Olber's Paradox is one of my favorites. I watched another video many, many years ago on the topic and I use its ideas routinely to bait hard-headed young-earth creationists into a science discussion that leads to them accepting that the Big Bang(or one of them anyway) happened billions of years ago.
I certainly feel it is lots of ideas for 10ish minutes which isn’t wrong obviously but Smarter Everyday in particular talks about how this is challenging for RU-vid algorithms or whatever as I think I tweeted you... also, as I mentioned for instance on the latest Tibees I have a very unusual mind AND definitely science/math/tech RU-vidrs however defined certainly do too I’d argue - one aspect outside of purely technical content is that it is fairly dark/night like of an episode which is appropriate but perhaps overwhelming to many viewers however perceived!? - maybe also even more panning across various skyscapes etc would be drawing viewers in and along with you and the comprehension gaps they may have encouraging them to watch again as happened for instance for myself when I watched this Cool Worlds episode over a year after I first watched it ( m.ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-b_TkFhj9mgk.html ) and was able to connect it in my comprehension (as I wrote about in the comments shortly after you uploaded this to RU-vid) in a weird way to this latest offering from you - the goal of Cool Worlds is raising awareness of a laboratory that does exomoon and similar research whereas a more general RU-vidr probably is shooting for not necessarily a smash hit very occasionally but more steady interest and learning and so on however perceived... also I’m curious about the rights issues I guess it was fair use the film clips in that Cool Worlds episode and yeah obviously Tom Scott knows the latest hahaha - anyway I certainly liked your latest here and it is definitely an unusual astronomical RU-vid and that is excellent and who knows about RU-vid metrics and so on - Hollywood studios do focus groups for their largest budget stuff I guess and occasionally even give a broad release to something that doesn’t have extremely positive focus group data however derived - the art and science of show business wow teaching/learning STEM etc is an exciting corner of it and thanks again for this episode in particular!🌌🌌🌌🌌🌌🚀🌈☮️💟🤯🎬
Just perfect, science was never my strongest point. Your videos prove however, that the teacher plays a huge role in our understanding! A great teacher like yourself, and the lesson 'hits home'. Thank you so very much.
That can also be the answer of how something comes out of nothing, you are assuming that it doesn't, that's a rule, and there's no rules, there's nothing, so it just can, therefore 0 becomes 1. (at least this works in homotopy type theory, as a basic axiom to create the rest of the entire mathematics).
@@Ozelea 🙋🏻♂️Hi Abubaker, you definitely should! You could also play around with the structure and phrasing a little (even though Jade's delivery was excellent), if you wanted to that is. For example: "*Nothing* can travel faster than the speed of light...Except...Nothing, which *can* travel faster than the speed of light...In fact because *nothing* can travel faster than the speed of light it means that *nothing* else is faster than *nothing* when it comes to cosmic speeds - *not one thing*!" Or any variation you like really. A few other cool facts are that the speed of light isn't really about the speed of light. It's just the fastest speed that any information can be communicated between any two things. Light travels at that speed simply because it's a massless particle, and all massless particles *must* travel at that speed. It's our universes law. To give an idea of the vastness of cosmic scales you could try giving the speed in km/h or mp/h for a bigger 'wow' factor - and then tell your class how long it would still take them to reach the next nearest star or galaxy! But, interestingly, for an individual photon of light that long journey would seem to pass in precisely no time at all. Because for anything travelling at that speed time just completely stops - you would arrive in the Andromeda galaxy without noticing even the tiniest fraction of a nanosecond having elapsed. That long, long, long journey would feel like...*Nothing*🤦🏻♂️! Good luck with the project 💁🏻♂️✨
Absolutely deadly effective demonstration of Doppler Effect! Seeing a demonstration like that makes it readily apparent and practically eliminates the need for a lengthy explanation. I wish there were more easy to grasp demonstrations like this because I think it would have and would have had a huge impact on the general public's understanding of science in general. I think, too often, the average person might have a good intuitive understanding in their own mind about something that they have integrated into their knowledge base, but when some science sceptic or a child asks them: Explain this to me so I can understand, they might struggle to do so because they lack easily replicated demonstrations like this. Imagine just being able to put water in a bathtub or basin and show Doppler Effect in a way that you can SEE it, rather than asking someone to first imagine what the sound waves of an ambulance siren might look like. Seeing is so important to humans for us to understand something. Seeing, for us, often produces that 'Eureka!' moment. You still might not be able to explain it, but you GET IT! and you get it immediately. This is great stuff, and if you do nothing else with your channel but simply spread this demonstration like a meme, you will have contributed greatly to your fellow human's understanding of key scientific and cosmological concepts/theories. Keep up the great work!
