Fermi Paradox Great Filters: Space & Time

This episode begins our look at solutions to the Fermi Paradox - the question of why the Universe appears empty of intelligent life besides ourselves - by looking at some of the reasons why life may simply be very uncommon. Before we can contemplate what might be special about Earth, we first need to consider what might be special about our region of space, and even our epoch of time, or our Universe itself.
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Cover Art by Jakub Grygier: www.artstation...
Graphics Team:
Jarred Eagley
Katie Byrne
Misho Yordanov
Murat Mamkegh
Pierre Demet
Sergio Botero
Stefan Blandin
Script Editing:
Andy Popescu
Connor Hogan
Edward Nardella
Eustratius Graham
Gregory Leal
Jefferson Eagley
Luca de Rosa
Michael Gusevsky
Mitch Armstrong
MolbOrg
Naomi Kern
Philip Baldock
Sigmund Kopperud
Steve Cardon
Tiffany Penner
Music:
Lombus, "Cosmic Soup"
Markus Junnikkala, "A Memory of Earth"
AJ Prasad, "Aether"
Lombus, "Hydrogen Sonata"
Dan McLeod, NeptuneUK, "Mysterious Universe"
AJ Prasad, "Staring Through"

[@dlt074]

The Isaac-Arthur paradox. Given the size of the Internet and the number of channels on youtube, there should be at least one other channel as awesome as Issaac Arthurs channel. Yet, we have yet to find one.

[@stanjohnson5868]

Indeed, some candidates Arthur proposes in his videos. :)

[@AtheistBelgium]

Fraser Cain, but Isaac found it for me :)

[@Skankgodx]

there are some great channels on youtube. the problem is that they are so many trolls and flat-earthers around :(

[@christophercarr5865]

Sláine Mac Roth Needs more jump cuts and whacky, melodramatic narration. And Isaac's videos need to come in at around 4 minutes. Gotta cater to 16-year-olds with attentional deficits. ;-)

[@mickelodiansurname9578]

Rather interestingly also related to the Fermi paradox in that it would also explain where 'THEY' are... they are where they always are....and we never actually searched for them, we just think we did. There are channels better than Isaac's... they simply have more resources. But if we don't look for them, then they will look like they are amazingly absent...

[@Electronic424]

Step 1: Like Step 2: Tell him I liked it Step 3: Watch video I can hardly contain myself for this one! Fermi episodes are the best.

[@toddprifogle7381]

Two years ago! How are you now ?

[@simmarshall69]

Steady On. They are vaguely interesting but let’s try and keep this real shall we?

[@ferretappreciator]

@@toddprifogle7381 two years ago! How are /you/ now?

[@chrisgarcia6098]

We have found the Holy Grail of videos. My brothers our search is complete.

[@burgzaza]

Congratz !

[@zak7181]

Glad you found the channel! Check out his older videos too, there's SO much good content. At the very least it'll entertain you & make you think; or quite possibly it'll spark (or feed) an obsession with futurism. I dabbled before, but now I constantly find myself researching about carbon nanotubes, the composition of lunar regolith, and whether any known materials can filter out infrared light while passing other wavelengths. This channel supercharges my inner geek.

[@edthoreum7625]

Zak!

[@ShadowKSG]

Agreed

[@jameshumphrey9939]

anti Isaac Arthur - u fail

[@taith2]

I will be completely honest, I use your videos, when going to sleep, your voice tone is really helping me to fall asleep. However I also watch these videos properly later!

[@isaacarthurSFIA]

I routinely play my favorite audio books to fall asleep to, so I count that as praise :)

[@crazyahhkmed]

taith2 same here.

[@ClifftopTragedy]

taith2 haha I first found Isaac Arthur when I couldn't sleep and I actually searched for "the most boring video on KZbin". Somehow I got into space elevators and I was up for hours listening to more videos. Sometimes I don't even watch them, only listen. Think I've been through them all now. Great work indeed from the thinking man's hero. Thanks Isaac

[@SujithIshtar]

I do the exact same thing!

[@jlo4259]

Same thing here

[@hellfiresiayan]

The proposition that the early "bath water" universe could be the source for the panspermia hypothesis just blew my mind.

[@manw3bttcks]

Bath water universe (T=300K) would have been about 10 million years after the big bang as seen here: sites.ualberta.ca/~pogosyan/teaching/ASTRO_122/lect31/figure28-11.JPG The only molecules you can make with H, He and Li alone is H2 and Lithium Hydride (LiH). The question is, would the Pop III stars have made enough elements beyond the H, He and Li that existed from the Big Bang to make any kind of life possible. You'd probably at least need oxygen, nitrogen and carbon added.

[@spaeron]

it just makes me want to stick to showers.

[@boobah5643]

@@manw3bttcks It always bugs me that we count star 'generations' backwards like that. And I can get why we started with Sol as a Pop I star... except that once you've got an accepted theory of the universe that more-or-less establishes that Sol is made of matter that has been in two previous stars, why don't you fix your terminology? Or am I misunderstanding what the stellar 'populations' are?

[@chriscooke109]

An absolute masterpiece of a video as always; I am so glad I found this channel, I can't thank you enough Isaac. The amount of videos that youtube contains is huge in number but the amount that actually engage the mind at this level are extremely rare, keep up the excellent work!

[@isaacarthurSFIA]

Thank you Christopher!

[@dalecorson1367]

I wanted to take a moment to say thanks. I watch your lectures all the time and except a couple I am finally up to date. you keep all your subjects interesting in a way that isn't common. please keep up the great work. it's easy to see the passion you put forward.

[@cananyonebringmesome]

Isaac Arthur, I simply wanted to thank you for this channel, projects like yours are the diamonds of KZbin.

