What WOULD be adequate proof of alien visitation to Earth?

[cybernetichero]

Perseverance's successful landing has scared up some UFO conspiracists online. I used to be like them and I was into Charles Forte as well, encouraged by people who should have known better (yes I AM looking at you Arthur C. Clarke) until I realized I just really wanted to believe rather than was convinced. Since then I have made friends with Occam's Razor.
So, given the Drake Equation and Fermi Paradox are taken as read what would be proof enough to convince the world? I always said I would believe it when they appeared on Letterman (#datedreference, whaddaya want I'm old) because, like Carl Sagan said, "big claims require big proofs".

 

[jim mcnamara]

Check out Panspermia as a hypothesis about life else where coming to earth. Let's start smaller with bacterial spores. If that can be proven using biochemical means - possibly biochemical analysis done a by a Mars rover - then it would lend credence (and funding) to efforts like you seem to describe.

https://en.wikipedia.org/wiki/Panspermia

In case you don't know, try this as well:
https://en.wikipedia.org/wiki/Fermi_paradox This is sort of like running the problem analysis backwards

 

[russ_watters]

I always said I would believe it when they appeared on Letterman (#datedreference, whaddaya want I'm old) because, like Carl Sagan said, "big claims require big proofs".

The "Independence Day" scenario would be pretty convincing. Alderaan too, but only briefly.

But I'm not sure that's really what you mean to ask:

So, given the Drake Equation and Fermi Paradox are taken as read what would be proof enough to convince the world?

Those have nothing to do with alien visitation, so do you really mean to ask about proof of life or convincing alien visitation?

 

[hmmm27]

As a non-scientist, I'm going with "concensus of the hard-scientific community that's relevant to the evidence".

(you may or may not find it bizarre that - as a standalone datum - simply the existence - of evidence that our planet has been visited by ET's - isn't that interesting to me ; notwithstanding that I would/will be totally 'OCD' about the actual evidence, itself)

 

[cybernetichero]

Those have nothing to do with alien visitation, so do you really mean to ask about proof of life or convincing alien visitation?

All I really meant was to head off any chance the conversation would get bogged down by either. If aliens had been or were here now what would be adequate threshold of proof from a scientific POV.

 

[Mondayman]

Independence Day/Mars Attacks.

I am not a fan of the speculation and conspiracy theories that people buy into about aliens. Particularly that awful show that my step dad watches on History Channel.

 

[cybernetichero]

Independence Day/Mars Attacks.

I am not a fan of the speculation and conspiracy theories that people buy into about aliens. Particularly that awful show that my step dad watches on History Channel.

I feel like I was made a fool of by these hucksters and can only say in my defence that I was only a kid at the time but it sure makes me see red.
The high school librarian got me into Forte and had several books by and about him in the school collection.

 

[Algr]

Anything that was clearly manufactured would do it. It would have to be something that could not be explained by natural processes, or human involvement, or random chance. (The face on Mars). If we had gotten a good look at Oumuamua, and found it to be a hollow metal tube bolted together, that would have done it.

 

[Jarvis323]

I feel like I was made a fool of by these hucksters and can only say in my defence that I was only a kid at the time but it sure makes me see red.

You can also be double fooled, e.g. by your reaction to perceiving that you had been fooled or that someone had been trying to fool you.

As an example, a lot of people think that radiation therapy as a treatment for Covid-19 is an absurd idea, because it was presented absurdly by a widely discredited person. But radiation therapy as a treatment for Covid-19 is being seriously investigation by medical researchers.

 

[PeroK]

To take a more realistic and rational view of this:

1) A visit from an extraterrestrial species would be, for them, a monumental undertaking. They would need a very good reason to come here. Not to mention how they would know where to come.

2) It seems unlikely that space travel would involve the aliens themselves. Instead, it would most likely be a computer operated probe - perhaps one of many sent out to random exoplanets with a generic message of introduction.

3) The whole idea of an alien spaceship traversing the galaxy and crash landing on Earth (with aliens inside it) is just absurd.

