Brady asking questions while filming is an important part of why these videos are good. It gives us the layman's perspective as well in a very natural way. :)
This is glorious, I have been researching "what universe is earth in?" for a while now, and I think this has helped. Have you heard people talk about - Bannrial Bizarre Bulldozer - (Have a quick look on google cant remember the place now ) ? It is an awesome exclusive product for discovering your spiritual animal and the clues it has to your future success without the normal expense. Ive heard some incredible things about it and my work buddy got cool results with it.
off all the lectures, videos etc that I have seen on this particular subject this explanation for me at least, is the best one. The way the professor explains it just clicks like a light bulb just lit up lol Thank you for this video I truly do enjoy Dr Copeland and his way of explaining things. It would be just a privilege to take any class from him in my honest opinion.
What a wonderful man. Not assuming we are idiots but taking his time to explain it with out using layman analogy so we actual learn about how it worked. Thank you Prof Copeland I truly appreciate you.
for me it wasnt that easy to comprehend fluctuations in the field that imprinted themselves on what ? is CMB old light, or those fluctuations in the quantum field, or is CMB statisticly calculated by subtracting all other radiation ?
MarakanaCacak1989 The cosmic background fluctuations were captured by the COBE (cosmic background explorer) satellite. Cosmic background is basically old light yes, and that light traveled long distances to reach cobe. What happens when light travels long distances is that it's wavelength changes through space. So scientists look at the sky with cobe and capture a lot of kinds of wavelengths, but they know what wavelength to expect and what not to... And they map the cosmic background. Anyway, if you want a suggestion to read more about stuff being explained from the very basics go take a look at Stephen Hawkings books "a brief history of time" and "the universe in a nutshell "
Amazing video Brady and Ed. 17 minutes of my life well spend. Wouldn't mind watching more about Planck and the CMBR though I know there isn't a lot more to talk about right now. Keep up the great work. Your work is greatly appreciated!
Please someone answer this question if you can. If this light was released a few hundred thousand years after the big bang, how did we (our matter) get to where we are now, before this light reached us? The universe doesn't expand faster than light does it? If it did the light would never reach us. Wouldn't we have to out run it for some of the 13 billion years then slow down for it top catch us up? Which I know doesn't make sense.
Let me try to (partially) answer your question. You seem to imagine that we are at a 'location' where we weren't in the past. On the large scale (galactic supercluster level) we aren't moving and haven't moved - much. The expansion of the universe is the expansion of space, not specifically objects moving apart - even though it seems that way. This means that there is no central point in the universe. Everything on a large scale, appears to be moving away from us, so it SEEMS like we're in the middle, but if you were to go to a galaxy 10 billion light years away in any direction you choose, it would look the same. You'd still appear to be in the middle. The universe appears to be spherical, with us at the centre. But, due to the finite speed of light, you could never get to the 'edge' - not even theoretically. As for the universe expanding faster than the speed of light (c), think of it this way: Nothing can move past another thing faster than c. But picture a galaxy 5 billion light years away, moving away from us at 55% of the speed of light (this might not be an accurate figure - I'm going from memory) relative to us. Now imagine that a galaxy 10 billion light years from us is moving apart from the first galaxy at 55% the speed of light. Add the 2 velocities together and you get 110% of the speed of light - which should be impossible. But it's not, because nothing on a local scale is moving apart at more than 186 thousand miles per second (c). It's the SPACE which is expanding, and the accumulation of sub c velocities (on a large scale) CAN exceed c. This is why we estimate the size of the universe to be some 90 billion light years across, not 2 x 13.8 billion, which you might expect. Just remember that it's the SPACE which is expanding!
Deepanshu Gajbhiye Because we are seeing photons from it when it was younger and closer. If it only came into existence 'now', we would never see it - it would be beyond our horizon.
but i cant understand how that photon is able to reach us also i dont think that that photon can exceed speed of light bcoz it will require very high energy and extremely low mass as E=MC2 then c= sq root of E/M
Deepanshu Gajbhiye You're mistaken to think of 'that photon'. Photons are continually streaming from all stars and galaxies. When we look at a galaxy which is 10 billion light years away, we are seeing it as it appeared when it and the universe were only 3.8 billion years old. All of the photons it emitted after that point, haven't reached us yet. In the far future, it will disappear from sight, because of the expansion of the universe. This does not mean it has ceased to exist, but it means that the expansion we talked about before has caught up with us.
