Extraterrestrial Civilisations in our own Galaxy

I think we're alone. If we weren't we'd be able to detect it by now, or conversely it would have detected us. It's dead out there.

originally posted by: Xtrozero

originally posted by: Asmodeus3

A few things.

The Universe isn't 9 billion years old but 13.7 billion years old plus or minus a few hundred million years.

You might have a reading comprehension issue... I said "The universe as we see today is about 9 billion years old. Prior to that we are talking massive supernovas with really no planets and normal stars to get life going."

What this means is the universe spent billions of years in mostly a supernova state as 90 other natural elements were created too that makes up what the universe is today.

The age of our solar system is around 4.57 billion years and to have forgotten the other two planets in the habitable zone which may have had already sustained life earlier in their history. I am talking about Mars and Venus.

Still Mars and Venus could sustain microbial life at the moment we speak.

So I wasn't talking life in general, but advance life. Life in general is going to be all over the place, but advance life as I spelled out is most likely very rare.

Furthermore moons such as Europa could be placed where entire ecosystems can be found. Europa contains salty water underneath its icy surface. About 2-3 times the water here on Earth.

So good point, but what are the chances of advance life ever forming there? You seem to be mixing up my post as to say life in general and I was talking about advance ecosystems and not just any form of life.

There are about 100-2000 billion galaxies in the Universe and each one has on average around 100 billion stars and at least as many planets. Many of them in the habitable zones...

Ya so, two very determents to a species is time and distance. Species just can not deal with either very well. If we ever run into another race it will be in the form of self replicating AI that would be doing some mission maybe billions of years after their builders have come and gone. Life is most likely everywhere but species come and go in a blink of an eye.

You say about liguid core? Which one is the liguid core? Planets that can sustain life must have a metallic core with a solid inner core and a molten outer core so to produce a magnetic field according to the dynamo effect.

"Which one is the liquid core?" The liquid one... 100% solid and you get Mars...

And to put it all into perspective: physics as we understand it, everything we’ve observed and studied, only deals with normal matter. The universe is mostly made up of dark energy and dark matter. We have no idea what those are since they do not interact with normal matter. Normal matter is less than 5% of the entire universe.

This fact always blows my mind. The probability is high that most intelligent life is not made of normal matter. We humans may be a huge anomaly in the universe.

a reply to: CyberBuddha

All theoretical. None of this is proven and never will be. Understanding the workings of the universe is beyond our capability and scope. So why even worry about it?

originally posted by: RMFX1
a reply to: CyberBuddha

All theoretical. None of this is proven and never will be. Understanding the workings of the universe is beyond our capability and scope. So why even worry about it?

You forget, everything is one. It's just the cycles dictating this space/time, and as a species we have this inherit ability of survival that has been embedded in our DNA. Naturally, we anticipate things that could compromise the efforts. We're constantly adapting due to this factor. Studying our position and its surroundings is another defensive mechanism for survival... Even if it's just subconsciously. Studying the universe is studying ourselves.

Also... Studying a subject is never completely finished, so it is for the future generations to pick up where we let off.

originally posted by: RMFX1
a reply to: CyberBuddha

All theoretical. None of this is proven and never will be. Understanding the workings of the universe is beyond our capability and scope. So why even worry about it?

Why do we have an issue with understating the Universe? And why it is beyond our capability and scope?

You may have noticed that in the last few hundred thousands of years humans went from living in caves to be able to accomplish remarkable things.

originally posted by: RMFX1
I think we're alone. If we weren't we'd be able to detect it by now, or conversely it would have detected us. It's dead out there.

I don't think you have taken into consideration several factors of have come to a premature conclusion.

It's like having a glass of sea water and concluding there is no life in the sea as you can't see much going on in your glass apart from salty water...

originally posted by: Asmodeus3

originally posted by: RMFX1
I think we're alone. If we weren't we'd be able to detect it by now, or conversely it would have detected us. It's dead out there.

I don't think you have taken into consideration several factors of have come to a premature conclusion.

