What is the Cosmic Microwave Background Radiation? And what does it mean?
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- Опубликовано: 2 окт 2024
- This video provides an overview of the accidental discovery and explanation of the cosmic microwave background radiation, the afterglow of the big bang, and follows the narrative of Steven Weinber'gs fantastic book: The First Three minutes. After reviewing the initial experimental work of Penzias and Wilson, a detailed account of the theoretical interpretation is presented, including a discussion of the thermodynamic legacy of the big bang, the Planck radiation law, recombination, and galaxy formation.
References:
The First Three Minutes - Steven Weinberg
Cosmology - Steven Weinberg
The Inflationary Universe - Alan Guth
Introduction to Cosmology - Matts Roos
An Introduction to Cosmology - P. OLESEN
An Introduction to Modern Cosmology - Andrew Liddle
Introduction to Cosmology - Barbara Ryden
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Hi Andrew, it’s Gianni here from our PhD days. Just massive congratulations on your videos, I’m happy you stayed in contact with all this fascinating stuff. I’m watching all of them and steal some ideas and explanations here and there for my students, hope you don’t mind. Hope all is well, best.
Hey Gianni! It is so good to hear from you :-) Thank you for your very kind words, they mean a lot. Seeing your message brought a massive smile to my face and transported me back in time - we had some wonderful conversations. Are you still in Argentina? Would love to catch up
@@PhysicsExplainedVideos I got a permanent position in Santiago, Chile, where I’ve been living with my wife, a dog and 3 cats for 7 years now. How about a zoom call one of these days? I speak of you often with my wife, just a fantastic, incredibly bright and interesting human being. Some real happy memories of you in a tough moment of my life. Would love a chat again.
@@PhysicsExplainedVideos huge fan of your videos. Love, from Argentina. ;)
He will be flattered your sharing his ideas.your students also benefit.As long as it’s not plagiarism the point of ideas is to share. Hope all is well.
It's Andrew? I could have sworn you were Brian Cox! You sound just like him and explain things just as well. Best physics videos on RUclips! I watch and rewatch them all.
Thank you, this channel is simply the "best" physics channel.
Thanks!
@@PhysicsExplainedVideos Um, forgive me this naively stupid question but I rly don't know who to ask about it. So if one does learn about Rindler horizons and Unruh radiation one may come up with the probably stupid question that how their effects (if they are present at all) are seperated from the CMB ? Let me explain a bit, and you correct me where I went wrong, so our reference frame can be thought as an accelerating one relative to certain distant parts of the universe due to the expansion. If that is true then this would mean that from our point of view the empty space in those regions would have black body radiation which should look like smooth thermal equilibrium. Now the question is that could this be really similar to the CMB itself ? I mean ofc the CMB has tiny temperature fluctuations, but is it possible that the Unruh effect modfies somehow the data ?
Agree 100%. Thanks for doing this kind of videos
I'm watching every video of yours, they are enlightening me.
Glad to hear it!
Same
I watch chess games and it enlightening me
We all have had our fair share of "White Dielectric Material"
I was spewing it liberally all over the disc golf course just this afternoon.
Apparently it’s good luck to be struck by it.
I met Penzias shortly after he and Wilson had been awarded the Nobel Prize; for some reason he gave a lecture at a Unitarian Church in Tulsa, Oklahoma, to an audience of about 30 people. I felt so bad for him- he was led to believe that they were interested in Cosmology. In fact, they were using him as a status symbol in a rivalry between two Unitarian "ministers" engaged in "one-upsmanship". When he took questions after the talk it became quite apparent that the audience was trying to use leading questions to put words in his mouth and he got pretty indignant.
As the meeting broke up I tried to offer some condolences about how they had used him, but he was pretty terse and got out of there as fast as he could. I couldn't blame him. I myself, though an electronic technician doing avionics but with an interest in physics, had not been aware of this topic in cosmology and attended on a whim; if I had been up to speed on the subject I'd have asked a real question of two. As it was, I'm sure he left with a very bad taste in his mouth regarding the level of intellect in Oklahoma.
Fascinating story, thanks for sharing!
Oklahoma's average IQ is below the planck scale.
Awe-inspiring, as usual. You assemble the pieces of the story without getting bogged down in the details but disclose the details in boxed digressions. It was good to see how this video built on your video about the ultraviolet catastrophe. Also as usual, you've given me a few days worth of homework. Thank you and please keep up the good work.
Thanks for the kind words and continued support, I really appreciate it!
