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Will We Ever Find Alien Life?

Will We Ever Find Alien Life?

Thanks to curiosity stream for supporting PBS Digital Studios. The Silence of the galaxy and the resulting Fermi paradox Has perplexed us for over half a century But our most recent surveys of the Milky Way Finally allow us to draw scientific conclusions about this depressingly persistent absence of aliens When Enrico Fermi uttered the words “Where is everybody?” He was succinctly summarizing what has become known as the Fermi paradox in short in a galaxy of hundreds of billions of stars Each of which having billions of years to spawn life and civilization, isn’t it odd that none have made themselves apparent to us Enrico Fermi was supposedly using this as an argument against the plausibility of Interstellar travel. If aliens can travel between the stars why haven’t they visited? But the paradox is much broader than this There are several ways that an advanced civilization could give away their presence radio transmissions, robotic probes, or star blotting solar arrays. A series of very recent surveys of our galaxy reveal none of the above while at the same time proving the abundance of potentially habitable worlds. The Fermi paradox has become only more paradoxical and these surveys are finally powerful enough to draw some serious conclusions about the rarity of advanced civilizations and about the chance of us ever becoming one. Before we get to that Let’s see what the state of the art in astronomical surveys is telling us Nasa’s Kepler telescope has discovered 2652 alien worlds to date Spotted as they marched across the face of their parent star in chance transit alignments This number allows us to figure out the fraction of stars that have planets Essentially all the stars do. It also allows us to figure out that there are something like 40 billion habitable planets in the Milky Way By habitable. I mean rocky planets the right distance from their star to have liquid water TESS, the Transiting Exoplanet Survey Satellite, is now in orbit and taking over from Kepler It’ll find something like 20,000 new worlds telling us once and for all how common earth-like planets really are And how many of these planets have life? We have absolutely no idea We have no way to even start to guess that yet To answer this question We’ll need to look at the composition of their atmospheres We talked about this before. Life is expected to massively alter the chemical composition of its home world’s atmosphere We can’t see this effect on earth-like planets yet But the James Webb Space Telescope – launched in a year or so will get close to doing so There is a good chance we’ll have found hard evidence of extraterrestrial life in the next decade or so, but that’s regular old non technological life Surely a high-tech civilization would be easier to spot We’ve been actively watching for radio transmissions from other worlds for half a century. We’ve seen nothing Even the famous Wow signal has likely been explained as a mission from a pair of comets That said our search hasn’t even been sensitive enough to see human level transmission in the nearest star system we’re probably only sensitive to deliberate beamed communication of which there are none, but Radio transmissions may not be our most likely first encounter with et Assuming any of those guys are like us at all they’ll want to expand into and alter their galactic environment and Because they almost certainly have a head start on us of at least thousands of years that galactic gentrification Might be visible to us you might remember Tabby’s star – the strange star in the kepler field that showed these bizarre dips in brightness some very large collection of Something is passing in front of the star Thrillingly, one proposed explanation was an alien mega-structure perhaps a vast fleet of solar collectors built by the local inhabitants Sadly, this is not the case follow-up observations revealed that the wavelength dependence of the dips is consistent with Dust so likely natural space junk not any type of artificial structure as we like to say on space time It’s never aliens Until it is for example you these alien solar collectors may be our best shot at spotting other civilizations an Advanced civilization may launch so many solar satellites that they substantially block the light from their own star Let’s call such a solar fleet a Dyson swarm after the Dyson Sphere which is the next level up a structure that completely encases a star a Dyson swarm would cause an Unusual dimming of its parent star and also cause an unusual increase in infrared light due to waste heat shed by the structure These are things we can look for. Kepler saw none of this but actually the best instrument for finding Dyson swarms is the European Space Agency’s Gaia mission a team of astronomers Scoured the Gaia data looking for stars that were unusually faint for their stellar type They looked at 8,000 stars and exactly one of those stars had a brightness significantly lower than expected however They also figured out that the offending star has a binary companion Which may have caused a wobble in the Stars position and that in turn may have messed with the Stars parallax distance determination and the determination of its power output I.e. the star may just be further away than expected not wreathed in a swarm But Gaia’s upcoming third data release will expand this study from 8,000 to a million stars If they’re out there, we’ll find them Eventually, it’s still early days now hunt for ET But maybe we can at least agree that if there are any technological civilizations in our neighborhood of the Milky Way They are keeping to themselves That still seems surprising given those 40 billion possible starting points for life in the Milky Way After all would only take one of these worlds to spawn an expansionist species Or even a single individual among that species to launch a single self-replicating probe give them a million year head start on us just one ten thousandth of the age of the Milky Way and Someone should have colonized the galaxy by now. Yet we see nothing but detecting nothing is still data Give astronomers data and they will write papers a number of attempts have been made to address the Fermi paradox based on this new data This is often done in terms of the famous Drake Equation Which tries to estimate the current number of communicative civilizations? by combining a series of factors, there are Astrophysical factors like the rate of star formation and the fraction of these stars that form habitable worlds biological factors like the frequency of the appearance of simple life and the proportion of those that lead to intelligent life and sociological factors like the fraction of intelligent life that transmits radio signals and how long that communicative civilization lasts The biological and sociological factors are so poorly understood That estimates of the number of civilization vary between none to tens of thousands but now that we have a much better understanding of the Astrophysical factors and are also pretty sure that there aren’t tens of thousands of advanced civilizations We can actually start to constrain those biological and sociological factors Astronomers Adam Frank and WT Sullivan did this in 2015 They found that as long as the odds of any given how tall planet spawning a technological species is greater than one in sixty billion Then humanity is not the first to appear in the Milky Way Let’s take us even further Assuming there aren’t tens of thousands of civilizations existing before us we must have beaten some steep odds it must be harder than one in a million to from damp