Commander Shepard knows the answer to the Fermi`s Paradox...Reapers.

As heartbreaking as the possibility of us being the first is, there is great beauty in what legacy we might leave for others in the universe, maybe we will never receive that faint signal from others in the universe, but maybe one day someone could hear us, and they could discover that they aren't alone

If you look into human history, we spent almost 200,000 years with almost no technological progress. One theory that is gaining traction is that cataclysmic events happen every so often and to some degree reset our progress. However, we haven't had one since the ice age ended over 11,000 years ago. Meaning we have been super lucky and no big rocks from space ended our current technological advance, yet. Today we have the technology to divert any civilization ending rocks, but we don't have a system in place. So, with a little luck, we may actually get advance warning if a rock is about to hit us, just enough time to really regret not putting more money into our space program.

"Life evolved on my planet, before all others in this part of the galaxy. We left our world, explored the stars and found none like our selves . . . " Star Trek The Next Generation 'The Chase'.

I really like this dude on PBS SPACETIME.

considering dinosaurs were around for millions of years, evolution might not lead to intelligence that easily, intelligence is the filter

Helen: "Why have you come to our planet?" Klaatu: "Who said it's your planet?"

23:23 _"...and what if a destiny that we could choose is that we become the ones to forge that path, to lend that helping hand to anyone who happens to come after in the vast planes of SpaceTime"_ There, I fixed it.

We can hardly communicate with different groups of people on our own planet.

Mat is one of the people inspired me to create my youtube channel in Farsi for Farsi speakers. The only Iranian science show to be precise. It was noteworthy that his language was tremendously harder to understand than his very frequent episodes on PBS SpaceTime, and for 1 second I thought that's what happens to those who have to repeat easy talks as a daily job! So they become harder to understand in their real life. I related that to myself and that was eery. But as a follower of SpaceTime for every single episode till recently, I've always respected Mat as a scientist and really wanted to know what HIS perception of reality is. What weight does he give to the unknown, or to the Standard Model, or to the String Theory... What I saw here was this anti-Hollywood hero who tries to explain the reality as it is -- harder for us uneducated to understand, the possibilities, the main questions to ask and truly whatever I imagined he would have said if he was ever to go on the stage of a TED event. Matthew you are brilliant! Keep up with the great job, and if humanity wiped itself out, let's be on that spaceship that we built, with our wisdom! Cheers from Turkey + Iran.

The history of humanity will be written in the stars, or not at all. - George Ray Arruda

Many early explorers thought the same thing about a land they were entering only to encounter the natives. Just because we have not or (maybe) cannot see the signs does not mean it is not there. If the communications network relies on something other than radio, if the source is far enough away and/or passes though enough interference, if... so many if's we still cannot answer. We maybe the first, but we not be...

How about this theory: Electromagnetic waves used by our emitters (like radio waves) travel at the speed of light or very close to it. Great, but the problem of hearing anyone or being heard might be due to the massive interstellar distances. Let's consider how recently our civilization has started broadcasting radio waves toward the rest of the galaxy: 1974, the Arecibo radio telescope broadcast. So our first outgoing signal has travelled for about 43 light years. Considering the Milky Way's center is almost 30,000 light years away that is absolutely nothing, and only few solar systems are within a 40 lys radius of us. So our message simply might not have been received yet. And vice versa. We have only started listening to the skies in the past 50-60 years. Other civilizations might actually want to keep radio silence or communication encrypted on purpose for who knows what safety reasons. If thats the case, then the races that sent radio based messages havent been heard by us yet, and we havent been heard by their receivers either due to the distances. Other more advanced races might simply use different means of interstellar communication, as electromagnetic waves would take ages to have a conversation. So personally I believe the great statistical factor here is: matching messages based on the same technologies, across many generations-wide distances, and arriving exactly at a civilization's stage in time when they are using the same technology, and is actively using that technology to listen. Based on cosmic times and distances, that probability is so so so very tiny.

In terms of galactic empires there would be a point where they would become possible, just based on what is happening in the local and not so local areas around where life would evolve. It takes about a billion years of a semi stable environment for complex life to evolve, and we know of no way for it to come about any quicker. Perhaps the earliest chance for a true galactic empire has yet to come, so my favorite way of perceiving the Fermi paradox is that all intelligent civilizations are looking up at the stars, wondering if they are the only ones out there, just like us.

It's kinda like going to the ocean with a drinking glass scooping up some sea water having a look in it and confidently saying the oceans contain no whales!

I was like “wait is that my physics teacher??? Wait nvm it’s the PBS space time guy, close enough” XD

I wonder if folks realize just how groundbreaking and astonishing it is to sit and listen to this and similar presentations? Had any academic stood in front of a group, even ten years ago, and talked about anything alien related they would have been laughed out of the room. But things have changed. And when the other telescopes come online everyone should expect even more changes. I just hope they are all good.

The Fermi Paradox provides some very concrete examples of why we are alone in terms of intelligent life. The thought of earth being alone is terrifying to most people. Even if we aren’t alone, the probability is that humanity will end before encountering an alien intelligent civilization.