The truth is that fictional space travel - from Star Trek, to Star Wars to Alien and all the rest - is predicated on loopholes in the laws of physics. It reality it may take hundreds or thousands of years to exchange a few messages (via space probes) with an alien species. The idea of hopping about the galaxy like it was an extension of the Bakerloo line is absurd.

Space exploration and alien contact is most likely to develop extremely slowly.

 

[Jarvis323]

To take a more realistic and rational view of this:

1) A visit from an extraterrestrial species would be, for them, a monumental undertaking. They would need a very good reason to come here. Not to mention how they would know where to come.

Not necessarily. Humans have been in the space and information age for an extremely small amount of time, and already we are at the stage where we could detect us if we were them, and could send robotic missions to us (if from a relatively close by solar system) within a relatively small amount of time.

It seems more likely that these things would be trivial to a civilization many times more advanced.

2) It seems unlikely that space travel would involve the aliens themselves. Instead, it would most likely be a computer operated probe - perhaps one of many sent out to random exoplanets with a generic message of introduction.

Not necessarily, because a very advanced civilization will possibly have altered themselves to have longer lives and survive in space, and they might get bored. Alternatively, at some stage, artificial things might appear as biological things, or the line might be blurry.

3) The whole idea of an alien spaceship traversing the galaxy and crash landing on Earth (with aliens inside it) is just absurd.

The truth is that fictional space travel - from Star Trek, to Star Wars to Alien and all the rest - is predicated on loopholes in the laws of physics. It reality it may take hundreds or thousands of years to exchange a few messages (via space probes) with an alien species. The idea of hopping about the galaxy like it was an extension of the Bakerloo line is absurd.

Space exploration and alien contact is most likely to develop extremely slowly.

By the 50's we already had designs drawn up for interstellar missions that would have travel times less than 100 years. What might we be capable of if we keep at it for 1 billion more years?

Besides, AI changes everything. In fact, it likely will not be too long before we are capable of mass producing interstellar probes in space.

 

[PeroK]

Not necessarily. Humans have been in the space and information age for an extremely small amount of time, and already we are at the stage where we could detect us if we were them, and could send robotic missions to us (if from a relatively close by solar system) within a relatively small amount of time.

It seems more likely that these things would be trivial to a civilization many times more advanced.

Not necessarily, because a very advanced civilization will possibly have altered themselves to have longer lives and survive in space, and they might get bored. Alternatively, at some stage, artificial things might appear as biological things, or the line might be blurry.

By the 50's we already had designs drawn up for interstellar missions that would have travel times less than 100 years. What might we be capable of if we keep at it for 1 billion more years?

Besides, AI changes everything. In fact, it likely will not be too long before we are capable of mass producing interstellar probes in space.

If the nearest civilisation is, say, 100, light years away, then that's a 200 year round trip even for a light signal. Unless you postulate a loophole in the laws of physics, then you simply cannot beat that.

AI won't change the laws of physics.

Also, this is where Fermi's paradox kicks in: if it were so inevitable, then the alien probes would be here by now. Therefore, it cannot be as inevitable as you say.

 

[Jarvis323]

If the nearest civilisation is, say, 100, light years away, then that's a 200 year round trip even for a light signal. Unless you postulate a loophole in the laws of physics, then you simply cannot beat that.

AI won't change the laws of physics.

Also, this is where Fermi's paradox kicks in: if it were so inevitable, then the alien probes would be here by now. Therefore, it cannot be as inevitable as you say.

But why do you think 200 years is a long time?

I never said it was so inevitable. And I also don't believe that I would necessarily know, or be privy to the evidence, if the alien probes were here or had been here in the past.

Personally, I think the Fermi Paradox is invalid. And I think the Drake equation is useless in practice.

 

[cybernetichero]

They would need a very good reason to come here

Well everyone within 30 LY of Earth has seen Knight Rider by now. An act of war if ever there was one.

But seriously, you make a good point. If they bothered to come that distance they would probably not come to **** around on lonely farms in the middle of the night.

 

[PeroK]

But why do you think 200 years is a long time?