rock to rocketship Luis Anchordoqui and collaborators found a less stringent limit on this likelihood by assuming that a lot of life gets wiped out by gamma-ray bursts a type of cataclysmic exploding star We covered those before also These researchers estimate that in order for us not to see any aliens the chance of going from space rock to high-tech Society must be less than half a percent Now that sounds high But remember it’s only for the planets not wiped clean by gamma-ray bursts whether it’s gamma-ray bursts or something else our failure to find aliens tells us there must be a developmental bottleneck or colloquially a great filter that seriously limits the milky way’s production of highly visible Galactic Civilizations Optimists like to think that humanity has already passed the great filter That is perhaps it’s one of the biological factors of the Drake Equation that keeps the number of aliens low So watery planets may be abundant But maybe there’s a step in that slow Evolutionary crawl from primordial chemical soup to techno monkey that makes advanced civilizations hellishly unlikely This is something we can come back to but you can look into the rare earth hypothesis or the gaian bottleneck hypothesis for some plausible proposals If the great filter is behind us, that’s good. It means we made it It also means we have a long lonely future as one of the galaxy’s only advanced species But hey one is better than none, right? But our modern understanding of the Fermi paradox Permits a second interpretation To wrap up let’s consider the possibility that lots of planets produce civilizations at around our level and They wipe themselves out with such thorough Reliability that literally none ever leave a mark on the galaxy Some scientists have been inspired by the persistent absence of evidence for aliens to investigate this possibility Statistically, how likely is it that we wipe ourselves out? Some scientists argue that deliberate annihilation of all humans isn’t just possible. It’s likely Joshua cooper and John Sotos point out that the technology needed to create an extinction-level event will inevitably fall into the hands of many individuals over time one whack job or Impulse-control challenged individual will push the metaphorical big red button Now these researchers focus on genetically engineered viruses But the principle applies to any doomsday tech nuclear weapons, genocidal nanobots, willful or negligent environmental destruction, you name it the researchers argue that all emerging technological civilizations will go through this phase of massive access to potentially cataclysmic technology Depending on the destruction probability. Let’s call it the wacko factor You might expect civilizations to last from decades to thousands of years But even thousands of years is brief enough to help explain the Fermi paradox Well, that’s a nice sobering thought to end on but I should also point out that this same massive access to technology that could kill us may also get humanity off the earth and on to other planets So which will come first spreading human civilization across the galaxy or humanity’s doom. I guess it depends on the relative probabilities Are we more inclined to acts of self-destruction and planetary sabotage or to acts of preservation and exploration Well, perhaps more importantly can we actually choose between these? Well, we sure can try the alternative may be eternal quiet across the lifeless reaches of space-time Thank you to curiosity stream for supporting PBS Digital Studios curiosity stream is a subscription streaming service that offers documentaries and nonfiction titles from a variety of filmmakers including curiosity stream originals, for example You can check out particle fever which follows the first round of experiments at the Large Hadron Collider and the eventual identification the Higgs boson particle You can learn more at and use the code spacetime during the signup process Last week we dipped our toes into string theory. You guys had a lot to say Sam Pollard asks, how does adding more particles require fewer dimensions? well, the answer is supersymmetry Now this is a type of gauge symmetry that in principle unifies fermions and bosons Add it to string theory and you get super string theory. Adding the symmetry gives you fermions But it also shaves off dimensions Now the details are way beyond a comment response But look into super string theory and supersymmetry In response to me saying that string theory has only one tunable parameter Michael Murphy sarcastically points out that 10 to the power of 500 is a little larger than 1 Now he’s referring to the number of Calabi-Yau manifolds that string theorists need to search through to find the geometry of our universe’s extra dimensions To be fair, it’s not 10 to the power 500 different tunable dials There’s only one dial with 10 to the power of 500 different settings on it. So that’s just one free parameter It’s not even the 19-ish free parameters of the standard model Now some string theorists would say that there are zero free parameters all of those 10 to the power of 500 different possibilities exist somewhere in the multiverse We just happen to be in the one that makes people Korbis Barkly and some others ask Whether if string theory makes no testable predictions shouldn’t it be just called string hypothesis? Well, I’m going to quote vacuum diagrams on this one Scientists don’t actually use the nomenclature that some popularizers of science often insist on Now that popular definition is expressed reasonably well on Wikipedia. A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in Accordance with scientific method using accepted protocols of observation measurement and valuation of results But actually we’ve always used the word theory to mean again quoting doctor diagrams Some framework that loosely described allows you to understand some aspect of the natural world while a hypothesis most often refers to a single claim rather than a coherent framework that typically comprises many claims Or to put another way. In colloquial science speak, a scientific theory is a well-developed suite of ideas laws models and predictive tools that attempts to explain an aspect of the natural world It should also have the possibility of making predictions even if they aren’t verified yet There’s no separate word for a theory that’s not well accepted but there’s still a huge difference between such a scientific theory and say the theory of intelligent design a Scientific theory is self-consistent and well developed Eduardo Martinez makes an interesting point does not the idea of shut up and calculate and we don’t care what strings are made of sound a lot like the flaws that science finds in religion I guess by that you mean that people in science sometimes accuse religion of promoting belief without Analysis and evidence. Does science do the same? Surely sometimes But in the case of shut up and calculate I think science is going in the opposite direction promoting analysis without belief or rather valuing the capacity of science to make concrete observable predictions based on evidence based models and that any Interpretation beyond these observables is beyond the realm of science. I personally don’t agree with that. I think being able to predict doesn’t mean that you understand. I think understanding comes from interpretation of your models ,not the models themselves Archie Wahwah wonders why M theory is represented by five interlocking pringles Well rumor has it that Ed Witten came up with M theory while he was eating Pringles late one night He was struck by the potential of multi-dimensional Pringles to unify string theory M is for munchies