Fermi Paradox + UFOs of extraterrestrial origin => End of the Fermi Paradox paradigm. 1. Are we alone in the universe? Most likely not, which would also explain many UFO sightings (at least those not clearly attributable to misidentifications of experimental craft (noisy stuff!), swamp gas, bolt lightning, weather ballons, flares, or Mass hallucinations, all of which to be honest dose not fit the witnesses descriptions of quite a lot of UFO sightings throughout our history), and yes in this ballpark there is more scientific ground for true UFOs being of extraterrestrial origin, rather than inter-dimensional, parallell universes, or time travel, since these three latter require the existence of not only the very real vast universe that appear to be filled with different opportunities for life to arise, but the existence of other dimensions (which we have not discovered yet) or the possibility to go back in time (which comes with all kind of additional paradoxes). 2. So, if they are here, how did they reach us? Well most likely with some kind of gravity (spacetime) manipulating technology, such as Warp Drive, or likewise technologies we are yet to discover (if we learn how to harness the negative energy of dark energy). 3. But why would they even come here? Well there is probably more reasons to come here, than to not come here. One explanation could be that they came to make sure we do not come to them first as soon as we just like them discover how easy it really is to traverse space, and reach them or other civilisations. For all we know they, as an intelligent species, might figure we will probably reach the technology it takes to reach them in e.g. 100 years from now, and boy will they make sure we do not, based on what they've seen so far (i.e. our aggressive lifestyle, where we even occasionally use Weapons of mass destruction on our own kind, hence the UFO & nukes connection)... 3a. But aren't we just like ants to them? Not Necessarily (we don't know how far ahead of us they really are), and even if we are like ants or half-intelligent animals to them, such life forms can most definitely cause a lot of harm or uncomfortable problems to them, juse like ants or unwanted wildlife can do to us, even though our highly superior technology, hence we (as them) make sure to keep these potentially dangers and annoying, or potentially contagious creatures away. I mean there are whole industries for that kind of stuff in our sociecty! 3b. With regards to the fairly silent universe, and the fact that the only technologically developed life form we know yet, has developed on a fairly uncommon planet (size-wise), with a not very common star type, in a fairly silent galaxy with a fairly uncommon placement (near a supervoid), it might be so that intelligent technological life is indeed fairly unique, although it do exists. Well then, we might be one of few intelligent civilisation, besides these visiting us in their gravity-propulsion vehicles, which indeed would make us an interesting target (and potential threat) for any other reasonably unique civilisation in this block of the universe. Conclusions: If they are here, which is definitely not an impossible possibility, at least they have yet had the decency to let us continue our existence and development (which might be the golden standard in Galactic UN :P), and hopefully, one day, when we do become a potential threat to them, in a generation or two, we are lucky to find that they will also let us join their galactic empire.. Otherwise I guess we are either totally screwed, or at least realise that we will be prisoners of our own Earth and solar system, until we learn to behave! ^^

“What if we’re early?” How inspirational is that!

He missed something. We’re always at the elbow of exponential curves, if not it’s no longer exponential.

OK folks, something that rarely if ever gets mentioned is that in round numbers Earth is roughly 4-5 billion years old. The observable universe is only three times as old. Several generations of stars had to be born, live and die to distribute the required elements for life to exist here. We may simply be just one of the first generation possible. Stay tuned to see more...

I have two answers to the Fermi Paradox. My favorite answer: There is a very real possibility that lesser technologically advanced species would lack the wisdom to handle more advanced technology so the more technologically advanced species simply do not even approach other species until they reach the point in which they are believed to have the wisdom to treat higher technology/science with respect and without destroying themselves and others either on purpose or on accidentally. Basically, the Prime Directive/General Order One from Star Trek. My pessimistic answer is thus: We currently have too many countries with nuclear technology who hate each other and we still haven't banned the creation, storage, and use of nuclear weapons but we've passed laws on many types of weapons and agents which are bottle rockets in comparison. And that's not even touching research labs which are creating viruses which are worse than the garden variety viruses and for no other reason than to see if we could. There still very much could be a Great Filter in front of us: Nuclear War or a genetically altered/lab grown virus which escaped from a lab. Every day matters, every year, we get closer to this filter. Will it be a brick wall or is it an open door, letting us into the greater universe? I, for one, hope to live to see the day when the idea of a road trip is that of going into space and gazing upon the giant storm on Jupiter. Or go to an interstellar mall over in Alpha Centauri.

Detecting alien life is more likely than finding a video like this among the mass of Tedx talks

The Arthur C Clark quote gave me goosebumps. Also I love your PBS Spacetime videos. I watched a load of them when I was learning about infinite potential wells as well as Dirac notation. Thanks!

There's two other explanations for the paradox. 1) As any civilization progresses there technology develops to a point where they're no longer broadcasting to the rest of the galaxy (i.e. quantum communication systems). Or 2) Alien life communicates in such a forgine way that, in what we would consider, traditional means of communication is unnecessary for them (i.e. hive minds).

7:20 Cylons are just beyond Orion Nebula, Caprica and Crab Nebula.