@@PhysicsExplainedVideos व,शव,चक्वबक,
@@PhysicsExplainedVideos सीसीकोचकसीक्सी,,हचकसीसीक्सी,सकचव,व्हवसीसीसीसीवबचककववववव,व,वेब,कि,बकच्छकवक्वब,कि भ,जब च,कककववहकवचवबचवकब,कवचकिववक्व,ब,वववचसवव,कसवच,वच, हसीब,9ककवव0किसी,हसीब हककवबछव,, हवकववक्वव,कि,ब,कककवच्चव वचक्व,च,कवव,शव सीसीसीसीववववक्सीककब,ववकच्छ,कसाव ,हवभकवसीसीसीसी,वककककवव हचचक कच्छ,कवसीसीकोह,कवसीसीसीसीगकव,भबच्छकव,सीसीसीसीब,ववसीक्सीक छह,सहसीब, किवकसीghcckccv,cvivvcvvhhv,chccchvvvvcvh,v ccv,v,cvcvccchvvhvccc cv,ccvvkvbi,ccccv vccccvv ccchchbccchvchvchchv,chchccvcchcvvv chxhccvvccvococcvccv,vccv b,ix icchicb,ccccv b,ccccccch cccchcvcovv,vcccccccvcv,hvccvccc. Cccvh occcccIcccch,, h,vcvccccvvcvccccc,occvccch,ccccvcc cccv cc c c h,hch hhccccch,c vc kcccc hcch vkvvv,hcckcccccc,bcbv,cc vv, vcccc
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Former physics undergrad here, have been out of school for some years now. This content is incredible.
Makes me feel like I'm able to apply myself to thinking about this stuff again. Really hope you keep making videos
As a retired EE (30+ years of RF/MW engineering, in both military and commercial electronics arenas) I've found your physics videos to be very delightful to watch. I've covered a lot of material over the decades and appreciate your illustrative depth of the derivations and meticulous treatment of the physics principles.
This is technical pleasure-reading at its best. I particularly enjoyed your eight-part series on the maths of general relativity, the Bohr model of the atom, and of course this microwave background study.
I very much look forward to seeing more.
Thanks for the feedback, much appreciated!
@@PhysicsExplainedVideosMany articles say that the microwave radiation distribution corresponds to ~3K temperature because universe expansion has caused the temperature to “cool down” from 3000K at the recombination time. I think “cool down” is very misleading, 3K is not actual temperature, it is the apparent temperature due to Doppler shift effect. 3K implied by the microwave radiation distribution we detect today actually corresponds to the 3000K universe temperature 14 billion years ago. Can you kindly confirm this? Thanks
Another masterpiece. What I love about your videos is that anyone with A level maths can follow the working. For me though, this will require a second viewing. Thanks man.
Thanks for the kind feedback, it means a lot
This is the best physics related RUclips channel explaining concepts in detail…..thanks a lot sir…….
You are most welcome
You just have to continue to produce these videos. I have never really come across physics videos that I can listen to for more than ten minutes. Your work is great and it's so great that I had to come out and actually comment on a RUclips video which I don't do much at all. I am here to encourage you to continue producing these great works, I am hungry for this stuff and I am far from being satiated.
Thank you very much for your kind words of encouragement, they mean a lot! I have plenty more videos on the way!
Found your channel yesterday, going to binge watch all your videos now💯
Hope you enjoy!
my person deep down has an agonizing interest in answering questions i have for this universe. i have yet to fully understand the contents of this video but i will come back when im learned and do understand. thank you for your content
One thing that is almost never mentioned is that the CMB irregularities are extremely small and that lovely multicolor graph is a very exaggerated representation of the real thing
1 part in 100 thousand, as said in this video
Been a fan of your work and presentation since black body radiation video.. thanks for making productive content for us.. ❤️
Thanks for the continued support, I really appreciate it
Saw the video 4 days ago. Knew it would be awesome, so saved it for a quiet night, and enjoyed every single atom of it. Keeps getting better and better...
Glad you enjoyed it!
Really appreciate your in depth understanding of the subject you are presenting and doubly appreciate the meticulous nature of your explanation. Great work. Keep it up.
Wow, thank you! I really appreciate the kind words and feedback
Yet another wonderful explanation of formation in such a lucid way. It makes my day when I watch your videos. It is comforting to know that universe works on a basic laws of physics, yet it looks very complicated when looked at it with bare eyes. Thank You!
