why when it comes to relativistic masses and velocities, you can't ignore quantum effects either.
You've heard of the progress of entropy and the "thermodynamic arrow of time" right? Time travel into the past, violating causality... it breaks the math used to formulate the most basic physics at a very fundamental level.
Definitely the latter, there's no way to say it's impossible, just incredibly unlikely. It's easy to imagine a universe in which it is possible, and that universe could be consistent with the math. The big "but" however is that our universe has none of the features we'd expect from one with the necessary curvature or exotic matter/energy.
Does that make sense? I mean, if we discover that there are multiple universes, or that Block Universe is true.... who knows? Even then however, I suspect we'd run into something like Novikov Self-Consistency Principle, or we'd have noticed time travel by now.
Personally, I like to believe that NP hard problems can be solved efficiently in our universe. If time travel is possible, PSPACE can be solved efficiently. That is a pretty good argument for me that time travel is not possible.
That's an interesting perspective I've never considered, coming at it from the physics end of things. I appreciate what amounts to a much more grounded and logical take on why time travel makes so little sense, and is so hard to consider seriously.
I'm as Astronomer. I think it's very interesting to read about these kind of scenarios in novels, but I don't think they have a place in a scientific publication.
We are researchers, we try to explain the universe by improving our understanding of the physical processes that lie behind what we observe. The moment we bring aliens or gods into the picture to explain something for which we don't have an answer, we are doing a disservice to science.
Although the possibility that FRBs are produced by
extragalactic civilizations is more speculative than
an astrophysical origin, quantifying the requirements
necessary for an artificial origin serves, at the very
least, the important purpose of enabling astronomers to
rule it out with future data.
Never mind the fact that it makes testable predictions:
It should be possible to distinguish between FRBs of
natural and artificial (light sail) origin based on the
expected shape of the pulse, as the beam sweeps by to
power the light sail. More specifically, the sail
would cast a moving shadow on the observed beam,
thereby leading to a diffraction pattern and multiple
peaks in the light curve based on the sail geometry.
A series of short symmetric bursts would be observed as
the beam’s path intersects with the observer’s line of
sight. Hence, looking for similar signatures in the
signal could help determine whether FRBs are powered by
extragalactic civilizations...
Yeah, but you don't have experimental design for the alien intelligence "hypothesis." This is just emotionally satisfying drivel. There's nothing unscientific about not having a hypothesis when more information is being gathered. The paucity of data on FRBs makes any hypothesis right now almost worthless.
We don't even know for sure that the majority of FRB data we have are from non-terrestrial phenomena. FRB occurrences at Parkes correlate strongly with lightning storms near the observatory.
But sure, it's probably angels or little green men. Why not. That's a hypothesis, you're doing science Jimmy!
So if you're observing a rain forest in Central America or a high mountaintop in South America, and you see some strange patterns or interestingly-stacked rocks, you think we should only look for non-human explanations for these things?
With this attitude, much archeological evidence of pre-Columbian civilizations would never have been found. In fact, the entire field of archaeology wouldn't exist.
Nobody mentioned elves. You're trying to make his argument absurd. We explain most phenomena scientifically and this is no exception. It most likely isn't an artificial signal, but who knows.
What's absurd about elves? If it could be little green men, maybe they have pointy ears. This is science after all, as long as it's a hypothesis, it counts, right?
We should always look for the simplest explanation but be willing to acknowledge and embrace our ignorance too.
Your attitude turns people off science; it's a plodding, unimaginative attitude that pours cold water on every novel idea without even bothering to explore it properly. The history of science is full of discoveries resulting from accident or whimsy, and I think speculation is an important exercise. Nobody ever got to the top of a mountain by meticulously documenting every step of the route.
So there's a risk you'll pin some hopes on an idea that turns out to be wrong. That shouldn't be bad for your career unless you do it all the time. A scientist who is never wrong about anything isn't taking any risks.
Now-a-days with the social networks, everything seems to be about excitement for some people, but the scientific method survived almost two centuries very well without it, thank you very much.
If you want that kind of excitement, try other area, in here, the only excitement comes from finding an answer to a problem based on science, not in some sci-fi novel.
P.S.: The simple explanation in this case is of course some physical process we can't understand. Not an alien civilization making planet sized machines to power their spaceships. This ain't star wars.