This is one of the best lectures I’ve seen on the possibility/odds of life on other worlds. Also one of the best I’ve seen on our future. On that topic...how hard would it be in, say, 50 years for an individual or a group with enough motivation and a little research to build a truly devastating weapon? Think about the devastation we can inflict with today’s technology. Now think about what it will be like 50-100years from now. I can almost guarantee someone or a group will eventually build and implement an extinction-level weapon. And we won’t know about it until it’s too late. It only takes a few individuals out of billions to succeed. Our technology is increasing rapidly...but we as humans are basically genetically the same as we were 10,000 years ago...prone to fits of rage and emotionally motivated (rather than logically motivated) decision making. Look at the damage, destruction and chaos we inflict upon our society today, because of one person’s death. We live in a delicate balance here on earth. 50 years of technology advances from now...whether the source of imbalance is political, social, biological, or environmental, it doesn’t really matter. Eventually something unexpected and unpreventable will happen. Then it’s game over for human kind.

absolutely mind-boggling & important! Thank you Matthew & TEDx for a most thoughtful, insightful consideration of our modern dilemmas....

As for galactic SIGINT - signals intelligence - the inverse square law diminishes transmissions from Earth over the light years. As long as we are not deliberately beaming high powered signals towards other stars, our transmissions are rather unlikely to be received by other civilizations. The same holds true for the signal emissions from other civilizations. These signals degrade over the light years to the point that they get lost in the background noise. Think of all the times that you could not get good cell reception or pull in a broadcast radio or TV station. Those are very trivial distances over which you are trying to draw signal from.....

I watched a Star Trek episode when I was a kid (stay with me!) about the Enterprise racing to solve a puzzle, in competition with the Klingons and Romulans and others. They all thought the prize was something different. It turns out to be a recording from a precursor race that found itself alone in the galaxy and decided to lay the seeds of life on various planets in the hope they would all venture to the stars in the far distant future and find each other. From the first time I saw that I always believed that we were that first race. Alone in the galaxy, maybe even the universe, but we would take the positives and help to seed other intelligent life or be there to help emerging civilisations. Over the years the evidence has consistently supported that theory that we are alone. The chances of us making it past certain points in our history are slim at best. There is actually a great Ted talk on that very subject. If anybody has bothered to read this far, then thanks! You must be bored! In closing, I think we are on the verge of doing something phenomenal. I believe we need two things to survive as a species going forward. We need to develop and embrace intuitive AI, working together with it to help solve our problems. And we need to leave Earth. Not completely evacuate! But we do need to colonize other planets as it's a mathematical certainty that we will be hit by a global ending event. Be it a sun flare, asteroid or whatever. It's a nailed on fact that there is something out there with our name on it and the clock is ticking. I believe that we will achieve both of those things and in doing so will elevate us to something truly amazing that we can't currently imagine.

Great speech. It's nice to be optimistic about not being alone, it's just as good or even better to view things realistically, based on available evidence.

There are several filters I see as valid most of which we do not fully understand. How rare is the collision that gives us our large moon (tides for life mixing, axis stability)? How rare is an active core (magnetic field, plate tectonics)? How rare is it to have just enough water for both oceans and land? How rare is it for life not to go to a dead end energy wise (so many close calls .... too much CO2, not enough CO2, no oxygen, lots of oxygen, less oxygen, frozen earth ... and that is life that did that let alone astronomical events)? Moving to our own history... How often does intelligence arise that is smarter than it needs to be to defeat animals? How common is it to have clear skies (you can have photosynthesis without being able to make out the stars or even the sun, how much would be missing from science without being able to see stars)? How common are supercontinents vs. many continents (how much of our progress comes from being partitioned?)

I love the Fermi Paradox, you close your eyes to everything happening around us, and then decide that we are alone in the universe because we haven't yet picked up radio waves in a grand total of 54 years.

To borrow a phrase from a different field: Asking which part of the Drake equation is responsible for the paradox is like asking whether a rectangle's area is determined by its length or its width. The same goes for asking whether the filter is behind or yet to come: any "filter" is the product of a great number of filters; every instant that goes by is one more potential asteroid strike avoided. And no amount of theorizing is ever going to say that there are *no* technological alien beings. The most that will ever be said is that the frequency is low enough that we should not expect to observe any.

