Why we might be alone in the Universe 

Amazing video! Please keep them coming!

Very thought provoking. Good job, thank you.

Technically, you cannot answer that question, only the person you are addressing can do that. Also, if the universe is infinite, which it almost certainly is, then the emergence of life in an infinite number of places becomes (by extension) an absolute certainty.

I thought this video was all scientific and sht, showcasing something that is essential for life to grow and can only be happening on this planet or some sht. Not an ideology about life itself >.< Good video tho, keep it up!

Very good video! I agree that we cannot currently know. I guess and speculate, and I think we can look at the ribosome as a key here. A very basic proto-ribosome could have formed in two ways, with protein first or RNA first. Also a mechanism of inheritance could have formed either way first too. As long as at least one can occur easily enough abiotically, and give rise to the other (these are the things we don't know, except knowing RNA can probably form proteins on its own in a purely-RNA proto-ribosome and that proteins can certainly form RNA). If and only if it requires both to be simultaneously initiated, and that that is unlikely even in a vast ocean of hot chemical soup, then life could be much rarer. The problem I see is that although we can "initiate" some very basic form of chemical self-replicator via RNA or proteins (proteins being more likely to be capable of replication especially in a bath of amino acids), for actual viable life beyond just random chemistry we require RNA, proteins and lipids to come together in a special way. That might IMO be the hardest step. Despite that, I think that life can form relatively "easily" enough to be common. With lipids self-aggregating into capsules easily, amino acids being common in the universe and nucleic acids at least being present (haven't we detected evidence for that? Not sure) or being able to be naturally formed catalysed by volcanism or similar in a chemical soup, then life should be common. The problem i see is if amino acids and/or nucleic acids won't randomly polymerise enough abiotically. That woukd be a big problem. RNA is what really needs to form for life to begin IMO (I am no expert! And have little evidence). RNA can both code information like its stable cousin DNA can, but it can also fold into complex shapes and thus perform as a controlled repeatable catalyst for chemical reactions - like proteins. It can then form structures to replicate itself, and that is all that is needed (though it needs to happen 'en masse') for Darwinian evolution to begin. It can then later start catalysing the polymerisation of amino acids into proteins, and then those proteins can later start catalysing the copying of RNA into DNA. RNA is very much a poorer version of proteins and DNA. But we look at life from a very DNA-oriented perspective. I studied mechanisms in yeast by which proteins themselves carry inheritance and participate in evolution - unique prion-like proteins that can do some special things similar to RNA. This appears rare in nature, but it exists and happens. What if proteins like these (which are capable of converting other similar proteins into copies of themselves and aggregating into complexes, which can do stuff such as catalysing reactions) came first, and quickly gained the ability to produce RNA. We lost most of these Darwinian proteins over the aeons as they would be very poor in comparison to RNA, the RNA life they could have created would quickly overtake them. If amino acids, but not nucleic acids, are present in abiotic conditions throughout the universe, and polymerisation of amino acids can occur via common but abiotic means, then this protein-first start to life could be far more feasible than RNA first and solve the problem of either naturally-occuring nucleic acids or natural mechanisms to polymerise them, needed to form sufficiently long chains of RNA, being very rare or unlikely to be produced randomly. Excuse that awfully written sentence.

😂😂😂😂

That is so awesome!

😀😀😀 best comment of Internet 😀

Depends who you ask, once we agree that a miss is the best on the planet, it's safe to say that she's the prettiest in 'our' universe since beauty is in the eye of the human beholder. I'm sure every alien being that has beauty contests feels the same way as it's very difficult to think of a sexier lifeform than the ones that have evolved attributes to make us want to reproduce with them. We could never truly judge an unbiased interplanetary miss universe unless we judged our local lifeforms and then asked God to pick the winner...I think God is smart enough to not tell any single female lifeform that she is prettier than the other finalists. 🤪🤣🙏

Umm...Excuse me, did you just ASSUME the Earth's gender?

INDEED, MR. FOLEY..

foley15136 Yeah! Because if there were others out there we could be doing it to them or vice versa.