Sixty Symbols videos are always great, but I feel like Professor Copeland outdid himself with the explanations in this video. Thank you, Grady and Professor Copeland!
Brady's videos are awesome. They are extremely interesting and extremely informative. They encourage people to learn, and as everything is explained everyone should be able to understand. Brady, you are awesome.
Hi Brady! :) You are doing a wonderful work as always! This is one of the most interesting videos you ever made and I would be really thankful if you could add English subtitles :D Thanks :)
Brady, thank you for showing the sheer level of fascination and wonder that all of your interviewees bring to their respective fields. A question for you: have you considered doing any bits on the professors' reactions to fringe propositions? Asking Prof. Copeland, for example, about Plasma Cosmology; or, say, Dr. Aboobaker about ID? I'm keen to see how each deals with the woo in hir field. Be that as it may, congratulations for being so amazing!
I wouldn't say a science geek, but a more humble human being... definitely :) Astronomy, Cosmology and Physics, when well understood, usually leaves someone in awe and it changes a person for the better.
It's using the Mollweide map projection, it exists to enable more accurate proportions (so one area on the map of a certain area should have about the same mapped area as any other), at the expense of being less accurate in terms of shape. It is of course possible to map the data to any map projection, but using one that favours proportions over shape makes a little more sense in this case because it makes it easier to compare different spots.
This is the clearest most understandable explanation I have yet heard about the beginnings of the Universe & the forces & energies involved in its expansion/inflation. Trying to reconcile the extremes of scale is taxing. Please thank Professor Copeland for his patient & thoughtful explanations.
7:42 thank you so much brady for asking this question and appearing "silly" in front of a specialist in the field, I have asked myself this plenty of times but as I dont study cosmology I always thought it was just too technical for me to understand. Thanks!
WOOOOW! Brady you saved my day! I was bored so I looked loaded youtube and first video on my subscription list was from SixtySymbols and it was 17 minutes long! Thank you for your work!
The universe was opaque from the very start until the 380 ky epoch. The fluctuations in the inflation field led to fluctuations in the plasma that persisted until decoupling, at which point the spectrum became permanently fixed (ignoring cooling and matter interference) with those fluctuations embedded. Have they talked about peculiar velocity and how it doppler shifts the CMB? Also the consequences of having a natural "rest" frame in which the CMB is isotropic? I'd like to hear more on that.
You have so many videos, one of copelands videos gave me such a profound sense of appreciation of space. I self realized as a grain of sand grown of this great wave that happened to wash to the surface on a great wave. I wish I could’ve book marked that video
You are right, and I am quite sure he knows Kelvin is not counted in degrees, but just to clarify for people who might have heard/ thought it was this way. Also note (can't remember if he said this in the video) that the Celsius scale scales the same way the kelvin does, so the unit "Kelvin" \\Is the same as\\ the unit "Degrees Celsius", only with different datums.
The way in which we measure temperature is by monitoring radiation from the target object, or reflecting radiation off the target object. The radiation itself is bound by the speed of light. That said you make an interesting point about the temperature being roughly the same everywhere. I had made a misconception about what they were talking about, as I thought the were talking about the edge of the observable universe.
The Univers is 2,73K or to be very exact 2,7255K. The temperature differences between cold and hot spots is within 200 microK. The cold spot means CMB signal basically missing compared to reagions nearby. Nice interview!
In portuguese we say the corresponding to "X degrees Kelvin" much like we also say "Y degrees Celsius". This is because it helps your public better grasp the context of the sentence and is considered confusing/incorrect if not applied.