[@charlesrosenbauer3135]

I've found something that I think could be a pretty substantial filter that most people seem to not be aware of. I think intelligent life is actually reasonably common, but that intelligent creatures physically capable of creating civilizations are much less common. Currently, neuroscience and machine learning seem to suggest that the number of neurons in the brain is the biggest factor for intelligence. Sure, a large organism is going to need more neurons to control a larger body, but the additional neurons are going to be in the peripheral nervous system, and maybe some lower-level parts of the brain (direct sensory and motor areas). It seems like there are some clear reasons why this is; if you double the number of neurons in every region of the brain, you get a brain that can handle twice as many inputs and outputs, but you also get one that has twice as much memory. Sure, more I/O means that those memories are going to take up more memory, but much of that information is going to be repetitive; doubling the resolution in an image isn't going to mean that there are now twice as many objects in it. Now, brains also require a lot of resources. More neurons means more space, and more energy. In mammals, the majority of the neurons in the cerebral cortex (the part of the brain that handles high-level functions) are in the neocortex, which is a 2-millimeter thick layer on the surface of the brain. Everything underneath is is lower-level parts of the brain, and connections between different parts of the neocortex. This is why the brain is wrinkled; wrinkling maximizes surface area, which maximizes the neuron count. Non-mammals tend to either have very little in terms of cortex-like structures, or have higher-level brain regions structured in nuclei, essentially groups of spheres. For example, many types of birds are able to fit massive numbers of neurons into a small volume (Ravens have >2 billion neurons in their neopallidum, which is their equivalent of a cortex). What appears to be the issue is connectivity; almost all neurons in each nucleus sends an axon to a neuron in another nucleus. However, being spherical, the nuclei have a scalability problem. The number of axons (connections) scales with the volume (cube of the radius), while the amount of area for them to fit through scales with the surface area (square of the radius). This limitation doesn't occur with laminae, especially since mammalian cortices just organize these structures into sub-layers of the neocortex that are very close together. This is a bit of speculation, but this apparent scalability problem seems to be a pretty good explanation as to why many birds show incredible intelligence for their small brains, but why we don't see birds with intelligence past a particular point. Like I said, large brains also require a lot of energy. More neurons mean more energy, but so does sending signals longer distance (and expecting similar timing). Therefore, a smaller animal with a smaller energy budget is going to have a very hard time supporting a large brain. However, if an animal gets too big, it runs into problems supporting its weight. This is why all the largest animals live in the ocean; the buoyant forces keep their bodies from collapsing in on themselves. Now if we look at animals with comparable numbers of cortical neurons to humans, we find something: Long-finned pilot whale: 37.2 billion (Yes, that's ~2x more than humans. Proof: www.ncbi.nlm.nih.gov/pmc/articles/PMC4244864/) Human : 19-24 billion Various whales and dolphins: 8-15 billion Gorilla: 9 billion Orangutan: 8 billion Chimpanzee: 6 billion Elephant: 6-10 billion Notice anything? Humans are pretty small compared to most of the animals on this list. Orangutans and Chimps tend to be smaller, but they are similar in body structure. So why is size a big deal? After all, the long-finned pilot whale actually seems as though it's likely smarter than humans. Why haven't they taken over the world? Well, larger animals suffer from the square-cube law; an insect may be able to easily move items many times its own weight, while humans have extreme difficulty doing so. I think this is probably a large factor; moving objects comparable to one's own size seems pretty important to being able to build civilizations. This is going to be an even bigger problem on planets with higher gravity than Earth. Then of course, there's the water factor. Most of these large animals can only support their weight in the water. You can't start fire underwater. You can't smelt metal underwater. You can't make electronics underwater. I think it's safe to say that the dolphins won't be building any cities any time soon. If we make the assumption that only 10 billion neurons are needed to create civilizations (many humans with hemispherectomies seem to function okay in society, and that's what they're working with, so it's at least plausible), that means that there may be dozens of species of whales and dolphins that could create civilizations. Add to that humans, elephants (they have a lot of neurons too), and potentially dozens of other extinct species of dolphins, elephants, and species in the homo family, and we wind up with 1 civilization-capable species out of probably 50-100 species that have popped up so far. Humans seem to have gotten really lucky; we are able to have both a ton of cortical neurons, and have a relatively small body. If humans were much bigger, we likely wouldn't have civilizations. TL;DR : Intelligence is probably correlated with the number of cortical neurons (or equivalent in non-mammals). In this metric, Humans are #2, following the long-finned pilot whale (technically a type of large dolphin; Douglas Adams was kind of right about them). There are dozens of other species that are close, but they all are either too big to build civilizations, live underwater, or both. Most commonly both. Out of the 50-100 species (if we make some assumptions about extinct species related to the ones that are still around) that are/have been likely smart enough to build civilizations (or close), only one has. You should probably knock another order of magnitude or two off your drake equation results.

[@memedbengul4350]

good post. although there isn't really anything knew or unknown here. while it's clear that intelligence does correlate with cortical neurons, it isn'tnecessarily linear. the structure of the brain and how it's wired matters more. I seriously doubt the pilot whale is even remotely close to human intelligence, although I don't doubt that it utilizes most/many of its neurons in doing spectacular things other mammals can't. so, give a dolphin/whale some arms and fingers, get them out of the water, give them legs, i'm sure they'll fare well, but probably not significantly better than most smart mammals, vis-a-vis creating a civilization. .....though, i might not be giving them enough credit; iirc, they're one of the very few creatures that can recognize themselves in a mirror, beyond any doubt, along with non-baby humans, magpies and possibly gorrilas.

[@ameliaashford6131]

Thanks....this is very informative comment post! like i'll start my own research about neurologic corellation...

[@crazyahhkmed]

Even you're tldr, is long lol

[@OneOnOne1162]

29:40 - I rarely get scared during horror movies, but people speaking about this topic always create an existential dread in me that's very hard to ignore. Edit: Referring to what is basically the slow death of the universe. A universe of endless night where the only light comes from the collisions of dead stars. That is utterly terrifying to me.

[@LaserGuidedLoogie]

I know exactly what you mean, I have expressed the same sentiment to Arthur before. When you start actually considering the remote future in the sort of systematic way that Arthur does, you realize that it's going to be pretty horrific; not the sort of future that we might want to live in .

