The Outer Space Thread

[Renegade7]

On 11/23/2019 at 5:19 PM, Mr. Sinister said:

RE: "Planet Nine"

 

Anyone here got any ideas on what it could be? Gas giant? Terrestrial? Could it support life so far from the sun?

 

Theres a series on science channel called "How the Universe Works" that has an episode on some ideas of what planet 9 could be.  Some think it could be a mini-neptune.

 

As for can it support life, keep in mind there is a staggering amount of life on earth beneath the earths surface.  life as we know it doesn't need the sun, it needs energy and liquid water.  That's why its entirely possible to find life on Europa because its so close to Jupiter tidal-friction is keeping it core alive and could likely mean geo-thermal vents.  That ice sheet is thick enough it might be able to brought much of the radiation that would kill anything on the surface, then we'd be looking for what we'd expect at geothermal vents here on earth.  There could be microbes deep inside Mars surface were there are still traces of liquid water. 

 

Earth has had 5 mass extinctions (in the midst of a 6th imo), but none of them have wiped out all life on Earth.  That speaks volumes to me.

[RemoveSnyder]

https://www.wired.com/story/space-photos-of-the-week-parkers-potential/

NASA’s Parker Solar Probe is on its way to shed some light on those mysteries. This week the mission’s researchers released new results in the journal Nature—a tantalizing, preliminary look at our star. Some of the answers are there, along with a close-up look at subatomic particle events invisible from Earth. And more answers are coming in 2024, when the Parker Solar Probe enters its official “science orbit.”

Edited December 8, 2019 by Monk4thaHALL

[RemoveSnyder]

 

[PeterMP]

A paper related to Fermi's paradox. 

 

https://www.scientificamerican.com/article/alone-in-a-crowded-milky-way/?utm_source=pocket-newtab

 

"Alone in a Crowded Milky WayEven a galaxy teeming with star-hopping alien civilizations should still harbor isolated, unvisited worlds—and Earth might be among them"

Though, I think that's an over simplification of the problem.  The problem isn't so much that aliens aren't here currently, it is that we don't see any signs of aliens (radio signals, space garbage, etc.)

 

The relevant islands that they use as their example today receive lots of garbage that would pretty clear point to intelligence life elsewhere.  If you were living on said islands today and didn't have contact with the rest of the world, there would be evidence of intelligent life elsewhere in the world.

 

https://www.nationalgeographic.com/news/2017/05/henderson-island-pitcairn-trash-plastic-pollution/

 

2.  

 

 

[SoCalSkins]

1 hour ago, PeterMP said:

A paper related to Fermi's paradox. 

 

https://www.scientificamerican.com/article/alone-in-a-crowded-milky-way/?utm_source=pocket-newtab

 

"Alone in a Crowded Milky WayEven a galaxy teeming with star-hopping alien civilizations should still harbor isolated, unvisited worlds—and Earth might be among them"

Though, I think that's an over simplification of the problem.  The problem isn't so much that aliens aren't here currently, it is that we don't see any signs of aliens (radio signals, space garbage, etc.)

 

The relevant islands that they use as their example today receive lots of garbage that would pretty clear point to intelligence life elsewhere.  If you were living on said islands today and didn't have contact with the rest of the world, there would be evidence of intelligent life elsewhere in the world.

 

https://www.nationalgeographic.com/news/2017/05/henderson-island-pitcairn-trash-plastic-pollution/

 

2.  

 

 

But if the time life on earth existed was measured by the water in a Olympic swimming pool, humans would be one drop. So you also have a timing issue. In a few billion years when the sun goes red giant all evidence of our existence will be gone if we haven’t become multi planet and interstellar. So you need intelligent life simultaneous in time to measure the garbage and signals. That makes it exponentially more elusive.

[PeterMP]

7 hours ago, SoCalSkins said:

But if the time life on earth existed was measured by the water in a Olympic swimming pool, humans would be one drop. So you also have a timing issue. In a few billion years when the sun goes red giant all evidence of our existence will be gone if we haven’t become multi planet and interstellar. So you need intelligent life simultaneous in time to measure the garbage and signals. That makes it exponentially more elusive.

 

That's an already accepted solution to the Fermi paradox.  What this paper is arguing is that interstellar colonization might be common in the galaxy and we just aren't seeing it because we aren't in a area where colonization is happening.  I would say that you have to go beyond colonization isn't happening here to there is little evidence of it happening anywhere.  We not only aren't being visited by aliens.  We don't detect any real or regular signals of intelligent life anywhere else.