It's like having a glass of sea water and concluding there is no life in the sea as you can't see much going on in your glass apart from salty water...

I like that analogy.

I will add something that seems to be overlooked so far, but plays into the idea that we don't even know where or how we should be looking.

We spend a great deal of time talking about the goldilocks zone, but looking for the goldilocks zone is like trying to find the first root of a seedling when you're really looking for trees.

Our limited technology and advancement puts us much closer to bacteria than it does a species with an order of intelligence above ours. We have limits we don't even know.

If life originates in what we might call the goldilocks zone, with tidal motion to spur the evolution of that life, volcanic activity, a living planet, then there would be a time limit to them remaining there based on my understanding. On our little time scale that seems irrelevant, but the kind of intelligence we might be looking for in a 15 billion year old system is likely to be at a very different place in their evolution. A sufficiently advanced species would likely leave their planet at some point, even if they master sufficient technology to mitigate the natural shift of their planet to conditions that no longer support life.

With sufficient technology it would seem that planets outside the goldilocks zone, inert and relatively stable, would be better places to set up shop. They have no existing life to deal with, no cataclysmic geological events, and can be chosen based on abundsncd of base resources needed to set up life supporting system. This life may not even be carbon based or biological as we understand it, having developed alternative housing for their consciousness.

I think life is definitely out there, but intelligence and life may both need new definitions for us to ever understand it. Self-discovery will likely need to advance before we get a better grasp on that.

originally posted by: RMFX1
a reply to: CyberBuddha

All theoretical. None of this is proven and never will be. Understanding the workings of the universe is beyond our capability and scope. So why even worry about it?

Dark energy and dark matter do exist. Not a matter of belief.

originally posted by: CyberBuddha

originally posted by: RMFX1
a reply to: CyberBuddha

All theoretical. None of this is proven and never will be. Understanding the workings of the universe is beyond our capability and scope. So why even worry about it?

Dark energy and dark matter do exist. Not a matter of belief.

In reality there is good evidence that these two forms of matter and energy exist however there is no proof yet for either of them. Obviously some readers don't understand the difference between pure belief and a hypothesis based on good evidence.

For example we can't see dark matter as it doesn't interact with light. We just postulate its existence due to its gravitational affects. Galaxy rotation curves is one thing you could look at.

Same with dark energy. Not knowing what it is but a very good candidate for the accelerated rate of expansion of the Universe. Supernovas can give good data on how much on the accelerated rate of expansion.

The very interesting part is that if we modify Einstein's Field Equations there is no need for dark matter or dark energy. See modified theories of gravity.

a reply to: Asmodeus3

we can't see dark matter as it doesn't interact with light

If that definition were correct, then you wouldn't be able to see any of the many common non-charged particles. What you mean is that you have not detected dark matter there where you should have detected it, which opens the question to its very existence.

You don't need light at all to ascertain the existence of particles, except obviously, photons themselves. Photons interact to first order only with all charged elementary particles, and to higher order with the neutral elementary particles. Light occupies no special position in particle physics. Photons are just bosons, and they are given equal standing to the rest of the particles.

originally posted by: Direne
a reply to: Asmodeus3

we can't see dark matter as it doesn't interact with light

If that definition were correct, then you wouldn't be able to see any of the many common non-charged particles. What you mean is that you have not detected dark matter there where you should have detected it, which opens the question to its very existence.

You don't need light at all to ascertain the existence of particles, except obviously, photons themselves. Photons interact to first order only with all charged elementary particles, and to higher order with the neutral elementary particles. Light occupies no special position in particle physics. Photons are just bosons, and they are given equal standing to the rest of the particles.

I think there is some confusion between matter and particles. You are able to see matter but not the particles that make up this matter. Examples are many. Asteroids, planets, stars, galaxies, and everything material.

This is from the CERN website.

home.cern...#:~:text=Unlike%20normal%20matter%2C%20dark%20matter,to%20have%20on%20visible%20matter.

