Life Begins: Crash Course Big History #4

In which Hank and John Green teach you about life on Earth. They won't be giving advice on how life should be lived, because this is a history series. Instead, they'll teach you about the earliest forms of life on Earth, and some of the ways that they developed into the types of life we know, love, and sometimes don't love so much (I'm looking at you here, opossums). You'll learn about prokaryotes, eukaryotes, panspermia, reproduction, a little about DNA, and even a thing or two about trees. Maybe.
Crash Course Biology
DNA Structure and Replication Episode: • DNA Structure and Repl...
DNA Transcription and Translation: • DNA, Hot Pockets, & Th...
Learn more at www.bighistoryproject.com
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[@GeographyNow]

I know John Green is kind of reserved in presenting his Christian faith yet I find it kind of interesting how he tackles such topics from a simple unbiased viewpoint, unshaken in his beliefs. Respect for you on that Mr. Green.

[@reececrump8483]

I take a few online collage courses. While I was watching this video, my mom looked over my shoulder and said "is that your professor?" ha, yeah I wish.

[@manstervision]

collage, or college? there's no "a"

[@misterbil4637]

Must be an art student

[@-dennis3755]

@@misterbil4637 (ba-dum-tiss)

[@fbk8004]

Lmao. You wrote this 4 years ago 😂

[@asterism_s]

@@fbk8004 without coronavirus, he still took online courses

[@ahouyearno]

I love it. "I don't know" is the only honest answer and all speculation has to be qualified. If you take anything from this video, it must be that "I don't know" can be used to answer a question. If that's the truth, it is the correct answer and you should proudly say it.

[@oa3255]

"I don't know" isn't as satisfying or catchy as saying "someone who lives in the skies did it".

[@lourdessasser3965]

Lol I was confused as to why John green was teaching me science and I was like ohhh there you are Hank my science buddy!!

[@Shane8]

If those molecules had known how angry everyone would be getting in the comment section, they just wouldn't have bothered.

[@2-dsynctium773]

Shane H And yet it did and realized it's horrible mistake

[@27STS]

I love that every living thing on Earth is related to one another. Powerful stuff.

[@ParanormalCacti]

If you were to have sex with a tree it would technically be incest... weird

[@SangoProductions213]

ParanormalCacti incest - sexual relations between people classed as being too closely related to marry each other. No. it wouldn't be incest.

[@Vesarret]

SangoProductions21 It might be for him if he's a cactus.

[@thanksking4372]

Hallo cousins!

[@mabbie7451]

I don't mean to be rude but the definition of incest is basically being in love with some close family like a sister or a cousin

[@Executor009]

"if you want this mind boggling question come down a few boggles in the boggle scale" ultimate lolz.

[@crashcourse]

In which ***** and John Green teach you about life on Earth. They won't be giving advice on how life should be lived, because this is a history series. Instead, they'll teach you about the earliest forms of life on Earth, and some of the ways that they developed into the types of life we know, love, and sometimes don't love so much (I'm looking at you here, opossums). You'll learn about prokaryotes, eukaryotes, panspermia, reproduction, a little about DNA, and even a thing or two about trees. Maybe. Crash Course Biology DNA Structure and Replication Episode: DNA Structure and Replication: Crash Course Biology #10 DNA Transcription and Translation: DNA, Hot Pockets, & The Longest Word Ever: Crash Course Biology #11 Learn more at www.bighistoryproject.com

[@ovidiuc]

love the way you guys explain and the way you put accent on what is actually valuable information. keep up the good work!

[@Grafknar]

I think your channel has the widest gap between immensely entertaining and informative videos and insufferably ignorant comments.

[@ClemensJason]

it's really amazing how you explain everything in a simple way but it could be better if you put some sources/journals for further reading in the information panel

[@ovidiuc]

CJ1707 quoting the description: "Learn more at www.bighistoryproject.com" :)

[@TheArchevil]

If you find what created energy you'll find what created life, because energy created matter as in that there would be no matter without ernergy. We all function by energy as well (our brains) and in every cell our mitchochondria, produces or works with energy. The big bang was a explosion of energy and the "God" that created our universe was this explosion of energy (or as some would like to say it was the proces he used to create our universe). That's why nuclear fission produces energy. Our body is just a vessel to contain our energy and when it dies our soul (our energy) goes back to form something else (this theory includes "heaven"and "reincarnation"). Now i need to copyright this theory, but you guys can have a go with this, i developped it when trying to figure out what God is and energy is the result, something that's in literally everything.