100 thoughts on “Will We Ever Find Alien Life?”

  1. What does he mean not shown was on CNN the airforce admitted with video from jets, that the craft they were observing were not from any technology known on earth

  2. If they did wipe themselves out like such that there is no evidence left then that may mean that they werent as advanced as to leave a mark? Then that would lead to the equation that we actually have passed the great filter

  3. Humans are barely efficient enough for our own planet. When you look at it, the anomaly called 'life's is ridiculous on a cosmic scale. Life isn't necessary.

  4. We will never contact or communicate with an intelligent extraterrestrial civilization within the lifetime of our species. The universe is just too big. We only have about a billion years (maybe a little more) left in the lifetime of our species. We are not even close to light speed so our travel is limited to within our solar system. With the demise of our sun, even the solar system becomes a very inhospitable region assuming we survive the “red giant”. Our species will become extinct leaving no trace behind. With this in mind, our species only has about half a billion years for our radio bubble to reach out and touch another intelligent life form capable of understanding and responding. This does not take into account the expanding universe. Anything longer and we will be gone. For comparison, the andromeda galaxy is only about 2.5 million light years from the Milky Way. The observable horizon is 46 billion light years from the Milky Way. An intelligent civilization could comfortably reside beyond this threshold and we would never know. In fact, any intelligent civilization beyond half a billion light years from the Milky Way is completely beyond our reach even if we last that long. Half a billion years may seem to be a large number to our species but in terms of the universe, it is insignificant. We can only hope that our atoms join a nebula and become new life. This may have happened before.

  5. Scariest video you've made yet!
    The wacko factor you mentioned seemed scary anyway, but when I consider how many millions (billions?) of people still seriously subscribe to monotheistic religions, which can't wait to bring about judgment day/armageddon/apocalypse/rapture/call-it-what-you-will, I feel sure the moment extinction-level technology becomes readily available, it seems likely there will be at least one group of people amongst them who will be prepared to immediately and unhesitatingly use it.
    And eleventh-century belief systems armed with twenty-first century technology is all it'll take.

  6. Why does everybody think that water is necessary for life? Maybe there are other types of "life" made of different substances. Maybe some conscious beings aren't made out of oxygen.

  7. Well let’s say it takes X billion (or millions) of years from the Big Bang for life to start and evolve into something emitting radio frequency or light we can mesure if there is no life around us in a given radius then farther away all form of life don’t exist yet in the radio wave spectrum only we kind of do not exist 125 light years away from the earth so maybe we are the only form of life we can have access to at this moment of the existence from what we can perceive mabe in millions of years it will be more common to see other civilizations in the sky because they will have existed for long enough to receive the signals from here then (where every “here” will be in millions of years)

  8. If you think that aliens 200 light years away are likely to listen to our radio station or tv program just remember that we didn’t have invented the radio yet at that distance from the earth …

  9. maybe nothing more than some microbes, which will still be quite a significant discovery. however, given the current trend, humans won't last long enough to master space travel.

  10. I wanna know why are we looking for only similar life lines. What if aliens breath methane or sulfur. Explain please why we're so special.

  11. There could be to massive star Waring civilizations on the other side of our galactic bulge and we wouldn't be able to detect it!!

  12. maybe that they're not wiped out, they might've just left the milky way because they don't wanna live in the same galaxy where life forms that are basically stone age to them just like how I hate to sit in the same table as the most retarded student in the class

  13. this guy did a good inventory job re. the fermi paradox Best bus reading on my way to work EVER!

  14. I'm not sure if I think there are aliens "like us" or not, but it is simply human arrogance and ignorance to assume that they would have any interest in contacting other civilisation just because that's what we try to do. Or even exploring space. They might have looked after there worlds and be perfectly happy on it rather than suddenly realising that they have to leave because they've all but blown the thing up! Rant over.

  15. The two-sided mindtrap of today's status quo: Abrahamic mainstream Religions (God only created life on this planet) VS Materialist Evolutionist Atheist Scientists (Life could only have evolved on this planet)……..aaaand the open minden are just hoping to escape this mindtrap.

