My astronomy professor used to explain the expansion of space this way: imagine you're baking a blueberry muffin. When you add the batter with the blueberries in the cupcake liners, the blueberries are in certain places. After baking, because the batter has cooked and expanded, the blueberries have also moved with it, but only because the batter took them along for the ride.
+Ray Majka Hmm, asking the tough questions are we? Haha, I think they'd still have shifted, and in all seriousness, it's not the best example, but it gets the message across to younger viewers especially. It's actually how I explained it to my younger sister while we were watching this.
@@leodrps if you draw dots on a balloon and blow the balloon up you can see this effect. All objects move away from one another, objects already further from each other move even further at faster rate from each other
@@adampickard9880 It's been three years since I posted this comment, I had completely forgotten about it, but I was actually explaining this exact thing to a friend yesterday who was under the impression that planets were expanding along with spacetime. He compared it to a T-shirt with a design on it, and I told him if the T-shirt was the fabric of space time, then the objects in it were like physical objects lying on top of the shirt. This is a much better example though, so I'm going to text him it. Thank you!
The thing that I love most about crash course hosts is that they are all passionate about the subject they are imparting knowledge on. They have the twinkle in their eyes and the spark in their words telling us how awesome all of *this* is.
aperson22222 That's not totally true, we don't know for certain wether or not the Earth will survive the Sun's first Red-giant phase, there are 4 possible scenarios, 1 - The worst: We spiral in towards the Sun and get fried like Venus and mercury, Earth and life on it are lost 2 - The most likely: We kinda go in but we don't, all life on Earth is lost but Earth remains. 3 - The happiest: The Sun's wind push us away from it faster than it burns us, some forms of Life survive and Earth itself is the luckiest planet of the inner solar system. 4 - We are still arround and we save ourselfs: We move the Earth away from the Sun in a way that stay on the Goldelock Zone and thus we keep everything on Earth safe, and after the sun is about dead we put Earth the closest when can without being destroyed by it's Roche limit and becoming a ring, but the Sun will still be too cold, so we'll need another source of energy. I hope for 4 but if we're all dead by then then of course i hope for 3 as lanother intelligent life from may come after us
+Altarya DeFlammes 5) (extreme) we colonize several extraterrestrial planets and throw a party like its 1999, but today I'm throwing a party like its year 13,999,999,999! :D
YEEESSS! (claps) I was literally about to write something about "HMMM, interesting that the episode about the origin of the universe is number *42* ...! ;)" but you beat me to it. By three years. Ah, that's what I get for not even knowing about Crash Course until fairly recently. :P
The Universe has no beginning. It is infinite. It had no beginning and it will have no end. The Universe has no maximum size. It is infinite. There is no center to it and it has no outer boundary.
Hi, I love how you explain how science is fluid and sometimes you have to break the entire framework. It supports the growth mindset for students. Thank you for sharing these wonderful videos.
From a novice point of view these lessons are amazing even though they can start to get confusing as I go along.once complete I will start from the beginning again
+Lornext I came down here to agree with this very thought, given the presumed ridiculous length of time the universe should exist, we are SOOO near the start of it all.. almost makes me a believer of the 1st runners solution to the fermi paradox
+Lornext That's what make me think that we may be one of the first intelligent species in the universe. If you think about it, the first several billion years it was just hydrogen. It took entire star life cycles to seed the universe with elements required for life. Not saying we're the only ones out there, but we could be the first wave of life. Don't know about you guys, but that makes me feel a bit less meaningless in the grand scheme of things. We are the universe discovering itself!
I love these crash courses. I have been using them to get my husband up to speed. He used to think the Big Bang was how the dinosaurs died. Now our dates consist of stargazing through or telescopes. The structure of crash courses allow me to show him one thing at a time. We love it
Thinking about what was anything before the Big Bang and what will happen in the future breaks my mind. Was there anything before the Big Bang? Was there another universe with different laws of physics? Will our universe just end? Is it like a giant heart that is pulsating and we're just in the expanding portion? Will the universe contract and recreate the Big Bang? It's too much for me to fathom. But these questions are what make me feel alive. And glad to live in the universe we live in today. Thank you, for another great video!
+Ricardo Berrios (c0mrade) I wish more people engaged in discussing questions like this instead of spending their time in pointless youtube arguments. Regarding your questions, I think the problem lies in how ignorant we are of the universe. We are born blind, with no inner knowledge of the world other than our individuality. So this leads to considering all possibilities in the search of knowledge. Right know we can only really speculate since there is no solid evidence to hang on. As far as we know the question itself may outlast our species. Another reason is the scale of the universe. We don't really know what the tiniest thing is nor what the biggest is. Maybe what we call universe is just an atom inside another one, or maybe is our universe which holds an infinite number of them. That is just two of the thousands of possibilities, so you can see is no easy task to answer them. Despite all that uncertainty, like you said, it is thanks to these questions that life is worth living.
+Ricardo Berrios (c0mrade) What's really fun is that this universe used to have "different" laws of physics. A long long time ago the forces were all one, then as the energy density of the universe decreased gravity split, then the strong force, then the electroweak force decayed to the weak and electromagnetic force. Isn't physics fun?
Thanks for the explanation on Hubble's law. I just learned about it in class. You really helped clear up confusion I had by distinguishing the fact that "Galaxies aren't actually moving away, rather the space between them is expanding, hence Hubble's law".
it makes me sad that give or take only around 1 million people are interested enough to watch this series :/ out of 7+ billion. clear skies! and keep looking up!
I agree with the theory, but I still have a question. If all observable galaxies are moving away from us, then what about the Andromeda Galaxy? Isn't it suppose to collide with us, i.e. Coming closer to us?