Woyam Chny It was more of a commentary on the idea that if there’s only 7 billion intelligent beings currently alive in this universe, we’re even more rare and precious. If that were so, it makes it extremely sad. To us, 7 billion sounds like a lot, but on a universal scale, it’s almost nothing.

True, we need to take care of one another and move forward into the universe.

Yep. It would mean life is extremely delicate. We could ultimately be the reason life ends in the entire universe lol. But I dont believe we're alone in the universe. Just because we dont see it doesnt mean it's not there. We dont even know that life doesnt exist in our own solar system (outside Earth, I mean). We dont know that at some point in the past that life didnt exist elsewhere in the Solar System. To find evidence of life, we'd have to be looking in the exact right place at the exact right time. I also doubt that intelligent life would be so careless as to shoot radio signals off into the universe like we do. History has shown that lifeforms finding other lifeforms when they migrate doesnt fair well for the less advanced lifeforms. Native Americans are prime examples of that.

yes! completely alone! even simple life form doesnt exist! not in this universe! maybe in another universe!

But unfortunately the democrats ruin the special nature of us. Bunch of dirtt bbags

@@M4R10_ thats hard to say until we send mission to each planet in our solar system its bad idea.

Nope sorry. I don't care how any smarter person than me tries to make it sound. If we are alone for the size of the universe then we are in an experiment. Some form of captivity and what we see as the universe might be a type of gel holding us in our fish tank. For reason I cannot fathom.

I see no reason to believe we're alone. We might be aline but there's no way to know either way.

The hell that´s right

...and what if we are in some extremely complex simulated reality ? oops, a third possibility has entered the chat.

@@Gizziiusa , only 2 possibilities exist , if we are simulated it means we exists and so does someone else , so it pretty much is the second possibility that we are indeed not alone.

If we are alone we can own it all. That’s cool not really scary. We can do whatever we want and control the life we put out there. I’m just trying to be optimistic I guess.

@@subspace666 granted, your point is valid. I didnt elaborate with the possibility/probability of a intelligently designed "reality construct" wherein with our limited ability of perception (3 dimensional reality with time), we will never really know if we are alone or not. thus, this third option is still on the table, the third option of "never knowing". aka neither A or B.

no one really knows to be honest

Hey, I just say "More for US!" It only takes 10,000 years to colonize the entire universe, plus travel-time.

@@SovereignStatesman Exactly! If there are other civilizations out also colinizing the universe that would just mean more compitition for us also trying to expand. If there was no life thay wouln no compitition and we could exand and colinize freely with the universe. If there was no life one possibility is that we could just stay hers on tnis planet or solar system and let the rest of universe die. If there was other life and we just stayed here would be just letting them take all that space for them selves! If you did leave to colinize other planets and star and maybe eventualy galexys and there is onther life out there, there would probobly be some compitition or war I mean unless you make some sort of treaty or get endorsed or somthing.

People see what they want to see.

Indeed!

Why? We’re currently in the most peaceful era in human history

​@@cesarrobledo2583even better, we are the most peaceful planet with life that we know of in the universe.

@@cesarrobledo2583 lol you dumb pissbrain we are destroying the planet hahahaha not by wars LOL dont reproduce

​​@@justinmiller947granted, but there might be just the slightest bit of bias in that sentiment

​@cesarrobledo2583 yeah, but for most of that peace period, from the end of WW2, we've developed swathes of WMD that, if misused, could threaten human existence. Best case scenario, devolved society. Worst case scenario, slow and painful extinction due to mass famine, disease and radiation.

Which is unfortunate. As the universe continues to expand, any civilization will become completely isolated.

@David Lucey yes but what if you could bend space time to your will? Given enough energy the laws of physics allow for the creation of a wormhole. A super advanced species might be able to pull that off and would thus be able to visit other areas of the universe that would otherwise be impossible. Also... you have to consider that a super advanced species might not even be 100 percent biological anymore out of shear necessity to adapt to the elements of space and foreign worlds and would be able to live for thousands maybe even millions of years therefore distances wouldn’t even matter. Or both.... 🤔🤭

@@all0utmetal735 interesting tell me more

Well they found the way to us still after the Pentagon officially confirmed the existence of UFOs and they have no idea what’s going on. Apparently even the US Senate wants to investigate this further… ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZBtMbBPzqHY.html

@@doesnotexist305 Yess but is a paradigm rather than crude reality when science of 👽 have already Tahionic speed spacetime traveling.