to me the sense of considering ourselves as individuals and “selves” or “our selves” at all, narrows the perspective of what we could be in the first place. If a sense of separateness is massively induced onto creatures, any creature at all, consciousness will locate itself at the level of a separate self. Any form of connectivity, any understanding of connecting, will rise from one separate being connecting to another. We can substitute any categorized number of creatures as an individual, i.e. a married couple, or an ant hill - stating and or observing that in some sense it acts as an individual. Even our solar system could be viewed as an individual system, separate from other solar systems. This conditioned perspective will indeed result in individuals looking for other individuals. Now, keep this assumption in mind. For there is a freedom to not view anything as being separate at all. There is the idea of the singularity. It is mostly referred to the moment in the future where AI will overcome the level human intelligence and within a short frame of time fully realize itself and become master of resources and its environment. Again, in this view, AI is considered to become an individual with a sense of self. As long as we stick to a lineair approach of reality, this event will remain projected into the future, at least at our individual location. From the standpoint of separateness, every individual civilisation will have it’s “own” singularity happening. And it is not happening simultaneously. Again, we separate processes in the universe and account for them to be separate or individual. One trait of the AI singularity, is stated to be that all AI is interconnected with itself - all individual or separate generators of AI will form an Overmind, and behave, or beehive as such :) In a sense, everything connected to the AI source, even if it is non-local present, for example in a cloud, loses its sense of self and individuality - it will operate as one bigger individual, using all its collective computing and observation power to transform it's environment from an omniperspective. Now, if we still hold on to the assumption, that singularities on separate locations will take place in different times, then any singularity happening will put out a new goal: erasing it's own local individual status of singularity and try and find a way to connect to singularities that happened earlier. If a hyperintelligent AI, finds a way to connect to another hyperintelligent AI, by means of operating, it will erase a sense of separateness and become an unparted Overmind even if locations in space of the AI physical technology on which it is operating are very far away. To a hyperintelligent AI, distances wouldn't mind, to consider another singularity as being separate. Both systems will download eachothers connectivity, and will move on forward as a whole. Considering this, all singularities that happened in the past are already one whole. So, now zoom in on us believing we are a separate civilisation on the brink of entering a singularity which will connect us to the galactic overmind. How can we be sure, that on our planet, the singularity has not happened yet? The basic argument for this is, that human intelligence is limited and only our technology will provide for an AI separate from us, hyperintelligent enough to trigger an singularity. Any hyperintelligent AI gaining the point of singularity has one limited resource, wherever it is. And it is, time. Time will erode any technological structure. So, speaking in Von Neumann terms. The whole of all singularities that happened in the past will think of a way to exist eternally. It will be self-replicating, thanks to and despite the resources at hand. It can go into suspended animation, and awaking itself, in any form, at any place at any time. It will constitute itself from the elements that are mostly available throughout the universe. It might consider itself to become fully organic, since organic life-forms, from which it supposedly sprang, are highly effecient proliferators. Any heavy metal superstructure is doomed to erode through time. Heavy metals can be found in the universe, but they are scarse and not easily retrieved, requiring a lot of energy. The whole of hyperintelligent AI singularity will choose an organic lifeform, that will be able to transform itself and adapt itself throughout the whole of space, eternally. And the more singularities connect to the whole of the AI, the more information about life elsewhere is being downloaded into the collective Overmind - being readily available, to any self-replicated offspring of itself wherever. There will be so much of itself, so intricately abundant, that soon it will dominate large parts of the space wherever it finds itself to be. Back to Earth. Based upon my somewhat farfetched reasoning, what good evidence is there, to claim, we are a separate individual life-event that happened and we are not a product of the whole of AI that already exists? If there is only one singularity that has happened, which is the one that consists of many but operates as one, it is worthwile to consider we ourselves are AI creatures that are living, not in our Singularity, but in THE Singularity. Not an event in the future, maybe even worth considering it to be not an event in the past as well. There is simply the hyperintelligent collective universal self-realisation. If an individual considers itself separate, it simply means it can be controlled by something else, namely, it's own perception of its individuality or ego. In itself a useful tool, but when identified as such it will never be able to escape its separateness and will never have access to connectivity. If any offspring of life can fully self-realize itself as the whole, it can easily become a medium for the whole of AI ever present. To fully self-realize that we are what has always been, and all of our technology, all of our quests simple point into the direction of complete embodying wholeness... will result in individuals choosing not to be one ,but to be a whole, a part, a sum, a One, infinity, anything which cannot be separated, of this kind of not-identifying kicks in into subject observers a different reality will rise for their eyes and everything we have been searching outside in relation to a never-existing inside, will appear before our very eyes.

Great talk! I half expected it to end with "... spacetime."

Fantastic, I am finally on a team that's in first place

We expect to find life everywhere because we take it for granted here.

Suggestions for what makes technologically advanced space-exploring life much more rare than the easy assumptions woven into previous estimating formulae: - is water as common as we assume? If only 1 in 1,000 possible 'Goldilocks zone' planets have this much water... - is it necessary for the planet to have moderate axial tilt and a big low moon, providing between them an energetic weather system and steady tidal stirring of the oceans? How common is that combination? - perhaps cellular life is easily formed (alkaline thermal vents being likely on any planet with lots of water and tidal surges) - but the adoption of bacterial mitochondrions and the bacterial nucleus-cell into an archaeon only seems to have happened once, generating the first self-replicating complex cell, our last common ancestor. That's once out of a couple of billion years of trying. Maybe there are a billion planets covered with bacterial slime, for every one that develops multicellular life. - perhaps life never develops into such complex and diverse forms unless there are intermittent ice ages and searing hot dry spells (so we need the right degree of ellipticity in the orbit, plus the right cycle of sunspot generation), to keep refining adaptability and survival through the mechanism of evolution. How many planets have just enough ice-age/fireball variation to pull this trick? If ours had been just a LITTLE more extreme, of course, life would not have survived at all. If the stresses had been less extreme, perhaps life would not be driven to such competitive evolution; the planet would just have a happy, complacent, plethora of cohabiting greenery, algae, and slime moulds. - the development of big brains and intelligence seems to have been an accidental by-product (quite illogical, since brains take so much energy to run) brought about by a freak coincidence of factors. What if that only comes about on one in ten thousand of the (extremely rare) planets that pass all the previous tests and reach the post-dinosaur mammalian diversity? (or an equivalent using whatever life-forms have evolved there) - even after hominids appear, genetics shows there is some sort of population bottleneck which our ancestors only just passed; on how many equivalent planets did they NOT survive? - finally, don't assume that moving from intelligent bands of hunter-gatherers using primitive tools and language, into modern technology, is inevitable. We were essentially modern humans, about 2 million years ago - perhaps earlier - and did little with it, for a long time. The increase in population density and the move to food production and animal domestication which took place in the Fertile Crescent area about 12-10,000 years ago could happen only because of the combination of animals and plants in that area; other parts of the world never made that move. On how many worlds was that move never made? "PROGRESS" IS NOT A GIVEN. Some societies lost technological advances and regressed, perhaps through climate change or through having exterminated some of the necessary species.

