Are We Really Alone In The Universe? | Answers With Joe

this video supported by curiosity stream science is good for anything it's for shattering the illusion that we have some kind of special or privileged place in the universe as a great Carl Sagan once said astronomy is a humbling and character-building experience we went from believing that the Sun and Moon and stars revolved around us to understanding that we're just one of several planets around one star that's one of billions of stars in a galaxy that's one of billions of galaxies we went from believing that we're separate from the animal kingdom and created in the likeness of an all-powerful deity to understanding that we have a common ancestor with apes and descended from the muck and slime billions of years ago we went from believing that our planet is some kind of special bastion for life to understanding that we are just part of a teeming sea of life that spans the cosmos except wait we actually don't know about that last part in fact we spent decades searching the Stars for any proof whatsoever that we're not alone and so far we come up with zilch no radio signals that and ambiguously prove that there's alien life out there no sign in the composition of the thousands of exoplanets that we found that indicate that there's any life on them yet but numbers don't lie with billions upon billions of stars out there all with their own planetary systems the idea that we are the only planet in the entire universe the holds life just flies against all logic I mean how is that possible could it be that we are right all along is it possible that the conditions required to create life are so incredibly specific that this planet and the conditions that formed it are the only place in the entire universe that allows a life to survive long enough to become intelligent this is the basis for the rare earth hypothesis the video that I did on the Fermi paradox way back earlier on in this channel was the first big video that kind of took off and became something and really if that hadn't been the case this channel probably wouldn't be what it was today it was a very random topic kind of channel back then but after the Fermi paradox video did well got a lot of sort of science people coming along and asking questions and it just kind of went that way so if it wasn't for the topic of the Fermi paradox this channel would not exist the way it does right now that's my way of making everything about me the point is the Fermi paradox is a fascinating topic and if you're not up on that topic you can watch my video from way back in my youtube channel here or just search YouTube for the millions of videos that are on this topic but here's just a quick refresher so the Fermi paradox was credited to the physicist Enrico Fermi who apparently in a conversation about aliens just asked a very simple question where is everybody now we can see how vast the University of so many billions of stars out there the numbers are so ginormous that no matter how low the possibility of life springing up like you did here on earth no matter how small that percentage is that's still a huge number of civilizations that should be bouncing around out there and yet we're seeing no proof of them whatsoever so why is that now there are a million different solutions to the Fermi paradox everything from super predators hunting down other civilizations to us being kept in a galactic Zoo by other aliens but if you're gonna get serious about the Fermi paradox you have to consider what is really the most obvious answer to it which is the reason why we're not seeing in the aliens out there is because they're just not there when it comes to @ro biology we have a sample size of one and that's life on Earth that's all we know there could be all kinds of life out there that doesn't fit our definition of life whatsoever life that doesn't depend on DNA or carbon or water for that matter all we can do is look at the life that sprang up here on the specific conditions of Earth life that began actually pretty fast in a few hundred million years as unicellular MUC just self-replicating macroscopic organic machines and it stayed this way for more than two billion years before eukaryotes appeared this means they developed organelles that did specialized functions like the nucleus in the mitochondria unicellular organisms became complex just took 2 billion years to get there 600 million years ago multicellular life appeared 87% of the time that life has been on this earth it was simple one-celled organisms after 3.9 billion years it finally made that leap but look what happened next 540 million years ago only 60 million years after multicellular life appeared we hit the Cambrian explosion hundreds of millions of different species swimming around in the oceans plants and animals just appeared on the scene out of nowhere every plant and animal today can trace their evolution back to those creatures that popped up here okay look at how fast that happened after four billion years of just sitting there doing nothing boom when people talk about the Greek filter you have to consider the leap from unicellular to multicellular life as one of the great filters that life must go through how rare is that how stable must have planet B to sit there for four billion years before it makes that leap humans popped up here by the way this question is prompt many a scientists to consider what if we are alone what if the conditions required to create intelligent life are so incredibly specific that it can only happen here and if so what are those conditions this was put forward in the year 2000 by Peter Ward and David Brownlee in their book rare earth why complex life is uncommon in the universe appropriately this has become known as the rare earth