 

Some of our signals and garbage will out live us even if we never get people out of the solar system or colonize another planet.  Even now, we have multiple objects (satellites, stage 3 boosters, etc) and untold radio waves that have left the planet and are travelling into space.  Realistically, for many stars/solar systems what we'd be seeing is actually evidence of life from billion of years ago because that's how long it would have taken that stuff to reach us (assuming there was/is significant sub-lightspeed travel prior to larger space colonization/travel).

 

There doesn't appear to be much interstellar intelligent life now (in that we don't seem to be visited) or in the far past (we aren't seeing space garbage, radio waves, etc.) reaching us from past interstellar space societies.

 

It'll only take about a million years for evidence for us to disappear on Earth unless you look really really careful.  That's discussed in the paper.  It is possible that there were interstellar visitors that even had an advanced society here a million years ago that then failed or was abandoned.  Our space garbage and signals we've sent out into space will almost certainly out live evidence of us on Earth.

Edited January 6, 2020 by PeterMP

[Larry]

8 minutes ago, PeterMP said:

It is possible that there were instellar visitors that even had an advanced society here a million years ago that then failed or was abandoned.

In one of Arthur Clarke's sequels to 2001, there's a throwaway line about the famous archaeologist who discovered abandoned movie props in the Tunisian desert, and announced they were evidence of a past visit by an advanced technology. 
 

(Ever since, I've had a mental image of a stereotypical Brittish archaeologist. Khaki vest. Pith helmet. Monocle. Holding up a synchronizing gear, and saying "Look, sir. Droids!")

[gbear]

There is also the potential pointed out in the Sci Fi book series, The Three Body Problem.  In it, the author points out the dark forest possibility.  In the series, there is an alien populace with space traveling tech.  However, they do not broadcast anything out of fear that doing so will announce their presence to other more powerful aliens.  Announcing their presence is akin to announcing a potential threat, either now or down the road.   Thus a logical thing for the other aliens to do is destroy the potential threat.  In his series, a world with just enough tech to start exploring space is akin to a baby walking through a dark forest.  Just because we see and hear nothing does not mean there is nothing to be seen or heard.  It may mean they do not wish to be exposed. 

 

We make many assumptions about who may hear our broadcasts into space and what their reactions will be.

Edited January 6, 2020 by gbear

[Mr. Sinister]

3 hours ago, gbear said:

There is also the potential pointed out in the Sci Fi book series, The Three Body Problem.  In it, the author points out the dark forest possibility.  In the series, there is an alien populace with space traveling tech.  However, they do not broadcast anything out of fear that doing so will announce their presence to other more powerful aliens.  Announcing their presence is akin to announcing a potential threat, either now or down the road.   Thus a logical thing for the other aliens to do is destroy the potential threat.  In his series, a world with just enough tech to start exploring space is akin to a baby walking through a dark forest.  Just because we see and hear nothing does not mean there is nothing to be seen or heard.  It may mean they do not wish to be exposed. 

 

We make many assumptions about who may hear our broadcasts into space and what there reactions will be.

 

That's what I was going to say (on a dumber level).

 

We have stuff that can appear invisible on radar, and all kind of other primitive camouflaging and jamming capability here.

 

Who's to say that, with all the scientific and evolutionary possibilities, that we simply do not yet have the means to see what is out there in regards to signs from life intelligent enough to be space faring? It seems like our understanding of what's out there is always changing.

 

 

Edited January 6, 2020 by Mr. Sinister

[Renegade7]

 

 

[Chachie]

6 hours ago, gbear said:

There is also the potential pointed out in the Sci Fi book series, The Three Body Problem. 

 

 

A coworker tried hard to get me to read this. I gave it about 100 pages before I admitted to myself that I'm not smart enough for it.  😎

[PeterMP]

6 hours ago, gbear said:

There is also the potential pointed out in the Sci Fi book series, The Three Body Problem.  In it, the author points out the dark forest possibility.  In the series, there is an alien populace with space traveling tech.  However, they do not broadcast anything out of fear that doing so will announce their presence to other more powerful aliens.  Announcing their presence is akin to announcing a potential threat, either now or down the road.   Thus a logical thing for the other aliens to do is destroy the potential threat.  In his series, a world with just enough tech to start exploring space is akin to a baby walking through a dark forest.  Just because we see and hear nothing does not mean there is nothing to be seen or heard.  It may mean they do not wish to be exposed. 