+Radha Desai Both the Andromeda and the Milky Way galaxies are moving away from the point of the big bang, but it's not quite that we're moving away from a single point, it's that the space between stars and galaxies, the vacuum, is stretching. If you got some stretchy rubber sheet, and you poked two holes in it, then pulled it taught, the holes would move further apart, it's like that. The relative velocities of the galaxies are most likely the result of their gravity and the gravity of dark matter which we observe to have major effects on gravity (as explained in the last CCA video), so galaxies' gravitation towards one another is pretty much a separate subject from the big bang.
bryce Well, relatively we are moving towards each other. Catching up implies that the galaxies are actually moving away from a single point. The universe is not a 3D shape (as we understand it) and the galaxies are not really moving in the way that we're familiar with. The space between them is expanding, the galaxies themselves are not really 'moving'.
the only video that actually explains why further away objects move faster....... that ruller example of expanding space is the most wonderful i have ever layed my eyes on. Thank you.
The expansion of the universe also explains Olbers' Paradox, because if the universe were infinite and static, the night sky would be bright because no matter which point you look at would end in a star.
+Caleb Limb He explained how the galaxies all spread apart away from you, no matter where you are. The rate is directly proportional to the distance from you. This basically shows that EVERY point in the universe is the center of the universe. We don't know if the universe is infinitely large, but if we assume it is, then you can imagine the universe is infinitely large now, and was infinitely large at the instant of the big bang. At the instant just before the big bang (which doesn't exist, because 'time' was created along with space during the big bang, but let's pretend it did exist) the volume of the universe would be 0. From nothing, to everything.
+Caleb Limb that makes me wonder, is their any creature that sees in the microwave spectrum? they might actually be able to see the background radiation. That would be a cool experience
+Caleb Limb I dont think so. This paradox doesn't seem like a paradox to me at all. There would be infinitely many visible stars but most of them would also be infinitely far away. So the number of photons that would reach your eyes would be close to zero per second which is not enough to be able to see any light. There would be a star in every direction but you would be able to see all of them only with a camera with infinite exposure time. There is no paradox.
+Port Kapul 3 possibilities: 1. The background radiation is stronger than the radiation from the objects it needs to see - it would never evolve because it would be blinded by it and couldn't focus on anything important - this vision would be useless. 2. The background radiation is much weaker than the radiation from the objects it needs to see - it wouldn't notice it 3. The background radiation is about the same intensity than the radiation from the objects it needs to see - their brains would probably filter out these random signals so they could focus on the important things like we don't notice the floaters in our eyes most of the time
+rrozinak They would indeed be infinitely far away, but that's not a problem if the universe has been around for an infinite amount of time, as the old model proposed. You would still see all the light from all the stars in the endless entirety of the universe.
Just because human minds are bound by principles with limits, beginnings and ends, doesn't mean that just because you don't understand or can't comprehend a scientific concept that it is not true. Our minds are a product of this universe, it in no way has to be easily understandable.
How can there not be a cosmic center if the expansion started from a point? Does the cosmos not spin? I would imagine it does like most of everything else. Is the Hercules-Corona Borealis Great Wall orbiting the cosmic center? I really need help with these questions! Love the show more with each video
Tomi Odinson Ah, you’re thinking only in terms of physical space. It’s hard to wrap your head around, and it took me some time too...but think of it this way: spacetime is a curved, flat plane. That plane is on the surface of a balloon. The balloon is being blown up. The coordinate system itself is expanding from no discernible origin point, because the Big Bang didn’t just create physical space. It created time and the coordinate system itself.
One of my favorite things is that Georges Lemaître was a Catholic priest. Just goes to show that you can be religious and still study and believe science.
One thing I've never understood (and I'd appreciate an explanation greatly!) is how every galaxy is apparently getting further apart from every other galaxy, yet galaxies can collide (such as Andromeda and the Milky Way will in 4 billion years or so). These two statements seem to conflict, anyone help me out?
+Halal Burger It's answered a few comments below :) "The expansion of the universe is at a velocity proportional to the distance two objects are from each other. So if two galaxies are close enough, they will not "expand" away from each other quick enough to escape gravity."
+Halal Burger I had the exact same question when I was in cosmology class so you're not alone. Prochors Raudh is correct, but if it's a little vague, I can try and elaborate a bit. He or she is eluding to the fact that there are two forces constantly in a tug of war throughout the universe; gravity (contraction) and expansion (repulsion). Things are typically either moving away or getting closer together. The Sun, for example, is in a balance with these two forces for billions of years when the outward pressure of the sun doesn't allow gravity to push in and collapse the Sun. Eventually, the sun will stop producing the energy necessary to win the battle and our sun will become a white dwarf and spend trillions of years cooling off like a hot ember. In the case of the galaxies colliding, the gravitational pull between the galaxies is greater than the expansion rate of our universe. Imagine you're just about to go over the edge of a waterfall and someone is there to grab your arm and pull you to safety. That energy to counteract the flow of water at that distance is quite small in comparison to trying to pull you up from 300 feet down the waterfall. The further away you are, the more energy it would take to bring you back. So, the hand of Andromeda is close enough to pull towards the Milky Way because of it's relative close approximation. On another note, don't worry about our planets drifting apart and being lightyears away either because, once again, the relative distances between planets are far too small to notice a significant effect from the expansion of space.
+Halal Burger As stated, gravity. Like the video showed the expansion effect gets weaker as two galaxies move closer, whereas gravity gets stronger as they move closer. At short (on a universal scale) distances the force of gravity pulls them together faster than the expansion of the universe sends them apart.
+Halal Burger He kind of lied when he said the galaxies are standing still. They actually are moving, due to gravity. Gravity falls off as 1/r^2, but the cosmos expands linearly. Therefore when galaxies are close enough, gravity dominates and they cluster together and collide, but for galaxies that are far apart, universal expansion dominates and they are accelerated away from each other.
