The Birth-Death Drake Equation | Part 2 of 2

  • Published on: 02 April 2021
  • Welcome to Part Two of our deep dive into the Drake Equation. In the second part, we explore the temporal aspect of the Drake Equation and how it illuminates a path towards an alternative formalism - the Birth-Death formalism. Join us as we move forward to the bleeding edge of modern research on the Drake Equation. Written and presneted by Prof David Kipping. Thanks to Jason Wright and Nadia Drake for help with this video.

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    ► Kipping, D., 2021, "A Stationary Drake Equation Distribution as a Balance of Birth-death Processes", RNAAS, 5, 44:

    Music licensed by (SS) [], or via Creative Commons (CC) Attribution License (, or with permission from the artist
    ► "Waking Up" by Atlas
    ► "Always Dreaming" by Caleb Etheridge
    ► "The Sun is Scheduled to Come Out Tomorrow" by Chris Zabriskie
    ► "Y" by Joachim Heinrich
    ► "Fusion" by Indive
    ► "Cylinder Five" by Chris Zabriskie
    ► "The Oceans Continue to Rise" by Chris Zabriskie
    ► "Stories About the World That Once Was" by Chris Zabriskie
    ► "Trace Correction" by Indive

    ::Movies clips used::
    ► The Time Machine (2002) DreamWorks/Warner Bros.
    ► Noah (2014) Paramount Pictures

    0:00 Drakonian Time
    9:37 The Birth-Death Formalism
    15:25 Some Consequences of the Birth-Death Formalism
    22:14 Final Thoughts

    Thumbnail by Paul Brennus:

    #DrakeEquation #AreWeAlone #CoolWorlds
  • Runtime : 25:43
  • Drake Equation Number of Civilizations Alien Civilizations Astrobiology SETI Search for Alien Life Extraterrestrial intelligence How Many Aliens in the Galaxy Drake Equation Deep Dive Cool Worlds David Kipping Professor Kipping


  • Cool Worlds
    Cool Worlds   3 months ago

    Thanks for watching everyone and thanks to our sponsor, CuriosityStream. You can sign up for CuriosityStream here: and be sure to use the code: "CoolWorlds".

  • Brian Dufty
    Brian Dufty   23 hours ago

    Goasts. When you Died. Your soul.. Feeling. Emotions. Energy.. Your beang..siance..Good.. Can some people go And come back. In an instant. To where.. We are.. Can we travel without a machine. By thought.

  • Ronald Garrison
    Ronald Garrison   1 days ago

    David, I have a funny feeling that, maybe around 2050, your young assistant is going to be standing in front of an audience, maybe in a TED talk or whatever equivalent there is then, showing part of this video and having a good laugh about it.

  • Michael Henwood
    Michael Henwood   6 days ago

    You and jmg are my favourite learning I wish ikud go back. And do physics and astronomy and astrophysics instead of chemistry and biochemistry

  • re_exist
    re_exist   2 weeks ago

    I doubt Drake, when he came up with the equation, could have anticipated that it would be turned upside down and dissected. What's stopping us from changing, evolving the equation? Many ideas in physics have had revisions, changes or complete revamps.

  • Tyler Coovert
    Tyler Coovert   1 months ago

    I doubt anyone will see this, I cannot remember what video it was in but you discussed the Earth and it being in what is called the "habital zone", but there was many many different theories of what this number could be, now what if scientist can hone in and figure out with a highly specific margin of error and calculate the optimal temperatures for an earth-like planet. That would certainly narrow down the number. Jupiter is also a big protector for the Earth acting sort of as big brother for our little Earth. Now wouldn't narrowing the star systems that have similar celestial layout as our solar system make it easier to hone in on certain solar systems? idk im 17 probably talking out of my ass

  • aniruddha upadhya
    aniruddha upadhya   1 months ago

    I really wonder even if we made first contact how we are able to communicate as they dont know our language and we dont know theirs. So there will not be any translation from their language to ours. Its like trying to decode what a dog is trying to say when it barks. If you say binary I ask how will you know what is their sign for "1" and "0" ?