(character limit) What I'm struggling to understand is the difference between your capitalised how and why questions. It seems to me that in this case the two are equivalent. I could easily be wrong and I'm sorry if I'm not more helpful, but your original question intrigued me :)
Penrose actually published a paper on certain observed anisotropies in the CMB data from WMAP a while back, which suggested the effects of a universe prior to the big bang. It's on arXiv somewhere! He also has some popular lectures on youtube about the theory. He's a pretty sound guy.
Most photons can xfer heat in some way, depending on the material (I'm glossing over a lot due to char limit): Microwave (and some RF): EM dipoles in food rotate to align with fluctuating EM field, called dielectric heating. Also see ion-drag. Infrared: causes vibrations in the molecules. Visible/UV: typically absorbed by electrons, then can be re-emitted at lower energies to xfer heat. Microwaves are nice because they can penetrate deeper into food. Also note they run at high energy: ~1 kW.
The photoelectric effect shows that light interacts as a single particle, or quanta (not as a wave) and the energy is proportional to its frequency, as in E = hf (with E = energy, h = Planck's constant and f is the frequency). So what does the frequency refer to in this context ? And just to 'warn' you: I have had not only different but contradictory answers to this question from several qualified physicists. And you might also like to describe the size and shape etc of a quanta of light.
I met Roger Penrose in Oxford and he was talking about these ring features in the CMB from colliding black holes from BEFORE the big bang. I asked him about the Planck data which he said he was looking forwards to seeing, as these features were seen in the WMAP data. Any ideas about this? It's not a theory I've heard much about.
This, yes, THIS! 1. Does the CMB have a rest frame, and are we moving relative to it? (Possible dipole explanation, but it breaks everything else...) 2. COBE -> WMAP -> Planck -> ??? What's next in exploring the whole-sky CMB? 3. What have we learned (since BICEP2) about E-mode and B-mode CMB polarization? Will this finally end all talk about cosmic strings? 4. Does CDM have any imprint on the CMB? If so, what is it and where is it? If not, why not, and what does it tell us about possible CDM candidates? So many fundamental questions!
since redshift has 'concluded' that the objects are receding from us, (one of the roots of the big bang concept), i'm trying to ask if anything else can potentially cause the observed shift in absorption lines? how good is the geometric method of distance measurement beyond a certain limit? regarding gps - aren't corrections required on top of those predicted by the relativity theories?
For the first time in my life, i actually understand the Cosmic Background Radiation. I was always so confused by the seemingly random 380,000 years and the ability to distinguish original background radiation from all other sources of heat in the universe. Thank you Brady and Ed.
I'm "assuming" that it's uniform because the premise was that the universe, including every field in it, was isotropic. The wavefunction only gives a probability distribution in the Copenhagen Interpretation, which requires something to "observe" it, but if there's nothing else there, it stays as a coherent wavefunction, and will still be uniform. In other interpretations, there also needs to be something else to interact with it non-uniformly. We don't see that, so something must be off.
Brady, regarding the spectrum part of this video, you really should make a Fourier transform video with James Grime and then building on top of that videos on formats like JPEG and MP3 with James Clewett. Oh, Wavelets would be huge while you're at it but first things first.
I remember reading that there are predictions for String Theroy in the Cosmic Microwave Background. Are those predictions met or is it still not detailed enough?
From what I have read, standard model proponents say that the Higgs fields hadn't set up until after the universe exceeded the schwarzchild radius in size.
What is the viewpoint of the map? Is it a 2D view of a spheroid universe as seen from the outside (like looking at a a globe from one angle)? I have a hard time figuring out how they can read temp differences at, for example, 1 light year out, 2 light years out, 3, 4, etc all the way to the edge of the observable universe, and in every direction. Then to place this info on a simple 2D map. Or are the measurements only taken at the outermost limit?
What are the units measured by the Kelvin scale, which happen to exactly correspond to degrees C, called? Not, "how do you say it," but, "what is that unit called?"
Could you maybe also explain how to read this map, since I assume they measured a spherical map nominal to the surface of the earth. But did they choose to represent it as an elliptical surface?