Unlike normal matter, dark matter does not interact with the electromagnetic force. This means it does not absorb, reflect or emit light, making it extremely hard to spot. In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter.

You can't see the matter itself as it doesn't interact with light i.e no absorption, emission, or reflection of light or any other part of the electromagnetic radiation.

The only way we can 'see' dark matter is through its gravitational effects.

In addition the existence of dark matter isn't a given. If you modify Einstein's Field Equations then there is no need for dark matter.

originally posted by: Ksihkehe

originally posted by: Asmodeus3

originally posted by: RMFX1
I think we're alone. If we weren't we'd be able to detect it by now, or conversely it would have detected us. It's dead out there.

I don't think you have taken into consideration several factors of have come to a premature conclusion.

It's like having a glass of sea water and concluding there is no life in the sea as you can't see much going on in your glass apart from salty water...

I like that analogy.

I will add something that seems to be overlooked so far, but plays into the idea that we don't even know where or how we should be looking.

We spend a great deal of time talking about the goldilocks zone, but looking for the goldilocks zone is like trying to find the first root of a seedling when you're really looking for trees.

Our limited technology and advancement puts us much closer to bacteria than it does a species with an order of intelligence above ours. We have limits we don't even know.

If life originates in what we might call the goldilocks zone, with tidal motion to spur the evolution of that life, volcanic activity, a living planet, then there would be a time limit to them remaining there based on my understanding. On our little time scale that seems irrelevant, but the kind of intelligence we might be looking for in a 15 billion year old system is likely to be at a very different place in their evolution. A sufficiently advanced species would likely leave their planet at some point, even if they master sufficient technology to mitigate the natural shift of their planet to conditions that no longer support life.

With sufficient technology it would seem that planets outside the goldilocks zone, inert and relatively stable, would be better places to set up shop. They have no existing life to deal with, no cataclysmic geological events, and can be chosen based on abundsncd of base resources needed to set up life supporting system. This life may not even be carbon based or biological as we understand it, having developed alternative housing for their consciousness.

I think life is definitely out there, but intelligence and life may both need new definitions for us to ever understand it. Self-discovery will likely need to advance before we get a better grasp on that.

Yes indeed, as looking at a glass of sea water and concluding there is no life in the ocean seems to be the same principle upon which others conclude there is no life in the Universe other than us without even looking in the history of our star system where it's very likely life existed on Mars and Venus. At the moment there might be an entire ecosystem underneath the icy surface of Europa.

The habitable zone is a well determined concept however life can exist outside these zones especially when there are large giant gas planets such as Jupiter, Saturn, etc. The tidal forces between them and their smaller moons or other nearby planets can result in liguid water in abundant quantities where life can easily be developed.

Life is very likely to be found everywhere however we are still very primitive and haven't even mastered space travel and nor we have a good understanding of what life is, generally speaking.

originally posted by: CyberBuddha

This fact always blows my mind. The probability is high that most intelligent life is not made of normal matter. We humans may be a huge anomaly in the universe.

The problem is what can we interact with within our existence? I have always said that life in general is most likely everywhere when the conditions are right, but once you start to define what that life is like that really starts to cut down the numbers of possibilities.

We can say life is out there, but lets define what kind of life we mean. What if I said I'm looking for a fire breathing, flying, purple, hippo with green spots, 6 eyes and 10 legs? What are the odds we would ever run into one if we had the capabilities to travel everywhere?

Now when we say highly intelligent, building capable, land based etc etc type life that can do what we humans have done so far it really starts to cut down the possibilities every time we add another disclaimer as to what that life is like just as with the hippo.

When I say that earth only had one species go to the moon in 4.5 billion years I think we are an anomaly mainly because evolution doesn't need that much intelligence for a predator and the mass level of energy our brains need can be more of a determent evolution wise. If we think about it, if we died out like some other humanoids then earth would be sitting with chimps, dolphins and maybe elephants as the top intelligence on the planet.