Agree this channel is really inspiring and uplifting! It really does breathe new life into me as well

Man yearns for everlasting life because man is made in the image of God. There's the natural and the Spiritual so life does exist .

A single candle holding back the darkness.

OK, you make me laugh, and cry, and want to hug you, all at the same time. But here's the deal. I'm 70, and frankly you sound like me.

@@GBNationalist There is exactly ZERO way to know for sure whether you are right or whether the person you are responding to is right. Which makes you as big a fool as what you accuse them of.

The smartest person or people are/is the one who knows they know nothing

@@Mikey-ym6ok Dunning Kruger syndrome

Fear of the Lord is the beginning of wisdom

@@zimbabwe_twinnedwithanfield Curious as to why the Lord should be feared?

@@chadwomack919 For wisdom is more precious than rubies, and nothing you desire can compare with her. I, possess knowledge and discretion; wisdom dwell together with prudence. To fear the Lord is to hate evil. I hate pride and arrogance, evil behavior and perverse speech. Counsel and sound judgement are mine; I have understanding and power. By me kings reign and rulers make laws that are just: by me princes govern and all nobles who rule on earth.” These things stand out clearly here: • Wisdom is to depart from evil: “I hate pride and arrogance, evil behavior and perverse speech.” • Wisdom is greater than rubies which is money • Wisdom is knowledge, discernment, power, sound judgement, understanding and discretion. • Wisdom is to listen to God’s word.

"I don't know" is the starting point of all science . Pretending to know everything the basis of all religion .

@Zurround100: The great thing about actual scientists is that they have to publish results to get noticed. They have to defend their theses, or the models they create via peer review. The geologist who first theorized plate tectonics was laughed to scorn. Time has a way of correcting or at least adjusting false theories.

@@WyreForestBiker: "I don't know" is the starting point of all science." I disagree, the starting point of science is "WHY"

@@wittwittwer1043 I framed my response in reaction to the original posting. Asking "why" infers that you don't know in any case.

Even more important is that, when new evidence comes in, scientists are willing to update their position to reflect the new data :)

Even if we’re not alone, we are still incredibly lucky to exist. Incredibly lucky!

Not currently with the MAGA nuts.

The FPV Life I wish I could argue with that! 😃

@@thefpvlife7785 don't like it then leave.

Luck don't exist

@Nick Miller who asked nigga

@@JJBenavidez Who is this Nigga you speak of? I've never heard of him. Does he usually know these types of questions?

@@mikeytodd7 bruh

@@JJBenavidez hey it's the nigga guy

@@mikeytodd7 im dead ahaahahahahahha

@@SuperYtc1 I agree. Although I'd argue that beauty is in the "eye of the beholder" as they say, and although I struggle to see it sometimes, other times I absolutely love life, but you're right.

@@SuperYtc1 As somebody who struggles to love himself (and is quite ugly), I feel content knowing I will never have a wife & kids. My genes shall die with me.

Right, this just makes me appreciate life more.