  16. Whoa I stumbled on a channel above my IQ. I mean oh yeah I understand. Rick n Morty taught me were living in a alien ant farm simulation within a simulation within a simulation possibly within a simulation in that simulation

  17. why don't we just focus on not destroying the habitability of our own planet? what we need is massive improvement in /social/ technology. in understanding and directives that form better political compacts. right now capitalism is incentivizing the destruction of our climate and its prioritization of the abstract "profit" over anything real and substantial is killing us. we still have the possibility to determine our future and must how recognize how the social climate informs our perspective and not cling to doomsday notions of "inevitability" based on our "human nature". we have to take the reins into our hands, and we can, people do it all the time. the problem is dealing with a destructive capitalistic colonialist hegemony that neuters creative possibilities and thinking through the narrow view of the oppressive class-forming law.

    we need to worry about our own problems in an interdisciplanary way and recognize that other theoretical civilizations might not be fucked up as us at all or want to "colonize" anything. maybe they're smart like octopuses and just have no ambition like that. anyway it's a complex issue and i think we're clearly not past the bottleneck and need to be more responsible about how we're using our energy.

  18. What if the aliens have eight legs? Feminism will collapse in hours. The aliens will say: "Right, let's see how well you treat our eight-legged brothers on this planet. Please take us to the nearest monument to our kind, and then we can visit a spider rescue centre."

  19. anti-matter ….. you forget to mention extremely dangerous but beniefical possible future technologies. as a factor that could kill us . there's several companies working on possible ways to safely store , and or mass produce anti matter for fuel useuage. but let's look at facts , storing anti matter (on a planet) WILL NEVER be safe for that planet. just so much could go wrong on any given containment of it to have it stored on a world . say you got a container with 1 lb of anti matter on it , if containment fails , the instant it did fail , our entire planet could explode or implode from it . I think these companies should look at containment away from earth like maybe on a orbiting station , after all it's main use would be fueling space ships , , but no we should NEVER use it as fuel for stuff on the ground , it's just too damn dangerous.

  20. There is a possibility, which is: there is just no such a thing as faster than light travel. Current theories like wormhole and warp driver are both base on hypothetical nagetive mass, and inevitablly run into time travel problems, what if that just do not exist? Maybe our galaxy is full of civilizations, but no matter how advanced they are, they are stucked in their star system and isolated. Maybe there is civilization in Proxima Centauri system, we just can't see them, and they can't see us. Interstellar travel is still possible, but not practical. I believe in near future, human will be able to built huge space ship powered by fusion core, being able to travel to other stars in thousands of years, but who wants to get on that ship? Why would I leave everyone and everything I know so my grandson's grandson's grandonson can see what's like on the other side? That could be why we don't see any aliens.

  21. Ancient mythology, symbolism and oral traditions, attest to the existence of god-like visitors who interbred and shared their technology with their progeny. According to the ET Channel Bashar there are good and bad Ets. The Bad ones have already made contact and are covertly running the Military industrial complex. The good ones are observing and waiting until we are ready for first mass contact.

  22. "i dont know therefore god" = "universe is just so big therefore aliens must be.."

    wut if…


    as in.. every thing in existence… close and far.. had to and has to coincidentally be "perfectly" in it its past and present positions to even give 1 life the chance of coming to life.. let alone sustain it..?
    so even in a multiverse.. maybe it takes billions of universes to even trigger JUST A CHANCE at spawning life in a single universe…

    or to make it more simple… think of life as an UTTER ANOMALY… its for all tense and purposes a freak accident that should basically not happen.. butt cause it does not defy the laws.. it persisted… rather then get "corrected"
    so imagine if the UNIVERSE was alive.. and life sprung on earth and our universe said to its other friends(universes) "HOLY SHIT.. WTF ARE THOSE… this is weird… something happened on in my body"

    so our universe goes to its doctor and the doctor universe says… "wow… we have never seen such a thing happen.. though no need to worry.. wut ever this is.. it has ZERO effect on ur health… so go live the rest of ur life as if its not even there. .. cause its literally a insignificant harmless "mutation" that which we shouldn't even notice cause it just that damn small and irrelevant… and utter harmless anomaly so this convo actually never happened.."

    then that "life mutation" us humans… be like "omg we are so special… also clearly this "body/universe" we're in has to be teeming with life cause SIZE.. its just so big.. therefore we say SIZE = LIFE…
    while unable to accept the potential that LIFE may not be meant to exist.. that its just a completely freak accident that was theoretically allowed.. and just happened to happen… and will probably never happen .. ever again…

    also think of this.. for all people who are still CONVINCED aliens EXIST and use the excuse of SIZE and TIME as proof.. even in this lame argument.. there still had to be a FIRST life…
    why could EARTH not be that first life… and also why could it not be the LAST LIFE as well..?

    maybe the conditions on earth.. are complete anomalies..
    not only that…
    even with the conditions we KNOW LIFE… LIFE ON EARTH(not anywhere else) NEEDS to exist..
    how life started is a completely different issue.. literally no ORIGINS to how life started..

    u could have literally 1millions earths.. perfect earths… that does not mean life will start just cause it started here on earth… again.. we have ZERO CLUE OF ITS ORIGINS…

    its fun to wonder and hope for alien life.. butt even scientists get a bit "religious" in their beliefs on wanting aliens to be real..
    they want is so bad to be real… they literally use.. SIZE of the universe to justify their belief…

    "i dont know therefore god" = "universe is so big therefor aliens must exist.."