  • AmblesJambles
    AmblesJambles   1 months ago

    I feel like we're just discussing the anthropic principle on the whole and it always struck me as a spanner in the works. We're too close to this question to be able to determine an answer until we make contact

  • falconeye4
    falconeye4   1 months ago

    @Cool WorldsGreat video but missing the elephant in the room! You could have done better, like so:The Drake equation lives on an assumption which shows its era (the 60s). Which is a stationary process with an equilibrium. Think of creating an equation written by „a first replicating cell“ trying to compute the probability that other cells exist. It would then contain a term „L“ about how long a cell survives. Rubbish, because as we know, a first cell as we know it would replicate and seed life for possibly infinite time.A modern Drake equation would work with time-delays ti. The time ti it takes to form a star, a planet, life, intelligence, civilization, replicating space faring intelligent machines, to emerge a reproduction factor>1. Each time ti follows a probability distribution (incl. infinite time) and you take the path integral over all possible evolutions. You end up with the average time it takes a galaxy to bear galaxy wide machine life. And because our galaxy has a finite age, a probability that no such machine life has spread yet.The very fact that human technology emerged so short before Earth leaves its habitable zone suggests that said time is many billions of years. Which gives us a fair chance to be first.My understanding is that Fermi did actually understand this implication and that this is what is really meant be the Fermi paradox. I.e., that L does not exist in a formalism coping with a dynamic process.

  • David Rapalyea
    David Rapalyea   1 months ago

    The earth has been spewing out life signaturs for a verry very lomg time and we know what they are. I would like a discussion of what level of technology is needed over that time to siscover earth from various distaces.

  • Sven Weihusen
    Sven Weihusen   1 months ago

    You are totally right about the best of the Drake equation: it gives a a way to cut down the uncertainty. First you find out the birth rate of stars etc. This way don't face an unsolvable problem like the birth rate of communicating civilizations. It is pinning down the conditions that are needed for a civilization to be born. In the end it provides a way of how to find civilizations: you define where you might find civilizations so you in know where to look. It is exactly what it was intended for: an equation to start discussing how and where to find civilizations. If we find life on Venus, Titan or Europa it will change the way we search for civilizations but ultimately we might never know N with any certainty.

  • Colin Reynolds
    Colin Reynolds   1 months ago

    In these two videos, I gradually became aware that there was a large L (the last term in Drake's equation) on Prof. Kipping's left; and when he suggested his 'revised formulation' involving the Greek gamma (Γ)... I saw what appeared to be the top of that letter below the L, a very bright green one (as can be seen at 14:56). And after this, I hoped he would shift over to his right a bit to see whether it was actually a Γ -- but he never did. I guess we'll never know? ;)

  • Marvin Adams
    Marvin Adams   1 months ago

    Assume there are N events that must occur in order for an intelligent species to evolve with the ability to communicate with us (by any means). Furthermore, assume that each event has a 50% chance of occurring. Then, we can model the cumulative probability of all of these events occurring by the simple function P(N) = 1/2^N. Note that P(80) = 1/1208925819614629174706176. I fear we may truly be alone...

  • AppNasty
    AppNasty   1 months ago

    Lambder mean Half Life L. Anyone?

  • George Mancuso
    George Mancuso   1 months ago

    I life is a random process it is likely we are alone, if however there is some force in nature which organizes the formation of life we may have company.

  • Jerbi B
    Jerbi B   2 months ago

    Each tech-civ could expand into the whole galaxy in less than 5 million years. So, it doesn't take many tech-civs to get here and affect us. How do we calculate this? I think it's much more relevant to us.

  • Allen Kleshchik
    Allen Kleshchik   2 months ago

    Its Sci FI formula. There is No formulas! 1ST We need to find 1 ET world. 2nd we need to find 2 ET world and go on!

  • Omer Karacay
    Omer Karacay   2 months ago

    Wow.. You deserve millions of subscriptions and views. This channel deserve so much more than this. Keep up the excellent work! Thank you so much for the great content!

  • Objects in Motion
    Objects in Motion   2 months ago

    I don't think you can even say "all civilizations at least have a birth rate and a death rate". We have never observed a communicative civilization stop existing. People assume that since humanity has multiple empires live and die in its history, that civilization as a whole likewise must to. But its very possible that civilizations that manage to develop to the point of interstellar communication don't die out at all. Extinction (at least until heat death) is not a guarantee.

  • The COVID-19 Coronavirus

    I bet the good doctor put the number of green chips in the bag based on his own private theory of how many life-filled galaxies there are. He couldn’t help it

  • simontmn
    simontmn   2 months ago

    I think the biggest problem for the Drake Equation is that it pretty much assumes a steady state universe with civilisations birthing and dying regularly. If we think of the universe as very young, with birth of civilisations still very rare but the rate becoming more common over time, and civilisation death vastly rarer still, you get a picture completely alien to the equation's assumptions. Eg there may currently be a 1 in a trillion chance of the current observable universe containing a civilisation, but the average duration of a technological civilisation could be close to infinite, and the chance in a billion years might be three orders of magnitude higher... and so on. We go from an empty universe today to a crowded universe later.