[@victoryprime2915]

I hope that some day we discover a massive Kardashev 3 civilization and call them Intelligent Critters

[@crazyahhkmed]

Afro Russian We might become a K3 before we discovered even a K2. Don't forget the timeline to a K3 isn't that long. Maybe w few million years at most for use to expand across the Galaxy.

[@TheCobCAP]

smartbois

[@lazergurka-smerlin6561]

Are you anarcho trans?

[@76rjackson]

I remember a story I read about an alien who plugged into our communication network and started feeding advanced information to us anonymously. The first time I watched your videos it was such an intellectual leap beyond anything else I wondered if perhaps that story had actually manifested into reality.

[@egorka2201]

One filter that we might underestimate and that is unmentioned here is the fact, that we have had oil to fuel our technologic development. Oil and fossile fules in general are the sole foundation, why we are not living on the same level as say the ancient Rome. So what if most planets, even hosting complex civilizations, don't have access to such readily available energy resources, as we did? They would live on the surface of their planets for millenia, until their ecosystem would collapse and find no way to leave their gravitational well.

[@jamesfra1311]

egorka2201 Exactly.

[@AtilaElari]

They would, eventually, get to the solar, wind and nuclear power. It is a delaying factor - possibly a drawback for centuries. But it is not a filter.

[@yogsothoth7594]

That one filter is unlikely to be true for all civilisation but there are loads of things that could prevent them. Firstly how large groups are they willing to be with? If their phycology prevents them from forming cities and towns because they find living near more than 20 people disgusting or are really paranoid and would be unwilling to live near more people than they personally knew to be trust worthy then civilisation can't arise. If they don't live longer than 10 years then they could only advance so far as they would struggle to learn all the existing science in a field before creating their own theories to advance on. If they reach their maximum technological levels they can learn in a single life time before they get to a point where they can increase their natural life span significantly then they're stuck. If they have no form of sight that would allow them to view stars and heavenly bodies then they are unlikely to attempt to explore them.

[@Smathalgoth]

I wouldn't be so sure, both solar and nuclear power are highly reliant on petrochemical based industry and materials. Wind is easily possible, but not nearly reliable enough to build a technological civilization around.

[@darklight6921]

thats what i was thinking.

[@TheGunmanChannel]

So glad I found your channel today.

[@ericvulgate]

the union of separate creatures that gave us our mitochondria situation seems to me to be a major obstacle. single celled life might be on every wet rock out there, but remember it took billions of years for this join to happen here. it seems to me this is potentially a huge barrier not just to civilization, but to complex life.

[@isaacarthurSFIA]

Yes we'll be covering exactly that point later in the series.

[@Le0nnh]

Late reply but whatever. I like how Isaac just briefly mentioned it being a great filter all on its own, but then be like "Actually, this is about intelligence...", and just casually drops it. Honestly, the number of generations/individual cells vs the time that's passed, etc; why is this never taken into account anywhere else.

[@boobah5643]

@@Le0nnh It takes someone special to properly sort things between the stacks of 'this is blisteringly obvious, no point in mentioning it' and 'this matters, we need to bring this topic up.' Too much in the first pile and it's hard for people to follow, too much in the second and you risk talking down to your audience. There's also the problem of 'I know this, the people I talk to all the time know this, doesn't everybody know this?'

[@AstroFocus]

YES! Arthursday! :D

[@postmortemprince3086]

nice videos astrofocus, saw u last time

[@lazaruslong697]

AstroFocus: You stole my comment!!! :D Just joking, i am as glad as you are! By the way, interesting channel, gave you sub and will definitely check on you later. Although your vids seem a little too short for my taste, i am more like 30+ minutes kind of guy...

[@fatetestarossa2774]

indeed super nice

[@KlaasDeforche]

AstroFocus After all these months I only now get that it's a pun. Doh!

[@rickyjp9086]

Ah man... In Australia we have to call it Frisaacday

[@TheAndroidNextDoor]

My biggest issue with this channels is that EVERY VIDEO is one I want to watch. And they're all basically 20+ minutes. Like dude! I don't have that much time in a day to watch your awesome videos! Halp.

[@jgr7487]

The Android Next Door I do it in lunch time

[@Appletank8]

Extention: Video Speed Controller. Watch 'em all at 2x.

[@KaKam0u]

I felt that way at first too but after some time I realised I watched them all and now I have to wait 1 WEEK for a new video, feels bad man..

[@jeova0sanctus0unus]

Thats not even a first world problem anymore.

[@mykobe981]

all of you made me rofl. Best comment string of the week award! =)

[@AlbanianThrash]

man this is hands down my favorite youtube channel

[@kyhber1]

This stuff should really be on the best documentary TV stations world wide , The guy is good ..

[@mwbgaming28]

I just finished playing mass effect, and after watching this, I realized the mass effect story is not just about saving the galaxy, it's about overcoming a great filter that destroys advanced civilizations but leaves primitive civilizations alone and if you overcome that filter (destroying the reapers) there's an even bigger one waiting around the corner (the thing the reapers were actually trying to save organic life from, which is self aware AI) Needless to say, over the years, I have downloaded literally every video you have ever uploaded because your content is simply amazing Your channel will be stored on a hard drive and if our version of the reapers wipe out humanity, the next inhabitants of earth can watch it in their cycle

[@weaselhack]

The show is looking great Isaac! I've been looking forward to revisiting the fermi paradox with you! So great. Keep up the awesome work my man.

[@aztelin]

Great video, Isaac! Something in this video made me recall a conversation I had years ago about "fine-tuning". I tried to explain the anthropic principle to my dad and ended up with some sloppy analogy involving frozen sapient mud puddles discussing how the holes in the ground were obviously fine tuned for them. Good times.

[@isaacarthurSFIA]

Yeah Anthropic Principle examples are always tricky, they tend to be either arcane or so obvious the person can't see the point to miss it.

[@EmberArcher]

Isaac Arthur we love you!