[@ottavioperuzzi6089]

the sperm entering the globe bothered me so much... I keep expecting the globe to burst open into a horrifying man-earth hybrid

[@DustinMillerPolyInnovator]

God jizzed on our planet

[@ROFLMAOtheNARWHAL]

This won't be controversial at all. No need to look at the comments, there's nobody arguing down there.

[@kaylajane6756]

Hank is a blessing to all Biology students and my eyes

[@giggity1471]

This episode perfectly utilized John's historical knowledge and Hank's scientific knowledge and mixes them in such a way that makes me wonder why real classes aren't taught like this. It seems to be much more interesting and efficient. Great episode guys!

[@marenz]

Thanks for giving Roselyn credit. I read The Double Helix last year and my jaw dropped at just how awfully they regarded her in spite of how valuable her work was the overall project. That is all.

[@zhiracs]

Probably the best video on abiogenesis I've seen. You two never cease to impress me! Also, obligatory inb4 inevitable shitstorm

[@headbangben1]

[insert bible quote that you are wrong here]

[@EmptyCha]

No, this is Patrick.

[@misterbil4637]

No reasonable hypothesis was postulated.

[@kaylajean8497]

I appreciate this video! I'm personally atheist and living where I do every time we talked about life in any science classes the teachers would mention God. Now I've got nothing against Christians and their beliefs, and Christians are some of the nicest people I know, but I'm glad that here is a lesson in which God isn't mentioned once. It's a first for me.

[@abyssiniaempire8672]

Juno Donat I mean if they don’t let religion interfere with what the teach then its fine

[@dandiaz19934]

I just came from watching an hour-long doc. on the origins of life, and this 13 min. video was WAY more informative, interesting, and helpful. God bless Crash Course! :D

[@hobbeycat]

bacteria = that awkward cousin no one talks about

[@julkkis666]

that lives in our kitchens, the guts.

[@cleodello]

***** om nom nom

[@ANDELE3025]

Rebecca What about creepy uncle virus and stomach rub grandpa archaea?

[@hobbeycat]

manband20 I just felt a shiver

[@julkkis666]

manband20 that reminds me of todays biology lesson, we spoke of certain parasites. they live in your guts(the bigger one closer to the rectum). at night when you sleep, they get outside of the body thru the Anal opening and start having sex. then when you feel a tickle in your rear, you scratch it and their bodies explode and their seed spill around the anal opening.

[@ElijahVT]

2:03 It's called scootilypoopin Hank

[@amisner2k]

Hank, did you recite that Darwin quote from memory or were you reading from a prompt? Because that was most impressive.

[@aprilcerritos6385]

So this is the first crash course video I've ever watched. And I was watching it thinking, "Wait. Why does that guy look so familiar?" And I realized that it was the same guy (aka John Green) that frickin ripped my heart out and tore it to pieces with his NY Times bestselling book The Fault In Our Stars! Ah...Good times

[@EtrielDevyt]

As RA Wilson once put it, "Few of our ancestors were perfect ladies or gentlemen; the majority of them were not even mammals."

[@ayesha9349]

"Today we are going to get a life" :/

[@fleecemanjenkins6648]

i dont wanna

[@ayesha9349]

Ali Hussain Al-Nasser kskekwkwospskqmq

[@ayesha9349]

Ali Hussain Al-Nasser wiowksnahauiq

[@ayesha9349]

Ali Hussain Al-Nasser I like to eat large quantities of pasta everyday.

[@ayesha9349]

Ali Hussain Al-Nasser how

[@AlltimeNumbers]

Incredibly interesting.Thanks for sharing guys!

[@johnchaser7369]

Hello Alltime Numbers!

[@AlltimeNumbers]

John Chaser Hey!

[@johnchaser7369]

Alltime Numbers How are you?

[@FROPDESAI]

Alltime Numbers Notice me senpai!

[@Ensittare78]

thank you for making this series, it is presented in such an entertaining way and you guys are really funny and interesting to listen to.

[@orangeburrito_]

How come Hank doesnt have a hank from the past?

[@efenollal]

I finished watching this amazing video and when I scroll down the first thing I see is somebody mixing Science with God. Hey! If you think it is impossible for you to respect people who trust in research and tangible proof you should not be making comments about neither Bible nor God here. You can go and watch a religious channel instead of being looking for controversy here. The theory of an almighty loving and powerful God who we can trust and put our trust on is cool. But don't troll others that doesn't share your way of thinking.