hypothesis and these are some of the conditions that the rare earth hypothesis calls out our place in the Milky Way and we're all familiar with the Goldilocks zone the distance from a star that a planet has to be in order to have liquid water we'll talk about that more in a second but there's also the possibility of a galactic Goldilocks zone and we just happen to be in it Milky Way is actually on the bigger side as galaxies go and for the longest time that was considered most likely that life would show up near the core of the Milky Way because that's where all the action was the problem is this action produces massive amounts of radiation is this amazing video made of a Hubble photo of the Andromeda galaxy shows the center of galaxies are an absolute cauldron of massive stars and supernovas hyper Nova's gamma-ray bursts and yes black holes all this activity throws around massive amounts of radiation that might render planets in the vicinity sterile at the very least you can say goodbye to having at night if you live there whereas we are no we're near the core and actually in between two spiral arms this places us far away enough from the chaos of the star factories and the spiral arms but close enough to take advantage of all the heavy elements that get blasted out of supernovas next door plus being in the location where the lower density of stars provides a lot fewer opportunities for a star to swing by and have its gravity muck up all of our orbits could it be that we're nestled into a nice little Goldilocks zone in our galaxy because if that is required that rules out the vast majority of stars in our galaxy our Sun type our Sun is categorized as a g2 main sequence star which means it remains very stable for a very long period of time it's also possible this just the right size and temperature for life larger hotter stars would also have habitable zones but they also put out a whole lot more ultraviolet radiation which would ionize the atmosphere and smaller red dwarf stars require their planets to orbit so close that they become tidally locked which is not very good for life but even stars exactly like our Sun have a limiting time factor earlier on in the star's development it's a lot more volatile it varies in luminosity and intensity and then it smooths out for a long time before it eventually goes red giant and collapses so it's in that middle period that's the sweet spot for life now luckily that's several billion years but still once you eliminate all the stars in the really active regions of the galaxies and then you eliminate stars that aren't like our Sun and then you eliminate the stars that are too young or too old to be likely to have life you're getting rid of the vast majority of stars and we're just getting started our distance from the Sun once you've got your hands on the right kind of star you've got to have the right kind of planet in the right kind of distance from the star that means a rocky planet in the habitable zone now our solar system is set up with four rocky inner planets and four outer gas giants and we thought that this was normal I mean it makes sense Rock is denser so you would imagine it would gravitate toward the center of the the solar system and then the gas giants would form further out so we expected to be seeing that as we started finding exoplanets out there in the universe we thought we would see this same pattern nope a team led by Lauren Weiss at the University of Montreal studied 355 stars that contain 909 planets using data from the Kepler space telescope and what they found was that actually in most of these cases the planets were roughly the same size and very evenly spread out whereas in our solar system we got everything from mercury that's the size of our moon to Jupiter that's a thousand times bigger than Earth and Saturn is as far away from Jupiter as Jupiter is from the Sun and Uranus is as far away from Saturn as Saturn is from the Sun it almost gets exponentially further away the further you go this extreme variation in size and distance makes our solar system kind of the oddball it turns out and it's making us really have to rethink how our solar system was formed and why it's so much different from all the others that we're seeing out there in fact judging by the planetary model we're seeing around other stars it's almost like we have two different solar systems going on the inner and the outer solar system and then in the inner solar system we have one planet us that just happens to be in the habitable zone but could the fact that we have this unique configuration of planets be one of the factors that created life here on earth maybe so we have Jupiter space is a shooting gallery of asteroids and comets and as we're finding out interstellar objects any of which could have slammed into Earth and disrupted this all-important stability required for life to form thankfully we've got Jupiter out there being all big and sucking up all these objects like a big interplanetary Roomba in 1994 Comet shoemaker-levy 9 slammed into Jupiter and we actually got to watch this in a real-time with the Hubble Space Telescope it was one of the most amazing things I've ever seen we never seen anything like this before and it left scars on Jupiter the size of Planet Earth and another impact site showed up again in 2009 so this vacuum cleaner phenomenon is real in fact some studies have shown that Jupiter gets hit by comets and asteroids 2,000 to 8,000 times more than the earth does and if it wasn't for it being out there we would be bombarded with this stuff all the time that asteroid that wiped out the dinosaurs turns out would be just like a pretty common event and life would have been set back over and over and over again and again while Jupiter is the biggest that's just one