@@PedroOrtega1993 I know that the world we live in is terribly superficial, and that the standard of "beauty" we are programmed to accept, is ridiculous, and virtually unattainable... The faces and bodies that Hollywood parades in front of us are only possible with health, beauty, and medical regiments that are available to the chosen few.... and even the A-list actors/actresses, models, celebrities, etc. were not BORN looking this way, and I guarantee you that without all the makeup, editing, filters, plastic surgery, enhancements.... even these assholes DO NOT wake up looking like their avatar! Besides all that, for me personally, I find that branded beauty boring and FAKE AF. Normal people do not look like that and they dont even look like that at home on a Sunday night. I know it sounds corny, and I may not represent any majority, but FOR REAL REAL.... True Beauty, Real Beauty...... That shit is NOT skin deep.... It is NOT shallow.... It is not false..... It is authentic and natural and deep.... It begins INSIDE a person and radiates out..... And whoever has tricked you into thinking that you are not worthy of love because of your outer layer of skin not being up to par..... then they are a superficial, cruel, trivial, bully piece of shit..... and Pedro, if you are a kind, compassionate, useful human being - then you are more beautiful than all these mofo's.... Anyone who tries to convince you otherwise or who cant see past the shallowness of outward appearances and ACTUALLY SEE you in there..... you dont want those people anyway. I know many people out there are shitty, and that the world puts an impossible pressure on us to be like the "beautiful people" on screen. But I also know there are people out here like myself, who value the good stuff in the middle of someone, and who take the time and care to LOOK and SEE the humans around them. So, give yourself some love for the things that matter. Dont be like them.. they have it all wrong. With kindness and respect, Emily.

@Uranus you seem like fun guy to party with.

well that's the if scenario, if we are really alone then yes

Respecting all life.

Being born out of extremely low chance is not a reason to be respected.

@John Grygus No. That's called a FAIRY TALE.

@John Grygus No, moron. Even if I did believe that, adding a god to that theory would recreate the exact same problem. It would only add an extra unnecessary step and would solve nothing. Believing in god is shallow thinking for simpletons. Everything changes states but nothing is created nor destroyed. I don't think there even is such a thing as a "void". What you think of as a void is just non-oscillating quantum fields. And why would you assume that nothingness is more probable than the existence of matter?

it takes an idiot to think doubt is good. knowledge transcends everything. Ive spoken to aliens face to face I don't have to dumb down and live like a retard. Ive learned the secret to reality and mind. Mind is the final frontier not space

then you richard feynman have a small mind!

@@VG-rj8pn Sorry you feel this way.

@@-A-c you need to be sorry YOU FEEL this way. You are the one who will suffer due to the wrong state of mind.

@@-A-c and its not how I feel its how it is.

IT DOES TAKE AWAY THE FEELING OF BEING STEAM ROLLED ON A GIVEN TOPIC..

That's why I watch the video at 1.45 speed.

@@martinkunev9911 poor thing..

Why is it terrifying? What possible difference does it make to your life?

I'm sorry, but I think you are emotionally underdeveloped.

@@NobodyYouKnow98 Are you plankton?

We won the universe equivalent of the lottery. The Odds were trillions and trillions to one against winning, but we won it.

I hear you. People can be edgelords about this subject, but it doesn't take a philosopher to recognize there's a profound, existential component to this idea. Especially when you consider that the human race is less likely to survive as long as people often imagine, in science fiction. There may not be an inhabitable world within reach, and the less inhabitable ones like Mars may not be practical. We might have a few thousand years left, and after that, sentience leaves the universe. Maybe it'll return, maybe it won't. We might be living in the only little sliver of time that the universe had life, had consciousness.

Do not fear. You will live until you die and most of the people on this world and all of the people on other worlds will not know of your existence.

@@normjohn217 Like so many millions, or billions of trees or trillions of plankton that live and die, and nobody notice any particular one of them fall or die or ever be alive in the first place.

Beat me to this comment. By 5 months.

Watched it 5 or6 times in the past couple of years. Will probably watch it 5 or 6 times in the next couple of years. Just can’t put it down……

Your Feelings of sadness and loneliness comes from not knowing God...? Your wonderment is knowing that there is indeed a Devine plan in the creation of the universe and Life on Earth and your feelings of fear is the acknowledgement of God and the true reality of your existence this understanding would have in your daily life...? Possibly?

this is exactly what happens to me

The feeling is existentialism. Welcome to the club

Yep.

Outstanding Cruise I couldn't have said it better myself this video was deep

Seek you Lord and Savior Jesus Christ! You will never feel alone again God Bless.

Outstanding Cruise, yes assuming we are alone. This video hit me too bro.

lol for someone that doesn't like enormous responsibility that would be like a brink in the face lol

I'm gonna steal that quote.