You guys should discuss "Heat Death" and other theories like the one that talks about cycles of the universe expanding and contracting, I think its called "The Big Bump" or something like that.
I used to get sleepy or distracted easily with Phil's lectures. Now, he is enthralling! I wonder what was the biggest reason for that change? Practice? Training? More passion? Am I getting older and more tolerant? lol
Not as many religiously/politically charged arguments in the comments as I was expecting. Good on you internet, for not confusing philosophy and science.
When we contemplate the origins of the universe, is this not a philosophical exercise? Where does a scientific hypothesis come from? Doesn't it start as a hunch?
@Larry Cavalli Really. It all can be proved? Show me the experiment that proves the earth spins. A proper scientific experiment. Need the obsrevation, the hypothesis for earth spinning, and the the experiment with a independent and dependent variable? Now do the same for gravity, and being able to have gas pressure without a container. Show the scientific experiments and proof for those. These are the most basic of basic that need to be proven before running off into thing like black holes etc..
The contents of this comment section: 1) Interesting, thoughtful comments by people who are interested by this topic 2) Intelligent questions from people who want to know more or know that they're having trouble understanding a concept and want someone to clarify it for them 3) People who don't understand the concepts being discussed, conclude that because they don't get it it means that it's wrong and God must be the answer 4) People who don't get that the words and explanations used to explain the Big Bang to non-physicists are metaphors and abstractions to explain the core concepts of math and empirical observations that people far smarter than them have spent decades working on and analyzing, and take them literally, concluding that because the literal phrasing doesn't make sense it must be wrong, so God must be the answer. Almost as if they're used to taking everything told to them at face value. 5) People using selective and confirmation bias to pick select passages from the Quran as evidence that it predicted modern physics
+Sir Dusky You forgot one. 6) Anti-theists childishly making a home run over the first twenty seconds despite that not being what the video is really about.
this is why i love internet, i was on a holiday for one week and i love cosmos since i was a little kid in this week i got a change to learn way too many thing and i find out that i was misleaded all this years about space kinda find out that 90% of the things that i thought i knew was no more than rumor, thanks for educating us by amezing videos
Here is a quick question: If Galaxies are not moving on their and are red shifting as the universe expands, then why is Andromeda galaxy(Meesier 31) moving towards us?
That's because its within our galactic neighborhood. In this neighborhood, the gravitational attraction of the local galaxies is still strong enough to beat out dark energies' pull in all directions. Eventually, the furthest galaxies to us will surpass the observable universe's bubble, and essentially cease existing to us. Our local cluster will remain together. One theory though, is that dark energy will win over all laws holding matter together, eventually even separating stars, planets themselves, everything down to all atoms bonded together. Tear them apart into their smallest unit to fill the ever expanding void that is the universe. Never to meet again to be recycled into different configurations of matter.
+nicholas andrzejkiewicz 42. Flying Spaghetti Monster. Why is it called the Big Bang? How can the universe be expanding if galaxies collide? 42. Flying Spaghetti Monster. Why is it called the Big Bang? How can the universe be expanding if galaxies collide? 42. Flying Spaghetti Monster. Why is it called the Big Bang? How can the universe be expanding if galaxies collide? . . . like this?
At 9:07, he made a huge generalization. My uncle is a creationist astronomer. I asked him what his community thinks. it's a group of about 200 or so astronomers and almost all agree with him.
I never completely really understood how the whole universe is expanding but that rubber ruler example cleared a lot of things up and made a lot of sense, it's not that the universe is expanding into something but space itself is expanding. Mind Blown.
I recently had a thought. So, we know the universe is expanding, but we really don't know why. All we can say when asked "Why is the universe expanding" is because of dark energy. "What's dark energy?" The term we came up for to answer why the universe is expanding. In reality, we just don't know. That's where my hypothesis comes in. (Well, not really a hypothesis, more like a guess). Is it possible that space is expanding from a high concentration of matter to a low concentration of matter, sort of like how air flows from areas of high pressure to areas of low pressure to cause wind? Is this within the realms of plausibility? Posting this on every episode so it gets noticed!!!
***** No not really, because from our perspective it would still look like everything is moving away from us. My comment was a bit tongue in cheek, really, because these two statements are equivalent. We'd need some sort of reference frame outside the universe to tell a difference! Still, a fun thing to think about :)
kris860 From our perspective nothing changes. It's a bit like saying that zooming into a photograph is the same as making the paper bigger, if that helps.
I dont want to argue with anyone but i found this mind blowing when the quran states "Have those who disbelieved not considered that the heavens and the earth were a joined entity, then We separated them, and made from water every living thing? Then will they not believe?” (Quran 21:30) And "Have those who disbelieved not considered that the heavens and the earth were a joined entity, then We separated them, and made from water every living thing? Then will they not believe?” (Quran 21:30) Agreeing with the big bang theory
OK, Phil, I dare you to convince me that you chose this number for the series' first episode that's about cosmology = the universe & everything, purely by chance!
I think black holes are creating big bangs. All that matter tearing a hole in space and time creating other universes like ours. That matter has to go somewhere and can't actually be destroyed, just turned into something else.
+Michael Dow I may be wrong, but isn't a black hole not *destroying* the matter, but absorbing it and getting bigger? If so, why would the matter need to go somewhere else?
+Mighty Roogna - Did I even mention politics? No. I merely made a statement. I made no offers as to how intelligent I am or am not, nor did I do it for "attention" as you seem to be so adamant about. Again I merely made a statement. Also I am not American, so kind of hard for me to a "democrat" but you go on thinking whatever you like dead certain that you're correct about someone because of one little comment they made on a youtube video, if anything it's kind of entertaining.
+Joe M - My apologies, you're correct! Hmmmm how to make a similarly horrible statement without insulting rocks.... I will have to get back to you on that one.