[@passthebutterrobot2600]

Fascinating episode, thanks! Your logical reasoning on these matters seems flawless I have to say, and very enlightening. Can't wait for the next great filter instalment

[@isaacarthurSFIA]

Thanks Steve!

[@mansamusa1743]

Thursday to me is almost a holy day now

[@DJSbros]

I respect it more than the concept of Sunday church.. Far more.

[@poeslaw1648]

Sadly a scifi author already created a religion... maybe the second time it's done it will be better?

[@mykobe981]

Lmao, Poes Law.. Certainly couldn't be much worse! =)

[@AtlasReburdened]

And the Isaac spoke saying "Remember the science, and keep it maximally beneficial".

[@kazaddum2448]

"almost"? You dare to not agree that Arthursday is the holiest day of the week? Heresy! I sentence you to rewatching all of his vids!

[@dirkstarbuck6126]

A cable network recently broadcast a TV show called Year Million. It has a relatively high IMDb rating of 7.1. It's highly polished, progressive, hip, flashy, fluffy, light, without substance. It mentioned futuristic concepts without explaining anything about them. It taught me nothing. I just sat there like a vegetable, taking it all in. I lasted an episode and a half before I erased them all from my DVR. Whenever I watch your videos, I have to rewind multiple times, turn on the captions (not because I can't understand you, but because I have to read stuff -slowly- to comprehend information) and look stuff up on the internet to "research" the topics so I can understand them. You've also introduced me to the Hard sci-fi classics. In some ways, you're providing an informal education; physics, math, literature (though I admit, I have at best a colloquial understanding of these courses). Please keep up the great videos! It's great to see you approaching 100,000 viewers. I hope at some point you take seriously my suggestion of an ArthurCon. I'm sure there are enough people in the northern who would love to come meet you.

[@isaacarthurSFIA]

I always try to think of a lot of the pop-sci stuff as feeding the channel, some chunk of that audience will want more info and can come find it here, who otherwise would never visit.

[@winpcapper]

going to be an amazing day! Isaac Arthur video, Space Engineers update, and I get to skydive for the first time ever!

[@lettuceprime4922]

SixMarbles - Whoa. Merry Christmas bro.

[@MrGeneralPB]

just remember the parachute XD

[@edthoreum7625]

12:00 It begins!

[@SuperYtc1]

Did you survive?

[@budgieentertainment9931]

Looks like he dead

[@CookingandWH40kVideos]

As an SLP I have started to show all my articulation students this channel to show them their speech isn’t holding them back. Great channel great videos

[@SoberGin]

Holy crap. That intro! This channel has gotten so much more professional over time. I'm seriously impressed and happy to see such a great channel get great looking intro's and graphics.

[@bradmiller1574]

This guy is fantastic. I started listening to him when he still had around 60k subscribers and I was shocked there were so few. Obviously time is an important factor. Great work, I really enjoy the depth of your speculation of the future. Your extrapolations are not at all hard to imagine.

[@N8844H]

Consider the possibility that natural selection is how species everywhere evolve. Now consider the possibility that natural selection favors traits that allow species to survive, and dominate. Seems reasonable, right? On this planet, those survival and domination traits tend to focus heavily on short-term advantages (there's not much point to assuring the well-being of the tenth generation if the second generation doesn't make it). For example, slash and burn agriculture is a sound strategy short term and for small populations. Longer term, not so much. So it also seems possible that a system of natural selection that favors short-term success dooms species before they can get very far off their home planets. It's the Greatest of Great Filters, and maybe why we aren't hearing from anyone.

[@musaran2]

Said otherwise : A habitable planet too stable might lead to an early dominant life form to stay so forever. Our massive extinctions might well be necessary to weed the primitive, easily widespread and favor more complex, long-term evolution paths.

[@jameshumphrey9939]

maybe however the perfect form may be ever adapting and changing as a thread that is the elusive and non-understandable to the physical manifestations you speak that are simple expressions of the underlying constant and continuing thread at its core all other being these infinite expressions no more to a greater non-god entity out of any filter - then words assembled are only stories, not true not false

[@Playa566]

It's the very path we are on.

[@punctuationman334]

James Humphrey please use punctuation. Reading your comment nearly gave me a stroke.

[@spaceclaw1958]

@Star Trek Theory Not sure WHY you had to use Jew as an adjective. Douche-bag.

[@jaedenvanderberg3890]

Somehow this literally keeps getting better with EACH and EVERY SINGLE upload.

[@maxfinazzo2443]

I'm mostly in the TEA camp. I think the reason we don't see other intelligent life is because we may just be the first.

[@crazyahhkmed]

Max Finazzo me too. Also that intelligent civilization building life is incredibly rare. Just look at how many smart/intelligent animals we have on Earth that have been evolving far longer than us. Yet we're the only ones who developed a civilzation and in a relatively short time too. On the geological timescale we came out of nowhere. Nevermind cosmic timelines.

[@ShadowKSG]

This is a scary thought... living out whole lives alone in the universe

[@maximuscomfort]

Max Finazzo, I do agree we are alone in the milky way galaxy. The universe is another story.

[@superbuneary8819]

I also believe this. We are not alone of course, but we are the first intelligent sentient ones. There are other life forms on other planets and advanced as well but advance as in like, maybe elephants and mammals. Just normal animal species. But really advanced technological race, I think we are the first to emerge...

[@milohobo9186]

ShadowKSG thinking about David Brin, night this lead us to uplift chimpanzees and dolphins in the future?

[@oraz.]

This us what I always thought the simple answer is. The variation in timelines doesn't overcome the distances. Intelligent life is relatively rare which means large distances, the variation in timelines is not great enough to get around the limit of the speed of light.

[@lakerclearly]

I just discovered this channel a couple days ago. Where have you been all my life?! Your video backlog is gonna keep me busy for months. Immediate bell icon.

[@aldenburton6240]

This channel does all which is needed to show in today's TV programme. Context and ideas about future living supported by educated gusses as well as facts. I am so thankful for the invention of smart TVs so I can watch all good TV programme without watching the grabage they feed to us on the instutionalized broadcast. I am thankful for your effort and workt you put into your videos, supposedly. I can watch and listen to this stuff all day.