of four gas giants out there that are sucking up a lot of these objects so we have multiple layers of protection here our moon so ironically while we have benefited from these you know bouncers of the solar system preventing impacts from hitting our earth it turns out that the biggest impact that ever occurred on Earth may have been the best thing that ever happened to us I'm talking of course about the impact that formed our moon I won't spend too much time on this because I've already covered this in a previous video you can watch it here down description but it turns out that our moon is very unique in the solar system and may play a huge part in why life was able to arise on this planet it stabilized our rotation and brought about tides which it turns out may have played a huge part in life forming because it's thought that tide pools that evaporated and concentrated organic compounds or we're the first replicating cells came from but the question for this video is how rare is this phenomenon and all we can say is we don't see anything else like it in our solar system now there are moons around Jupiter and Saturn that are bigger than our Moon but in terms of the ratio and the size between the planet and the moon there's nothing else like it that we've seen Mars is the only other rocky planet that has moons and those are really more like captured asteroids and before anybody says anything about Pluto and Charon those are really more like two dwarf planets that sort of found each other and rotate around each other this is such an unusual situation that the only thing that we can think of that would have caused this would be a mars-sized proto planet hitting a glancing blow on our planet and peeling away and in forming a moon in that way a theory that has been backed up by evidence of moon rocks and if that's the case just think about how perfect this angle had to be in order to get it to create this moon if they'd have been any steeper it may have blown the planet all the bits or it could have just gotten sunken in and created one gigantic planet either way it's something we've only seen happen in our solar system once and it's still kind of early to be able to tell if we could find something like that around other stars we've only found one EXO moon last October and it was a neptune-sized moon orbiting a jupiter-sized planet okay there's a few more things I'm gonna go through here I'm gonna go through them really quickly strong magnetic fields we're the only rocky planet in our solar system that has a strong magnetic field produced by an internal dynamo of liquid and solid iron nickel alloy spheres in the core of our earth and this strong magnetic field plays a huge part in protecting a life on the planet our strong magnetic fields more common in rocky planets around other stars we have no way of knowing right now but judging from our own solar system there's no reason to think that they would be tectonic plates we're also the only planet with tectonic plate activity and most rocky planets and moons have at least a layer of liquid rock underneath the surface but earth is the only one that has these tectonic plates with fissures that allow for superheated gas to escape into the atmosphere and thicken up the atmosphere enough to support life Mars for example doesn't have tectonic plates but it does have magma under the surface so when it comes up it just kind of like comes up in one spot over and over again over billions of years do you want an olympus mons because that's how you get in olympus mons but here on earth the crust is in this constant state of renewal getting sublimated underneath and melting down taking with it all of its organic molecules from the life up on the surface this gets melted in to the crust that comes back up through those fissures and it's thought that this kind of helps remineralize and make that land more fertile and easier to grow life life that changed the atmosphere as plants took in you know carbon dioxide and nitrogen turned it into oxygen animals did the same thing in Reverse but earlier on in the life cycle of our planet it was totally different the earliest Earth had a toxic atmosphere of methane sulfur ammonia carbon monoxide and even hydrochloric acid not exactly a kind of place you'd want to go on vacation but it might be just the right mix of ingredients for life to form and this specific group of ingredients might be exceedingly rare amongst planets the point is a lot of very specific things had to happen for intelligent life to form on this planet things that have been around from the beginning and it's all we've ever known so we think it's normal we think it's common but the more we look around out there we're starting to realize it's actually not normal and it's actually quite uncommon in fact it might be so infinitely unique that these specific conditions might not exist anywhere else in the universe and that we are completely and utterly alone it's a sobering thought but we've got no proof otherwise now it needs to be said not everybody is quite such a debbie downer on this there are a lot of people that refute the rare earth hypothesis one of those things that they say is that it's a very human centric look at life you know as I mentioned earlier we have a sample size of one and we're looking for places that creates the kind of life that we know but there might be all kinds of life out there that's completely counter to our knowledge and understanding in fact we live on such an oddball planet maybe we're the oddball species in the universe you know maybe they stumbled upon us and we're like okay what is that and fundamentally for many people just goes back to that numbers thing you know there's just such an unimaginably huge number of stars out there in the universe