Donald Weber Well of course they can. I think what people mean when they say this is that a belief in the literal interpretation of religious texts such as the Bible and Qu'ran can't coexist with a belief in science, which is true.
That's the thing about much scientific knowledge we have today. It started off as theists setting out to prove their beliefs and ultimately stumbling into scientific knowledge. One example is when theists (Can't remember names so feel free to look this up to fact check) Tried to prove the great flood in the bible but instead created geology due to their observations.
I find it endlessly fascinating that regardless of whether we can understand something, the math can still bear it out. It offers hope that one day we will.
So it explains why I keep getting fatter and fatter. I'm just expanding. Thank you, Crash Course!
Ivan Chagas That is so funny!!!🤣🤣🤣
I am the center of my observable universe.
+Ryner
So am I...
+Ryner
NO WAY!!! Me too! :D
No, I am. The universe literally revolves around me!
mine is too big. i found idiots.
+Ryner I found out that I usually end up wherever I am going.
I love that Episode 42 is, infact, the meaning of life.. The Universe.. Everything.
My astronomy professor used to explain the expansion of space this way: imagine you're baking a blueberry muffin. When you add the batter with the blueberries in the cupcake liners, the blueberries are in certain places. After baking, because the batter has cooked and expanded, the blueberries have also moved with it, but only because the batter took them along for the ride.
+Leonor Diaz Does that work with Chocolate Chip Cookies, or is the melting effect a problem?
+Ray Majka Hmm, asking the tough questions are we? Haha, I think they'd still have shifted, and in all seriousness, it's not the best example, but it gets the message across to younger viewers especially. It's actually how I explained it to my younger sister while we were watching this.
@@leodrps if you draw dots on a balloon and blow the balloon up you can see this effect. All objects move away from one another, objects already further from each other move even further at faster rate from each other
@@adampickard9880 It's been three years since I posted this comment, I had completely forgotten about it, but I was actually explaining this exact thing to a friend yesterday who was under the impression that planets were expanding along with spacetime. He compared it to a T-shirt with a design on it, and I told him if the T-shirt was the fabric of space time, then the objects in it were like physical objects lying on top of the shirt. This is a much better example though, so I'm going to text him it. Thank you!
Oh my god that makes so much more sense
The thing that I love most about crash course hosts is that they are all passionate about the subject they are imparting knowledge on. They have the twinkle in their eyes and the spark in their words telling us how awesome all of *this* is.
This series is a great review and comprehension source for taking astronomy 101-102. Thanks, guys. (Got an A.)
We'll have to throw a big party when the universe turns 14 billion.
If we're still around as a species (doubtful).
+bryce We can allways hope to become the big sci-fi lords/mistress we've dreamt of
bryce The sun will still be around at that point, so there's no reason that Earth _can't_ be habitable.
aperson22222 That's not totally true, we don't know for certain wether or not the Earth will survive the Sun's first Red-giant phase, there are 4 possible scenarios,
1 - The worst: We spiral in towards the Sun and get fried like Venus and mercury, Earth and life on it are lost
2 - The most likely: We kinda go in but we don't, all life on Earth is lost but Earth remains.
3 - The happiest: The Sun's wind push us away from it faster than it burns us, some forms of Life survive and Earth itself is the luckiest planet of the inner solar system.
4 - We are still arround and we save ourselfs: We move the Earth away from the Sun in a way that stay on the Goldelock Zone and thus we keep everything on Earth safe, and after the sun is about dead we put Earth the closest when can without being destroyed by it's Roche limit and becoming a ring, but the Sun will still be too cold, so we'll need another source of energy.
I hope for 4 but if we're all dead by then then of course i hope for 3 as lanother intelligent life from may come after us
+Altarya DeFlammes 5) (extreme) we colonize several extraterrestrial planets and throw a party like its 1999, but today I'm throwing a party like its year 13,999,999,999! :D
In the beginning the Universe was created.
This has made a lot of people very angry and been widely regarded as a bad move.
great book and a surprisingly wonderful movie.
YEEESSS! (claps)
I was literally about to write something about "HMMM, interesting that the episode about the origin of the universe is number *42* ...! ;)" but you beat me to it. By three years. Ah, that's what I get for not even knowing about Crash Course until fairly recently. :P
Don’t panic you guys.
The Universe has no beginning. It is infinite. It had no beginning and it will have no end. The Universe has no maximum size. It is infinite. There is no center to it and it has no outer boundary.
Hi, I love how you explain how science is fluid and sometimes you have to break the entire framework. It supports the growth mindset for students. Thank you for sharing these wonderful videos.
From a novice point of view these lessons are amazing even though they can start to get confusing as I go along.once complete I will start from the beginning again
Only three times older than the earth doesn't really sound that old when you think about it.
yeah that's what I thought
+Lornext I came down here to agree with this very thought, given the presumed ridiculous length of time the universe should exist, we are SOOO near the start of it all.. almost makes me a believer of the 1st runners solution to the fermi paradox
+Lornext It is actually very, very young.
+Twitchi maybe the planet, but not "we"
+Lornext That's what make me think that we may be one of the first intelligent species in the universe. If you think about it, the first several billion years it was just hydrogen. It took entire star life cycles to seed the universe with elements required for life. Not saying we're the only ones out there, but we could be the first wave of life. Don't know about you guys, but that makes me feel a bit less meaningless in the grand scheme of things. We are the universe discovering itself!
I love these crash courses. I have been using them to get my husband up to speed. He used to think the Big Bang was how the dinosaurs died. Now our dates consist of stargazing through or telescopes. The structure of crash courses allow me to show him one thing at a time. We love it
Revisiting for my tiktok, this is such a surreal trip thru time and space. A feat of man to understand this!!! Don't forget that!!!