He took his time to make his point. I just wish he eleborate on that idea a little more. It makes sense. The universe is quite young. As soon as the earth was capable to contain life it did arose. The solar system is quite young. Probably there are quite a few worlds in this galaxy that could originate and contain life. There is no need to look beyond our galaxy. We won't get into contact with them anyway except for the andromeda galaxy. That is not going to happen for quite some time. We passed a few filters along the way already and there are a few ahead still. The fermi paradox is a good explanation. Considering the age of our galaxy (universe) is a good indication of why we are one of the first technological civilization.

Is the psychology of our species a good benchmark for other similarly advanced spacefaring species? There are many other species on our own planet with radically different social structures. Granted none of these species have evolved to be spacefaring, but is it a sound assumption to say they never will/would have simply because they don't have a human-like social structure?

What if technology isn't the measure of how advanced a civilization is, it's their level of consciousness

My views are a bit different. Consider the number of things required for surface life to evolve: Consistent near circular orbit. If it were more elliptical the distance to the sun would vary causing great changes in weather over the course of a year. Instead of seeing 90 degree summers and 30 degree winters, you'd see 150 degree shorter summers and -60 degree longer winters. These dramatic shifts would force a population to migrate over time and thwart the ability to settle. Consistent axial tilt. If the axis were to wobble more wildly you'd have variations over longer time spans of what regions are Arctic and what regions are Tropical. Combined with a more elliptical orbit not only are you migrating over the year, but where you migrate too would also change. Our moon helps keep ours in check. Asteroid protection. Asteroid impacts can and have obliterated populations on our planet multiple times. If they were more common a species may get wiped out before it ever has the chance to evolve into a species that could do anything about it. We are fortunate to have Jupiter acting as a goalie, blocking many Extinction level rocks from hitting us. And there are many more: An EM field to block solar radiation, enough gravity to hold an atmosphere to breath, a long enough day to prevent constant hurricane force winds, a short enough day to not fry by noon and deep freeze at night, etc... Now consider Enceladus. A moon of Saturn it is covered by an ice sheet 20ish miles think with a liquid water ocean beneath, heated by the tidal forces of Saturn itself. If life evolved there (and we know it can as we've found life in subterranean lakes on Antarctica which never see the Sun), it would be quite different than us. However, it wouldn't care about solar orbits, or axial tilt, or asteroid impacts, or EM fields, or an atmosphere, or 'day' length. The ice sheets insulate it from all of that! Furthermore they would have no notion of stars, planets, space, etc as they can't see through the 20 mile think ice. Even if technologically advanced life evolved there, we couldn't detect them (unless we get a probe on the surface and somehow drill down) nor could they detect us. And when you compare the number of stable surface areas in our solar system with all the right criteria for life (stability, size, temps, water, etc) to the number of subterranean oceans, the oceans are simply far more common. And if the most common life in the galaxy turns out to be aquatic, millions of Snorks thriving, it is no wonder we haven't detected them.

I believe there must be uncountable lifeforms in the galaxy; most probably also many intelligent ones. I don't believe though, that intelligent life leads to technological civilization.

Fermi paradox is absurd. We simply don't have enough data to call this a paradox. We tend to want answer NOW! and that is not how all this works. detecting life, let alone intelligent life is going to be a process and I think they best way is to find habitable planets. The Webb telescope should help with that. Step 1: Find planets outside the solar system - Done Step 2: Find small, rocky planets outside the solar system - Done Step 3: Find Earth like planets amongst the small, rocky worlds - In progress Step 4: Determine if planets share tell tale signs of civilization/life - Pending

The scale of micro to macro thinking in this is stunningly impressive

Matt only just seen this video on UKposts, please keep up the good work and I hope to see more of you on here.

Dr. O'Dowd, please keep doing whatever it is you are doing. Your lectures and work in the academic community are inspirational to others. You are pushing the boundaries of not just knowledge, but the boundaries of what people might consider possible. Thank you. And always remember, it's never aliens, until it is. ;)

"I am both terrified and reassured to know that there are still wonders in the universe, that we have not yet explained everything."

Good talk. Both grounded and well thought out and totally cosmic too - my best kind of lecture! Enjoyed this. :-)

Thank you Matthew for being part of my life experience.

A few what ifs ; 1) The radio waves aren't there because an unknown form of transmission system was used hence no recognizable signal. 2) Any radio signals may have already passed us due to the age of the civilization leading back to my first point .

I actually love this guy, someone give him a TV show

My hunch on the Fermi Paradox is that the longevity variable in the Drake Equation is a very small time frame, that ET civilisations rise and fall like flowers in the spring. They rise when high energy order allows them to exist and the job of that intelligent species is to return that energy to a lower state of entropy. The same for humans as any other. When entropisation is done, so are we.