Loved the bath tub Doppler explanation. Never seen that explained so beautifully. I would have liked to see you return to Keppler's wall at the end with the virtual horizon.
You guys- Up and atom, Veritasium, Science asylum, Real engineering, are all awesome!! The information you give is always authentic and the approach is always interesting. Thank you very much guys. You are doing an AMAZING job creating such an environment for education.
I have never seen that demonstration of the doppler effect before with the moving dropper - it shows whats going on literally! Thank you for a fascinating video, Jade! :)
Jade this was a great video! Wonderful job of explaining difficult concepts just enough to follow your overall theme. I had to laugh a bit though ... 8:18 Jade holds her rose, smiles, and mentions romance. Then 14 seconds later Jade nonchalantly tosses the rose aside. 😂
How you are still getting better and better with each video is ridiculous. In fact, HOW are your videos continually improving when they're already so good? IT'S A PARADOX. Please solve in a future video.
Well look at that! My other favorite creator that I met through a Tom Scott guest video! However while I now understand why some fishermen can hold their breath for 10 minutes, I still don't intuitively understand "how knot to hang a painting" :-/
Great videos! As an Electrical Engineer and 'A' level Maths teacher, I really appreciate your methods of explanation. Wonderful content and I hope you have a lot of success to inspire and educate the youngsters coming through! Much love from the UK
The illustration with the tub was the best I've ever seen, and I'm an old nerd. I've seen a lot of them. If Olber had known about black holes, which can intercept light and not get hotter (getting cooler, even), he could have used those to muddy things a bit.
The light is more luminous than the light bouncing off of her face. If you have a porch light next to your front door, put a brighter light a few feet away to keep bugs from hanging out near your screen door.
You're like Hannah Fry: Your voice-accent combo is fantastic. I'd love to hear audio of you reading William S. Burroughs in a cheery, upbeat tone. The juxtaposition would be hilarious.
Jade, this is so brilliantly done. What a marvellous explanation, delivered in your unique style, and which couldn’t have been done in any better way. Just fabulous. Oh... and bum to the critics, your presentation and acting in this is top notch, please don’t let them get to you. Much admiration and respect, from John, Wales, UK. 👍
the best visual explanation of the Doppler effect EVER. Your explanations are straightforward, without being insulting or TOO inaccurate. Truly elegant videos
Fun fact the Triangulum Galaxy (M33) is even further than Andromeda and can also be seen with the naked eye in really dark (Bortle 1 and 2) locations. This might be the furthest galaxy you can see with the unaided eye.
"It is depressing to know that we will never be able to see the stars beyond the visible universe" I hear that those people are a bunch of jerks anyway....
Wow, this horizon of the observable universe, behind which nothing can "escape" to reach the earth (our center of perception), this reminds me quite a lot of the event horizon of a black hole, where also nothing can escape, not even the light....could it be that the expansion of space-time is basically something like an inverse of a black hole? And what implications would that have?
Einstein's General Theory of Relativity also predicts the existence of white holes, which are the opposites of black holes. Even though a white hole has never been observed, I sometimes think that maybe the Big Bang was a white hole event. I sometimes also think that as black holes evaporate due to Hawking Radiation, that they might turn to a white hole when a critical mass is reached and it can no longer stay a black hole. At that point, the gravitational force can no longer overcome the repulsive forces of matter particles and energies inside, sort of like a supernova. These are just thoughts, though.
I’ve joined Curiosity and love it. Highly recommend it. That series you recommended about math being discovered or invented “magic numbers” was excellent.