Thank you for the kind feedback, it is very much appreciated :-)
Your channel is everything I ever wanted from RUclips. Hope you skyrocket to a million subscribers soon
Thanks!
This is great !
If opinion of a RUclips hobby physics follower matters, I think the best CMB short story so far
Thank you very much for keeping quality content going!
My pleasure!
Just amazing! I'm from Brazil and I would probably never find that level of information and detailed content by ordinary ways. Thanks.
Glad you enjoyed it!
Brilliant work. I will add that as a child I lived in New Jersey within a bike ride of the Penzias/Wilson antenna and I rode past it many times. I had no clue what it was, and neither did my parents. It was only much later when I got into university that I learned what it was, and how Penzias won the Nobel Prize using it. Penzias gave the speech at my graduation and I was a rabid physics fan, so it was an experience I will always remember.
Very cool!
This is a GEM. I am a Phd research scholar with my thesis on CMB. And this video is must watch for anyone to begin research in this field.
Cheers for the kind words, much appreciated. Good luck with the PhD!
@@PhysicsExplainedVideos thanx and can i have your email bcuz i tried to search in “about” section but its not there.
@@toxxikanshul you're lying that you're a PhD student
@@prateekgupta2408 oh lol okay bro. Im surely not gonna pleasure u with proof. Blessings for u.
@@PhysicsExplainedVideos I think it would be nice if you emphasized why the background microwave can be detected in any direction -- of course, the reason is that the point where we were was INSIDE the universe then and we are still inside the universe now, but this explanation could be hard for most viewers to figure out by themselves.
i forget if ive commented before, but just want to give a little encouragement along with the rest of the commenters here.
I'm reading up on JWST and am trying to grasp the general consensus about the LCDM model and obviously the CMB is a huge part of what any model of the universe must fit into. So I just want to say thanks for making such articulate and precise explanations in easily digestible video form. (your graphics are amazing too btw)
Your channel is one of the few that find a great balance between understandable-but-too-simple and accurate-but-too-complex-to-follow. I walk away feeling like Ive understood a majority of the maths and (equally importantly) the history of how theorists arrived at our current understanding.
Too many popular explanations of the CMB in particular fail to explain blackbody radiation, Dicke and Peeble's prediction of the recombination epic, and useful historical tid-bits like that Penzias and Wilson were originally looking for 21-cm lines and even pointed their telescope at Andromeda to rule out Milky Way origins for the unexpected microwaves.
Sorry for the ramble. No need to respond, just keep up the great work. This channel will undoubtedly be used in the classroom for generations to come. It's just way too insightful not to. (I can only hope you get compensated appropriately for your excellent work).
Your videos make me perceive the concept at the plank level of understanding ... keep it up ... Really appreciate your work!
Glad to hear that! Thanks for the feedback
Keep up the good content 🙏
Thanks!
Great video great channel thank u for these videos and the explanations that come with it. Maybe a video on Gravitational wave background
Great suggestion! One for the future
Excellent video. Well done
Thank you very much!
This is some incredible work. Also I love the dark theme, super friendly for our eyes
Glad you like it! Thanks for the feedback :-)
is it the actual, detectable remnant of the birth of the universe? or is it ... bird shit? what a great story :)
This is the clearest explanation of microwave background Radiation I've heard
I'm very much your average Joe who works a normal job and has a GED but I've come to realize in these last couple years I always seem to enjoying watching videos regarding science or reading about the history of math. I even enjoy videos like these when it's so far out of my pay grade but I still feel like it can teach me so much even from a conceptual standpoint. It helps me feel like I have a slightly better grasp of something that's still very foggy to me. Hopefully I will be able to understand this from a purely mathematical view someday too.
I really like these videos even if I have gone over it all a thousand times.
probably the accent
Ah,yes. Good vid,man. Disappointed to see it drew in some conspiracy theorists and flat earthers. Oh well. Subbed.
The first time I understand what all the pop science channels mean when saying the universe was opaque before it cooled down
13:45
Fantastic description! Crystal clear
Your videos are exactly what I need as I prepare to make the transition from being a lifelong chemistry and physics teacher to a second career as an actual physicist. I watch once all the way through for conceptual flow, then again stopping them until I can do the maths shown at each step. The single fastest improvement in my rigorous understanding.
This makes me happy :-)
You are to be commended for NOT making it so simple that the message is not presented. This video would have been so helpful during undergraduate days, about the time Wilson, Penzias & Pebbles were doing their work. Yes, I am old. Along with your Vacuum Catastrophe Video this is the best I have ever seen on these topics. Your work is very important; I thank you for your energy.