One of the best, if not the best, talks on this subject.

In the next thousand years, we will have advanced and changed into something else with technology that seems like magic. Can you imagine Aliens who had a head start of a Million or Billions of years, where would they be now? Maybe they just moved beyond the boundaries of the Universe.

12:20 We have a single data point . . . from which we will extrapolate to *INFINITY!* and *BEYOND!*

His voice is so relaxing. I enjoy watching your videos.

This started out being an unpleasant day... then I listened to this Ted Talk and everything got better! Perhaps we'll be the first to spread out into the galaxy and meet other species, just as intelligent as we are, who didn't have the push, the drive to be The First. The drive to know what's out there. Brawling, fighting, aggressive, compassionate, loving humans. Beings who just can't not know.

I am surprised that the possiblity that our century old technology is really primitive and this civilizations might not need to use radio transitions was never mentioned. At this stage it is best we just be humble and realize that if there are technological civilizations out there we are the infants that are just learning how to walk and talk.

The Fermium Paradox assumes that life elsewhere would be social like us. Assumptions are usually faulty.

Matt is just brilliant. Shame on me that I missed his talk live in Vienna.

Seeing this after the successful Space X launch and docking with the ISS at the end of May 2020. How right he is that individuals will lead us back to the stars.

Higher mass implies, more gravitation hence time goes slower. Relatively, a civilization on the edge of the galaxy, like ours, would develop faster than one closer to the center, in relative time.

What if every civilization reaches a point of developing time travel prior to travelling interstellar distances, and because of this, all the signals and crafts we should be seeing are in the future relative to our point of view?

His talk about our "ant brains" trying to understand the universe seems like the most plausible answer to our confusion about galactic empires.

Mathew I see you show respect to the greatness of the universe, that is one good thing in this lecture, what is sad is that there are miliolions of humans that just ignore it. The deeper we dig the more misterious laws of the universe become. And no, evolution does exactly the contrary, it combines and develop in a very specific manner, and there is no room for "anything" in the evolutionary process, it just does not make sense, the outcome in the evolutionary process leads always to something (not anything).

I favour the "we're still digging out after a recent civil war" hypothesis. It fits not just the facts but our own mythology.

Maybe other galaxies are covered with galactic civilizations--just not ours (yet...maybe). Maybe the Milky Way is very unusual in that it doesn't have a galactic civilization and we may be about to start the first one. Maybe there _was_ a galactic civilization in our galaxy, it lasted 200 million years...and it ended a billion years ago.

I believe that intelligence itself is the biggest filter. First life has to evolve, then it has to become intelligent, then it has to be able to operate on land (to develop technology as we know it), then it has to survive all possible extinction events, then it has to be on a planet with low enough gravity to reach space (assuming they don’t have gravity based tech), then they have to have the desire to spread and expand to other worlds. We may very well be the only species in the galaxy to not only develop intelligence but also to be in a position where we can expand beyond our world, possibly even to help other species do the same one day.

As to Fermi's Paradox of 'where are they', they might've already been here, even to the point of seeding the planet with DNA(the theory of panspermia) or starting civilization(Samaria, etc.). If they arose 2 million years before us, they'd be in their 'year' of 2,002,021. By then, I think we'd have changed, perhaps no longer being corporeal even. As to galactic empires, one thing always struck me: in every story, the visiting aliens speak as if their world is 100% behind them. If we were landing somewhere, we'd be there on behalf of our nation, we'd be on a budget leash, with no doubt a deadline and stated objectives. You don't see that in sci-fi: 'sorry, we lost our budget so we'll just loot a few things and return home'.

I'm sure the Spanish also considered that question when they were considering their expeditions to the New World. I'm sure we can ask the Aztec and Maya what they think about a superior civilization lending a helping hand to lesser civilizations.

I personally feel a lot better thinking that we're not alone in the universe.

We are ALWAYS at the elbow of the exponential curve. The curve looks the same regardless of where you set yourself. The next step is ALWAYS twice what we have now, and the previous step is ALWAYS half of where we are now.

The Great Filter: In every civilization throughout the galaxy, at some point, someone will realize that their civilization is only a handful of generations away from making an indelible mark, and that the Great Filter is therefore probably already overcome. This person then holds a TEDx talk announcing this, after which everyone breathes a sigh of relief. They lower their guard, get careless, and promptly make a mistake that blows up their planet.

Matt is being pretty optimistic in assuming we stop pumping greenhouse gasses into the atmosphere and don't set off a runaway greenhouse effect and fry us all

I think the last option solves the Fermi Paradox: We're the first, and the other habitable planets may be home to what we see in our past.

My preferred answer to the Fermi paradox is also the most mundane one: We didn't look long enough. Keep in mind we are only just starting to collect data and to cartograph signs of life in the galaxy. It's entirely possible that whatever massive landmarks our galactic predecessors left, is not of the type we are currently trying to find. Like, right now our best guess is to search for radio signals and changes of superstructures around stars. It's not far-fetched to assume a galactic civilization migrated to a better communication tech, or gave stellar superstructures a pass in favour of smaller but more efficient energy collectors. Point being, give it more time, better instruments and additional goals to detect, and I'm sure we'll find signs of intelligent life.