 

We make many assumptions about who may hear our broadcasts into space and what their reactions will be.

 

There's a couple of issues here.

 

1.  To get the point that they are space traveling populace, they probably did have to broadcast things as we are.  Even if they stopped somewhere along the line, we should still hear their old broadcasts (Hawkings actually warned that we should be careful with what we send out in fear of attracting a non-benevolent space faring aliens, but it is hard to imagine it will make much difference at this point in time because we've already been broadcasting things into space for generations).

 

2.  From there, in this analogy, we are then the baby in woods.  If others are not broadcasting because they fear something else, then that something should have found us (and we'd have evidence for intelligent alien life, though we also might all be dead).  The baby in the woods might not hear or see anything until its too late, but it will realize something is out there (accompanied with its death, most likely).

 

3.  To me the more likely idea where there are things out there that we don't see or hear is more along the Star Trek idea where alien spacefaring intelligent life is actually benevolent, and we don't hear from them because they are protecting us until our society advances to a certain point.  But you'd likely have to even further than Star Trek.  You'd have to actually block transmissions that were sent out millions and billions of years ago.

 

You'd have to imagine we've essentially been put in an incubator and are being allowed to grow.  Maybe somebody's placed something around our solar system that prevents signals from other ancient alien civilizations from reaching Earth.

 

That's an accepted sort of idea in the context of the Fermi Paradox.  But even that requires a very monocultural society with strong rules to prevent anybody from entering our solar system, which just seems unlikely.

Edited January 6, 2020 by PeterMP

[TheGreatBuzz]

11 minutes ago, PeterMP said:

You'd have to imagine we've essentially been put in an incubator and are being allowed to grow

Maybe we are exactly that.  Maybe we are but a alien teenager’s science project that he is growing in his classroom and we are just so tiny, we don’t even realize it.

 

 

*mic drop

[Renegade7]

1 hour ago, PeterMP said:

You'd have to imagine we've essentially been put in an incubator and are being allowed to grow.  Maybe somebody's placed something around our solar system that prevents signals from other ancient alien civilizations from reaching Earth.

 

The universe is old enough that we could've missed that signal because the dinosaurs didn't have radios.  Our signals that have made it out could pass by someone and stop before they could understand it, either.

 

I don't believe we've been around long enough to say we "know" much of anything.  If we were smart, we'd stick to ourselves because of not knowing what's out there.  What's left is probably doing the same if they figured it out before it being too late.

 

This is problem I had with Ad Astra, we can't even prove aliens haven't been here before, we just don't have enough evidence to prove that they have.

 

[PeterMP]

3 hours ago, Renegade7 said:

 

The universe is old enough that we could've missed that signal because the dinosaurs didn't have radios.  Our signals that have made it out could pass by someone and stop before they could understand it, either.

 

I don't believe we've been around long enough to say we "know" much of anything.  If we were smart, we'd stick to ourselves because of not knowing what's out there.  What's left is probably doing the same if they figured it out before it being too late.

 

This is problem I had with Ad Astra, we can't even prove aliens haven't been here before, we just don't have enough evidence to prove that they have.

 

 

There's a question of extent.  The Fermi paradox is based on the idea that advanced life should be common (based on what we see in terms of life on Earth and evolution on Earth).  Life appears to be have started pretty quickly after the planet cooled and even before the planet cooled possibly, and then from there we evolved relatively quickly) and what the paper that addressed in the link that started this paper is that life and inter-galactic travel is common- just not in this part of space.

 

What I'm saying is even if intelligent alien life is not just not currently in this part of space, it seems unlikely that inter-galactic species could really be common and we wouldn't see any evidence from anywhere (i.e. we wouldn't be detecting radio waves coming from somewhere they've been).

 

If you start to say intelligent life that creates radio waves and other things isn't very common, then that's another solution to the Fermi paradox.  i.e. There was intelligent life letting out radio waves, but they died, their radio waves stopped being transmitted, and at the time the radio waves passed by Earth, the radio telescope hadn't been invented, then that's a solution for the Fermi Paradox.  But then intelligent alien life isn't really that common.  They existed for some short period of time (with respect to the age of the galaxy) and then stopped existing.