"What else would we call the Big Bang?" Well, in the words of Calvin from Calvin and Hobbes, I believe "The Horrendous Space Kablooie" would fit well.
+Koceta GM YEEEESSSS that is perfect xD
I agree with you Koceta GM
It was a "crufuffle as such". I got that from a British sitcom.
Clever Catchphrase "Lord Calvin"
I love Calvin and Hobbes! Lol
1:32 - Thanks for giving the FSM a cameo in the video. I also would have accepted Russell's Teapot or the Invisible Pink Unicorn as substitutes.
Holy shit, a poke at religion at the beginning and then the Flying Spaghetti Monster like a minute in. Phil just became my new idol
spaghetti monster is always the best religion.
Always that one damn person...
+EvilNeon
I like odin, zeus and the sun myself.
+daniel117100 but is it really a poke at religion or is it a poke at folklore?
+daniel117100 Wasn't really a poke at religion, just the truth about religion.
0:11 I'm more surprised that there were perfectly cut wedges of cheese back in neanderthal days.
Thinking about what was anything before the Big Bang and what will happen in the future breaks my mind.
Was there anything before the Big Bang?
Was there another universe with different laws of physics?
Will our universe just end?
Is it like a giant heart that is pulsating and we're just in the expanding portion?
Will the universe contract and recreate the Big Bang?
It's too much for me to fathom.
But these questions are what make me feel alive. And glad to live in the universe we live in today.
Thank you, for another great video!
+Ricardo Berrios (c0mrade) I wish more people engaged in discussing questions like this instead of spending their time in pointless youtube arguments.
Regarding your questions, I think the problem lies in how ignorant we are of the universe. We are born blind, with no inner knowledge of the world other than our individuality. So this leads to considering all possibilities in the search of knowledge. Right know we can only really speculate since there is no solid evidence to hang on. As far as we know the question itself may outlast our species. Another reason is the scale of the universe. We don't really know what the tiniest thing is nor what the biggest is. Maybe what we call universe is just an atom inside another one, or maybe is our universe which holds an infinite number of them. That is just two of the thousands of possibilities, so you can see is no easy task to answer them.
Despite all that uncertainty, like you said, it is thanks to these questions that life is worth living.
+Ricardo Berrios (c0mrade) What's really fun is that this universe used to have "different" laws of physics. A long long time ago the forces were all one, then as the energy density of the universe decreased gravity split, then the strong force, then the electroweak force decayed to the weak and electromagnetic force. Isn't physics fun?
Praise the Sun, they included the Great Spaghetti Monster!
Indeed
That was an AWESOME episode! Thanks, Phil.
> Episode 42, The Big Bang
You guys did that on purpose.
How? Can you explain why is ep 42 related to big bang
@@phenomenalphysics3548 42 is the answer to THE question of the universe the answer to life, the universe, everything.
@@FranBunnyFFXII ohhk but how??! I'm confused totally😵
@@phenomenalphysics3548It's from The Hitchhikers Guide To the Galaxy
@@FranBunnyFFXII what is it?
this playlist just blows me away! love your work guys. keep up the great work.
Thanks for the explanation on Hubble's law. I just learned about it in class. You really helped clear up confusion I had by distinguishing the fact that "Galaxies aren't actually moving away, rather the space between them is expanding, hence Hubble's law".
Please continue making Crash Course videos for as long as you can. You're my favorite speaker and writer.
Waiiiiiiiiiit
GUUUUUYS!
We've finished astronomy...WE'RE ONTO CRASH COURSE COSMOLOGY!!!
Congrats!
To see Vesto Slipher's original spectra here is quite exciting--it makes what Phil is talking about more real.
So excited for this!!
All hail to the Flying Spaghetti Monster!
+the flying spaghetti monster Is Cthulhu your son, my noodley lord?
+Dan Turman Bless his noodly appendage
The Mantis yes i birthed atop the past pot on high
R'amen
***** the pasta is the sacred fruit of the gods! Only the good and just may feast on it
it makes me sad that give or take only around 1 million people are interested enough to watch this series :/ out of 7+ billion. clear skies! and keep looking up!
and the series gets better each episode. brilliant.
I agree with the theory, but I still have a question. If all observable galaxies are moving away from us, then what about the Andromeda Galaxy? Isn't it suppose to collide with us, i.e. Coming closer to us?
+Radha Desai Maybe some are moving quicker than others for some reason.
+Radha Desai Things move away from us faster the farther away they are from us. At that "short" of a distance it is able to overcome expansion.
+Radha Desai Both the Andromeda and the Milky Way galaxies are moving away from the point of the big bang, but it's not quite that we're moving away from a single point, it's that the space between stars and galaxies, the vacuum, is stretching. If you got some stretchy rubber sheet, and you poked two holes in it, then pulled it taught, the holes would move further apart, it's like that. The relative velocities of the galaxies are most likely the result of their gravity and the gravity of dark matter which we observe to have major effects on gravity (as explained in the last CCA video), so galaxies' gravitation towards one another is pretty much a separate subject from the big bang.
We aren't moving towards each other, we are just sort of... Catching up to each other.
bryce Well, relatively we are moving towards each other. Catching up implies that the galaxies are actually moving away from a single point. The universe is not a 3D shape (as we understand it) and the galaxies are not really moving in the way that we're familiar with. The space between them is expanding, the galaxies themselves are not really 'moving'.
2:14 Vesto Slipher sounds like the name of a bounty hunter from a galaxy far far away. How is that a real name?
I can totally see a high school teacher showing this video to his students 100 years from now, and they are all laughing at our ignorance.
Oh dear, lol.
and our wisdom , to not destroy our selfs
Nah it would be more like us looking back at people like Galileo, And others
Phil, you produce some of the best knowledge-videos there is. Thank you.
the only video that actually explains why further away objects move faster....... that ruller example of expanding space is the most wonderful i have ever layed my eyes on. Thank you.