[@efenollal]

you are right! But you have not idea of how much it bothers me to watch a science video and see a dozen "creationists" with their crap.

[@whatsmyusername10]

Well you did just bring up the topic yourself

[@ShadowDrakken]

Edwin Fenollal Loving? Who we can put our trust in? You've read a different Bible than I have... wrathful, vengeful, jealous and fickle are more God's style.

[@efenollal]

Hey I'm being polite. The bible presents a loving and caring God but just and who can't lie. Since he promise something that's what will be. If he promises wrath that's what will happen. If his people do what he says he promise love. That's it... Remember, religion is used to control masses. If you don't present a loving god who will punish you if you don't comply with what he says, how can you expect people to follow that specific belief?

[@VhasiWeiseJinn]

The only way to answer this question is a long in-depth conversation. The kind that you can't have on a KZbin comments bored. The only thing I can do is suggest reading material. Anything by Scott hon, GK Chesterton or Thomas Aquinas would be good. you might also want to check out wordingfire.org and EWTN.com. EWTN (Eternal word television network) is also a T.V. station, but I don't know if you get it.

[@BlueWizard48]

I love this channel! I'm learning so much, thank you guys. I was wondering, however, if you could start a new playlist on Food Chemistry? Or anything related to nutrition, diet and so.. I'm highly interested in this area and would love to learn more

[@hibiscusman]

Great series, this is really a fantastic way to proceed with Crash Course. Keep up the amazing work!

[@anselmareich3549]

"Today we are going to get a life." Me: *putting down her pen* We are?

[@Tesla_Death_Ray]

Panspermia is a non-answer. Like god. Saying we came from an asteroid just moves the question a step back and begs the question, ok, and how did it develop on that asteroid/planet/comet/whatever?

[@Alexaflohr]

It is, but it does open up the possibility that life can emerge in some other chemical setup than primordial Earth. If panspermia is true, then we're more free to experiment with a bunch of wacky situations from which living molecules may emerge. It's probably not that though. There is even less evidence to life starting (or even existing) beyond Earth than life starting here.

[@DrQuak]

It isn't really though, as it is an umbrella for several theories, one of which is that some of the complex molecules, that became life, may have formed in the hard vacuum of space, or under the flux of cosmic rays.

[@unvergebeneid]

Panspermia open up more time and space for the freak occurrence of molecules just randomly assembling themselves into a simple self-copying machine. Life showed up so quickly on earth that it's really hard to see how something like that happened in that short time span. Not that I'm really a panspermia advocate but I see its merits.

[@flaviusclaudius7510]

The thing that makes panspermia at all useful is that it challenges the assumption that the conditions on primordial Earth were suitable for the creation of life - it may not have been. It is often seen as a 'cop-out' answer, but it is important to examine one's assumptions.

[@Grokford]

I wouldn't say that god is a non-answer. If there is a god, in the traditional sense of the word i.e. all-powerful, omnipotent, omnipresent ect., than it takes no stretch of the imagination to think that such a being could create life. If there is a god then it would be far more likely that he created life because of the sheer complexity of life.

[@ssgtoconnor]

You guys are amazing. I love watching all these videos out of pure interest of learning. Please don't stop!!!

[@boblet132tx]

I love Hank and John G so much! Another great and informative video thankyou Crash Course!

[@songljudge]

I'm not even going to bother going through the comments section because I already know what awaits.

[@flaviusclaudius7510]

I've gone through it. You were right :(

[@josephstalin8423]

*scrolls down, oh shit, *scrolls back up, you were right

[@caelachyt]

Nobody of worth cares whether you do or don't.

[@erwinsmith9473]

You mean people talking about god and stuff??

[@KirstenMarie_MS3]

@@erwinsmith9473 Not so much just talking about God. There are plenty of people who manage to reconcile what the evidence shows with their faith. It's the fundies who think they know better than people who dedicate their lives to this research because they went to a Kent Hovind seminar that one time...

[@MasterChef306]

So here's something interesting, I find there are more comments here complaining about evolution-denying trolls commenting on this video than there are actual troll comments.

[@Zephyram]

Thanks for another great video. You guys seemingly never forget to be awesome.

[@isgdre]

Given the tittle, I was still a little worried John was going to say “God did it”. Glad that didn't happen.

[@PacXen]

Are you positive God didn't do it?