 

(If we say that we are special (as intelligent, mobile, tool building (-not just tool using, but actually tool building) and therefore rare, then the Fermi paradox isn't an issue.  The Fermi paradox starts with we aren't special.  Our solar system is a more recent creation in the galaxy and life forms the evolved much earlier than us the galaxy should be filled with their radio waves and other things.

 

Realistically, there's a couple of accepted solutions to the Fermi Paradox.

 

1.  Alien intelligent life is out there.  They just hide from us (for reasons of caution or benevolence).

 

2.  We are special in terms of evolution or the circumstances of our planet.

 

3.  There's an extreme bottle neck for civilizations reaching from where we are to being actually inter-galactic and therefore a long living civilization (i.e. getting to where we are isn't special, but getting beyond where we are or even maintaining our current place for very long (in the context of the age of the galaxy) is special).

4 hours ago, TheGreatBuzz said:

Maybe we are exactly that.  Maybe we are but a alien teenager’s science project that he is growing in his classroom and we are just so tiny, we don’t even realize it.

 

 

*mic drop

 

Possibly, but seems more likely we are a computer simulation than an actual physical experiment.

 

https://www.vox.com/future-perfect/2019/4/10/18275618/simulation-hypothesis-matrix-rizwan-virk

 

(This is another quasi solution to the Fermi Paradox.  We are special, but only in our simulated environment.  For whatever reasons our simulators have no need to simulate alien civilizations so they only created us even though they could have created others.  Our creation, in this simulation at least, is special.)

Edited January 7, 2020 by PeterMP

[Chachie]

16 hours ago, Renegade7 said:

 

This is problem I had with Ad Astra, we can't even prove aliens haven't been here before, we just don't have enough evidence to prove that they have.

 

 

 

 

Are ancient aliens part of the plot of Ad Astra? 

[Renegade7]

3 hours ago, Chachie said:

 

 

Are ancient aliens part of the plot of Ad Astra? 

No, worse, they had the audacity to imply that because they couldn't find extraterrestrial intelligent life that their might not be any after only a couple years looking in a different way.

[Renegade7]

17 hours ago, PeterMP said:

 

There's a question of extent.  The Fermi paradox is based on the idea that advanced life should be common (based on what we see in terms of life on Earth and evolution on Earth).  Life appears to be have started pretty quickly after the planet cooled and even before the planet cooled possibly, and then from there we evolved relatively quickly) and what the paper that addressed in the link that started this paper is that life and inter-galactic travel is common- just not in this part of space.

 

What I'm saying is even if intelligent alien life is not just not currently in this part of space, it seems unlikely that inter-galactic species could really be common and we wouldn't see any evidence from anywhere (i.e. we wouldn't be detecting radio waves coming from somewhere they've been).

 

I would agree that we should separate extraterrestrial life from intelligent extraterrestrial life.  Life is hard to kill, but intelligent life is in no way common, it just requires too many factors that we're seeing play out in our own civilization.  You can make the argument intelligent life actually isn't even common in Earth's history, modern humans dating back at most 300,000 year while dinosaurs ruled the planet for at least 200 million.

 

In regards to extent, this is article I posted that picture from:

 

https://www.sciencealert.com/humanity-hasn-t-reached-as-far-into-space-as-you-think

 

There's reason to believe that radio waves at the extent of this 200 light-year radio wave diameter we've created is so weak and garbled up that its pretty much unintelligible.  This is what I mean by us not getting the message from some other civilization that may be trying to contact us, I don't believe radio is the best way to broadcast "Hello" omidirectionally.  METI in 2017 tried pointing radio directly at a solar system 12 light years away, that's nothing in space terms, inside that 100 light-year window we supposed to already pass, and ridiculously unscalable if they are serious about pointing at one star system at a time like that.

 

In fact, given we are already experimenting with quantum entanglement digital communication, there's no doubt in my mind any species that has acheived light-speed has mastered this technology in order to communicate faster then light, not radio.  Intelligent life may be more common then we can prove because of how hard it is to get to a certain level of technology, could be plenty of intelligent civilizations that are in their version of BC or industrial revolution.  If intelligent life is rare, intelligent life that can travel faster then light is even rarer.  We know there's at least one Type 0 civilization because we are here, how many Type 1s?  Would Type 3 even bother with us?