Just curious, what's going on with the equations behind Dr. Copeland? It looks like something involving gravitational potential, maybe, but I don't know what that V(phi) is supposed to be. At first I thought it was Verf and was some kind of error function.
Search The Origin of Helium and the Other Light Elements. Burbidge. Redshift is (roughly) proportional to distance as light interacts with (the plasma of) the intergalactic medium and decreases slightly in energy as it does so. Although Halton Arp has found some discordant redshifts which further complicate the issue.
Prof. Copeland could totally do a relaxation series. His voice is amazing. Here he is describing THE most violent event in the entire history of the universe and my pulse rate and blood pressure are probably the lowest they've been all day.
they used to be called degrees absolute, before they were changed to kelvins in the late '60, I wasn't correcting the prof(even if he was wrong in that one regard), I was only trying to lessen the tension the guy above me was showing. Also, wile I know what you are saying to be the official position, I don't really agree with it since the whole Kelvin scale is an expansion based on the Celsius scale like the Rankine scale is one for the Fahrenheit scale.
But that's assuming that a wave function can be completely uniform, isn't it? I mean it's probability density is just that - the probability that a particle will be at a given location at a given time. If the particle is phasing in and out of its specific locations as determined by its probability density, isn't it possible that 2 particles can potentially be closer together and form its 'bond'? And even if its wave function is uniform, it's nonzero, hence its probability density is as well.
I understand your coment and I think it's a good question. My answer is those things are observable, you can "see" how those things are in nature like the speed of light or how the energy of light transfers to heat; but what has not been understood is why they behave the way do to begin with.
From what I gathered up from other sources, the Universe cooled down to 3000K after about 380.000 years (and even for that first "few" years time, the whole universe expanded). I get, that the distiribution of energy (and thus light) was quite uniform at that time, but even looking from total opposites of a transparent sphere: Shouldn't the light have passed shortly after 380.000x2 years? Or did the space expand with a speed much greater than the speed of light?
15:32 Your question is correct, except that it's actually the cold spots that form structures. This is in spite of the contracting gas getting a little warmer. It happens because the light coming to us from the densest patches must climb out of a gravity well, and in doing so has its wavelength stretched. You then have two opposite and competing effects and gravity wins.
... we can only see as far as light can travel since it was radiated (and that far out, things generally balance out to look pretty much similar...) but the universe goes on and does not have a boundary in the spatial dimensions we comprehend, as a flat person wouldn't be familiar with the concepts of "inside" or "outside" the balloon... and the homogenization of the background radiation could be vaguely paralleled with the increasing transparency of the stretching balloon material...?
I'm not sure if you are joking, but I think it would be a good scheme to have the nice compact videos and then always have the option to watch a longer one with extra details. Its like a zoom knob for science.
It's a so-called Mollweide projection. As you probably know, any 2D map of a sphere distorts some aspects. For example, a Mercator projection of the Earth distorts the sizes and shapes of countries near the poles. Cosmologists use a Mollweide projection for the CMB, because this projection doesn't distort the sizes of the temperature fluctuations. See also wiki.
By the standard equation relating temperature to energy (E=kT/2) that particle would have a temperature of 2Eu/k where Eu is the total energy of the universe and k is boltzmann's constant. There are 2 problems with this. 1st E=kT/2 does not work for a single particle, it should be applied to macroscopic collections of particles. (Essentially temperature has to be "felt" by other particles, if there is only one there is nothing to fell hot!). cont...
Actually random thought, wouldn't places appear to be warmer than closer objects (despite actually being roughly the same temperature)? Or am I making another misconception?
Excellent video! I appreciate what you do, Brady. Hearing this stuff straight from the horse's mouth, as it were, is incredible. I wonder if all your questions are equally inspired, even the ones that don't make the final cut. Every time Professor Copeland said "degrees Kelvin," I cringed a little, but I love hearing from him. :D
remember E=MC^2. But what he was talking about is that after the basic forces froze out, then you got quarks, electrons etc., then you got protons neutrons, etc., then after 380,000 years you got atoms.