[@ynkybomber]

Don't forget if you are ever feeling useless your brain is some of the rarest move valuable matter in the entire universe.

[@DescendantSaga]

I have only in the past couple months discovered this channel. I am a science fiction author with my debut novel to be released in spring of 2020 and isaac's information has helped me greatly with world building and cultural definition of the races my space epic contains. I would consider this indespensable.

[@drnitwhite567]

Great video Isaac! I really look forward to the next one in the series- I myself find the subject of evolution one of the most fascinating, so I look forward to see how you handle it here!

[@NikoAbston]

Isaac Arthur is my favorite subscription on KZbin!

[@Soppybobs]

Much love Isaac! This is what our species should start pondering more rather than what dress Kim Kardashian farted in.

[@isaacarthurSFIA]

More Kardashev Scale, less Kardashian :)

[@elpinchecholito8384]

I was thinking the same thing, countries here should stop fighting with each other and start working on figuring these things out together as one

[@Ian_sothejokeworks]

In fairness, I've never actually been a part of, or even heard, a conversation about any Kardashian. I mean, I understand the point: frivolity should be less important, by its very nature. However, there's an argument to be made that Kardashian farts have more of a theoretical impact on your life than very distant stars do.

[@Uroshius]

What I really love about this channel is how objective it is most of the time - heck, all of the time. It is becoming so rare to hear someone talking about science and using "it might/ought/could possibly be..." and "we don't know, yet", which are for me clear signs of a real scientific approach to a subject, that is, not presuming you already know everything. It is what makes me believe most things that Arthur states as fact, which as a non-scientist I find hard with many other authors and public figures that tend to just state everything and anything as fact, although it might not be so.

[@StormSilvawalker]

the simulation hypothesis seems scarily clear now...

[@2MorrowsPeople]

Storm Silvawalker I'm with you

[@punctuationman334]

Storm Silvawalker doesn’t mean it’s true though. There’s no way we can prove it currently so we just have to assume. I’d rather not know anyways.

[@charadremur333]

It doesn't matter

[@smokegames1179]

When I use dmt they are there aliens are gods

[@dennycrane6253]

Good job! Very interesting! Haha. I was worried about work not anymore. It appears I'm 3 years late

[@The_Viscount]

My favorite and most hopeful hypothesis is simply that we are among the first advanced civilization in our galaxy and that other civilizations within a few thousand years of our technology level exist concurrently with us. This still opens the possibility of life and wonders and interspecies diplomacy. Until we have any evidence one way or another, I may as well choose the solution I like best. I'll subscribe to this until I learn differently.

[@Ryukachoo]

I wonder, maybe collab with a robotics channel and do a practical pathway to a Dyson swarm video? in a lot of way, the problem is mostly an automated manufacturing and space manufacturing problem

[@zombieninjapitbull3856]

Ryukachoo dont forget materials, we have the materials to build Dyson swarms but we are not mass producing them yet.

[@isaacarthurSFIA]

We're doing Dyson Spheres July 6th

[@barkingbob1401]

id like to add that the light hitting our telescopes is aged. for example proxima region is the closest to us and its 6 light yrs away so when we look at it we are seeing what took place 6 yrs ago. the milky way being 200 000 light yrs across. there could be an entire galactic fleet on the other side of the milky ways and not only would the galactic centre block the images but also it would take 100,000 yrs for the image to reach us. SO TO ANSWER THE FERMI PARADOX - We are gazing into the past not the present.

[@baltvdb]

Such complicated stuff made so easily understood. Excellent video 😎

[@supershenron9162]

I heavily lean tword the side of Intelligent life being incredibly uncommon to the point of only 1 MAYBE 2 exist in a galaxy at any given point and not every galaxy has or will ever have 1 as such the reason we cannot detect them is how young the universe is, how long in its history it took before the raw materials existed that could give birth to a system in which life could develop. As such since I believe it's so extremely rare we either don't possess the tech level needed to observe such a rare phenomena. Or it happend recently enough and far enough away that the signal simply hasn't had time to make it this far out into the universe. Thus is the reason I like this video as much as I do. Certainly one of my favorites top 5 for this channel (hard to make a top anything.. all the uploads are just sooo... ddaammnnn.....ggoooodddd) xD

[@Spudst3r]

10:52 One quirk of our Moon is it just happens to be 400 times smaller than our Sun, and 400 times closer, meaning it creates INCREDIBLE eclipses with regularity not seen elsewhere in the solar system. Could these moments have created spiritual awareness for our species that motivated certain behaviours, such as belief in god, existential awareness or a belief in higher purpose? The idea of a species inventing a god is a curious one that leads to peculiar social beliefs and structures. Maybe eclipses seeded them?

[@paulgreene7424]

This is the first of your videos I have watched. It was in my recommended and I almost skipped over it. Thank God I didn't. You should have MILLIONS of subscribers, but I'll help by giving one more. Thanks for the vids!

[@thesenate1844]

Been waiting all week for this

[@hellstormbishop2165]

The Senate "Not yet"

[@thesenate1844]

Henrique Borges Manzke Its treason then

[@TiaguinhouGFX]

OBI-WAN WHERE ARE YOU COWARD

[@firebornliger]

The FTL = Time Travel argument relies on a mathematical assumption that the time dilation effect of velocity is both a linear relationship AND a relationship that continues beyond the "zero point" that is assumed to exist at the speed of light.

[@israeldiaz2392]

beautiful opening Arthur... I love your videos

[@thomashernandez1004]

I think the real solution to the Fermi Paradox is probably a lot more simple. 1) Populations of intelligent species tend to shrink and stabilize with time. 2) It's impossible to transfer conciousnes. Human population has been growing, but all demographic science points to it stabilizing and begining to shrink and stabilize again. Even within just the next 100 years. If the planets population isn't growing, and any colonies don't grow much either. There is absolutely no reason to consume large amounts of a solar system or even a planets resources (even less so those of a galaxy). If it isn't posible to transfer conciousnes (which despite how advanced technology could get might just be how things are) then there is no reason to build giant power hungry computers.