My pleasure, thanks for the kind feedback
You need not mention radiation as microwave is a type of radiation only 😄
Btw Loved the video 🤩
I hope you will continue making these excellent video's :)
That's the plan! Thanks for the feedback
Can you make a video about general relativity?
Yes, and all relativity theories!
Your work is simply beautiful 👍
Thank you so much, that is very kind of you to say
It really is fascinating...how much we can learn from equations ---- the most awesome power of all is "="
I just had my car washed, but this morning it had a big blotch of white dielectric material on it.
Hi great fan of your videos but could you add the subtitle
Yes, sorry, something that I am looking to do
i absolutely love these videos
I appreciate your work.
Thanks!
Straight up in my top three physics channels for accessibility and making complex topics available for under grads, thanks!
20:50 Hey, I remember integrals that result in a PI from your other video!
Always makes me happy to see a new video of yours :)
Happy to hear that!
Your videos are so in depth. I'm glad the algorithm brought you to my attention. Keep up the great work!
Thank you!
Awesome videos, love your content. Keep them coming👍🏻👍🏻
Thank you! Will do!
This is tons better than the usual "they heard extra static" explanation I've heard from everywhere else
@paulwolf3302 Do you agree that 1+1=2? 😳
I love these videos. Thank you so much.
Another excellent video!
Glad you enjoyed it!
Fantastic videos. Historical background, physical explanations (really good and insightful), some mathematical formulas to show how works the numbers, and great presentations with graphics and so on. Thanks for this, keep working on it, great material.
Glad you enjoyed it!
Hype
For a visible light telescope, its easy to cancel out the noise of the electronics. You just need take an exposure with the camera shutter still closed. The resultant image is pure electronics noise (along with the occasional cosmic ray strike).
I'm not a microwave or radio astronomer so I don't know if the procedure is as easy.
I feel as though I have just stumbled across a gem. Thank you for creating this wonderful channel. Liked and subscribed.
Awesome, thank you!
Can I ask what is your professional background? You have such a good grasp on topics like these. I wish I received the same process of thinking from uni professors. I keep rewatching some of your videos because I always seem to gain a new perspective on how intimate our world really is. From the cosmos down to the atom, these series beautifully compliment one another. Man what a great time to learn physics.
Thanks for your comment, much appreciated. In terms of my background, I completed a PhD in theoretical physics (focusing on String Theory), and have been teaching physics for the past ten years.
@@PhysicsExplainedVideos that is awesome, 10 years?! Can I also ask why did you started a RUclips series? Your videos have a lot personality to them. They give me vibes that you are really approachable to ask questions about physics.
@@PhysicsExplainedVideos That teaching background really shows and shines, yet it's importance is often underestimated. The didactic punch really is what produces the prerequisite number and quality in the next generation of science, for someone within it to "stand on the shoulder of giants".
I really love your videos, I look forward to the next fascinating deep dive. Best wishes man 👍
Thank you very much!
I love well done physics videos that aren't scared of explaining the math!! New favourite channel
Cheers, glad you enjoyed the video
These are great vids..even for a retired EE/software guy...
Glad to hear it, thanks for the comment!
They're also great vids for a software guy relatively fresh out of university :)
30:41 For me this is the most difficult part to intuitively understand. We have to accept that while the wavelength of all the photons does expand with the universe at the same rate, all photons are still infinitely small in size, because that's the only way we can draw the conclusion that their density decreased. Is there something to learn about how the expansion of the universe affect particles at the quantum level?
Yes this is a tricky concept. In fact, you can show with a relatively simple calculation that the 'average' separation of the photons is proportional to the wavelength of the photons. Hence, longer wavelength, means greater average separation, hence lower density.
Very nice and informative video.
Arno Penzias was quite the character. He probably still is, at age 87. About 25 years ago I worked for a startup company of which Arno was one of the chief instigators. One day my boss and I were talking and he allowed as to how sometimes, when investors, etc., were giving them problems, they had to "wield Arno."
The two of us decided that Arno was a +5 Nobel Laureate of Influence.
Thanks for the info! Very interesting :-)
sir , a little request i want you make the video on schrodinger wave function which you promised in the video of bohr model of atom
Yes, it is in production..
@@PhysicsExplainedVideos thanks for replying
I love how much of this stuff actually got started in New Jersey, which most people think of one of the most prosaic and least "cosmic" places around.