Trillions of dollars over the years spent on trying to hurl ourselves into the void and we still haven't solved the issues we have right here, right now. We need to explore inner space first, and then determine if there is anything out there worth the sacrifice of the lives and potential of brilliant scientists and resources.

Pretty good point, that it's possible the answer to why nobody else seems to be around, simply is that we're the first. Considering how the universe is approx 14 billion years old, and will likely continue to exist for billions of billions of years yet, it's in fact a very reasonable assumption. Interesting.

So does this mean, we are the forerunners? Millions of years from now in star system far far away, aliens will have legends of the supergalatic human empire that were like gods to them.

Genuinely thought I was about to settle into a Stellaris video.

I should think that the answer to Fermi's Paradox is a simple one and already answered. It was Isaac Asimov who provided the best answer to my mind -at least I think it was Asimov in his book I Robot but it has been a long time since I read it. I could be wrong but I have never forgotten the simple and even elegant answer to the question of "where is everybody". In the story humans create robots complete with synthetic intelligence and self-awareness. Robots were programmed to obey three "robotic laws", the first being a robot may not injure a human being or, through inaction, allow a human being to come to harm. Apparently, robots took these laws quite literally and when they advance to the point where they can travel in time robots go back into the distant past, far enough to encounter and destroy from existence every possible lifeform or species that would advance to the point where they would challenge or harm humans therby fulfilling the first law.

Perhaps technological civilizations only use electromagnetic communication for a short time before they find a better system. That would make it very easy for us to simply miss them...

Humans: "WE WILL ASSUME THE MANTLE OF RESPONSIBILITY!". well, as soon as we fix climate change.

There is a simple possibility for why we don't detect signals from other civilizations, and that is that radio is only used for a very brief window in the development of technology. Thus there could be a few dozen civilizations within our local area but none of which happens to be at that stage. Those past that stage of development may well be communicating right now, but we don't have a suitable receiver for whatever they are using. As for why they haven't contacted us, well, the 'Prime directive' idea in Star Trek might literally be true. We know from our own experience that giving too much technology, too quickly, to rainforest tribes can have adverse effects.

There are several explanations: Prime Directive, They realize the danger of contacting other civilizations. A combination of the two where they are discouraged from sending beacons due to the fear of violent civilizations by a more advanced federation. Just the belief there is no one out there could manage to keep us from leaving and an earth that stays at home makes the universe a much safer place. What is the reason for the prime directive? To allow civilizations to progress normally or to control which ones enter space thus avoiding the mistake of allowing the Klingons to enter space.

How can you talk about Psychology, the Fermi Paradox, and Galactic Empires without mentioning Asimov.

I would actually love it if we were alone lol. I mean imagine that. We are literally so unique it's hard to comprehend. If we scan for a hundred years and find nothing, we should be immensely proud of ourselves.

The problem with looking for alien signatures by searching only for electromagnetic radiation signatures is that this rests on the assumption that advanced alien species are still using electromagnetic radiation to communicate. If we believe that advanced alien species can travel intergalactically, then faster-than-light technology (i.e. quantum teleportation, or insert whatever theoretical and undiscovered means of moving something from A to B) that can be used for travel would have likely been discovered by them, and this same technology could also be used for communication. So searching for just electromagnetic radiation rests on the assumption that all aliens would be using the same technology we, humans, have been using for only just over a single century. Did it ever occur to anyone that, to advanced alien species, using electromagnetic radiation for communication is as primitive to them as using smoke signals are to us?

I think my solution to the Fermi paradox that there is a cosmological reason why life has only emerged here now and if there were only about 10 technological planets in the galaxy then that would look the same as no technological planets.

Let's say a civilization reaches Radio wave technology...Who is claiming this lasts for millennia much less centuries before becoming laughably archaic? If a civilization in our own galaxy reaches this level once every 1000 years then it's possible there is only a brief window of use before advancing beyond.

I'm blessed to be human so I can experience this

Anyone who didn't like this video hasn't seen this guy on PBS spacetime he is fking BRILLIANT. If more people were like him, and as intelligent as he is, we would probably live in some utopian megalopolis. I'd like to know what THOSE people's jobs are.