I never said it was so inevitable. And I also don't believe that I would necessarily know, or be privy to the evidence, if the alien probes were here or had been here in the past.

Personally, I think the Fermi Paradox is absurd anyways.

200 years is a long time to exchange emails!

You didn't just say that human interstellar space exploration was inevitable, you implied strongly that it was imminent.

The Fermi paradox is what it is. It's an obvious question that has no answer. How can a question like that be absurd?

This is general discussion, of course, but you are blurring the lines between realistic engineering development and futuristic science fiction.

 

[Jarvis323]

200 years is a long time to exchange emails!

You didn't just say that human interstellar space exploration was inevitable, you implied strongly that it was imminent.

The Fermi paradox is what it is. It's an obvious question that has no answer. How can a question like that be absurd?

This is general discussion, of course, but you are blurring the lines between realistic engineering development and futuristic science fiction.

I didn't imply it was imminent. I just implied that we could do it. If we have interstellar neighbors, then it may be imminent that we (or our descendants), or more likely our creations visit them. Although we may either destroy ourselves or devolve.

It doesn't mean they would notice us, or catch a good glimpse. And if some of them did, it would't mean all of them would.

The Fermi paradox is invalid because the premises are faulty. We don't have a way to estimate the likelihood of visitation (the Drake equation is useless), and we don't know what evidence exists.

 

[cybernetichero]

I don't like to say something is impossible, "they" said the human body couldn't withstand speeds in excess of 8 miles per hour once but FTL drive in the real world has an asymptotically small chance of ever happening IMO. There may be ways to trick the universe with wormholes and such but I don't think to create an aircraft carrier sized wormhole over a couple of parsecs is going to be any cheaper, energy wise than just trying to go as fast as possible and to hell with relativity.

 

[russ_watters]

Let me try to re-frame the objection:

1) A visit from an extraterrestrial species would be, for them, a monumental undertaking. They would need a very good reason to come here. Not to mention how they would know where to come.

Not necessarily. Humans have been in the space and information age for an extremely small amount of time, and already we are at the stage where we could detect us if we were them, and could send robotic missions to us (if from a relatively close by solar system) within a relatively small amount of time.

It seems more likely that these things would be trivial to a civilization many times more advanced.

Not necessarily, because a very advanced civilization will possibly have altered themselves to have longer lives and survive in space, and they might get bored. Alternatively, at some stage, artificial things might appear as biological things, or the line might be blurry.

Because humans have only been significantly noticeable to potential aliens for less than a century, that sets stringent requirements on the potential explorers: they must be very close and very advanced ("a monumental undertaking") or be able to violate the laws of physics as we know them. That doesn't mean it's impossible, it just severely constrains the potential pool of alien explorers. It means Kang and Kodos from Rigel 7 wouldn't have even noticed us yet, much less have been able to travel here to enslave and eat investigate us.

Besides, AI changes everything. In fact, it likely will not be too long before we are capable of mass producing interstellar probes in space.

AI doesn't solve any of these problems. It doesn't matter if you build your spaceship on Earth or on Ceres using robots; Rigel 7 is still 860 light years away.
...and not for nothing, but "AI" and "self-replicating robots" aren't the same thing.

By the 50's we already had designs drawn up for interstellar missions that would have travel times less than 100 years. What might we be capable of if we keep at it for 1 billion more years?

I don't like to say something is impossible, "they" said the human body couldn't withstand speeds in excess of 8 miles per hour once but FTL drive in the real world has an asymptotically small chance of ever happening IMO. There may be ways to trick the universe with wormholes and such but I don't think to create an aircraft carrier sized wormhole over a couple of parsecs is going to be any cheaper, energy wise than just trying to go as fast as possible and to hell with relativity.

Whoever "they" were, "they" should have known humans can run faster than 8 miles per hour. Maybe you mean something different? Maybe a sound barrier reference?

Scientists know better than reporters and politicians what is possible and what isn't, and they know better today than they did 120 years ago. While such exotic technologies aren't impossible, their likelihood is diminishing rapidly.