  • John Itadakiman
    John Itadakiman   2 months ago

    I was praying he would pick up the guitar and sing about the planets

  • Peter Karig
    Peter Karig   2 months ago

    So the answer is still one, and will always be one until we find a second civilization. No amount of variables in this or any similar equation can make the number of civilizations other than one when the sample we have is one. That's elementary Watson.

  • Cosmic Onni
    Cosmic Onni   2 months ago

    The universe is HUGE! So what makes us think that it would follow a petty little equasion made by puny man. I don't believe the equasion is accurate.

  • Intellectual Redneck
    Intellectual Redneck   2 months ago

    I do not understand why you suggest that ANY civilization must eventually die? We have yet to meet a single species outside of our own terrestrial species. So it goes w/o saying that we have yet to see any proof that ANY non-terrestrial species, has ultimately died. Sure, we have individual civilizations within our own terrestrial sphere that have vanished with time, but that is NOT the same thing as saying an entire species of beings have ceased to exist. Until we actually discover a non-terrestrial species that has, in fact, perished, we CANNOT assume that ALL civilizations must ultimately die. I would even bet that there IS a species of beings out there that have already conquered death on an individual or even species-wide level. Anything is and will always remain, possible.

  • Darwin Maisner
    Darwin Maisner   2 months ago

    There's nothing special about Earth? I beg to differ.

  • Joel Rudey
    Joel Rudey   3 months ago

    Couldn't N then also be viewed as a wave function, whereas the number would vary depending on when it's observed?

  • Zarion11 A Nobody
    Zarion11 A Nobody   3 months ago

    Ha, the Drake Equation is more in the realm of philosophy. Love it. Science and philosophy overlap each other often. And I came to the same conclusion. N = 1! Ha, Facts!And I like to throw everything into the mix. All factors. Even the Fermi Paradox and interstellar travel. I imagine, for interstellar space travel, we need to develop AI first or ASI to be more precise. Humans or aliens are not very suitable for space travel. But we have not seen any evidence of alien AI neither. So, I'm not sure if it is possible at all or maybe we are really the first to reach this kind of level of technology and civilization. The universe is still very young. But if it is possible to build ASI before we go and we can reach something like a third of the lightspeed, you could colonize the whole galaxy in just a few million years time.But to make better predictions with the Drake Equation, we need beter data and understanding of what 'life' and 'consciousness' is. This whole topic never feels depressing for me. It's amazing we are here and we are self-aware.

  • Micheal Dean
    Micheal Dean   3 months ago

    Drake Equation. Meh.I have a greater interest in own evolutionary prosses then meeting some googly eyed monster from the planet 'Whothefuckcares'.The first being the formation of the Panamanian Isthmus, and how it may have effected our early ancestors by changing the long term climate, available food and nutrients, and move from being largely arboreal.Next is the Messinian Salinity Crisis, and how that effected our early ancestors.Last is the event of a series of nova/super nova cast a variety of isotopes in our direction. One being Iron 60 which has a half life of 2 1/2 million years.Could that have directly affected the genes of our ancestors, or indirectly by effecting the food supply.To me that is a lot more interesting then meeting any googly eyed monster, no matter how fetching or intellectually engaging they are.I have read a number of articles and papers on the above over the last 10 years or so, but haven't seen any conclusions that don't make my eyes cross.And give me really bad headaches .

  • Gregor Samsa
    Gregor Samsa   3 months ago

    Dont't think Poissan- Distribution applies as we have seen already a comet and Omomaou from outer space. Life in nearby stars will positive influence each other.Therefore they are dependent. Same is for intelligent live - creation. And as it wa s said that (at least on earth) "all that is concious, moves itself around" ... there will be influence from meeting each other at the end of such movements. Then.... At best.... intelligent lifes copies best practice from each other and supports itself e.g. we European in past did for sure not with human but with "items". (e.g. we "copied" grain, potatoes, chocolate, special wood, gold from south america... ), (Noodles, Black Powder, silk from ancient China), Arab number, zero from India etc.)Therefore I assume, there will be regional "Hotspots" of intelligent they will meet each other 🤯.

  • PJ A-OK
    PJ A-OK   3 months ago

    Hi David, this is not directly related to this video, but I am curious if you have a personal telescope at home and if so what type and size is it? Thanks as always for the awesome videos, I am learning a lot and they do make me think about concepts I have never thought of before. You are by far my favourite presenter on Astronomy and Astrophysics.