[@pianoguythe1955]

Amazing video! Helped me a heck lot! I am doing the Great Filter for my science fair, please tell me if my understanding is right or wrong and your understanding as well. Thanks! the Great filter says that time doesn't equal to the hardness of the step but each step, no matter how hard, must be finished in a specific time frame, so time could be one of our great filters for us to have interstellar colonization and the starting planet, like the existence of earth being suitable for life to form would be one too. Simple lives, however, COULD be normal but the transition to being a complex civilization could be count as a great filter. Anyhow, we could theoretically complete colonization, so the likelihood that we have passed the great filter in the past is extreme and our future survival is in our favour. Thanks, again, appreciate y'all's help.

[@Bob-yl9pm]

Mother Earth is an exceptionally lucky special place! With a unique billion-year history of life!

[@JasonPurkiss]

Do Not Disturb its Arthursday Time, purposely take my lunch break at this moment

[@pillbox1240]

We all love you Isaac! Thanks for all your great videos!!!

[@512TheWolf512]

daaaaaaamn, my toughest exam is up in just 7 hours! Arthur, at least wish me luck, if you're taking 40 minutes of my sleep away :

[@isaacarthurSFIA]

Good luck!

[@lordbear938]

one simple answer to the Fermi paradox is. C is the speed limit. if F.T.L. travel is indeed not possible, simple distance is the answer. in that case communication would be impossible let alone travel

[@louvenio7413]

37 minutes, thanks god!! :D

[@lazaruslong697]

Thank universe for Isaac Artur! :D

[@isaacarthurSFIA]

I think the next 3 episodes are all in the 35-45 minute range. Long topics

[@thevoiceofthelost]

I love the longer ones! i watch them as i have breakfast. haha

[@jacobyocom9598]

Your so close to 100k subscribers. Congrats in advance.

[@TheRational75]

Thank you so much for your work!

[@while_coyote]

I wish there were a video every day! You are a gem of science and the imagination!

[@urquizagabe]

Arthursday is the best day :D

[@eyeoftheun1verse]

I really liked this episode & looking forward to rare earth hypothesis episode. Thanks Isaac, your content quality is top notch and I watch every episode with great interest, many episodes multiple times.

[@JackDesert]

Every time I hear "Phenomenah' I'm saying 'doo dee doo doo' (The Mahna Mahna song) Now my roomies thinks I'm nuts

[@belmiris1371]

Awesome as always! Thanks.

[@alexwarevideos]

What about off-planet life, Isaac? Would it be possible for life to, say, spring up as some sort of space-jellyfish or something that consumes stars or asteroids or something?

[@Mr.Deleterious]

As of June 3rd, 2019 there was a paper written by a scientist and published in the Journal Nature that states the odds of an Earth analog surviving any other type of star other than G2V is very unlikely due to rapid atmospheric loss from solar wind pressure. Basically meaning, we are most likely truely alone in the entire Universe.

[@colinsmith1495]

Combine with various other factors, and yes, there are very good odds we are VERY rare. Consider that life on Earth would appear to need both a decent mass of heavy elements and a limited amount of interstellar radiation. Now consider that those two conditions are, generally, mutually exclusive. Heavy elements come from exploded starts, and if you're in a dense enough area to have large amounts of heavy elements, then you're in a dense enough area of unexploded (even young) stars that your planet is being sterilized by the night sky. If you aren't in a stellar area that dense, then you don't have the elements necessary for rocky planets (we think). How did Earth happen? Well, spiral galaxies are something of a special case. The spiral arms of the galaxies don't seem to be fixed. They're more like waves, where the stars involved change, but the compression wave stays consistent. This allows solar systems to form in dense regions of space (the arms), and then drift out and develop life in thin regions of space (where we are now, outside an arm). That alone immediately rules out 3 of the 4 known forms of galaxies (elliptical, spiral, irregular, and ring) for Earthlike conditions altogether. Not necessarily any life, but at least Earthlike planets. Even in spiral galaxies, the ranges they could occupy are pretty limited for the galaxies as a whole, and over a span of billions of years, planets would tend to get re-sterilized, though that's plenty of time for a civilization to migrate to other systems.

[@MarkusJunnikkala]

Great episode, one of my favourite subjects!

[@isaacarthurSFIA]

And accompanied by some great music huh? :)

[@MarkusJunnikkala]

Well now that you mention it.. it does sound pretty good doesn't it!

[@asahearts1]

If scientists are right about the universe, we are still suuuper early on a cosmic time scale. There's probably tons of things we would recognize as life out there, but there's also a lot of chaff and a lot of nothing. You could say the fireworks shells haven't gone off yet. Right now the potential is there, and soon the universe will be teeming with life. I'm sure of it.

[@aclearlight]

I like your idea! Maybe we should call it the "delayed fireworks" conjecture.

[@apple54345]

37 minutes. now that's more like it!

[@Sniper9773]

This channel appeared in my recommended after watching a bunch of mass effect videos, now I can't stop binge watching.

[@RidingWithDave]

My dream has finally come true of Elmer Fudd narrating space videos.

[@lazio9969]

Riding with Dave The fact this comment showed up first after 2 years and 2 likees blows my mind

[@reallyryan_]

@@lazio9969 probably cause it's a "big" channel

[@christianhamann1600]

Literally look forward to your videos every Thursday. Thanks for your awesomeness!

[@isaacarthurSFIA]

Thanks Christian!

[@runeespe]

Hi Isaac Just discovered your channel - I have been looking for this all my life, and you manage to put coherent structure to my many thoughts - so thank you! One observation: in this episode you mention "a (previous) period of several million years where the overall temperature is that of Luke warm bathwater". Considering IF we, as a civilization are emerging as what could be interpreted as "first mover" (someone HAS to be, irregardless the exclusivity argument) could this not be viable IF considering the averaging temperature are only just NOW closing in on 0 Kelvin, and this could be interpreted as an indication that the universe and all of its sub-components are at an, somewhat temporary, stable equilibrium allowing for intelligent life and we are "simply the first"?