 

[Jarvis323]

The one thing that has been holding us back from interstellar exploration (besides cost although that is a relatively easily solved problem) is that we need a survivable crew to maintain the ship and carry out the mission. It has always been hypothesized e.g. by Neumann most notably, that it would be automatons that would be used. However, in my opinion, we don't know how soon we will have AI that is up to the task, as opposed to how fast we might be able to have something that blends biology and technology that is up to the task. Nature already provides extremely sophisticated brains with outstanding general intelligence and ability to reproduce for longevity, and we already have the tools to manipulate DNA and are currently working on AI human augmentation (e.g. Musk, Facebook). It might be more practical that a genetically engineered and technologically augmented crew would be used, and so maybe we should consider this scenario more likely than just robots or automated probes.

 

[russ_watters]

The one thing that has been holding us back from interstellar exploration (besides cost although that is a relatively easily solved problem) is that we need a survivable crew to maintain the ship and carry out the mission. It has always been hypothesized e.g. by Neumann most notably, that it would be automatons that would be used. However, in my opinion, we don't know how soon we will have AI that is up to the task...

Huh? What's wrong with the robotic interstellar spaceships we launched in the 1970s?

I feel like you have some grand science fiction-fed vision of what interstellar space travel has to look like, which is far beyond what is really necessary to get started.

 

[PeroK]

The one thing that has been holding us back from interstellar exploration (besides cost although that is a relatively easily solved problem) is that we need a survivable crew to maintain the ship and carry out the mission.

It's completely the opposite! If we needed a crew on the recent Mars missions, then the missions would not have taken place. To have human beings on board multiplies the complexities many fold.

The biggest problem is that we can't make any spacecraft (crewed or uncrewed) go fast enough!

 

[russ_watters]

The biggest problem is that we can't make any spacecraft (crewed or uncrewed) go fast enough!

That's an issue of patience and goals. Many science fiction stories include generation ships (ships who's crew all die before arrival, replaced by their kids, or who's family on Earth all die before they return). There's no reason a robotic spaceprobe couldn't be a generation ship too. We just don't have the patience/desire to send a probe to Alpha Centuari that takes 500 years to arrive there -- but I think we could if we wanted to.

[edit] That's 200x faster than New Horizons; 1% the speed of light. Maybe not possible yet, but I don't think it is too farfetched.

 

[Jarvis323]

Huh? What's wrong with the robotic interstellar spaceships we launched in the 1970s?

I feel like you have some grand science fiction-fed vision of what interstellar space travel has to look like, which is far beyond what is really necessary to get started.

The prototype interstellar missions people have designed require lots of repairs. I'm considering that sometimes repairs could be somewhat non-trivial. What we have now (like what we used on Mars) is like self driving car technology, in which there are simple easily trainable tasks (like turning, controlling thrusts, etc.) to accomplish pretty simple goals. They don't have the capability to respond to events they haven't been trained to respond to, and it is complicated to train AI to be able to do so many different things and to do complex things like people can.

We have not yet developed any AI that can solve non-trivial unforeseen problem.

 

[Jarvis323]

It's completely the opposite! If we needed a crew on the recent Mars missions, then the missions would not have taken place. To have human beings on board multiplies the complexities many fold.

If we had the capability to send humans to Mars, then we probably would, because we could accomplish so much more. The complexity of designing robots to be able to do what humans could do, might be more complicated than modifying humans to be able to go there.

 

[russ_watters]

The prototype interstellar missions people have designed require lots of repairs.

Do you have any references for these designs/prototypes? I've never heard of such things, and it seems like an exceptionally bad idea to design a spacecraft to break down on the way to its destination.

 

[Bandersnatch]

Coming back to the initial question...
Results of intra-colonary probing across samples of wild terrestrial hominid population. First 50-year data release. Zorblax et al., Agricultural University of Altair VIa
...would be pretty convincing, if published in a high-impact journal.

 

[Jarvis323]

Do you have any references for these designs/prototypes? I've never heard of such things, and it seems like an exceptionally bad idea to design a spacecraft to break down on the way to its destination.