Lovely quote, a true testament to the human ability to state the obvious, however, those words are vain. We are not alone, we have never been alone. The question is not who they are and where they come from, but why.

To be honest there almost no chance we are alone, the argument that we are lucky that we survived through so many disastrous events only points towards that its not that hard for life to evolve! If you look at thousands of different species that live today on our planet and someone tells you that 99% of species that were alive on planet earth are extinct I would think that its impossible (if planet earth itself wont collapse) for living organism to go extinct! So being able to survive through 5 mass extinctions seems to point out to that its nearly impossible to go extinct once life started! Also if from simple bacteria evolved millions of animal, fish species then it seems in the Universe should be the same, from star dust there must evolve life and it must evolve everywhere! So it seems based on evolution on earth and based on how hard for living organism to die out and how easy through time for it to multiply and evolve (from small rat mammal to lions, monkeys, humans, zebras, elephants, giraffes....), Life in the Universe should and it did (from big bang to stars to galaxies to planets to life) to evolve in big abundance and variety!

@@PowerMixxes Surviving disaster is great but that has nothing to do with how likely or often life gets started.

Me too

There is something in that statement that deeply resonates with me too. Although diamonds are quite common in the universe, but that's beside the point.

We may not be the diamonds, but the blemish of the universe.

Inside the Casino There are enough life forms here on earth, yet humans cannot live in peace among them. Why look for life elsewhere in the universe...start a war over there too?

@@truthseeker3857 for us humans, exploration comes before peace

Dipanjan Ghosal That’s like putting the cart ahead of the horse. 👌

@@truthseeker3857 its true that discovering something has risks associated with it. However risks have never stopped us from discovering. Its our nature. Its how we progressed. An alien contact is risky, but we humans will pursue it regardless. This is why we have progressed so far.

We are the only ones , If there ARE others it is because God created them also , not because there are so many planets, That there just has to be others ! the only proff is ourselves , our awareness of ourselves is a special abilty that God gave us ,that no other creature developed or needed !!

The idea of lightning creating life is nothing new really. It was first proposed two centuries ago and that's how the story of Frankenstein came to be.

“Elucidation”…….there’s a word you don’t hear every day.

Agreed best video I have seen on the subject.

And how will the Webb telescope will change this if at all, will it find oxygen, chlorocarbons and oxides of nitrogen on any other planets indicating an artificial origin?

David T62, or every school in the universe. 😜

It is good to read comments from someone who actually watched the entire video. Your sentiments mirror my own.

Should be put out on public TV at least once a year perhaps on christmas day

David T62, doubt and ignorance - and much of it willful and determined.

more likely worlds that are nothing more than primitive single cell organisms

He is known for many.

@@scottslotterbeck3796 lol he said that because in every vid like this one there is 100% chance to find the exact same quote.

LMAO 😂

Feels like it - based upon the repetition rate of the most prolific peppered all over internet comments sections.

“And it isn’t even that one.” - Isaac Asimov

This kind of video makes me proud of being a human

@@erikincph Yes, this is very well-done. He changed my view on life in the universe. And, sadly, I hate him for it. GRIN ...

He is absolutely BRILLIANT

Maybe life is just a fluke... as stated on this video... and even if there is life out there in the universe... it may just be unicelullar life. It took billions of years for life to evolve from unicelludar to multicellular, it may had just been a fluke... and then to evolve for multicelluar life to inteligent multicelular life... may be even another fluke. Occam's razor... at the lack of evidence of life outside of our planet, the most simples answer is there is no life outside of this planet.

Well, not really. This whole video is trying to assess the probability of abiogenesis. He spends 25 minutes telling us: we don't know. We just need more data and to explore other places to find out. Brilliant, can you give me the 25 minutes back? For a more useful analysis, I suggest to check out Jeremy England.

Yes better than reading my astronomy book from year one good stuff

Gary Anderson II Yesss is Good done.

yes. and to have an appreciation of such a man needs to be compassionate about all these. cheers to you too Man. Bless you.

I absolutely agree, Andras. I’ve noticed that even the comments are gently progressive and humbly intelligent. Unlike the depressing juvenalia and vulgarity RU-vid often presents, and provokes.