The expansion of the universe also explains Olbers' Paradox, because if the universe were infinite and static, the night sky would be bright because no matter which point you look at would end in a star.
+Caleb Limb He explained how the galaxies all spread apart away from you, no matter where you are. The rate is directly proportional to the distance from you.
This basically shows that EVERY point in the universe is the center of the universe. We don't know if the universe is infinitely large, but if we assume it is, then you can imagine the universe is infinitely large now, and was infinitely large at the instant of the big bang. At the instant just before the big bang (which doesn't exist, because 'time' was created along with space during the big bang, but let's pretend it did exist) the volume of the universe would be 0. From nothing, to everything.
+Caleb Limb that makes me wonder, is their any creature that sees in the microwave spectrum? they might actually be able to see the background radiation. That would be a cool experience
+Caleb Limb
I dont think so. This paradox doesn't seem like a paradox to me at all. There would be infinitely many visible stars but most of them would also be infinitely far away. So the number of photons that would reach your eyes would be close to zero per second which is not enough to be able to see any light. There would be a star in every direction but you would be able to see all of them only with a camera with infinite exposure time. There is no paradox.
+Port Kapul
3 possibilities:
1. The background radiation is stronger than the radiation from the objects it needs to see - it would never evolve because it would be blinded by it and couldn't focus on anything important - this vision would be useless.
2. The background radiation is much weaker than the radiation from the objects it needs to see - it wouldn't notice it
3. The background radiation is about the same intensity than the radiation from the objects it needs to see - their brains would probably filter out these random signals so they could focus on the important things like we don't notice the floaters in our eyes most of the time
+rrozinak They would indeed be infinitely far away, but that's not a problem if the universe has been around for an infinite amount of time, as the old model proposed. You would still see all the light from all the stars in the endless entirety of the universe.
I'm going to be so sad when this series ends.
Just because human minds are bound by principles with limits, beginnings and ends, doesn't mean that just because you don't understand or can't comprehend a scientific concept that it is not true. Our minds are a product of this universe, it in no way has to be easily understandable.
you are Super great Cosmic teacher
LOVE WATCHING THESE VIDEOS. KEEP MAKING THEM!
How can there not be a cosmic center if the expansion started from a point? Does the cosmos not spin? I would imagine it does like most of everything else. Is the Hercules-Corona Borealis Great Wall orbiting the cosmic center? I really need help with these questions! Love the show more with each video
Tomi Odinson Ah, you’re thinking only in terms of physical space. It’s hard to wrap your head around, and it took me some time too...but think of it this way: spacetime is a curved, flat plane. That plane is on the surface of a balloon. The balloon is being blown up. The coordinate system itself is expanding from no discernible origin point, because the Big Bang didn’t just create physical space. It created time and the coordinate system itself.
How do you define a point when there is not universe as an immediate reference?
@@rollingkneebar3534
Space time is a conceptual medium.
It has no basis in reality.
Can you show me spacetime?
Where is it?
One of my favorite things is that Georges Lemaître was a Catholic priest. Just goes to show that you can be religious and still study and believe science.
One thing I've never understood (and I'd appreciate an explanation greatly!) is how every galaxy is apparently getting further apart from every other galaxy, yet galaxies can collide (such as Andromeda and the Milky Way will in 4 billion years or so). These two statements seem to conflict, anyone help me out?
+Halal Burger Gravity. And because the expansion is in greater effect over larger distances.
+Halal Burger It's answered a few comments below :)
"The expansion of the universe is at a velocity proportional to the distance two objects are from each other. So if two galaxies are close enough, they will not "expand" away from each other quick enough to escape gravity."
+Halal Burger I had the exact same question when I was in cosmology class so you're not alone. Prochors Raudh is correct, but if it's a little vague, I can try and elaborate a bit. He or she is eluding to the fact that there are two forces constantly in a tug of war throughout the universe; gravity (contraction) and expansion (repulsion). Things are typically either moving away or getting closer together. The Sun, for example, is in a balance with these two forces for billions of years when the outward pressure of the sun doesn't allow gravity to push in and collapse the Sun. Eventually, the sun will stop producing the energy necessary to win the battle and our sun will become a white dwarf and spend trillions of years cooling off like a hot ember. In the case of the galaxies colliding, the gravitational pull between the galaxies is greater than the expansion rate of our universe. Imagine you're just about to go over the edge of a waterfall and someone is there to grab your arm and pull you to safety. That energy to counteract the flow of water at that distance is quite small in comparison to trying to pull you up from 300 feet down the waterfall. The further away you are, the more energy it would take to bring you back. So, the hand of Andromeda is close enough to pull towards the Milky Way because of it's relative close approximation. On another note, don't worry about our planets drifting apart and being lightyears away either because, once again, the relative distances between planets are far too small to notice a significant effect from the expansion of space.
+Halal Burger
As stated, gravity. Like the video showed the expansion effect gets weaker as two galaxies move closer, whereas gravity gets stronger as they move closer. At short (on a universal scale) distances the force of gravity pulls them together faster than the expansion of the universe sends them apart.
+Halal Burger He kind of lied when he said the galaxies are standing still. They actually are moving, due to gravity. Gravity falls off as 1/r^2, but the cosmos expands linearly. Therefore when galaxies are close enough, gravity dominates and they cluster together and collide, but for galaxies that are far apart, universal expansion dominates and they are accelerated away from each other.
I always enjoy these videos. Keep it up Crash Course. :)
wohow...! that ruler thing was a bummer!! now the big bang theory makes sense
I find the episode number for this episode very apt.
You guys should discuss "Heat Death" and other theories like the one that talks about cycles of the universe expanding and contracting, I think its called "The Big Bump" or something like that.