[@jwat4166]

Kyle Walker haha go Kyle! :D

[@ActuatedGear]

houdini2233 Incanted. Pie jesu domine, dona eis requem. *SMACK*

[@ZURATAMA]

Even though I am not a believer, I kind of hope that John was a theist. Just think about it! After all the science talks and videos... John says "God don didit!". It would be lethally hilarious.

[@PacXen]

Yes and dolphins grew wins and flew away to become Pelicans. It's easy to twist people's words. Now use your head and tell me how questioning whether God created the universe or spontaneous generation did? Which one do you believe?

[@baegel49]

I'd love to see the Green brothers tackle the idea of God/gods. Sure, men created God, but i would love to see the analysis and history they would present. Great video once again!

[@MrBobor1]

John is a Christian so it probably would be biased.

[@ShadowDrakken]

Bobor Correction: "John is human, so it probably would be biased"

[@achmedaan]

Yeah... let's not.

[@MrBobor1]

***** That doesn't even make sense.

[@ShadowDrakken]

Bobor ... all humans are biased... and some are just special

[@jasonpina-hernandez721]

This is amazingly interesting i would love to know more 👍👍👍👍

[@harveenkaur4684]

Great explanation! Thanks!

[@malachiq7357]

One day people will accept the beauty of Evolution. One day. :(

[@odean14]

most likely wont happen there are to many aspects of it that don't make sense.

[@malachiq7357]

Like what?

[@emperorpalpatine9841]

Not really beautiful, as natural selection demands things to be killed to evolve. But details, who needs them?

[@TheCookiezPlz]

Emperor Palpatine 99% of the stuff in the universe will kill you if you get too close. Doesn't mean it's not pretty to look at.

[@Noxxiie]

Beauty does not equal truth

[@laynegrey2003]

Hey guys: God did it. **grabs popcorn, awaits the arguments**

[@tacticalshrubbery]

Okay, if God created everything, who created God?

[@laynegrey2003]

Trevithan Dæmôn His has always existed. There was no time before He made everything, so even if he wasn't immortal He would've existed.

[@tacticalshrubbery]

Okay, if nothing existed before God, what is he made of?

[@MrCrowbar00]

That makes no sense at all, watch the video again, read Origin of Species , pull your head out of your ass, get some common sense and realize that your god is as real to you as the Roman gods were to them !

[@laynegrey2003]

Alan Ridge you realize I was joking, right? I'm not getting into an argument. Also, Origin of Species describes how creatures evolved into better species. That's called microevolution. Macroevolution is what evolutionists believe. That's like going from a T-Rex to a chicken.

[@EveshkaGhost]

ah man you guys are great! I started with the crash course chemistry to understand atoms more because I was studying space and stuff, but then ended up doing the astronomy etc and now onto this :) It's addictive!

[@pitchscience]

I am absolutely loving this Big History series!!

[@luuchoo93]

Evolution is simply amazing and incredible.

[@kyledolor5257]

Now humans can create and modify life. Initially in a molecular level or small organisms such as mice or fish. Amazing!

[@happymikasa7226]

It's so fascinating, we can even maybe find the solution the world hunger with it!

[@lunacouer]

9:48 Just when I didn't think I could love Crash Course any more, y'all recognized Rosalind Franklin as one of the people that discovered that DNA was the genetic molecule. #SheGotRobbed

[@DavidLindes]

Indeed. Q: What did Watson and Crick discover? A: Rosalind Franklin's notebook. ;) Thank you, Greens, for including her! And Wilkins, I guess... whose name I think I've heard, but hadn't heard as much.

[@StephenRayner]

I love this channel, look forward to becoming a patreon soon.

[@7billion281]

Love your work! Deep gratitude. 🐣

[@andjarrod]

I just came here to read the comments

[@zhiracs]

Didn't we all?

[@colinsmith5123]

You forgot the Michael Jackson picture

[@A.Mayflower127]

1:48 they’ll never be satisfied never be satisfied (Hamilton)

[@mothman84]

I am in *awe* of these videos! I fail to understand your aversion to Aristotle, but that doesn't make your work any less awe-inspiring! If only I'd had these videos growing up, by now I would know much that instead I ignore. Thank you! :)

[@annabeloffenbach8183]

You guys make learning fun again! So thanx John and Hank!!