[@animistchannel2983]

The story I heard from an old physicist about the original form of the F.P., was one day Enrico & some others were sitting down to lunch at the cafeteria. There was the usual talking on other subjects, but he was sitting quieter than usual, sort of self-absorbed. Someone noticed this and asked how he was, and he just answered: "So where are they?" In a way, I think he was realizing that advanced civilizations are very quiet compared to earth, which suggested how primitive we still were. It was a self-reflection, that atom bombs and huge radio broadcasts were the hallmarks of his era, but that these aren't the way to reach the next level really. We were still doing it wrong, and at great risk. If he had lived to see fiber-optic networks, he might have felt better about our chances.

[@KuraIthys]

I should wait to see if you mention it, but I'm impatient and if I wait I tend to forget my thoughts... So... Here goes anyway. Apologies if you mention it later in the video. Anyway, an issue I have with the notion of fine-tuning the cosmological constants is that it pre-supposes a universe structure that depends on them. Which is, I think, logically invalid. For the logical position that the universe we are in is unique, I guess it's fair to question why it's tuned so precisely, but in a more general sense, it is rather problematic. For the position that ALL possible realities exist, then limiting it to just ones that fit into realities that follow our physical laws (which, let's face it, is implied by tuning the cosmological constants - changing the strength of gravity radically alters the form of the universe, but it doesn't actually change the basic logic of it.) It follows that in an infinite reality that is random. every possible combination that can exist, will exist. Already, we have working examples of realities that while incredibly simplistic, DO exist - they are computer models. Games, mostly. But look at a game objectively as though it's a reality in it's own right, and you notice it violates all kinds of laws of our own universe, and no amount of tweaking the cosmological constants create a reality that resembles these artificial ones, yet by virtue of being tangible things that exist and can be examined in terms of their underlying logic, they MUST be considered valid realities in their own right. One of the things pretty much every game reality ever made, from the simplest to the most complex violates is the conservation laws. They do not conserve energy, mass, momentum or any other such property. Things get created and destroyed all the time for reasons that were we assume that reality was the same as our own, make no sense whatsoever. Yet, by definition we can examine what the rules are, and why things appear out of nothing, or vanish... Point is, tuning the cosmological constants is missing a step, and already pre-supposes a reality with a specific structure and rules, but the rules themselves are as much subject to being altered as the parameters those rules are used with. The possible realities that theoretically can exist is at a minimum covered by anything that we can describe using logic, even apparently self-contradictory logic, (as long as there is some over-arching reason that ties things together - for instance, the over-arching reason in a fictional setting is because the writer said so. Which is awkward, but is nonetheless logically valid if your context includes an author of some kind as part of the definition of the reality.) We can also imagine that there may be realities that defy any logic recognisable to a human being, but these are harder to deal with because they are by definition something we lack the mental ability to think about. The rules of physics cannot be considered to be set in stone. That's a logical error in and of itself. The cosmological constants are a set of fine-tuning parameters related to a very specific construction of physical laws. But if those laws themselves are as subject to random variation as the constants are, the scope becomes vastly bigger... How many universes can host life in an infinite set of universes? An infinite number of them. How many cannot? Also an infinite number. That is implicit in the concept of infinity, as difficult a concept as that is to wrap your mind around. As for the idea of interdimensional travel in the context of an infinite set of universes that vary completely at random... It's unlikely to be possible to travel to a reality whose laws of logic vary from your own. Or at least, the result of doing so is likely to be... Terrifying and confusing at best, and disastrous at worst. However, if we expand the scope of possibility to include variations such as realities that DO allow interdimensional travel as well as realities that do not... This of course creates no end of logical paradoxes. However, something being a paradox doesn't actually make it impossible. Though it does seem... Interesting to posit what happens if you travel from a reality that allows travel between dimension to one that does not. You could argue that is impossible, but again, by the implications of infinity there may be realities that allow things that are inherently contradictory. The... Consequences this would have for the destination universe where interdimensional travel is not possible however are... Headache-inducing, to say the least. Anyway... I guess I've said as much as I reasonably can on this matter. Just... An infinity of realities that collectively follow the mantra of 'anything that can happen will happen' is bound to throw up so many different sets of rules and logic that most of them would seem broken, or absurd, or just... Strange. So there's a variation on a theme for you. In an infinite set of realities where basic reasoning would suggest most of them make no logical sense, why are we in a reality that does? (or at least appears to?) After all, it seems reasonable to suppose that the number of realities that follow no logic, or some very strange, inconsistent logic, would outnumber those that follow coherent, simple and consistent rules, simply by virtue of the nature of these two things. (when you think of mathematics or formal logic or the like, there are far more statements that are logically invalid than there are those that are logically valid. Thus, if you suppose that for a universe to be logical it must behave in a way that is logically valid, then these universes, clearly would be in the minority as well.) That's a fun mind-twister no doubt. - why do we live in a universe that makes sense? XD

[@isaacarthurSFIA]

Possibly because its late and this is just about the last comment on my 4 day backup of correspondence (I've been at a conference) I might not be thinking at full steam, and indeed I know I am not, but I wanted to congratulate you on being one of the rare people who left a comment that mind-screwed me. :) I didn't see anything obviously wrong with your reasoning, but I am tired, I'll try to give it crack tomorrow.

[@crazyahhkmed]

KuraIthys Would that same possiblity not also apply to logic itself? That is to say that logic may or may not be a constant/consistent thing.

[@johnhick5677]

Just found this channel, but his pronounciation of some words makes the video much more interesting, im hooked.

[@nazamroth8427]

So..... what you are saying is....that in this very young universe, WE are the future among-the-first-to-appear-ancient-wise-old-race-past-the-golden-age from oh-so-many novels? ......By the gods, I pity the fools coming after us...