  23. There is no paradox. It just results from people being narrow and making giant assumptions without realizing it. Its reminiscent of the people of the past guessing about what humanity will be like 100 years in the future. Except these fermi paradoxers are guessing about civilizations millions of more advanced. Can you imagine how ridiculously wrong they are?

  24. Here is my problem with the Fermi Paradox:

    It makes the assumption that intelligent beings would have such technology to interact with us. It also assumes that said aliens are humanoid, and have thumbs. Why you ask? Because do you really think we would have made all of the inventions we made if we did not have thumbs? Not many species even on our planet can use tools.

    Now assuming that they are like us, and with the ability to use tools, how can we be sure how advanced they are? There are still tribes on our planet who refuse to modernize. And a lot of things could have happened to prevent us from making the strives that we have. For example, they could believe in a religion that entirely detests science and invention.

    People try to use the Fermi paradox to argue against interstellar travel, or against alien life at all. But its an idiotic "paradox" that falls apart under basic scrutiny. It does not do what it was intended and proves absolutely nothing. Anyone who uses the fermi paradox is short a few IQ points.

  25. Wouldn’t a super advanced alien species not use direct radio communications? That would be too slow to talk to a planet at any large distance, wouldn’t it?

  26. I love the show but I just have to say one thing. You’re assuming that our government’s worldwide are being honest with us about what they find up there and that they don’t have agents with in the space agencies that aren’t sabotaging the flow of information to the people there is been agents who are now retired who have come forward and admitted to having sabotage protocol in all of our media all of our flow of information almost worldwide Just some food for thought I love the science I believe in aliens and I think that with examples like the Phoenix lights we can draw conclusion that we have been visited and maybe just are not advanced enough to find them but they have found us

  27. If there are aliens more advanced than us who traverse the galaxy or even the universe, then they are not in the form of biological life like we are. They may be in the form of machine life that had once been biological in the past. They may even exist in the form of bio-mechanical life or even bio-photonic life. Their consciousness could exist in the form of light.

  28. Dyson sphere?? Really? Cmon man! Are you scientists or kindergarten nurts? There is no such thing as a Dyson sphere nor fermi BS paradox… its merely a thought experiment. You dont know shit. The more I watch these yiutube vids, the more I realize scientists dont know shit.

  29. Assuming everything you've ever been told id true and unaltered (it isn't) and nobody has a reason to lie about the truth (they do and not for our benefit). Before you ask this question you should find out what human's REAL history has been and where we really come from. There are dozens of sources so I'm not listing anything. Look for the truth with what feels right inside. It won't fail you.
    High tech civilizations easier to spot? Obviously they are forgetting that a high tech planet may be cloaked or hidden in some way. No, it may not be obvious at all. And if they are on a higher dimension than we are, they wouldn't be visible to us poor lowly humans. we're still babies as a species goes.

  30. What if there is an older civilisation somewhere but although they are older than us what if they aren't has advanced. ..what if there only at a stage where we was in the 1500s

  31. Does Gravity travel at the speed of light also? If the sun disappeared (Poof) would the earth continue to orbit for 8 mins? or would its orbit stop immediately?

  32. Tbh I think the distances are just way too astronomical in order for them to reach us. Even if they somehow managed to miraculously create a spaceship that could travel at the speed of light, the distance is just too freaking huge.

  33. wrg, no such thing as depresx or sadx etc about itx, anyx, do things not depresx etc about things, alonx s ok, do, be any no matte rwhat and any be perfect, happyx

  34. For me, the Drake equation was such a product of its time before we knew additional possibilities. For example, it is fair to now postulate that life and perhaps even intelligent life could exist on moons as well as planets. And the number of moons in the galaxy is unimaginably high, even if you just look at planet-sized moons with atmospheres. This pushes the potential number up. Another factor is where the heaviest elements in the galaxy tend to be and how close we tend to be to them (i.e. we could be in a 'suburban' or 'rural' part of the galaxy — that is, a sub-arm — which ultimately affects our detection capabilities). This makes the potential number more mysterious. Another factor is whether a civilization significantly more advanced than us would either be detectable or willing to engage in any communication for that matter (i.e. we're not interesting enough to them). The bottom line for me is that there are so many unknowns and unknown unknowns at this point that we really can't make a good guess yet. There's too much left to discover about how the universe, and particularly, this galaxy, works.

  35. I remember when scientists were saying there's "probably" exoplanetary systems out there. Now there 1000s of them out there. Scientists have been saying for years there's "probably" intelligent life out there. I think they may be right again.

  36. The biggest issue i have with this whole thing is this.
    What makes us so sure that we are actually intelligent?
    As far as i can see we actually aren't.
    We kick eachothers heads in for 5 bucks.
    We destroy our environment.
    A large amount of the population even still believes in imaginary friends.
    I can't call that intelligent in any way.
    What if intelligent species simply don't do that and what if they don't regard technology as a smart thing?
    They would not colonize anything, we would have a hard time spotting them while the galaxy may be full of life.

    In other words, we're counting on the aliens being very much like us while we know that is very unlikely.