That question has actually been around for even longer. I made my best try to translate the first conversation about it in modern english: "why sky dark?" - "night no sun" - "uga"
I notice that a lot of us "light duty physicists" do not understand that "gravity" is an attraction between localized warped space-times, and that it is energy that warps space-time. So, some of us can't understand why photon paths can be bent "because it does't have mass". I try to tell them that E = mc^2 and E = hf BOTH warp space-time...and, incidentally, a coiled spring, mass at the top of a cliff, and a TBSP of gasoline (petrol) in an O2 gas also warps space-time (potential energy), ie, "rest mass". It sure would be nice to see a documentary on this...and thanks for your wonderful presentations.
I read about this paradox almost 50 years ago, when I was a boy, in an Asimov's book. For one reason or another, I took for granted that the solution was "dust". Today, RU-vid suggested this video to me and I said to msyself: "Hey, that was the paradox from that guy...! Was it Oorst? Dilbert? Obsert?" And now, after all this time, I've found that I already knew all the elements of the solution, but never assmebled them to get the correct answer! A girl had to be born, grow, learn, understand, and make a video to show me that truth is, sometimes, so ridiculosusly evident... Thank you so much!
The bathtub demonstration was great! You could use that same set-up to talk about the shockwaves on supersonic aircraft, too! A practical demonstration of moving faster than "the speed of sound" would be awesome to see!
This is such a clear explanation, thank you! I’ve also not seen such a clear demonstration of the Doppler effect before, very good. Question: would the sky look bright if viewed through a sensitive infrared camera? Also, does some light “shift” further into radio waves?
If the universe is expanding and the expanding speed is rising (because of dark energy) doesn't that mean that eventually that speed will pass speed of light and then we won't be able to see stars we see now?meaning the visible universe will shrink?
Indeed, things slip beyond the horizon out of the visible universe all the time, we just don't notice it. And as expansion accelarates, this will happen more. See en.wikipedia.org/wiki/Cosmological_horizon especially the section on Hubble horizon.
Here's a fun thought experiment: To understand the base idea here, imagine 3 objects in a row; A, B, and C. Now, imagine all 3 are in motion with the following speeds in the same direction (think of cars on a road, if it helps) : A= 50, B= 100, and C=150. From each perspective, the distance between each is growing. A sees B and C racing ahead of it. B sees A falling behind while C races ahead, and C sees itself as leaving A and B in the dust. Now, imagine if these objects have no point of reference to know which direction they're actually moving. A and C both see the other objects racing away from them with the further object moving the fastest, but to B, both are moving away from it at equal speeds. Without any reference point, motion of each is relative, and there's no way to know if A or B is the fastest, all you know is the motion relative to each. We know that space itself appears to be expanding and at its current rate of expansion will eventually do so at a rate that exceeds the speed of light resulting in the entire universe eventually becoming too spread out to see any stars. So back to the objects: what would it look like to an objects inside a black hole as they fall inward (presuming they are not actually ripped apart by the gravitational forces)? As each falls into it, they'll accelerate at their different speeds, and each will seem like the other two are racing away. This means that should the objects survive the initial tidal forces, they'd have no way to even know they're in the black hole, especially if the warping of spacetime itself continues inward, rather than outward, inside the black hole. To the objects, it would appear to them as though the black hole were expanding. Further, I don't know if there's any established limit to how much space can expand or contract, and since physics is pretty much universally relative, it's entirely possible that it can happen both directions infinitely, but the observer's perspective wouldn't ever notice a change. (Think time dilation in principle, the faster you go, the more time slows down for you, and no matter how fast you go, light speed always remains the same relative to you.)
6:14 Our whole universe was in a hot, dense state Then nearly fourteen billion years ago expansion started, wait The earth began to cool, the autotrophs began to drool Neanderthals developed tools We built a wall (we built the pyramids) Math, science, history, unraveling the mysteries That all started with the big bang (bang) Since the dawn of man is really not that long As every galaxy was formed in less time than it takes to sing this song A fraction of a second and the elements were made The bipeds stood up straight, the dinosaurs all met their fate They tried to leap but they were late And they all died (they froze their asses off) The oceans and Pangea, see ya wouldn't wanna be ya Set in motion by the same big bang It all started with the big bang It's expanding ever outward but one day It will pause and start to go the other way Collapsing ever inward, we won't be here, it won't be heard Our best and brightest figure that it'll make an even bigger bang Australopithecus would really have been sick of us Debating how we're here, they're catching deer (we're catching viruses) Religion or astronomy (Descartes or Deuteronomy) It all started with the big bang Music and mythology, Einstein and astrology It all started with the big bang It all started with the big bang
I'll take explicit pitches by RU-vidrs over repetitive ads chosen by Google executives every time I'm offered. But yeah it's got a strange 50s-TV feel to it then they cut to a sponsor promotion, even when Adam Ragusea does it, and he has all but mastered the art of the sponsorship segue.