 

Quote

 

If you start to say intelligent life that creates radio waves and other things isn't very common, then that's another solution to the Fermi paradox.  i.e. There was intelligent life letting out radio waves, but they died, their radio waves stopped being transmitted, and at the time the radio waves passed by Earth, the radio telescope hadn't been invented, then that's a solution for the Fermi Paradox.  But then intelligent alien life isn't really that common.  They existed for some short period of time (with respect to the age of the galaxy) and then stopped existing.

 

(If we say that we are special (as intelligent, mobile, tool building (-not just tool using, but actually tool building) and therefore rare, then the Fermi paradox isn't an issue.  The Fermi paradox starts with we aren't special.  Our solar system is a more recent creation in the galaxy and life forms the evolved much earlier than us the galaxy should be filled with their radio waves and other things.

 

Realistically, there's a couple of accepted solutions to the Fermi Paradox.

 

1.  Alien intelligent life is out there.  They just hide from us (for reasons of caution or benevolence).

 

2.  We are special in terms of evolution or the circumstances of our planet.

 

3.  There's an extreme bottle neck for civilizations reaching from where we are to being actually inter-galactic and therefore a long living civilization (i.e. getting to where we are isn't special, but getting beyond where we are or even maintaining our current place for very long (in the context of the age of the galaxy) is special).

 

Again, I believe space is just too big to confirm anything until we finally do.  We're talking about hundreds billions of stars in this galaxy alone, most of which on the other side of us.  And radio certainly isn't going to make it through the core of the milky way to the otherside.  And there's hundreds of billions of galaxies and reality we are limited by what we consider the observable universe.  We don't know what the edge looks like or beyond it.

 

Back to this galaxy, which is who we'd likely run into first, I believe in your third scenario scenario that most that intelligent life is hard because civilizations being too far away form each other to share their mistakes before other ones do.  But what exactly is common, ya know, in context?  Would five intelligent civilizations including our own out of all the stars in the milky way count as common?   Given how big the milky way is, are we talking about common or close enough to talk to?  Because this galaxy is big enough that we'd be talking about 100,000 years waiting for responses from someone on the other side if we are trying with radio : )

Edited January 7, 2020 by Renegade7

[Larry]

22 hours ago, PeterMP said:

To me the more likely idea where there are things out there that we don't see or hear is more along the Star Trek idea where alien spacefaring intelligent life is actually benevolent, and we don't hear from them because they are protecting us until our society advances to a certain point.

 

Keep going back to a science fiction story I read decades ago.  

 

It takes place on the bridge of the alien spacecraft that's been circling the Earth for the last 10 years.  Seems that whenever a civilization achieves space flight, and nuclear weapons, then the coalition of spacefaring races (I'm gonna say "the Federation") dispatches a ship to observe the new species.  

 

The job is boring as hell.  Ships are assigned for 20 year tours, because of the incredible boredom.  Of course, the ship's vastly superior technology means that the humans cannot possibly detect it, unless they choose to deliberately reveal themselves.  

 

And from time to time, they do intentionally reveal themselves.  But only under carefully chosen, controlled, conditions.  Intentionally vague, often contradictory, conditions.  

 

They'll reveal themselves.  But only to three drunk rednecks out in the woods.  Or to the pilots and passengers of three jetliners, but not to anybody on the ground.  Or to everybody in Los Angeles, but not to air traffic control radar.  

 

And, once a year, through appropriate cutouts, they'll run a public opinion poll, asking whether "UFOs" are evidence of non-human intelligence.  

 

They don't care how many people say "yes" or "no".  Well, other than to adjust who and where they reveal themselves, to keep the numbers roughly even.  

 

Their orders are, if the "Don't know" results ever go below 10%, to exterminate the human species.  Because humans are about to develop the technology to be dangerous, and they make up their minds with insuffecient evidence.  

[Renegade7]

20 minutes ago, Larry said:

 

Their orders are, if the "Don't know" results ever go below 10%, to exterminate the human species.  Because humans are about to develop the technology to be dangerous, and they make up their minds with insuffecient evidence.  

 

Reminds me of Childhoods End, hated the way that book ended, in sense of other species deciding what's best for us or themselves.  All the more reason to let them come to us instead of letting them know we are here, I dont get how any species can be a threat to space faring civilization if they cant even get out their own solar system.  Prime Directive was basically wait until they achieve light-speed, right?