that the possibility that we're alone is just well impossible let's go back to that end drama to a picture for just a second every dot in this image is a star a star with possibly multiple planets around it is it really possible that none of these stars have rocky planets with atmospheres that not one of these stars have planets with a large stable moon in the Goldilocks zone then not one of these planets have tectonic activity or magnetic shield is it really possible that not one of these millions of stars in this one corner of this one galaxy develop the way ours did with a large gas giant surrounding a ring of rocky planets is it really possible that the Venn diagram of chemicals necessary for life and conditions necessary for life never touch in any of these stars I think it's naive to think that life could have never possibly formed in all this vastness but that doesn't mean I think the universe is teeming with intelligent life intelligent life has only existed for a blink of an eye in cosmic history of our planet it took 4.6 billion years to get here and there's no guarantee that we're gonna last the extra billion years that the Sun is gonna be able to support life on this planet before it gets too hot it makes it impossible to live here anymore in fact depending on who you ask we're doing our damnedest to end this thing as fast as we possibly can so it is possible that millions of stars have been able to create intelligent life throughout their life cycles but those life-forms didn't make it and you can go down the rabbit hole the great filter here to explain that but you don't have to stars die and maybe interstellar travel just isn't possible maybe the the distances are just too vast maybe the history of our galaxy and the universe as a whole is just a series of explosions of life popping up like twinkling Christmas tree lights no two ever popping up at the same time this is why it would be the most amazing discovery in all of history if we were able to find microbes somewhere else in our solar system we were able to dig underneath the ice of Europa and find little you rope in bacteria swimming around that would completely make us rethink everything we know about life if life could spring up twice in one solar system the possibility of us not being goes up exponentially but until that happens let's do our best to treat this planet like the rare and precious jewel that it is this moment of existential dread is brought to you by curiosity stream curiosity stream is a place to go online for science documentaries and programs that make you think expand your horizons and basically nerd out properly if you like my channel if you follow other science channels on YouTube you're gonna absolutely love curiosity stream it's basically the Netflix for cool science documentaries the best stuff from all around the world on space stuff history medicine technology futurism you name it the only problem I have with curiosity stream is it keeps me from getting my work done I just I'm just watching it constantly if the topic of today's video is interesting to you check out the birth of the solar system which goes into detail about how the planets found their orbits and how the solar system might destabilize someday and cause Earth and Venus to switch places so now you have that to worry about and you can get a month of curiosity stream for free if you sign up at curiosity stream calm /jo Scott link is down in the description big thanks to curiosity string for supporting this channel and a huge shout out to the answer files on patreon who are supporting this channel keeping the lights on creating an awesome community and dealing with me being sick I appreciate you guys there's been some new people to join let me murder their names real quick we've got lars Walsh Lander Gustav Kampf Patrick Westland Timothy night Larry Schwartz Brandon Laza days Kat Pike Patrick Minzy Amanda Novick Anthony Burks Alexander and zoloft ski Richard Budd Mitchell Rodriguez Lee Kirschenbaum Glen Mellon Rev Layden Andrew Hendricks mark plays akin Shannon McDowell nice thank you guys so much if you would like to join them get access to early copies of the videos and get to interact with me and do cool stuff and just brag about it you can go to patreon.com/scishow Joe t-shirts available in the store answers with Joe comm slash shirts you can see where our little dynamo comes from I was talking about right there there's lots of cool designs or some new stuff if you want to go check out fun stuff to wear around and good gifts why not so yeah answers with Joe go slash shirts please like and share this video if you liked it and if this is your first time here welcome you might enjoy this video Google thinks you might like it and there's all kinds of other videos down below you can go check those out too and if you like them please do subscribe I comeback of videos every Monday and every Thursday alright I apologize my voice has been going in and out and if I look a little Louie I've been sick this week so this has been a rough week and a rough recording sessions hopefully this came out alright I Pro piu guys enjoyed it and I'm gonna stop now so you guys go out have an eye-opening week and I'll see you on Monday let me guess take care

Channel: Joe Scott

Views: 374,778

Rating: 4.9091611 out of 5

Keywords: answers with joe, fermi paradox, rare earth hypothesis, enrico fermi, alien life, life on earth, evolution of intelligent life, jupiter, comet shoemaker levy 9, goldilocks zone, milky way, main sequence star, dynamo theory, earth's magnetic field

Id: owHPGkIdOWI

Length: 19min 57sec (1197 seconds)

Published: Mon Feb 18 2019

Reddit Comments

[u/gingerdacat]

Love answers with Joe. He is legit smart and funny.

[u/HarmlessWater]

I don't like that hypothesis