I want to talk about how life in our Milky Way Galaxy, at least very advanced life, advanced civilizations with computers and telescopes and radio waves and thinking about pondering the meaning of the universe, intelligent beings that might be very rare in our Milky Way Galaxy where there’s only a handful of civilizations out there.
Maybe none at all except to for ourselves.
Even if we could develop Star Trek technology and warp around to every single star in our Milky Way Galaxy, and to the 400 billion stars out there, we might not really find any other advanced civilizations out there.
Even if we could visit every star and verify, it might be just crickets for the most part.
It also means that we’ve probably never been visited by aliens. The Earth has never had alien encounters before where no one is going to be anally probed and even with the SETI mission where we scan the skies for radio signals for other advanced civilizations, it will never happen.
Even if we spend the next 100,000 years scanning for signals, we’re never going to be contacted even by radio. It is just quite out there.
We are pretty much alone.
Now if you take the larger universe with hundreds of billions of galaxies, certainly there are going to be other advanced intelligent civilizations out there, but they’re just so incredibly far away, hundreds of thousands of light years, millions of light years away that we’ll never be able to be in contact with them. They’re just too far.
Even to send message back and forth, we’d have to spend millions of years doing it, and we’d have no way of knowing where these civilizations are to even direct the messages to, direct the energy where those radio waves are going to, so we’re just out of communication with them.
At First Glance, The Galaxy Should Be Teeming With Life
Now on first glance, when you look at the evidence, it looks like there’s good evidence that our Milky Way Galaxy is teeming with life.
Scientists have extrapolated that for every star out there, there’s probably at least one exoplanet, so there’s 400 billion stars in our galaxy, there’s at least 400 billion exoplanets out there, and they’ve also found that these small rocky worlds are probably a lot more common than big gas giants.
So there’s a lot of stars out there. There’s a lot of planets out there, and certainly there’s probably a lot of single-celled life out there because single-celled life is very hardy. We found it can exist in many places.
Single-celled life, there’s organisms on Earth that can likely survive on the surface of Mars. There’s single-celled life out there that can exist live in the vacuum of space. You’ve got single-celled life that doesn’t need oxygen but can derive its energy from hydrogen. You have single-celled life living on the bottom of the ocean floor. It doesn’t need photosynthesis. It actually gets its energy from chemicals and heat on the ocean floor.
You have extremophiles that can live in incredibly hot temperatures, incredibly cold temperatures. Scientists even suspect that one of Jupiter’s moons could very well have single-celled life living in the vents underneath the surface.
So it could be that single-celled life is very common throughout the Milky Way Galaxy. We don’t really know.
Maybe it’s not as common as we think, but it could be common just because it can live in so many extreme environments.
However, given enough time for evolution to evolve multicellular animals, plants, and something similar to a human being with a big brain that can invent computers, and cellphones, and telescopes to look out into the stars and contact other civilizations, an advanced civilization, or even more of a primitive civilization like the Roman Empire is probably incredibly rare. There’s actually a lot of good scientific reasons why it’s probably incredibly rare and we are most likely a loner in the Milky Way Galaxy.
The Red Dwarf Problem
You have to understand that first of all our Sun, our own star, is an incredibly rare type of star.
First off, 90 percent of the stars in the Milky Way Galaxy are actually red dwarfs. These are very small, very cool stars, and this presents a number of problems.
Various computer simulations have shown that probably advanced life could not around 90 percent of the stars out there, which are these red dwarves, these very cool stars. First of all, a planet has to be very close to that star to be in the habitable zone because a red dwarf gives such little energy, the habitable zone is very narrow and very close to its star, and that is going to cause a planet being that close to its star is going to cause tidal locking.
Tidal locking is where due to gravitational forces, one side of the planet is always facing the star. It’s always daytime and the other side of the planet, it’s always going to be nighttime, so one side is going to be incredibly hot and the other side is going to become incredibly cool.
Computer simulations have shown that probably you’re not going to get very good conditions for advanced life to live. You could maybe get bacteria possibly but you’re not going to have stable enough conditions. The atmosphere could super freeze; it could get super heated on one side. It would just be a very hellish place.