All that doesn't look good to me that there are any space fairing or tech level aliens anywhere we would ever run into them...ever.

originally posted by: Asmodeus3

Yes indeed, as looking at a glass of sea water and concluding there is no life in the ocean seems to be the same principle upon which others conclude there is no life in the Universe other than us without even looking in the history of our star system where it's very likely life existed on Mars and Venus. At the moment there might be an entire ecosystem underneath the icy surface of Europa.

Is there anyone that actually says there is no life out there but us? Too many people generalize by saying any life when what the OP is talking about is life at the level of "Extraterrestrial Civilizations". That is a huge difference to debating if life could be on Europa, as example.

originally posted by: Xtrozero

originally posted by: Asmodeus3

Yes indeed, as looking at a glass of sea water and concluding there is no life in the ocean seems to be the same principle upon which others conclude there is no life in the Universe other than us without even looking in the history of our star system where it's very likely life existed on Mars and Venus. At the moment there might be an entire ecosystem underneath the icy surface of Europa.

Is there anyone that actually says there is no life out there but us? Too many people generalize by saying any life when what the OP is talking about is life at the level of "Extraterrestrial Civilizations". That is a huge difference to debating if life could be on Europa, as example.

The topic of this thread is different but still related to the question of whether there is life in the universe. If there is life elsewhere then it should come on different forms. And for more complex forms we need the much simpler ones.

There are those (not necessarily on this thread) who argue that life is very rare, generally speaking.
However as I see it life seems to be a very frequency event and part of this event is more complex life according to how slow or rapid evolution is in different planets and parts of the Universe.

a reply to: Asmodeus3

I see. But you said we can't see dark matter and my point is that whatever you, as an observer, can see is irrelevant for physics. From Einstein's field equations you cannot infer the need for an observer. At all. This means that if dark matter exists, it must be inferred even by blind observers, in case you need an observer at all.

I understand you are talking as a human observer, but my point is that if we wish to discuss about dark matter or particle physics in general, then we must remove pesky observers from the table. Otherwise you are not doing physics: you are doing philosophy. Dark matter is only needed for humans to make sense of their observations, and not something the Universe requires.

Mistaking observations of the Universe and models about the Universe as the Universe is heresy.

This conects with the OP question, which reduces to whether humans are alone in the Universe. The question is just typically human. If there is another civilization you cannot communicate with, then you are alone. If you can communicate but they refuse interacting, then you are alone. If there is none out there, then you are alone. Whatever you do, you are alone. And that's exactly what makes this Universe so life-agnostic: loneliness.

Therefore, the existential question of whether you are alone or not says nothing about the Universe which, by default, does not care about life.

There is one beautiful case: the case in which there is indeed another civilization and you both interact. The result is, again, that you both will be one... alone.

You have a nice example in your own civilization: you are all alone. Is just your biology. Even your God is alone.

Unless, for some strange reason, you think being together is a way to scape loneliness... To be alive is to be alone.

originally posted by: Asmodeus3

There are those (not necessarily on this thread) who argue that life is very rare, generally speaking.
However as I see it life seems to be a very frequency event and part of this event is more complex life according to how slow or rapid evolution is in different planets and parts of the Universe.

I agree and have said that life most likely happens anytime conditions are correct, but what does that mean overall? I listed a good number of factors as to why advance life has been able to grow on earth well beyond just the goldilocks zone that really starts to reduce the number of planets capable to do the same while still capable of life of some kind.


This is not to say that advance life will include something like us in capabilities either. We came very close to going extinct during the Ice Age and if we did we would be looking a Chimps and Dolphins as the top dogs intelligent and capability wise.

a reply to: Direne

I see. But you said we can't see dark matter and my point is that whatever you, as an observer, can see is irrelevant for physics. From Einstein's field equations you cannot infer the need for an observer. At all. This means that if dark matter exists, it must be inferred even by blind observers, in case you need an observer at all.