Oh, almost forgot "The Big Rip"
+Ryner Big Bang, Big Crunch, Big Bounce (what you're referring to), and Big Rip. Oh, and Big Freeze. That's all the Big's there are.
Question: if space expands, and spacetime is a single thing, does time also expands with space since the Big Bang?
I used to get sleepy or distracted easily with Phil's lectures. Now, he is enthralling! I wonder what was the biggest reason for that change? Practice? Training? More passion? Am I getting older and more tolerant? lol
Great job. Clear articulation and a great summary of facts with excellent vocab, graphics and expression.
Not as many religiously/politically charged arguments in the comments as I was expecting. Good on you internet, for not confusing philosophy and science.
When we contemplate the origins of the universe, is this not a philosophical exercise? Where does a scientific hypothesis come from? Doesn't it start as a hunch?
You forget, many of us believe in science, we just believe God is the ultimate Chemist
You are actually wrong.
This info is all philosophy.
It's the world view of the people who came up with it.
It's all theoretical.
@Larry Cavalli
Really.
It all can be proved?
Show me the experiment that proves the earth spins.
A proper scientific experiment.
Need the obsrevation, the hypothesis for earth spinning, and the the experiment with a independent and dependent variable?
Now do the same for gravity, and being able to have gas pressure without a container.
Show the scientific experiments and proof for those.
These are the most basic of basic that need to be proven before running off into thing like black holes etc..
@Larry Cavalli
Gas pressure.
You said nothing.
Dropping something is not a scientific experiment.
Go find them
Flying spaghetti Monster!
-Ramen
R'amen
He boiled for our sins🙏
+Go Shrills old meme is old
+Adrian Fahrenheit how dare you call my religion a meme.
bryce so dank
It all started with a Big Bang....
Bang!
Phil is such an amazing host! His enthusiasm is contagious and the script was so well written!
hope u never stop making theese episodes! :D
This makes me feel small, insignificant and skeptic about my whole existence
Can you please make a video on multiverse ???
The contents of this comment section:
1) Interesting, thoughtful comments by people who are interested by this topic
2) Intelligent questions from people who want to know more or know that they're having trouble understanding a concept and want someone to clarify it for them
3) People who don't understand the concepts being discussed, conclude that because they don't get it it means that it's wrong and God must be the answer
4) People who don't get that the words and explanations used to explain the Big Bang to non-physicists are metaphors and abstractions to explain the core concepts of math and empirical observations that people far smarter than them have spent decades working on and analyzing, and take them literally, concluding that because the literal phrasing doesn't make sense it must be wrong, so God must be the answer. Almost as if they're used to taking everything told to them at face value.
5) People using selective and confirmation bias to pick select passages from the Quran as evidence that it predicted modern physics
+Sir Dusky UA-cam comments are the worst. And that's why I love them. They confirm my bias that most of humanity is comprised of incompetent morons
+Sir Dusky You forgot one. 6) Anti-theists childishly making a home run over the first twenty seconds despite that not being what the video is really about.
this is why i love internet, i was on a holiday for one week and i love cosmos since i was a little kid in this week i got a change to learn way too many thing and i find out that i was misleaded all this years about space kinda find out that 90% of the things that i thought i knew was no more than rumor, thanks for educating us by amezing videos
I always have a smile on my face when I see a new video for crash course astronomy comes out
Here is a quick question:
If Galaxies are not moving on their and are red shifting as the universe expands, then why is Andromeda galaxy(Meesier 31) moving towards us?
That's because its within our galactic neighborhood. In this neighborhood, the gravitational attraction of the local galaxies is still strong enough to beat out dark energies' pull in all directions.
Eventually, the furthest galaxies to us will surpass the observable universe's bubble, and essentially cease existing to us. Our local cluster will remain together.
One theory though, is that dark energy will win over all laws holding matter together, eventually even separating stars, planets themselves, everything down to all atoms bonded together. Tear them apart into their smallest unit to fill the ever expanding void that is the universe. Never to meet again to be recycled into different configurations of matter.
Warning: Comments are full of whiney creationists saying the universe is 6,000 years old.
what if both are wrong? why is it one or the other?
+ImageSounds The Universe has to have a finite date cause it expands, but it hell aint 6000.
wrong!! they think it's 10,000.
I have my weapons come face the logic gun
LOGIC🔫
+ImageSounds That's not what the evidence points to...
WHY IS THE COMMENT SECTION AN INFINITE LOOP?!? Every time I click load more comments a few times, it repeats comments in the same order, endlessly.
Even this comment though on the top for me, appeared further down as well.
And that one
And that one too
+nicholas andrzejkiewicz bruh take a break from youtube, close yours eyes and inhale fresh air.
+nicholas andrzejkiewicz 42. Flying Spaghetti Monster. Why is it called the Big Bang? How can the universe be expanding if galaxies collide? 42. Flying Spaghetti Monster. Why is it called the Big Bang? How can the universe be expanding if galaxies collide? 42. Flying Spaghetti Monster. Why is it called the Big Bang? How can the universe be expanding if galaxies collide?
. . . like this?
At 9:07, he made a huge generalization. My uncle is a creationist astronomer. I asked him what his community thinks. it's a group of about 200 or so astronomers and almost all agree with him.
I never completely really understood how the whole universe is expanding but that rubber ruler example cleared a lot of things up and made a lot of sense, it's not that the universe is expanding into something but space itself is expanding. Mind Blown.
Vesto Slipher
That's gonna be me child's name""!!😎
I though you would call them Boruto and Hinata 😂
So, less of a "Big Bang", and more of an "Everywhere Stretch" would you say?
Slipher truly was a sky dragon
in my opinion, excluding Exodia, Slipher is the stronges yu-gi-oh card in history. i once got his atk and def up to 20000
Extraordinary video and Extraordinary explanation. Good work crash course
Well done Phil Plait
Best show on UA-cam :)
Am I the only one who expected Phil to hold his pinkie next his mouth when he repeated the estimated age of the universe?