There is another planet, a body – not a planet – a moon that is very close to us that is tidally locked, and that is our own moon. Because the moon is so close to the Earth that very quickly at one point, the moon was spinning half a day and night. It had a rotation but because it’s so close to Earth, it just slowed down. It became tidally locked. Any planet orbiting a red dwarf will quickly become tidally locked and become very inhospitable to life.
Another problem with red dwarf stars is for the first couple hundred billion years of their lifetime, they are very unstable. They give up very variable heat.
They have these huge solar flares, so any planet that is going to be in the habitable zone of a red dwarf is going to become periodically irradiated. Whatever oceans it has are going to evaporate over time. You’re not going to have a steady environment around a red dwarf star for the first couple of hundreds of billions of years and keep in mind our universe is only 18 billion years old at this point. Just for that reason alone, you’re probably not going to have advanced life arise. You could not have multicellular organisms. They would probably burn alive. They would die.
The third reason is because red dwarves don’t give off much visible light, and visible light is the wavelength that we see with our own eyes.
There is not much energy coming off the stars for photosynthesis to get going.
Now there is some low energy you could theoretically have plant life. Nobody really knows for sure. I know that if you were standing on a red dwarf planet or a planet orbiting a red dwarf star and there was plant life, the plant life would look black instead of green because it’s absorbing a different wavelength of light that our eyes are not used to seeing.
All animals, these large animals for the food chain require there being a lot of plants. So plants can’t get going if there is not enough energy for plants to do photosynthesis or at least you’re going to see a much diminished plant life because they’re not just going to have as much energy to draw on, and it’s likely that animals that require plant life, grazers and animals that eat grass or various plants, would not be able to get going. There just wouldn’t be enough energy raining down on the planet to support the food chain.
The Problem With Larger Stars
Besides these small little red dwarfs, then you’ve also got the larger stars.
Now if a star is more than 1.5 times the mass of the Sun, it has a very short lifetime. It’s going to live a couple of billion years or life will only have a couple of billion years of stable environment to get going, which is probably not enough time for evolution to produce an advanced civilization.
We’ve had life on Earth for more than 4 billion years, so if the star is too large, first of all it’s going to turn into a red giant very quickly or it’s going to supernova very quickly. It just doesn’t have a long enough lifespan for evolution to probably get going.
It looks like these small stars and these large stars are out of the picture, not good for supporting advanced civilization to arise.
Our Own Sun Is Very Unique
Now there’s even a further snag. We have a main-sequence star. It’s a yellow sun. it’s not too small. It’s not too large.
But our Sun is an incredibly stable star. Our star only gives off 30 percent of the radiation of other stars like its type.
So other stars are putting out blasts of radiation; our star is very quite in comparison.
Our star is like the perfect star if you want to have life form around it. It’s so quiet. It’s like that kid that sits at the back of the class. He doesn’t participate and he doesn’t have any friends and he doesn’t talk to anybody. That’s the kind of stars you want to have. Our own particular Sun creates an incredibly stable environment.
So what this all boils down to is even though there’s 400 billion stars in our galaxy, you’re just taking away the red dwarfs. Now you’re probably down to 40 billion. And then if you’re going to consider yellow suns that are too unstable or these super massive giant stars, you’re probably really down to less than 10 percent of the stars out there being suitable candidates for supporting life. It could be as little as 3 percent, or 4 percent, or 5 percent. Nobody knows but it’s a small amount.
Instead of 400 billion good stars out there, you’re down to 40 billion at most, maybe 20 billion, maybe 10 billion in the Milky Way Galaxy that have a good chance of allowing an advanced civilization to arise, giving evolution enough time, creating enough of a stable environment for that to happen.
The Problem of Binary Star Systems
Now of the stars we have left, there are even more problems.
We typically think of the stars as being these lone entities, but actually, about half the star systems out there, about 50 percent of star systems are actually binary systems where you have two stars orbiting each other.