The analogy of walking too slowly on an escalator going the wrong way really helped me grasp the concept. This was a great video taking a complex subject and making it easier to understand. New sub!
I found this channel due to extra free time (covid recovery). I am already subscriber for some other similar channels but i just can’t stop watching Up and Atom. Jade is really sweet and super interesting with easy understandable, fresh way of going through topics. Keep on going! Cheers from Serbia
I was a bit confused by the initial explanation of the paradox. I thought maybe the solution was that the sky is dark because our eyes/telescopes have limited resolution and limited exposure time. If photons from very distant objects only hit our sensors very occasionally, we won’t perceive their light, I thought. Isn’t this was the Hubble Deep Field experiment showed? That a dark patch of sky actually contains a lot of light if you significantly increase the exposure?
At the stage where you're torn between an infinite universe casting infinite light on the Earth, vs a finite universe, shrinking due to mutual gravitation, a finite universe isn't necessarily shrinking. It can have enough outward kinetic energy to overcome the mutual gravitational pull. BTW, there's another resolution to Olbers' Paradox that I saw in a book-collection of astronomy articles from Scientific American from the late 1950's, and have never since run across. And I think it's a very good one. An article on Olbers' Paradox in that collection pointed out that, even in an infinite universe, you could have the luminous objects (the stars) distributed, not uniformly, but hierarchically. For instance, stars would be grouped in clusters, with a certain average distance apart; • the star clusters would be separated by some multiple of their size, and grouped into galaxies; • the galaxies would be separated by that multiple of their size, and grouped into galaxy clusters; • the galaxy clusters would again be separated by that multiple of their size, and grouped into superclusters; etc., etc., ad infinitum. There would then be an infinite number of stars whose cumulative light would be a converging geometric series, and therefore, finite. With the right choice of the hierarchy's parameters, you could obtain the actual starlight intensity that we observe. Of course, this isn't the actual resolution of Olbers' Paradox; that being an expanding universe of finite age, with a finite speed of light, all of which prevent infinite intensity from ever building up. Fred
Great video! I only have one minor nit-pick: I would not say that the expansion of space constitutes "traveling", or that nothingness "travels" faster than the speed of light. That being said, thanks for teaching me why the night sky is dark!
The expansion of the universe may darken the whole universe, but your smile brightens up this video! ...also, good animations and writing and editing and stuff
I really enjoyed how you went deeper into a topic that’s not usually discussed. Also I like how you referred to a specific show that’s related to this topic, so that we can learn more about this fascinating area (better than a generic endorsement).
"Its true that nothing can travel faster than the speed of light...except: NOTHING can travel faster..." Whole video is great but I especially loved that line.
For the first time in my life I have finally been able to understand the space-time concept of this universe and what is the meaning of the term visible universe. Great explanation. Fabulous job.
Hi. Just subscribed. RU-vid suggested your video and the title had me interested. I watch a lot of PBS spacetime RU-vid vids and I really enjoyed yours it was much simpler to understand without having to stop go back and watch again lol. I have a short attention span and I zone out pretty quick but you kept me engaged. Thanks. I will be watching more of your videos in the future. Expect more comments
A correction Already in 1845 Lord Rosse, using a 72" telescope, draw several "nebulae" with their characteristic (for ex. M51, Whirpool galaxy) In April 1920 there was the "Great Debate" at National Academy: Shapley and Curtis presented their hypothesis. Shapley about a big MW (diam=100kpc) including everything, also the nebulae; Curtis the Kepteyn Universe, a smaller MW (diam=17kpc) and the nebulae are other "galaxies". Then in 1922 Hubble measured the distance of Andromeda's Nebula using Cepheids and put it definitely outside MW (~300kpc; actually it is 700kpc). And the Universe was way bigger than we thought! (at least bigger than Shapley thought)