Another excellent programme. One of my favourite things about the history of Planck's radiation law is that Wien had found this relationship empirically in 1896, 4 years before Planck's solution to the ultraviolet catastrophe. Then, as you show, Wien's law just falls right out of Planck's work.
I cannot understand why this channel has only ~54k subscribers. It should be *compulsory*. Along with 3Blue1Brown.
I am an EE graduate who once considered switching to Physics. To this day I remain fascinated by these topics. These are brilliant videos.
Hi Andrew, I'm a stem cell biologist watching your videos for... fun. They are so good. I'm writing a lecture series and I'm so impressed with your style that I'm going to use some of it in my own delivery.
Thank you
Sounds great!
Amazing video.
Glad you think so!
Thanks for such a comprehensive explanation of one of my favorite stories in physics!
You're very welcome!
I'd be interested in your opinions regarding Planck stars.
I love your videos! Somethimes I can't understand some of the maths in some of them because I'm only 12..
But I bought a few books in physics, so I hope to understand them in the future
Glad you like them! Keep working at the Maths and I am sure you will progress
@@PhysicsExplainedVideos 😁
Beautiful video. Thank you.
I find myself struggling at times with transitions you make and having to pause, rewind and listen many times... Even with such great videos, this is no easy stuff!
Thanks for the comment and feedback. You are right, there is a lot of content squeezed into a short amount of time, so I think it makes sense to pause and process all the information. Good effort!
Lol ty calculus was really killing me so i opened yt and saw this
Amazing video, I think Im starting to understand the famous 2.7 Kelvin number that I've heard so much about. One question... lets say we mesure the CMB again in 2 billion years... because of the expansion of the universe should we see a different (lower value) of the thermal radiation?
you'll be in the school curriculum soon, keep it up mate
To make all these conclusions we assume that all of the used constants ( c, k etc.) were having the same values for the entire lifespan of our universe. Have this been checked to be true or we are just assuming that? (Not a physicist😂)
i did a calculus do not know if it is correct, but the cmb is relative to the planck volume when the universe was really small
Got 0 (out of 15) points in circular motions & harmonic oscillators and 1 (out of 15) points in mechanical waves - why am I watching this? Im literally incapeable of understanding physics lol. Still enjoy your videos a lot. Your voice is so comforting.
I think time stamps would be of great help.
Good idea, let me see what I can do
Thank you youtube for recommending this video.
Amazing! Thank you very much.
20:44 ah good old proof by its a standart integral
this comment was made by mathematics gang
The other day I heard about xray emission from supermassive blackholes and thought aha! the CMBR might be shifted xrays. This video has falsified that naïve hypothesis. ;-)
You know you are watching too many physics explained videos when you can slightly predict how he is going to calculate the radiation pressure.
26:10 "the details of this calculation are beyond the scope of this video" - *sweating*
"but for those who are interested, I've put some links in the video description" - *sweating intensifies*
Already in the very beginning of the video is probably the best explanation of the 21cm hydrogen emission on RUclips. I'm not knocking other channels but most just say its a wavelength at which hydrogen emits a photon without this deeper understanding. It was very well explained in this video.
Cheers, thanks for the feedback!
the # 21 is all over.
I don't know if there's any truth behind this correlation, but something that fascinates me is how similar the universe was before recombination to the internal structures of stars. Both are plasma soups that are opaque to photons and both are upwards of 3000K. Really cool to see physical commonalities in today's universe outside of the math.
Some background rattle on your mic. Otherwise yet another stonking broadcast, thanks.
Thanks RUclips ❣️
Quiet sadly, Georgi Gamov was never mentioned in this video
Yes, I should have included him..
The clearest and most profound presentation I came across! Keep up the good work.
Thanks for the kind words, much appreciated
Wow, brilliant video, cheers. I've heard this story enough times that I've actually come to resent the white dialectric material, i.e. "here we go again". I heard the pigeons got whacked, when they came back, after an initial try at relocating them. Anyway, this is crammed with stuff I didn't know, including the first emergence of the ~3K temperature, which is such a crucial piece. But I don't quite get the apparent correlation between a given wavelength and its "effective temperature". If the key variable is intensity, wouldn't that depend on the amplitude of the waves, as opposed to the wavelength itself? So, 7.35cm wavelength ~ ~3K... I'm not quite getting that.
I guess it's the association of higher photon energy with shorter wavelengths.
Glad it was helpful!
they are in New Jersey, of course they would get whacked. capisce?
How do the sensors that detect this work?