 

Edited January 7, 2020 by Renegade7

[PeterMP]

28 minutes ago, Renegade7 said:

 

I would agree that we should separate extraterrestrial life from intelligent extraterrestrial life.  Life is hard to kill, but intelligent life is in no way common, it just requires too many factors that we're seeing play out in our own civilization.  You can make the argument intelligent life actually isn't even common in Earth's history, modern humans dating back at most 300,000 year while dinosaurs ruled the planet for at least 200 million.

 

In regards to extent, this is article I posted that picture from:

 

https://www.sciencealert.com/humanity-hasn-t-reached-as-far-into-space-as-you-think

 

Common becomes a matter of time, but unless we are going to say the Earth is very special, then it seems right to say that evolving intelligent life in ~4 billion years is "average".  Given a 100 sided die rolling any given number might be considered rare, but given enough rolls rolling any given number becomes common.

 

We currently think there are about 40 billion Earth like planets in this galaxy alone.

 

The galaxy is over 13 billion years old.  The Earth is only 4 billions years old.   ~77% of the livable planets are believed to be in solar systems billions of years older than our sun.

 

Even if we say intelligent life evolved faster on Earth than average and only 1/2 of those 77% have developed intelligent life (even though they've been given even more years) than on Earth, then we are talking about 15.4 billion planets with intelligent life.  

 

And again, Earth is a younger planet.  If we are "average", then it is reasonable to expect that there are billions of intelligent lifeforms out there that are billions of years older than us.

[Larry]

5 minutes ago, Renegade7 said:

Reminds me of Childhoods End, hated the way that book ended, in sense of other species deciding what's best for us or themselves.

 

I consider Childhood's End to be the best book I've ever read, and don't at all think of it as that.  

 

(I am aware that one copy of the book I've owned, contains a foreword from the author, in which he kind of apologizes for the book.  Seems that when he wrote it, he believed that things like ESP were the cutting edge of science, and wrote the book accordingly.  And now he's ashamed that he fell for that crap.) 

 

But me, I think it's a fantastic story, in numerous ways.  Including what I think of as numerous big surprises.

[PeterMP]

54 minutes ago, Renegade7 said:

In fact, given we are already experimenting with quantum entanglement digital communication, there's no doubt in my mind any species that has acheived light-speed has mastered this technology in order to communicate faster then light, not radio.  Intelligent life may be more common then we can prove because of how hard it is to get to a certain level of technology, could be plenty of intelligent civilizations that are in their version of BC or industrial revolution.  If intelligent life is rare, intelligent life that can travel faster then light is even rarer.  We know there's at least one Type 0 civilization because we are here, how many Type 1s?  Would Type 3 even bother with us?

 

There's little reason to think that quantum entanglement can be used for communication (currently).

 

https://www.forbes.com/sites/startswithabang/2016/04/30/ask-ethan-can-we-use-quantum-entanglement-to-communicate-faster-than-light/#426da214fbcd

 

Whether they would bother with us or not is irrelevant.  The question is would we realize they exist.  If an alien civilization decided to do something like build a Dyson's sphere around our sun, they might not bother with us, but we would recognize them.

 

But even if we didn't recognize them at all, the point is that as they did things they would have to do to get type 3, they would leave behind things that we would recognize.  As they went through stage 1 and 2 to 3, they would leave behind things that we would recognize.  And we don't really even see that.

Edited January 7, 2020 by PeterMP

[Larry]

11 minutes ago, Renegade7 said:

Prime Directive was basically wait until they achieve light-speed, right?

 

Like virtually everything on Star Trek, they intentionally never exactly said.  The Prime Directive means whatever it needs to be, for this particular episode.  

[Renegade7]

6 minutes ago, PeterMP said:

 then we are talking about 15.4 billion planets with intelligent life.  

 

And again, Earth is a younger planet.  If we are "average", then it is reasonable to expect that there are billions of intelligent lifeforms out there that are billions of years older than us.

 

That does sound like a high number.  But does that factor in updates to Drakes Equation?  Even our planet has a habitability window, how many of those 15.4 billion made it to another solar system before theres was destroyed or they destroyed themselves?  How many did or didnt destroy other civilizations jus to keep them from being threats?  Then how many of those civilizations existed at the same time?  

 

When you say "Earth-like", do you mean our size with our size sun with liquid water and functioning magnetosphere?  Because it feels like every time I see an article about they found an earth like planet, 9 times out of ten it's around a red dwarf, which is likely tidally locked and getting blasted be mega flares once a year.  Even super earths arent earth like, technically.