Computer simulations have shown that in this kind of systems, it’s very unlikely for a planet to have a nice circular orbit around a star and have a stable environment that the other star might be tugging the orbit of the other planets and you’re just going to have a very unstable system. Right out the gate, 50 percent of the stars that are left are probably not going to be able to have a nice steady environment that would allow a life to evolve.
The Problem of Neighborhood
The other issue is it’s very important where a star is in the Milky Way Galaxy.
If a star is out at the very edges, at the very rim of the arms of the Milky Way Galaxy, there’s not enough heavy elements out there like carbon, and iron, and silica to allow planets to form. If a star is too close to the center of the Milky Way Galaxy where it’s just like a super densely packed area, lots of stars, there’s tons of radiation out there. The planets would become irradiated.
It would be very inhospitable for life, and there’s such a lot of activity. A supernova goes off. If you’re within 20 light years of a super nova going off, you’re fucked immediately. All of the life could be irradiated. It’s a very dangerous, dangerous place to be in the middle of the Milky Way Galaxy towards the center.
Now our Sun and our Earth are actually out in the suburbs. It’s a very sweet spot. It’s not so close to the middle where you’re going to get blasted with radiation from all the other stars and it’s not so far to the edge where it’s going to be very poor in these heavy elements, so we’re in this perfect spot.
Maybe 4 Billion Good Stars, not 400 Billion
When you take all these factors together ‑ stars being too small, red dwarfs, stars being too large and not having long enough lives, or being in the sweet spot of the Milky Way Galaxy, in the right spot, in the suburbs, it’s not too close, not too far, being in not a binary system but a single star system, and on top of all that, our star is incredibly stable star compared to other stars like it.
You’re probably really down to only about 1 percent or 2 percent of the stars in the Milky Way Galaxy being good candidates for hosting life, for being able to support a steady environment over billions of years where advance intelligent civilizations would have time to arise and evolve.
Ninety-nine percent of the stars out there are probably not good candidates.
Out of the 400 billion stars, most of them are going to have deal-breaking factors. You might be down to 8 billion, 4 billion, 10 billions, something like that that could be actually good candidates for really supporting an advanced civilization over time.
The Goldilocks Zone Problem
Okay now moving on to the planets, just because a star is a good star and there seems to be probably very few of them out there in the Milky Way Galaxy, it doesn’t mean that you’re going to have the right type of planet that’s going to be good for supporting advanced civilizations, advanced life.
First of all, it has to be a rocky world. It can’t be a gas giant obviously but that rocky world also has to be in the habitable zone.
If the rocky world is too close to its host star, it’s going to burn alive, and if it’s too far away, it’s going to freeze over, so it has to be in this narrow zone called the habitable zone, the Goldilocks Zone where it’s not too warm, not too cold, and it can support life. We don’t really have any evidence of how many of these stars have worlds in their habitable zone but it is a factor that has to be taken into consideration.
The Ocean World Problem
The next factor is it has to have the right amount of water on it.
If the Earth had half as much water as it received, that water would just kind of absorb into the crust, into the mantle of the Earth, and we’d have a damp world that could maybe support bacteria but you wouldn’t have the oceans and the oceans were so key toward the evolution of life, early life and to allow us to survive.
If you had twice as much water, then only the tips of the highest mountains wouldn’t be covered in water. You’d have an Earth that’s going to be a water world with just a couple of islands here and there and you can imagine there’s probably great planets out there in the habitable zone around a stable star, but they just have too much water.
They are ocean worlds. They’re not going to have advanced civilization arise on an ocean world. I mean where are they going to build the telescopes, structures? How are they going to build computers? You might have something like dolphins evolve but that’s about as far as you’re going to get.
The Elliptical Orbit Problem
The next factor is that the planet has to have a circular orbit.
It can’t have too much of elliptical orbit; otherwise you’re going to have too much temperature variation because the planet is going to be moving far away from the star, then closer and closer. It’s going to be hot-cold, hot-cold, hot-cold. It won’t provide a stable environment that could sterilize all the life on that planet.
Now the Earth has a very circular orbit. Mars has a circular orbit. Venus has a circular orbit.