I feel like he’s about to demonstrate a dyson vacuum.

@@prototropo 'Progressive' can mean regressive, and it very much depends on what one is talking about. 'Progressive' is politics on earthly affairs is a deadly characteristic.

I don't agree. All the statistical analysis seems to leave out the immense time and space involved. The little experiment with electricity and amino acids didn't result in life within days, but the Earth had billions of years as well as an entire planet. It's failure really doesn't tell us anything. Give everyone billions of years to pick the locks, and you'll get a lot more open doors.

@Oni 100% agree the odds are just so insane that it would be crazy not to think this has happened before else where

My best guess is it is somewhere between the "crowded universe" and us being totally alone. It's extremely rare, but not so rare that we are literally the only ones. And the universe is also very big, the raw amount of empty space is much greater than the number of potential words. If other civilisations are so far away from us that we will never come into contact with them or find evidence of them, we might as well be alone. The most boring and realistic answer to this question is probably "it doesn't matter because we will never encounter it either way".

@@jrpipik did you not watch the video? The immense time and space is irrelevant. That is the whole point. Yes, that experiment tells us nothing, but no experiment ever conducted gives us any idea how rare life is. Your assumption on more locks being picked if you give them billions of years ignores the possibility that the difficulty of picking the lock could be scaled up billions of times(thus the probability would be the same). It is simply an incomplete equation. We cannot comprehend how immense the universe is(infinite?), could it be that we cannot comprehend how rare intelligent life is? (infinitely rare?). Believing there has to be life elsewhere is no different than believing there has to be a God. (By the way, I have no problem with "believing" either, you just can't use science or statistics to back the belief of either one)

Do not propose that "I don't know" is a valid answer about the mystery of life to any religious person. Such people go to a lot of trouble persuading themselves that they do know, and rely on constant affirmation from fellow believers. Faith is the capacity to believe something that is not true but must be true because it supports a person's world view. And that is why religious people put so much emphasis on having faith. If something was obviously true -- for instance, that we are born and eventually die -- not a shred of faith would be required to believe it. On the other hand, believing there is life after death requires a huge amount of faith -- often backed up by some hefty tome of dogma describing supernatural beings who create us in their image, or similar nonsense.

Your word for God is cosmos.

_ One possible understanding is that "we", but actually "I AM" the Cosmos.

there is nothing to examine, everything we see is so far in the past. closest galaxy we see it as it was over 2 milion years ago. we are out of our depth here.

The next generation of a space telescope is going into space soon. It could very well give us photos of several identified Earth-Like worlds (size, mass, location in life zone around parent star) and analyze their surface temperatures and compositions of their atmospheres. We could likely identify if they have plant life.

If that is so, I highly recommend you to read the book "Rare Earth: Why Complex Life is Uncommon in the Universe" by Peter D. Ward, Donald Brownlee". It is one of the best books I have ever read.

@@NomenNominandum Thank you Nomen. I will look this book up.

Yes, in this video, Dr. Kipping neatly encapsulates and articulates my worldview. The conclusion elaborates a philosophy of existence I find compelling and breathtakingly beautiful.

@@Involent Indeed. Me too

And the background music really made it extra special. It's from one of the best movies ever !!!

But it would also be really cool if we're not

@@sakesithole6295 Yes some species which could answer Why or How everything started which I think our species would take very very long time or never cause the Question is not for us to answer I suppose.

I imagine every civilization out there is saying the same thing, we're the only ones in the universe, and every single one is wrong.

Highly doubtful. Are we talking intelligent life or life in general? I think that’s when people get confused.

I think intelligent life is extremely common, just because we can't prove it yet, it doesn't mean we are special and unique. Mathematically is just impossible, we have gazillion planets and we're supposed to be the only ones or first ones lmao don't be so naive people. Life doesn't start out of nothingness like scientists been telling us, we're the seed of much intelligent life. Every single DNA on Earth wasn't born out of nothing, someone put us here. (And no, not an imaginary god).

Upravo tako. Svaka mu cast.