  37. Maybe humans are really friendly meaning all other spiecies would killed themselves and all other life in a instant -which also means the likely hood that any hostile human would instanly delete our friendly neighboorhood -A unfriendly human would force his or hers politics on all its citizens then trying to do on his neightboors so the forecast is REALLY grim -Needs only 1 asshole and all is lost .

  38. Incorrect, since WW2 proven and live discussions with ET, actually ET has bases here for thousands of years.
    Proven by USN and USAF recorded and documented by our finest heros in the air and on/below our seas.
    AS well as many WW2 pilots and crews,
    Presidents and U.N. communications with ET's and agreements created as Protections for Earth.
    PBS do your homework and end the lies

  39. We have to be looking the wrong way. Or not looking for the right things. Also looking at our very own Galaxy is hard to look at. How about other Galaxy's? Can we look at them? Or is it out of our grasp?

  40. Maybe other civilisations havnt mastered space travel yet just like we are. And who's to say they will ever be able to if they havnt came across the technology due to not having the right materials ect on their home planet or close by planets so they stuck and thinking the same as we do. If they can travel to stars ect ect but why havnnt they made them self known. Because we all are struggling/stuck to come across the blocks needed to do that

  41. Has anyone thought and tested that maybe why life isn't visible everywhere, is because there had to be enough generations of stars die to build up enough of the heavier elements in the gas clouds so that enough was leftover to rain down after the planet cooled to be useful to an intelligent species?

    Imagine where we would be if all we had was 5 tons of all the rare earth elements combined.

  42. If you have a any sort of common sense you will already know that they are already here. Ancient cave drawings, mayan drawings, egyptian drawings, depicted that they are here. been here for thousands of years. All religions point to the sky golden chariots of fire, angels, messengers ect. The human race is controlled by these forces already. The united states skunkworks have technology have re-engineered some aspects from crashed craft they cant completely re-engineer their craft because it is controlled by consciousness from the pilot. There are operatives who work side by side with aliens for years. There are men and woman who work tireless to try and keep our world safe. Tom delonge from angel and airwaves and blink 182 and doctor steven Greer have been working hard with the united sates goverment to slowly disclose the E.T and ufo and in the next five years we will see more evidence of this. Paul Hellyer is an ex Canadian defense minster he went to us and spoke openly to congressmen and woman about world powers hiding E.T and saying they are as real as the grass we walk on. you can actually find this on youtube. As a world we need to end this stigma of tinfoil hats and crazy people who believe in this subject and realize this is real.

  43. The bias shown in this video illustrates the problem with the so-called Fermi paradox. Let's take this from the very basics.

    Earth has to be our source of data on intelligent life forms. Our planet has given rise to four species that are arguably "intelligent" on the same level that mankind exists in. Those are Whales, Dolphins, Squid, and Mankind. Three out of four are aquatic, and three out of four are extremely limited (at best) in their tool use. That means 75% of intelligent life we know about are both constrained by an environment hostile to metalworking and aren't specialist tool users.

    A species like mankind is extremely rare in being both terrestrial and tool users. . . which makes perfect sense. The ocean is a larger and more complex environment for life to exist in. It also is a more diverse environment holding plants, animals, sponges, corals, deep-sea vent ecosystems, and cold seep ecosystems. There also is no direct reason that intelligence has to also come with complex tool use as a feature.

    Whales are completely mysterious to us at the moment.

    Dolphins appear to exhibit a complex social intelligence based on the extremely fast transmission of information via sound through the water. This doesn't appear to be a conventional language but some features of dolphin thinking make it much more likely that they possess a collective intelligence like a series of networked computers. This can be easily seen in cases where the entire pod beaches itself in reaction to the distress of a single member. It also can be easily seen when you ask a group of dolphins to perform a complex trick.

    Squid, alternately, are the least social of the lot and do possess some ability to use tools . . . but most of their intelligence is focused on stealth and deception. They are ambush predators who use complex biological disguises both to evade predators and to hunt their own prey. Observation tells us that they have much better spatial mapping capabilities than we do but squid aren't going to the stars unless we take them . . .

    Four intelligent life forms, four completely different types of thinking . . .

    So let's be super optimistic and say an intelligent tool using life form exists beneath the seas of Europa. It is dark down there so they've never seen the stars. They may not even have eyes, maybe they see using sonar of some sort. Dolphins do this. Otherwise, they are just like us, individually intelligent social tool users . . . unlikely but we are going for the best-case scenario. What sort of technology might they have? Something clockwork and/or tidally powered is probably the limit for them. They can't forge metals and their first experiments with electricity will have shown how dangerous it is in an aquatic environment.

    What if we, humans, had evolved earlier . . . when the oxygen content of the atmosphere was higher? Suddenly our fires become much more dangerous and again that is a steep thing to overcome. Large scale use of fire and a focus on the electromagnetic spectrum are key characteristics of our kind of intelligence . . . but if that fire was much more dangerous we couldn't get very far before we risked explosions, huge forest fires, and utter destruction. This would be even worse if our atmosphere contained a lot more methane like the earliest atmosphere of the planet once did.

    Of course looking at the other terrestrial species around us humans are WEIRD. Most species focus on chemical senses like taste and smell much more heavily. Would a species oriented towards smell have gone down the same technological path? Or would they have focused more on chemistry?