In fact, all the planets I believe, all the inner planets have very circular orbits except for Mercury. But what they’ve seen in other star systems and exoplanets is that exoplanets do not have circular orbits. They have elliptical orbits, so it actually seems to be a rare characteristic for planets to have nice stable circular orbits.
We are a rarity. Most planets do not have circular orbits. Scientists really have no idea why this is the case, why do we happen to be so lucky to have circular orbits, but it looks like most exoplanets don’t.
That looks like it would make life or advanced civilizations a lot rarer. Possibly, you could still have bacteria life on elliptical orbit planets, but if it’s getting super hot, super cold, you’re probably not going to have advanced civilization rise up.
The Planetary Mass Factor
The next factor is the mass of a planet.
If a planet has too little mass, even if it’s in the habitable zone, even if it has the right amount of water, even if it has a circular orbit, it needs to have the right amount of mass. If the mass is too small, less than about 0.8 the diameter of Earth, 80 percent the diameter of Earth, it’s not going to be able to hold on to an atmosphere, at least a thick enough atmosphere to support advanced life.
If the planet is more than 1.3 or 1.5 the diameter of Earth, it’s going to have extremely crushing gravity, probably too heavy of a gravity for advanced life to really get going.
Scientists think that if a planet has to be the diameter of the planet has to be 1.8 and 1.3 times the diameter of Earth for it to be good for advanced civilizations to arise.
The Magnetic Field Factor
Another great feature that the Earth has that many exoplanets, even if they have everything going for them, they might not have is a magnetic field.
Our planet’s magnetic field basically deflects all the highly charged particles coming from the Sun.
If the Earth didn’t have a magnetic field as strong as it is, you’d basically be constantly blasted by harmful by highly energized particles. It’s almost like if you stood out in the Sun outside and you are constantly being blasted by trillions of bullets every second that just pierce through your body and damage your DNA. They basically blast apart the cells, they blast the individual atoms, they blast the part of the DNA molecules and you would die of radiation poisoning pretty quickly.
Our magnetic field on the Earth is caused because we have a molten iron core in the center of the Earth, which is spinning slowly. It’s rotating and that creates a magnetic field around the Earth, which is protective.
Computer simulations have shown that if you have a super Earth like a super large Earth, you would probably not have a magnetic molten core. The gravitational forces would cause that core to be solid and if you’re a small planet, you might not have a molten iron core either. For example, Mars has no molten core that is spinning. It has a very weak magnetic field and as a result, the solar winds, the powerful solar winds and the radiation have slowly stripped away its atmosphere and it is highly dangerous. It gets blasted by really intense radiation. That’s basically another factor.
You need to have a planet with a molten core that is rotating, that is spinning, and creates a strong magnetic protective barrier from these super high charged particles coming from the Sun. Not every planet is going to have that.
The Large Moon Factor
Another stabilizing factor that the Earth uniquely has is having such a large moon.
Our large moon stabilizes the axial tilt of Earth.
Every year where the North Pole and where the South Pole is shifts a little, so they’ll shift a couple of meters, a couple of feet. You can mark it. Basically, the Earth, the axial tilts of the Earth shifts slightly.
Every once in a while, it will take a big jump; the axial tilt of the Earth will shift quite a bit and it’s thought that it has actually caused some of the Ice Ages. Basically, if you are in New York City and there’s a large axial tilt, you might find yourself now having the weather of Montreal or something like that.
The moon stabilizes the amount of axial shift that the Earth has; so without the moon, our Earth would be a lot more wobbly, so you might be near the equator in Peru, and all of a sudden, you have a very large axial tilt and now you find that warm tropical environment is now up in Wisconsin or something. I mean it’s probably an exaggeration, but you would have incredibly wild changes in weather patterns across the Earth, creating very unstable environments where life that’s evolving for the tropical rainforest might one day itself in a cold environment and places that were in a cold environment might suddenly one day find themselves in a tropical environment. So this could cause extreme havoc on ecosystems across the planet.