He's exactly right.

Emerging scientific data in the journals agrees that life is rare. The increasing habitable zones means that less then 1% of the planets in each galaxy being unsuitable for life. Known Current Habitable zones as of 2017: - Water habitable zone - Ultraviolet/Radiation habitable zone - Photosynthetic habitable zone - Ozone habitable zone - Planetary rotation rate habitable zone - Planetary obliquity habitable zone - Tidal habitable zone - Astrosphere habitable zone - Electric wind habitable zone For host stars with an effective temperature more than 7,100 K (7,100 °C above absolute zero) or less than 4,600 K, even for just microbes, a team of four Chinese astronomers showed that the liquid water and ultraviolet habitable zones will not overlap. This may seem like a fairly wide effective temperature range, but it is narrow enough to eliminate all but 3 percent of the Milky Way Galaxy’s stars. Japanese astronomers Midori Oishi and Hideyuki Kamaya established that the zone of overlap is even narrower including the metallicity requirements of the Host star, this leaves less than 1 percent of our galaxy stars as candidates for bacterial life. Advanced life has even more stringent requirements. Scientific Articles: - Jianpo Guo et al., “Probability Distribution of Terrestrial Planets in Habitable Zones Around Host Stars,” Astrophysics and Space Science 323 (October 2009): 367-73 - Rory Barnes et al., "Tidal Limits to Planetary Habitability," Astrophysical Journal Letters 700 (July 20, 2009): L30-L33 - David S. Smith and John M. Scalo, “Habitable Zones Exposed: Astrosphere Collapse Frequency as a Function of Stellar Mass,” Astrobiology 9 (September 2009): 673-81 - Midori Oishi and Hideyuki Kamaya, “A Simple Evolutionary Model of the UV Habitable Zone and the Possibility of Persistent Life Existence: The Effects of Mass and Metallicity,” Astrophysical Journal 833 (December 2016): id. 293, doi:10.3847/1538-4357/833/2/293 - Glyn Collinson et al., “The Electric Wind of Venus: A Global and Persistent ‘Polar Wind’-Like Ambipolar Electric Field Sufficient for the Direct Escape of Heavy Ionospheric Ions: Venus Has Potential,” Geophysical Research Letters (June 2016): doi:10.1002/2016GL068327 - Glyn Collinson et al., “Electric Mars: The First Direct Measurement of an Upper Limit for the Martian ‘Polar Wind’ Electric Potential,” Geophysical Research Letters 42 (November 2015): 9128-34, doi:10.1002/2015GL065084 - adsabs.harvard.edu/cgi-bin/nph-ref_query?bibcode=2003ARA%26A..41..429K&amp;refs=CITATIONS&amp;db_key=AST

I don't know of the gaps

Amen brotha

Unique? You sure?

The inhabitants of the earth have only been able to send radio and TV signals out into Space for about 75 years out of our long history,so the chances of another civilisation being at the stage of being able to communicate across the vastness of the Galaxy alone is not very great,If they can launch a small probe to the nearest star,Alpha Centauri,,which could travel at one tenth the speed of light,it would take 40 years to get there ,and another 40 years to beam the information back to Earth. "They" have had 80years to receive our signals and send back a reply.The silence is deafening! Nothing has been received

Does that include Hitler or people like him?

WE ARE NOT!

By this logic you'd then also expect your other neighbor to be form of life 500 million years more advanced than you.

At least use proper terminology. Abiogenesis NOT evolution

@@ungmd21 Abiogenesis is and always will be an unproven theory. To say Life was started by non-life is as crazy a theory as we were created by a divine being.

@@PaulRobert474 abiogenesis is not a theory but a descriptive term. Evolution IS a theory

@@ungmd21 Evolution is fact. Species evolve every day. Offspring are more adapted every time. Look at every mammal in the Ocean and how they changed from living on the land. They are evolved from the land, other than fish such as sharks. There's so many proof in bonestructures that you cannot say that it is a theory.

Agree.

As do I.

go out more man, seriously ?!