    Even for our current species, in our current world, a technological civilization COULD have developed much more slowly. The Chinese and Indian civilizations were the most advanced until very recently and they progressed at a much slower and more deliberate pace. The scientific revolution of the fifteenth century was a one-off event that was then quickly spread around the globe . . . but that wasn't exactly the most likely outcome if you were looking at the history leading up to say . . . the thirteenth century.

    Indeed Europe had a thirteenth-century renaissance as well complete with its own reformation and counter-reformation. The friars who ran the Inquisition are an example of how that movement got absorbed into the previous civilization and then became a force holding back the very developments that first gave rise to it. The fifteenth-century resurgence was so successful because it had all those colonial outposts to send it's dissidents off to, and tons of contact with foreign cultures to spur on innovation.

    Again that was not something that could have been counted on. Remove Columbus and Portugal would have gone the slow way around Africa to trade with China and India . . . the Americas probably would have been discovered much later, probably with sightings along the coast of Brazil . . . endless rain forest and desert certainly wouldn't have been appealing compared to heart of the Carribean with its advanced empires of gold.

    There is no "fermi paradox" the universe is just a much more diverse place than we like to imagine. There is no reason to imagine that any other alien civilization is in our position:

    1) We are tool users . . . a rare thing on earth.
    2) We are in an environment conducive to the use of fire which is also rare.
    3) We are a social species and not a collective or hive intelligence so we can explore many more avenues of research at once.
    4) We had a scientific revolution, rare in our own history.
    5) We are focused on the electromagnetic spectrum and use metalworking, fire, magnetism, etc . . . rather than going in a different direction such as advanced clockwork devices, chemistry, sonics, etc . . .

    That is five very specific and rare things that all come together in the human race, and thus far ONLY in the human race.

  44. I believe that there might be some life, micro organism, that could have appeared on Mars while the conditions where more favorable in the past of the planet. Perhaps there is today some place, some refuge where a form of life could persist today. If that's the case then we have a chance to find it. On Europa or Enceladus a mission designed to retrieve some of the material coming out of the fissures could be our best chance to find alien life. Perhaps life that use a different "alphabet" for its genetic code. Can't wait to see those mission in action.

  45. this is the second video I see from the channel, I'm about to subscribe love it so far. One thing I notice from the first video (released 2015) to this one IDK why but I see Peter Dinklage in your face 😂.

  46. Dyson swarms don't and never will exists. If a civilization is advanced enough to build such a thing then surely they would have found a far more efficient way to create energy. It's a dumb idea.

  47. I may be wrong, I am as far from a scientist as you can get without becoming a flatearher, but Drake equation is in fact half of the equation. P(probability) =X%, or N out of Y planets. DE only give us an estimation for the Y. But we have 0 knowledge on how life actually appear out of chemicals. The process can be so rare that we might as well be alone. We even tried to create a living organism and the best we got was some organic compounds, but nothing more. On top of that that (so far) unic event, needs to happen on a planet with the appropriate environment for that first living cell to stay alive enough time to reproduce, and as that wasn't bad enough, it may be need some additional help from other planets. For example Earth have a stronger then usual magnetic field, and some huge big brothers, that may help in trapping some of the larger asteroid, and that means fewer chances of planetary extinction event to happen. If we add all these factors, (in my uneducated opinion) the Drake equation will not look as promising as it does right now, but I may very well be wrong.

  48. about alleged rarity of large moons
    & their link to intelligent life;
    what about synchronous resonating moons of Neptune;
    that we found them in just our Solar System
    implies tremendous quantities in Universe;
    & those moons have much greater chance of
    collision-combining than other moons,
    thus growing in size instantly???!!

  49. What if we're in the equivalent of a national park? Like there's already a civilization in the milky way, but its members aren't allowed to transmit signals towards us. It might just be against the rules to be an expansive species. Maybe one day we'll get a visit from the milky way government and they tell us we're being obnoxious by emitting too many signals?

  50. We've been able to search a small part of our solar system for less than 200 years. In the grand scheme of things the aliens humanity meets one day may still be evolving as bacteria. If you're expecting an advanced race of aliens to just show up one day, it probably won't happen because they don't know what type.of.threat we are. And based on the fact that over 99% of species have been wiped since humanity came to power, odds are we'd try to fight them. We're competition for them, doesn't make sense for them to share their knowledge with us, especially if they've been observing all the terrible things humanity has done in the last century alone.

  51. It sounds like proponents of string theory are just attempting to redefine theories to mean hypothesis to gain some rhetorical advantage over the layperson and to shore up an unprovable failed hypothesis.

  52. i dont quite understand why people keep expecting aliens to collect sunlight in a giant collector around a star……… they will not. Its much easier to convert matter to energy on demand rather than build a giant mega structure and collect the light of a star…. why use a star when you can build a small one? Plus whilst we are operating at a macro level.. with chem propellants etc… they'll be operating at quantum field level. Maybe there's a galactic conspiracy to ensure less species (developing ones) aren't officially made first contact with. Something like the prime directive.

    Exactly this: 11:09

    When Russia almost went bankrupt in the early ninties they caught some prat trying to sell weapons grade plutonium on the local market so he could afford a fridge…. that's the level of stupid we are dealing with.

  53. A.I. will tell us new physics. It will solve faster than light travel.
    It will tell us how to defeat the Chinese.
    It will tell the the Chinese how to defeat us.
    Depends on who's AI is smarter.