I think he means detection i.e. instrument detection. That's also an act of observation, but in a more objective sense. We wouldn't know any detail about what is out there without instrumentation. The field equations do not require an observer. But in order to confirm the rightness or wrongness of those equations or others, instrumentation is critical. Einstein developed relativity in 1915. But it wasn't until 1919 when it was observed and confirmed during a solar eclipse.

Humans are always congratulating themselves about how smart they are. But the reality is we are extremely limited in natural skills. Our brains help us develop around the problem, but huge limitations still remain notwithstanding our sophisticated detection techniques.

originally posted by: Phantom423
a reply to: Direne

I see. But you said we can't see dark matter and my point is that whatever you, as an observer, can see is irrelevant for physics. From Einstein's field equations you cannot infer the need for an observer. At all. This means that if dark matter exists, it must be inferred even by blind observers, in case you need an observer at all.

I think he means detection i.e. instrument detection. That's also an act of observation, but in a more objective sense. We wouldn't know any detail about what is out there without instrumentation. The field equations do not require an observer. But in order to confirm the rightness or wrongness of those equations or others, instrumentation is critical. Einstein developed relativity in 1915. But it wasn't until 1919 when it was observed and confirmed during a solar eclipse.

Humans are always congratulating themselves about how smart they are. But the reality is we are extremely limited in natural skills. Our brains help us develop around the problem, but huge limitations still remain notwithstanding our sophisticated detection techniques.

Yes indeed. Observations are critical when doing physics and science.

When I said that dark matter cannot be seen I literally meant that it is invisible to the human eye or any other instrument that cound use light or other parts of the electromagnetic radiation to detect simply because it doesn't interest with light at all. It cannot emit, absorb, or reflect light.

In a few words not only we cannot see dark matter but we haven't detected it yet in the lab and postulated its existence via its gravitational effects. It may not be there at all as one way to eliminate it is to modify gravity a little. It's called modified theories of gravity and there is no need for dark matter in some of them.

My question is can life develop as a result of being influenced by dark matter? Or could we find life forms that are made up of this type of matter?

a reply to: Phantom423 - Asmodeus3

Yes, I see what you mean. Therefore, the situation is that the postulated dark matter is thought to not interact, or to interact weakly and rarely. But that's exactly the situation with neutrinos, yet you can detect them.

The problem with dark matter is that its existence is just a particle physics' requirement, not a relativistic one. And certainly not a QM one. Depending on what nature you wish to confer to DM (heavy weakly interacting particle, cold dark matter, extremely light non-interacting particle, and so on) the question is that the standard model does not require such a particle, hence I guess the solution would be to modify the field equations for gravity (heresy!) or to postulate a normal, standard particle but introducing a novel cut-off mechanism that makes them undetectable using the usual means.

Anyway, I agree with Phantom423 that no matter the detection techniques, there are limitations that cannot be simply dismisssed. The first one is a crucial one: your observers are always biological life forms, hence they are limited by their biology. The neural setup of a human allows him/her to understand the world in human terms, and only in human terms.

So, assume you find an extraterrestrial intelligence with whom you wish to communicate. What does intelligence here means? It can only mean one thing: human intelligence. That's the only intelligence humans can understand. Assume those ET are highly advanced (again, in human terms). Does that guarantee communication is possible? Not at all.

You are apparently more intelligent than ants, yet you cannot communicate with them. What about jelly fishes? What about, say, lichens? What about snails? Or viruses? Can humans communicate with them, given humans are here the highly advanced civilization? No, you cannot not.

There is a limit you can not overcome: your biology, that keeps you inside a cognitive bubble out of which you cannot escape. And same for any potential ET civilization out there: there is no way, at all, you two could communicate. No way. Unless they are human-like in which case the only thing you have found is exactly the only thing you could aspire to find using human detectors, with human intelligence, and by humans: humans.

Humans are biologically limited to only find other humans, much as lichens are totally blind to the existence of humans. It is the cognitive bubble what poses a limit to contact. Not the vast distances and the huge size of the Universe.