[@lowearthsurfer]

shhhh the movies about to start (Starts scrolling thru comments)

[@ThatGuyNamedMatthew]

In undergrad my genetics professor made the point that RNA can replicate itself, RNA can mutate, any time DNA is used it has to be transcribed into RNA, RNA binds to other RNA molecules that are attached to amino acids, those amino acids are ordered based on the sequence in the original RNA molecule copied from DNA, those amino acids are then bound together to make the building blocks of cells. He said the best argument for the RNA world hypothesis is that we are still RNA organisms more than we are DNA organisms even 3.5 billion years later.

[@TheRglewis]

Fantastic video guys. It is stunning how the complexity of life and the replication process of DNA occurs and how it evolved. Science is wonderful.

[@simonmandel2621]

Great video. Really educational and fun to watch! Amazing how we all got here.

[@timothymclean]

I'm not convinced that we should be impressed with the fact that life survived several mass extinctions. Life is variable, life is versatile; life finds a way. What's more amazing is that someone who makes a habit of using VR headsets in the bathtub is still alive.

[@tonydavis6151]

At least he practiced honest science and admitted we don't know how it started. I give them credit for that.

[@JillH1995]

Thought Cafe's animations for this series are really great. The script is too, but Emily riding DNA like a roller coaster? Just awesome.

[@derekonlinenow777]

Wow, amazing episode! It actually makes me wonder where we or I am being wrong with things right now.

[@alexweirdyoung]

This has definitely been one of my favorite Crash Course episodes.

[@Mariomario-gt4oy]

"God did it". I love how people will use science for everything, yet they will ignore and go against it when it conflicts with their delusions and indoctrination.

[@ZURATAMA]

"Science did it". I love how people will use god for everything, yet they will ignore and go against it when it conflicts with their delusions and indoctrination.

[@Aeghamedic]

ZURATAMA1324 "God did it" doesn't have much of a track record for being right, though.

[@ZURATAMA]

Aeghamedic I agree.

[@cynic2201]

Ugh, open your mind to other possibilities and sped a good amount of time researching the other possibilities before jumping to god did it

[@Mariomario-gt4oy]

ZURATAMA1324 huh?

[@palvindarchhokar9821]

This series if FREAKING AWESOME!

[@NewJak14]

LOVE this series. Thank you!

[@BryantGilliamOfficial]

"Sex is a huge deal" © Hank Green October 2014

[@27STS]

Are you in the future?

[@BryantGilliamOfficial]

ceebee27sts yes i am but dont tell anyone.... i just changed the date back to 2014 to hide my identity. I am John Titor

[@BryantGilliamOfficial]

ceebee27sts John Titor = Steins Gate anime reference (a stretch for a pun know)

[@Maloolz]

Bryant Gilliam John Titor isnt just a Steins Gate reference. Steins gate was referencing someone who claimed to be from the future back in 2000. en.wikipedia.org/wiki/John_Titor

[@BryantGilliamOfficial]

yea i remember reading about this and totally forgot about it. Thanks for relinking me

[@etremelyinnpropiart6756]

Finally Other Evouloutionists!

[@chrisnguyen1186]

Me here, even though I'm Catholic! : D

[@JGold523]

Don't use that word. That's their word to try and pretend that everyone in the rational world doesn't already accept evolution as scientific fact. You wouldn't say you're a Round-Earther, right?

[@xXep1cMagicsXX]

You mean other people that accept scientific facts over dogma?

[@LatiasDita]

Yes, and I'm also a heliocentrist, a cell theorist, a germ theorist, a gravitationalist, an atomist...

[@greenzoid2]

Lol the only people who even use the term "evolutionist" are young earth creationists and people arguing with young earth creationists.

[@Jellyraptorzz]

I love learning about the world it gives me a better perspective on it, I get really exited to learn about everything. Im a 24 year old male with a dead end job but just because im not in education doesnt mean I should stop I dont think it should matter.

[@ivank5435]

Your videos are very informative and my high school teacher even used a lot of your videos for explaining many of religious fundamentals.

[@Kronecraft]

TARDIGRAAADES

[@squidpizza6320]

TARDIGRAAAAAAAAAAAAAAAAAAAAADES

[@Kronecraft]

Nicholas Cuevas THEY'RE THE MOST WONDERFUL ORGANISMS EVER TO EXIST

[@Kronecraft]

Nicholas Cuevas TTTTTTTTTTTAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRDDDDDDDDDDDDDDDDDDIIIIIIIIIIIIGGGGGGGGGGGGGGRRRRRRRRRRRAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAADDDDDDDDDDDDDDDDEEEEEESSSSSSSSS

[@squidpizza6320]

TAAAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRDDDDDDDDDDDDDDIIIIIIIIIIIIIIIIIIIISSSSSSSSSSSSSS

[@procrastinator99]

SEDARGIDRAT!!=

[@cleodello]

1:54 I'm eating pizza right now.