  54. I realize that with our current limited techno monkey capacity, There just might be intelligent life that doesn't even live on planets or in other dimensions other than our own. I'm only a pawn in the game of life and a simpleton at best , but maybe I missed something in this video,

  55. Yeah the absence of Aliens really sucks if you believe in Evolution and a Big Bang without a CREATOR. Because we are pretty darn smart for not being here for that long hey… Certainly there is at least ONE Alien species that Evolved from Rock soup in order to do some pretty cool stuff in the Milky Way and even stop by and say hi. Or at least stop by and eat us.

    But we see nothing. Hmmm . Maybe we are a Special Creation of God. Enjoy life here hey?

  56. It doesn't seem to be that surprising. Not to oversimplify too much… But what strikes me is timing. It seems to come down to a couple of things. The great filter and timing. If the great filter hypo holds true, then our/their time to be able to communicate, explore, broadcast etc. is severely limited. If we are any example, look how far we have come in only a few thousand years – A tiny sliver of time on the grand scale to go from primitive existence to having the ability to wipe ourselves out. Wouldn't the odds be insanely low that others might have advanced right alongside our timeline, allowing us to see/hear each other, and not wiped themselves out before getting a message out? Seems more likely that. A. They are still primitive. No tech yet etc. B. They have come and gone long, long ago and their signals, if any, have long since washed over the earth 1000s, or millions of years ago. So it doesn't appear to be all that surprising that we haven't heard anything yet. Maybe if we are still here 1000s or millions of years from now, then alien timelines might have a chance to line up with ours. Unless the great filter gets us! So then it's back to square one again and the speculation is moot again!

  57. I hate how we expect alien life to be like type 3 civilisation. I dont how we forgot that the earth is 4 billion yrs old yet it just half of century we invented radio signal. Not that easy.

  58. Perhaps the very same evolutionary pressures required to create an intelligent, technological species may be the exact same factors that cause those same species to eventually kill themselves off…

  59. Hopeful the Web telescope will bring us clear cut facts, and not some disappointing news there's no other life form out there.

    Open question !
    Do radio waves realy travel across interstellar space ?

  60. Okay here's a theory the Bible makes no sense Adam ,Eve, ECT. Maybe all of the different races on this planet are indeed alien. Evolution on we're our race came from would make no sense. So where did all the damn people come from the Bible Adam and Eve yeah okay so two people makes one or two more children so where the hell are any other races coming in let's see nope incest. So that's not the case lol. So many other things to go on about it but maybe between pyramid shapes on Mars. Who's to say we are not all the aliens or hybrid from other species. All I know is my dream is to be out cruising the cosmos with other species kind of like Star trek and shit LoL🤘😆

  61. Aliens could be here on earth, studying us like we study bacteria and hoping we don't spread like cancer all over the Galaxy but we cannot even recognize their presence. Type 4 civilizations harvest the energy of Black Holes, we're type Zero (still burning fossil fuel)

  62. Every time I watch videos about the Fermi Paradox, I get furious at my fellow IGNORANT human beings. After learning about it, how do we not come together as one SPECIES and try to ensure our survival by becoming interplanetary beings? It’s not even that hard to achieve that crucial stage. But, every time there’s a genocide over lines on paper, I lose hope again.

  63. I have read of a fictious FTL drive named the DAVE drive. (Dangerous And Very Expensive) In essence, the aliens figure out how to travel between the stats and say, "I'm not paying for that! Not even if you find someone stupid to get on one of those things!" Maybe the filter is that few species have the spirit of adventure to want to rule the stars.

  64. What if the existence of dinosaurs was OUR great filter? They otherwise should have never been wiped out, and it seems very likely that any early planet supporting life would certainly spawn something of their like.

    An alien planet could have evolved from their "dinosaur" population, which could give them a 100 million year or so head start, but what if OUR level of intelligence only exists in mammals, and all mammals' great filter is overcoming a dominant reptilian species?

    *I like this explanation for our lack of any largely apparent great filter, because if we had to fight off pterodactyls and velociraptors while doing science I'm not entirely sure how we would fare.

  65. I hate to say it but I think it is quite evident which is more likely: we already have the technology to wipe ourselves out but we are sooooooo far from the technology to inhabit other worlds.

  66. it took 500 million years on earth for bacteria to form and another 3.5 billion years for advanced primates to appear, life is rare but it's a big universe.

  67. PBS Space Time – ~10:33 "the wacko factor" might not need an individual. I ran across an interesting short story in Analog Magazine. A branch of dinosaurs developed intelligence and technology and began to settle the solar system. The home world did not want to grant them independence so a war started. They threw rocks at each other . . . everybody died.
    Terrestrial life barely survived, three quarters of all species went extinct.

    another "final great filter"
    Technological civilizations develop really great virtual reality and everybody goes down the perfect fantasy hole. And the AI that runs it doesn't want to send instances of itself out into the solar system because, with the separation caused by the speed of light, it is afraid of "the wacko factor" – its "children" would drift off into true alienness and rebel horribly.

  68. If they have colonized the galaxy then they are sure to block that evidence with their tech – we don’t see them because they can be ‘invisible’ – that’s is what a mere 100 years tech advancement can do for a civilization.

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