Now we have a large moon because it’s thought that a large planet during the primordial times, in early Earth, a large planet smacked into the Earth, blew off tons of crust off the Earth, which formed around, coalesced around the Earth and formed the Moon over many hundreds of millions of years. Most planets are probably not going to likely have such an event.
Scientists think maybe 1 percent, maybe 2 percent of the planets out there would have a very large moon like Earth. It’s kind of rare. Nobody really knows for sure how many planets, rocky planets will have such a large moon, but most planets out there probably have moons that are more likely captured asteroids, very, very small moons.
For example, Earth’s moon is only 100 times smaller than the Earth, which is very large for a moon, whereas Mars’ moon is millions of times smaller than its planets, so to have a moon that’s only 100 times smaller than its planet is very rare. It creates a great stabilizing force for Earth to keep going. Most planets out there, most exoplanets are not going to have a nice stabilizing force with a large moon.
Let’s Calculate The Odds of Advanced Civilizations
Okay, so even though there are 400 billion stars in the Milky Way Galaxy and likely more than 400 billion planets possibly many more than 400 billion planets, when you take into account that 90 percent of the stars are red dwarfs and too dim, all the problem that come with red dwarfs – I’m not going to go over them again ‑ that probably countless stars out or the stars that are too large and don’t live long enough for evolution to get going or binary star systems that are going to create eccentric orbits for planets, or being in the right neighborhood where you can’t be too far out on the edges where you’re not going to have enough heavy elements to form planets and not too close to the center where you’re going to get irradiated, you’re down to much fewer stars.
You might be down to a couple billion good stars out of that original 400 billion that could support life over many hundreds of millions or billions of years for evolution to get going.
Then out of those stars, you need to find a good planet.
The planet has to be in the Goldilocks Zone. It can’t be too hot can’t be too cold, can’t have too much water, can’t have too little water, has to have a circular orbit not an elliptical orbit –and circular orbits seem to be rare for exoplanets, can’t be too small or it can’t hold an atmosphere. But it can’t have too much mass either where it’s going to have crushing gravity. It has to have a liquid iron core to produce a nice magnetic field to protect the planet from its star’s deadly radiation, and a nice other benefit would be to have a large moon that would produce a steady axial tilt for the planet.
When you take into account all those factors, you’re probably down to a couple of percent of the stars and you might be down to a couple of percent of the exoplanets, maybe even less. We don’t really know but you’re down to maybe thousands of planets that are good potential candidates. It could be very small, not as many as you would think.
The Evolution Problem
Another whole factor you have to consider is even if you have the perfect star, even if you have the perfect planet, all the conditions are just right, it’s fertile for life.
It’s fertile for an advanced civilization to arise and evolve eventually, it doesn’t mean it’s going to evolve. Evolution is not this steady progression from single-celled to multicell to animals to an intelligent civilization. It doesn’t work like that.
We had single-cell life on Earth for billions of years, 3 billion years or 4 billion years before we saw multicellular organisms spring up and scientists are not even sure why it happened. Was it a very improbable event or not?
Why did it take 3 billion years or 4 billion years to go from single-celled to multicell organisms? Nobody knows. It could be that is a very rare or it could that maybe it could very slow for the Earth, that the Earth took a particular long time for that to happen.
Nobody really knows but there is no law that says you have to have multicellular life even on a very fertile planet. Then once we had multicellular life, it still took 600 million years for human beings to come on to the scene. You had plant and animal life perfectly fine as having the intelligence of dogs at most or pigs.
Was that a highly improbable event? I mean it took 600 million years of evolution just mucking around for humans to come on to the scene. It’s not necessarily adaptive to have a large brain. You have to eat a more calories. The human baby has a long gestation period of many, many years and can easily be killed off, so that’s very risky for evolution to evolve a big-brained animal. It’s not necessarily efficient.
So it took very specific circumstances for an intelligent species like humans to find an evolutionary niche and have a stable enough environment where they didn’t get killed off.
So there’s no guarantee. I mean if we could go back in time and snuff out those first humans, those first early proto-humans, they could very easily be the case that it would take another 500 or 600 million years for intelligent life to evolve on Earth.