[@cleodello]

2:51 Still eating pizza.

[@julkkis666]

Cleodel good for thee.

[@cleodello]

***** But alas, I am no longer eating pizza...

[@3Ravens98]

:O

[@amandadube156]

did you pay $1 for it?

[@jenjen94x3]

These videos are sooo good :) can't stop watching

[@richardkoenigsberg4271]

What an amazing series!

[@yasminseow2033]

reading the comment section is more headache-inducing than taking my science quiz on the origin of life.

[@CarolinaRizzotto]

I love all of your videos, they are extremely helpful, but it would make it a lot easier to understand if you spoke a littleeee more slowly!! I keep having to rewind, it's hard to keep up.

[@DustinMillerPolyInnovator]

why don't you just slow down the video in the settings? I like increasing the speed, but you can go half the speed

[@cj-seejay-cj-seejay]

I love the mystical, ambient version of the crashcourse theme music that plays from 5:55 to 6:05. Ooooh, the mysteries of liiiiife.

[@juanantoniovaldirimendez7819]

Thanks a lot, I love your videos.

[@theflamealpha3053]

inb4 someone starts a religion flame war.

[@oldmewtrino]

We don't know all of the details, let's just throw away the scientific method and say god did it.

[@querps1043]

*lits molotov* "did someone say flame war?"

[@theflamealpha3053]

Meow said Da Dog Do you see my name? I'm ready to fight a flame war.

[@querps1043]

Good

[@jrhermosura4600]

Yeah the educated vs the uneducated lol

[@bookerlr1]

I am learning so much from this series. Thank you!

[@valor36az]

Great summary of the topic

[@KitFisto1997]

Awesome Episode :)

[@Kikolyu]

About the undercooked burger thing, I'm already convinced my cousin will kill me.

[@sewingloon6877]

John! Your brother needs to learn the official phrase for reproduction... Scoodleypooping

[@katiehaslam5286]

i love this channel so much

[@chulebam]

"There´s a piece of wood sticking out of me, unpleasant". Hank could be quoted like a thousand times, great videos!

[@amandadube156]

that's what she said. :P

[@goldengameA]

1:06 has a reaper from mass effect on the left :-D

[@1234kalmar]

YEEEEEAY!

[@xelgringoloco2]

Reapers: We heard that you were going to build synthetics that would kill you, so we, the synthetics are going to kill you so that synthetics can't kill you.

[@1234kalmar]

xEl Gringo Loco Xzibit meme anyone :D

[@GopherTheNuts]

Ok...... 2:17 - 2:41 ......how many takes did that require, guys? I'm guessing you could make an entire blooper video out of it lol :)

[@talitasampaio3855]

Amazing! Funny and smart! Thank you!

[@atchph]

this is my new favorite crash course :D

[@sebMelgarejo]

"(...) next time you have a bad day remember that it is amazing that you are alive at all much less a member of the self aware species living at the height of human technological progress (,,,)" Crash Course team, 2014.

[@foo335]

How to start an argument on youtube: Post a comment

[@prohz9129]

And wait for a reply.

[@PinkChucky15]

Awesome video! :-)

[@johnmastroligulano7401]

Great show thanks gentlemen.

[@tylerasnow]

lol my cousin gave me food poisoning!

[@shadowzabyss]

+Tyler Snow Family feud... lol

[@gmosphere]

What's that thing by the lightbulb on hanks desk?

[@thebigitchy]

It's called a Crookes radiometer, and it spins in reaction to visible and infrared light.

[@amandadube156]

your mom. :P

[@gelatinocyte6270]

@@amandadube156 Wrong! It's *my* mom

[@jacodjaison909]

i love this channel

[@bambilawl27]

I appreciate this :)

[@SinisterSi718113]

So what you're saying is, that life is one big game of telephone?

[@Monteskills]

2:00 "Doing their thing in nature"??? The right word, mister, is scoodlypoopin? (spelling may be not accurate)

[@MrDjuk24]

You guys are AWESOME!

[@MJFAN666]

nice back to back. 2 really smart brothers. what a great pair.

[@negary666]

Is this Hank Green’s brother???