@@alext.9271 The irony of your comment is gold 😂

God made Adam

sigh...all this video said was 'we don't know', while logic dictates (considering how unimaginably numerous planets are in the universe, and the unimaginably numerous environments on said planets, and that we know it happened at least once) the chances that life doesn't happen elsewhere are damn near impossible. I mean, we've created amino acids in an early Earth environment, and like the narrator said "maybe we haven't run these experiments long enough" (especially when the Earth is 4 BILLION years old) is a very likely scenario. Even if life only happens on one in a billion planets, that still means there's trillions of planets with life out there. This 20 min video could be summed up in 10 seconds 'numbers suggest it's probable, but we don't actually know if life exists elsewhere'...a waste of my time.

@@DeathToTheDictators "a waste of my time" if that's the case why comment ? The guy said he enjoyed the video.

@@justanotherdrunk Don't start with all that!

@@milesstyles7428 Because I was disputing it was "fantastic"...are you new to YT comments or something? It's not all kumbaya, newb.

CARL WAS A SALESMAN FOR NASA, AND A GOOD ONE I MIGHT AD, BUT ONLY A SALESMAN

@@nonenone5326 CHILD, SO WHAT'S WITH THE LABELS..? SO QUICK TO CATEGORISE.. YOU CAN BE RIGHT IF YOU WANT TO BE.. IT'S FINE WITH ME.. THAT SAID, I'M NOT SO QUICK TO SWALLOW THAT CRAP THEIR PUTTING OUT W/CGI CARTOONS TO HELP PEOPLE BELIEVE WHAT THEY ARE SAYING.. (DISTANCE IS THE KEY FACTOR HERE) CARL KNEW THAT THINGS WE CURRENTLY SEE IN OTHER PLACES/GALAXIES ARE MILLIONS OF YEARS OLD BUY THE TIME THAT LIGHT GETS TO US.. A LOT CAN HAPPEN IN A FEW MILLION YEARS.. ITS LIKE WATCHING A MOVIE IN EXTREME SLOW MO.. BUY THE TIME YOU GET TO THE 1ST. HR. MARK, YOUR LIFE IS OVER WITHOUT SEEING THE END OF THE MOVIE.. SO ENJOY THE DAY --- MADD

@@nonenone5326 YOU ARE WRONG IN YOUR ASSERTIONS, THAT ASIDE YOU ARE EXACTLY THE KIND OF PERSON IM TRYING TO REACH OUT TO, BECAUSE IN MY DAY KOOL AID WAS LOADED W/RED DYE #5.. WHO KNOWS WHAT'S IN IT TODAY. THAT'S WHY YOU SHOULDN'T DRINK IT.. IS THAT SLOW ENOUGH FOR YOU TO GRASP..?

@@maddman4747 Carl Sagan was a legitimate scientist who made solid, if modest , contributions to his field. A workmanlike scientist, but a stellar communicator and publicist. But he absolutely was a solid contributing astrophysicist too.

@@nomdeguerre7265 really. that's what you think.?

the road to wisdom begins at the first uttering of "I dont know".

@@benedictdonald4338 I think therefore I am biased.

Only the Father knows

@@voidremoved stop

voidremoved who’s farther

@Slim Hyena if ailiens discover us we might be fucked or fine, noone knows if ailiens are nice, or bad. Noone even knows if their actually real.

The word would be a better place if there were more ppl like that

This is also a question that fascinates me

...and not to forget another haunting question: why is it of all things me, who can think about it. In other words: why am I Me and not someone else???

@@kloboklonz9589 I think consciousness and sense of self is universal. Just like with our appearance, tastes, traits, features - condense it all down, and it's really all the same, save for some subtle differences. The differences all add up of course... but really, I think nature cheats - individuality is just another magic trick. We all have subjective experiences, but those experiences are all incredibly normalised - to another intelligence, we might not even appear sentient.

Now that's a deep question and a brilliant one. Why how when what for.

@@kloboklonz9589 It's not you, it's us. Imagine being born and growing up in an empty tube. When you turn 20 the only think you would think is the dark tube and nothing else. It would be you and the mighty tube then. Humans evolve collectively.