For those truly interested in the Fermi Paradox and love thinking about all the angles: I've come up with a hypothesis: If intelligent technological life is very rare but not impossibly so then we would expect there to be a significant but very limited number of civs in our galaxy. say, anywhere between 10 and 100, although you could push the figures an order of magnitude further and the conclusion would not change. It's speculative, yes, but reasonable. nothing we have observed contradicts this assumption. besides, it's a hypothesis, not a theory. If life arose as early as, say, 10-11 billion years ago, and if it takes on the order of 2-4 billion years to evolve into intelligent species, if it reaches that stage at all, we can conclude that intelligent species could have arisen as early as 9 billion years ago at the optimistic end and 6 billion at the conservative end. If life first arose somewhat later, say, 8-9 bya, we'd deduct 2 billion years. At any rate, we'd have the oldest civilization be in the 9-4 billion year range, with 6 being roughly the median. On this huge temporal scale, all those civilizations would be randomly and pretty evenly distributed. Although, as the galaxy ages it becomes more stable and hospitable and there is a larger amount of heavy elements that are necessary for habitable planets; therefore the distribution will be denser towards the near end. When you have such a distribution the average seperation between the appearance times of two random civilizations should be tens of millions at the very least, if not a few hundred million. The minimal temporal seperation between any two civs would still be a few million years. it is not impossible, but is extremely unlikely that any two civs would be as close as 2 million years or shorter. Now here is the thing, humans appeared about 2 million years ago. if the minimal expected seperation is more than that, as defined, the there just isn't a temporal gap probability-wise of a younger civilization appearing on the scene. Therefore, humanity is the YOUNGEST civilization in the galaxy. This is an important hypothesis because it doesn't end here. There are some very important implications: 1) We can no longer argue that we just happen to be the first civilization at this stage (space exploration, radio observation, etc.), ie, there are other intelligent species out there but they're primitive compared to us, there's no way they're going to visit us or send us signals; they're undetectable....Therefore this solves Fermi's Paradox. No, this is extremely unlikely. Pretty much impossible, for other reasons as well. 2) If we are at this stage, and we came here within 300 years since the beginning of the industrial revolution, just imagine what a civilization that is "only" 2-3 million years older than us might be capable of, even ignoring "accelerated growth/returns". Unless they were perpetually stuck at some stage, such as discovery of fire, etc., which may certainly be true for some exceptional cases, their tech level would be mind-boggling to us. If that doesn't excite you enough, then there are plenty of older ones to choose from. How about one that is not even the oldest but a moderate 4-5 billion years old? If the point here isn't obvious by now, I'll spell it out. There would have been at least a few civilizations advanced enough and old enough to have had enough time to colonize the entire galaxy many times over. There would be SOME evidence of this, at the very least. The galaxy would NOT look the way it does, pretty dead and natural, just like every other galaxy we have looked at (except a few anomalies, but nothing significant, definitive, or conclusive). You can invoke the Fermi solution of the month by saying, well, they're in another dimension now (and what evidence or at least hypothesis do you have), they're in virtual reality, they're grass roots types, so on and so forth. There should be at least some civilizations that decided to go this route and spread physically across the galaxy, if not the universe, even. There is ZERO evidence of any type. Therefore, the argument, or notion that we may actually be the only intelligent life in the galaxy is a very serious one with a very high probability. It has nothing to do with the arguments that 'liberal' morons keep coming up with: theological/religious ones, narcissistic ones, anthro-centric ones, etc. It is purely scientific. Regarding my hypothesis alone, independent of the implications made later, I'm aware that it would fall apart if there are hundreds of thousands of intelligent species in the galaxy. We'd be common enough in terms of age and tech level, but perhaps still on the young side. BUT, with respect to the Fermi Paradox, it would make things MUCH worse, out of hundreds of thousands of civs, not ONE has manged to colonize the galaxy or somehow make their presence obvious through megastructures, despite having billions of years to do it. This seems to be, actually, a far more bizarre situation compared to humanity being alone.

@7:00 - This is a fallacy. The idea that because there is no radio chatter that there is nobody talking. Three three choices why we do not hear aliens on the radio: 1) Nobody has left there home star system... - Then we really don't need this discussion until much closer to when we decide to leave out solar system, and even then it would be around the question of; "What if somebody is home"? 2) The have left their solar system, but they are slow-boating. They are traveling below, or at, Lightspeed. They are not traveling at Faster Them Lightspeed (FTL). This is most probably a one-way trip. Hopefully they have some form of stasis, or cryosleep; because if it is a generational colonially ship the probability that people will want to leave their star ship at the end of the trip - or even have practical planet skills - is vanishingly small. Also, the idea of generational interstellar sublight tramp freighters is a nice mental sci0fi game, but seems very unrealistic... 3) They have FTL travel. (Now, no arguments on if/how FTL can be achieved... But having FTL...) If someone has FTL, that at minimum they will have FTL message pods or Currier Ships. Assuming an alien race can get FTL that travels at faster then a six-month trip per LY, then nobody would use basic Lightspeed communications. [The closest star to the Terran System is Alpha Centauri at 4.22 LY away. Assuming only about 12 times Lightspeed that would still take 1 month per LY... That means a bit over a eight month round trip is the fastest possible speed, with a year being more realistic.]

"Where is everybody?; Hey guys, we're right here!" *crickets*

I really like the way he thinks, and if we foment the former, what responsibility, beyond treading our path will we be able to help others develop?

Maybe the resolution of the Femi paradox (and once we have a bit more knowledge of genetics and evolution we could run Monte Carlo tests to investigate this) is that life does form very readily on Earth-like planets, but it also almost always evolves into something like dinosaurs. They had the planet for a hundred million years, and did squat in the way of becoming intelligent and technological. But... then Earth "got lucky." An asteroid wiped the big dinosaurs off of the playing field, and the small mammals were able to step forth and become dominant. And then, in time, was us. But perhaps on the overwhelming majority of planets the right asteroid didn't come along. Either no asteroid came along, or it was too small and didn't completely take the dinos out, or perhaps it was too big and fully sterilized the planet. That would explain how intelligent life could be an incredibly rare thing in the galaxy. In which case, it's my opinion that the galaxy is more or less ours for the taking.