Yes.
+Kwin van der Veen *holds pinkie next to mouth* 13 BILLION years.
If I had a dollar for everytime that joke was made...
+James A Clouder youd have a dollar.
+KanadianSpaceProgram KERRRRRRRBAAALS IIINNN SSSSPPPAAAACCCEEEEEEE
+KanadianSpaceProgram sorry couldn't resist.
I recently had a thought. So, we know the universe is expanding, but we really don't know why. All we can say when asked "Why is the universe expanding" is because of dark energy. "What's dark energy?" The term we came up for to answer why the universe is expanding. In reality, we just don't know. That's where my hypothesis comes in. (Well, not really a hypothesis, more like a guess).
Is it possible that space is expanding from a high concentration of matter to a low concentration of matter, sort of like how air flows from areas of high pressure to areas of low pressure to cause wind? Is this within the realms of plausibility?
Posting this on every episode so it gets noticed!!!
People say the world doesn't revolve around me. But the universe does 😎
Dear Sir, you are awesome!
LOL loved the Spaghetti monster, knows all, sees all, made all.
ouch! right in the superstitions
In before the creationists try to take down this video and start countless arguments.
What if the universe isn't expanding, but everything within it is shrinking? #dude
yooooo
+Schindlabua then things farther away wouldn't be going faster than things closer, everything's red shift would be the same.
***** No not really, because from our perspective it would still look like everything is moving away from us. My comment was a bit tongue in cheek, really, because these two statements are equivalent. We'd need some sort of reference frame outside the universe to tell a difference! Still, a fun thing to think about :)
in that case we would perceive distance objects with a blue shift
kris860 From our perspective nothing changes. It's a bit like saying that zooming into a photograph is the same as making the paper bigger, if that helps.
I dont want to argue with anyone but i found this mind blowing when the quran states "Have those who disbelieved not considered that the heavens and the earth were a joined entity, then We separated them, and made from water every living thing? Then will they not believe?” (Quran 21:30)
And
"Have those who disbelieved not considered that the heavens and the earth were a joined entity, then We separated them, and made from water every living thing? Then will they not believe?” (Quran 21:30)
Agreeing with the big bang theory
Great video. Good Job.
"What can change the nature of a man?"
+teknifix "Improve a mechanical device and you may double productivity, but improve man and you gain a thousandfold." -- Khan
Sex.
+teknifix Your question has no meaning.
Ghost7856
It was a reference.
+teknifix "What is man?"
i summon slyfer the sky dragon!!!
7:37 is that VSauce?
This is mind-blowing. What was before was the big bang and why is there a universe?
OK, Phil, I dare you to convince me that you chose this number for the series' first episode that's about cosmology = the universe & everything, purely by chance!
Who else is here just for the comments?
+isaac10231
Guilty....
+isaac10231
Yeap... Slapping down those pesky creationist.
+The Plebeian didn't it show a priest in the video?
AxemRush Your point...
I think black holes are creating big bangs. All that matter tearing a hole in space and time creating other universes like ours. That matter has to go somewhere and can't actually be destroyed, just turned into something else.
+Michael Dow That's quite an impressive theory there, take this upvote!
Haha, thank you ;)
+Michael Dow I may be wrong, but isn't a black hole not *destroying* the matter, but absorbing it and getting bigger? If so, why would the matter need to go somewhere else?
Black holes do not destroy matter, but absorb it. That’s how they can accumulate and grow.
Mass can be converted into energy so black uses mass for energy i believe
Disappointing. Episode 42 with no THGTTG references. :(
This video was... AMAZING!!!!!!!!!!!!!!😱😱😱😱😘
Great vid
You left out Father Georges Lemaitre's title.
+1 for flying spaghetti monster
*braces for creatards* "But the Earth is only 6,000 years old!" *facepalm*
+Grass Hopper That is an Insult to people whom are retarded, its like saying a rock has Asperger's
+Grass Hopper Never have i ever seen any of those people on these crash course videos.
+Mighty Roogna - Did I even mention politics? No. I merely made a statement.
I made no offers as to how intelligent I am or am not, nor did I do it for "attention" as you seem to be so adamant about.
Again I merely made a statement.
Also I am not American, so kind of hard for me to a "democrat" but you go on thinking whatever you like dead certain that you're correct about someone because of one little comment they made on a youtube video, if anything it's kind of entertaining.
+The Glorious GeneralDerpSide - It's the internet, they're EVERYWHERE! ;) No I really hope you're correct.
+Joe M - My apologies, you're correct!
Hmmmm how to make a similarly horrible statement without insulting rocks.... I will have to get back to you on that one.
One of the most interesting videos you guys made
Very good show I must admit. I like how you explain things.
"In the beginning, the Universe was created.
This has made a lot of people very angry and has been widely regarded as a bad move."
Bunch of people on here who don't realize Georges Lemaitre was a Catholic priest.
Why is that relevant?
PluT0iD 733
Many, many people believe that religion and science can't coexist.
Donald Weber Well of course they can. I think what people mean when they say this is that a belief in the literal interpretation of religious texts such as the Bible and Qu'ran can't coexist with a belief in science, which is true.
That's the thing about much scientific knowledge we have today. It started off as theists setting out to prove their beliefs and ultimately stumbling into scientific knowledge. One example is when theists (Can't remember names so feel free to look this up to fact check) Tried to prove the great flood in the bible but instead created geology due to their observations.
Please note that Georges Lemaitre was a Catholic priest. His full title was Father Georges Lemaitre.
Awesome video! :D
I find it endlessly fascinating that regardless of whether we can understand something, the math can still bear it out. It offers hope that one day we will.