All of the early prototypes involved things like pulsed nuclear propulsion, which would get the crafts up to something like .1c to .4c. Over long distances, damage would accumulate to the shields from dust, and the shields would need to be repaired. I'll look for the references in a bit when I have time. You can look up Daedalus and follow the links.

 

[Jarvis323]

All of the early prototypes involved things like pulsed nuclear propulsion, which would get the crafts up to something like .1c to .4c. Over long distances, damage would accumulate to the shields from dust, and the shields would need to be repaired. I'll look for the references in a bit when I have time. You can look up Daedalus and follow the links.

Here is one paper on dust damage.

EVALUATION OF THE HAZARD OF DUST IMPACTS ON INTERSTELLAR SPACECRAFT

RICHARD A. LONDON1AND JAMES T. EARLY21.Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.2.7056 Currituck Rd, Kitty Hawk, NC 27949, USA.Email: rlondon@llnl.gov and james.t.early@gmail.comAbstract
Spacecraft traveling to nearby stars will experience energetic collisions with interstellar dust grains. For thin structures, such as light sails, grains pass through with little damage. For thick structures, all the grain energy will be deposited, possibly leading to significant damage. This paper presentsa quantitative assessment of damage caused by grain-vehicle collisions and designs to reduce damage. Computer simulations of grain-vehicle collisions were performed with a radiation/hydrodynamic code, thatmodels deposition of grain energyin the material, energy transport by conduction and radiation, expansion of the heated volumemelting and other damage processes to the surrounding material. It is foundthat the grain energy is deposited in a long, thin cylindrical volume, creating temperatures larger than 107K. The spreading of this energy can potentially lead to a large damaged volume. Radiation and evaporation can remove energy, thereby limiting the damage. The reduction of damage by the choice of shieldingmaterial on the leading surfaceand by placement ofa thin shield in front of the vehicle to atomize and disperse the grainsbefore they hit the main bodyof the craftis described.

https://www.osti.gov/servlets/purl/1525731

 

[PeroK]

Here is one paper on dust damage.
https://www.osti.gov/servlets/purl/1525731

Are you sure you are not misreading that paper? It seems to be highlighting one of the major problems of interstellar travel. Is it really proposing that a human crew be onboard to repair the damage?

 

[Jarvis323]

Are you sure you are not misreading that paper? It seems to be highlighting one of the major problems of interstellar travel. Is it really proposing that a human crew be onboard to repair the damage?

I think you've misread my posts.

 

[PeroK]

I think you've misread my posts.

Okay, we're saying that:

a) An uncrewed interstellar craft is still potentially far in the future, but is plausible. Especially if a trip to Alpha Centauri that takes a hundred years is acceptable.

b) A crewed mission to Alpha Centauri presents an additional order of magnitude of difficulty. And, rather than be an overall help to a mission, a human crew would make the mission an order of magnitude harder to achieve.

What are you saying?

 

[russ_watters]

All of the early prototypes involved things like pulsed nuclear propulsion, which would get the crafts up to something like .1c to .4c. Over long distances, damage would accumulate to the shields from dust, and the shields would need to be repaired. I'll look for the references in a bit when I have time. You can look up Daedalus and follow the links.

Here is one paper on dust damage.

https://www.osti.gov/servlets/purl/1525731

That paper doesn't say the damage would need to be repaired.

 

[russ_watters]

Okay, we're saying that:

a) An uncrewed interstellar craft is still potentially far in the future, but is plausible. Especially if a trip to Alpha Centauri that takes a hundred years is acceptable.

b) A crewed mission to Alpha Centauri presents an additional order of magnitude of difficulty. And, rather than be an overall help to a mission, a human crew would make the mission an order of magnitude harder to achieve.

c) Neither "AI" nor general purpose robots are required either.

 

[Jarvis323]

That paper doesn't say the damage would need to be repaired.

I said that the prototype missions I know of included autonomous robots that would repair damage accumulating from dust.

 

[russ_watters]

I said that the prototype missions I know of included autonomous robots that would repair damage accumulating from dust.

Yes, and I said I'd like to see references for that. In response, you referenced a paper that appears to directly contradict your claim that repairs are needed.