[@davecarsley8773]

Nazamroth Industries Why? We're pretty damn smart.

[@p.bamygdala2139]

I just discovered this channel this eve. Fantastic and in-depth. Very enjoyable! I might be staying up pretty late to keep watching! Of course, subscribed.

[@lawrencekimmel352]

Happy Thursday everybody!

[@valrond]

Nearing the Silver Star ! 99k subscribers, yeah.

[@peddleandcrank]

is Barry Kripky narrating?

[@carminesassano6300]

That's who I thought was narrating these vids.

[@joeyparrack14]

Elmer Fudd

[@gregoryiwanek6974]

I remember back then, few months ago, when Arthur had less than 10k subs. I was wondering then how is that these videos have less than 1k views each. All of them very long (!), well spoken, done in scientific and logical way, just without a "fireworks" or stupid "bim-bap-bim" audio like on a most of other channels like this. Just keep it up man. Congrats for 100k subs ( 99k at when I'm writing that), you've earned it:)

[@OljeiKhan]

I wonder how First Contact will be. Will a man look the alien in the eye , as they both show signs of relaxation , finally an end to the fear of isolation in the universe , or will the man hear the alien scream "kh'wozlag dhoqtoQ!" psionically as a massive death fleet warps in to existence in lower Earth orbit...

[@Stellar_Story_Tonight]

Well there's a whole video dedicated to first contact! you should watch it

[@OljeiKhan]

Yeah it's a nice one , i did watch it earlier though.

[@slydevil4759]

Aliens land and walks out of the ship. See's a man walking around with a fidget spinner. Alien: "I don't see any intelligent life here", goes back in ship and flies away.

[@grimjowjaggerjak]

Aliens land and walks out of the ship. See's the kardashian family. Alien: "I don't see any intelligent life here", goes back in ship and flies away.

[@Skelstoolbox]

Or like star trek first contact when the Vulcan's land and it's the mirror darkly universe and they kill the Vulcans and raid the ship and become the dreaded and feared/respected Terran Empire..

[@4Solon]

Nelson corollary to the Fermi Paradox: By the time a civilization has the capability to search the universe thoroughly for life, it will be capable of creating alien life itself. Sub-corollary 1: That life can be completely artificial, or can be created from non-intelligent alien life.

[@BaronVonHaggis]

❤

[@Skelstoolbox]

BaronVonHaggis from North Kilt town? ... wait a minute, there's no BaronVonHaggis in North Kilttown!..

[@doctorkotton7010]

this guys speech is adowable

[@Scorch428]

There's an estimated 8.7 *MILLION* species on Earth. *8,700,000* How many of them can build a rocket? How many can we even have a conversation with? None, other than us. I'd say Intelligent life is EXTREMELY RARE, if not unique in the Universe.

[@dongurudebro4579]

Well so you just ignore that there are plenty of species on Earth we can communicate with? You know that we just decided that that isnt really important to us? I would say your statment is pretty overweening.

[@judewakefield7213]

@@dongurudebro4579 Plus he thinks 1 in 8 million is rare.

[@gabrote42]

A great exploration of a subtly different universe is Orthogonal, where a single timespace equation is made to obey Pythagoras' Theorem instead of being a²+b²=-c² or something like that, and then completely extrapolated from it. It also has good plot elements and characters!

[@manospondylus4896]

I heard an interesting solution to the Dyson-Dilemma, which is that dyson-swarms simply are not the most efficient energy-source. Instead a lot of civilizations could build just partial dyson-swarms to gain enough energy to create black-holes or a "kugelblitz" whose energy-output is way more efficient than that of stars. It's better explained here: kzbin.info/www/bejne/oIiYZpaMnr2obNU What do you think?

[@isaacarthurSFIA]

It's not a solution to the Dyson Dilemma :) We actually talk more about 'Kugelblitz Dysons' two episodes from now, July 6th.

[@manospondylus4896]

Isaac Arthur Okay, thanks for clarifying. Altough I meant solution as in explaining how all the stars can still be visible if there are spacefaring civilizations

[@tamasmihaly1]

Isaac, you'd be a bigger hit than Bill Nye if you were on T.V. back then. I'm addicted to these videos. You have a special way of making this difficult material easy(ier) to digest. Thank you.

[@isaacarthurSFIA]

:) Thanks Tamas!

[@ayindemurphy5243]

There is absolutely nothing "disturbing" about us being "alone" in the Universe

[@garneroutlaw1]

great vid. Would like to point out that the infinite universe argument is flawed in so many ways. We're alone, okham's razor. We are either the first, or alone at this point in time. Scary as hell.

[@FatFingerJack]

Isaac, have you ever thought the possibility that all the life on Earth can be the descendants of another civilization that colonizes planets just by seeding them with primitive form of DNA and letting it evolve?

[@isaacarthurSFIA]

We've discussed that option in other episodes

[@crazyahhkmed]

FatFingerJack The evidence for that isn't strong. However if it turned out to be true, that would shatter any pride we can have as a species. Our uniqueness would seem to disappear.

[@FatFingerJack]

That is what a truly advanced and intelligent civilization would do. Program an organism with the right characteristics, to evolve and spread and and just give it time. It will reach a point that will be advanced enough to spread itself. Truly brilliant

[@ameliaashford6131]

Well if that's true atleast we're still "biologically".... (not as depressing as simulation hypothesis, where all of we just a program inside matrix!! )

[@meisteryogurt1460]

a civilisation that plays God?

[@VictorianTimeTraveler]

I had that discussion about fine-tuned variables with several intelligent people who had different ideas about it and it wasn't long before I wanted to just bang my head on the desk repeatedly

[@THEBIGMEOW]

90k subscriber's I'm ashamed

[@zaboomafia]

Should be much higher!

[@andyeccentric]

Be vewy quiet. I'm hunting awiens.

[@arandomzoomer4837]

400k now.

[@videolabguy]

This is Emmy Award material. I love it. Keep it coming!