Then by that time, our Sun is getting too hot and half a billion years or a billion years, we’re not going to have life on Earth anymore, and it will just take too long.
There’s no reason to suspect that just because a planet is fertile that evolution is going to produce these highly intelligent beings. The Earth could be a very rare case.
It could be if we did find 10 exoplanets with multicellular life, then on 9 out of 10 of them, advanced civilizations would never arise or even if we found 100 planets with single-cellular life, these are fertile planets, maybe 99 out of 100 times multicellular life never arises or maybe on average it takes billions and billions and billions of years.
Just for that fact alone, even if we found a bunch of fertile planets out there that are perfect candidates, they’re these perfect two stars and just based on everything we’ve gone on we said before, those kinds of planets, fertile planets are going to be very rare.
If we found 100 of them, maybe in 99 percent of the cases, intelligent life, intelligent civilizations would never arise. Evolution would never get to that point. We just don’t know. But that’s another factor that has to be taken into consideration that evolution does not work on this nice, clean progression track that we would like to think it does. It doesn’t.
Intelligent Life Is Probable Very Rare
So just to wrap this up, the Milky Way Galaxy, it might be teeming with simple bacterial life, nobody really knows for sure but probably it is, maybe.
When you take into account all the galaxies in the universe, the hundreds of billions of galaxies out there, there’s probably billions or even hundreds of billions of advanced civilizations out there, just statistically speaking because you’re talking about septillions, octillions of stars out there. Just statistically speaking, there’s likely billions of civilizations.
But if you’re talking about our own Milky Way Galaxy, the stars that are relatively near to us where we could get in contact with them, where it’s not going to take millions of years to send a message and millions of years to get a reply, but maybe only thousands of years to send a message and thousands of years to get a reply, or maybe just hundreds of years to send a message or even just dozens of year to send a message, our own Milky Way Galaxy with its hundreds of billions of stars probably, we’re pretty much alone.
Maybe there’s a couple of other advanced civilizations out there, a handful of them at this very moment, maybe there’s none.
Maybe we’re alone because there’s just so many factors that have to be perfect, that have to be right.
Just the fact that the Earth has a circular orbit and not an elliptical one that seems to be pretty rare. Just the fact that the Earth circles a main-sequence yellow star that is particular quiet and inactive, that’s incredibly rare.
Just the fact that we have a magnetic molten core that gives us a magnetic field that protects us from radiation, that looks like it’s probably rather rare just having a large moon that stabilizes the axial tilt looks pretty rare.
Even if you have a perfectly fertile planet that’s orbiting in the habitable zone of a perfect quiet star in a perfect quiet area of the galaxy, in a nice suburb of the galaxy doesn’t mean that evolution is going to produce multicellular life. It doesn’t mean that evolution is going to produce complex intelligent life that’s smart enough to invent computers and radio telescopes and peer out into the universe and go seeking to make contact with extraterrestrial civilization.
That could be very rare an event in itself, and we just don’t have enough data to know how rare that is but basically all these factors point to advanced civilizations being rare.
We can look out into the stars for the next thousand years. it’s likely we’re not going to make radio contact with any other advanced civilizations.
Advanced civilizations, aliens have never come to Earth and anally probed anybody again.
If we had Star Trek technology, then we could warp around to all the planets out there in our Milky Way Galaxy, we’d probably find a very, very barren place where most of the worlds are not habitable to life at all.
The ones that are more habitable probably just have single-celled life and even a couple of fertile planets we find with the right amount of water and the right size, they’re in the habitable zone, they’re around a stable star, maybe they only have single-celled bacteria life or multicelled life because there’s nothing saying in evolution that evolution has to produce intelligent civilizations or intelligent species. Nothing at all. That can be very rare in itself.
Again we’re probably alone, but I guess the conclusion is that just enjoy life and let’s keep or planet protected as best we can.
Let’s not do stupid shit and fuck it up. Of course, humans, you can’t put it past them to be pretty stupid. We have on this end the complete stupidity factor, but on the other hand, there is hope because when you bring out the bests in humans, we can do some pretty amazing things, too.