Can anyone tell me why WMAP and Planck's model are an elongated sphere? Is this the shape of the areas that we can detect or is this the shape of the universe?
so basically background light is light coming from time,is there any possibility to see/verify what there really is in more recent time in those regions of space corresponding to that sources?I'm not sure this question makes sense.
OK I get how the CBM came into existance and what we can read of the measurements, what I don't get is: Why can we still measure the CBM radiation? From my understanding we can 'sense' radiation only, if it's headed towards us. Like when it's emitted (a fire or the sun in case of light and warmth), or reflected in the right direction. If the radiation departed the moment atoms formed, shouldn't the CMBR be long gone at speed of light, without anything out there to deflect it back to us?
Professor Coplend can announce the end of the world without causing public panic
Because 80% of the people listening wouldn't understand him, and the 20% that do would accept fate and maybe even be a little relieved by it.
@@SkywalkerSamadhi ugh
false.
Brady asking questions while filming is an important part of why these videos are good. It gives us the layman's perspective as well in a very natural way. :)
Professor Copeland is easy to listen to without getting bored or sleepy!
maybe a little sleepy, he's got a soothing voice. i'm thinking of asking him to marry me and read bedtime stories aloud every night
Who thinks Copeland is the best and most calm physicist in this channel?
This is glorious, I have been researching "what universe is earth in?" for a while now, and I think this has helped. Have you heard people talk about - Bannrial Bizarre Bulldozer - (Have a quick look on google cant remember the place now ) ? It is an awesome exclusive product for discovering your spiritual animal and the clues it has to your future success without the normal expense. Ive heard some incredible things about it and my work buddy got cool results with it.
He is the antithesis of Moriarty. If they ever meet and touch they will cancel each other's existence out, and the world will be an emptier place.
Affirmative.
I only come to this guy for my dark matter content.
you obviously haven't watched the four types of multiverse episode
One reason Brady is so terrific in these videos is that he asks very intelligent questions. Great job, Brady, as always. Thanks a bunch!
“If you can't explain it simply, you don't understand it well enough”
Excellent video. I love these. Keep up the good work.
off all the lectures, videos etc that I have seen on this particular subject this explanation for me at least, is the best one. The way the professor explains it just clicks like a light bulb just lit up lol Thank you for this video I truly do enjoy Dr Copeland and his way of explaining things. It would be just a privilege to take any class from him in my honest opinion.
Yep, totally agree.
What a wonderful man. Not assuming we are idiots but taking his time to explain it with out using layman analogy so we actual learn about how it worked. Thank you Prof Copeland I truly appreciate you.
Simple and easy to understand without turning us into fools and giving "dummy" examples. Excellent video! Thanks!
for me it wasnt that easy to comprehend fluctuations in the field that imprinted themselves on what ? is CMB old light, or those fluctuations in the quantum field, or is CMB statisticly calculated by subtracting all other radiation ?
i would be grateful if u could explain me this, i envy u that u can understand this stuff that easy..
MarakanaCacak1989 The cosmic background fluctuations were captured by the COBE (cosmic background explorer) satellite. Cosmic background is basically old light yes, and that light traveled long distances to reach cobe. What happens when light travels long distances is that it's wavelength changes through space. So scientists look at the sky with cobe and capture a lot of kinds of wavelengths, but they know what wavelength to expect and what not to... And they map the cosmic background. Anyway, if you want a suggestion to read more about stuff being explained from the very basics go take a look at Stephen Hawkings books "a brief history of time" and "the universe in a nutshell "
Igor Perfeito Vivo thank you very much
Hook 'Em Horns!
sixtysymbols is the best science channel on youtube. Thanks for all the videos
This prof is my favorite, he always has a smile on his face when he gets to answer Brady's questions.
Man I love these lengthy videos :) 17 and a half minutes of awesome!
Keep it up Brady (and the rest as well of course)!
I did my 3rd year physics project on this, glad to see it being explained so well so everyone can appreciate this beautiful piece of data ❤
Amazing video Brady and Ed. 17 minutes of my life well spend. Wouldn't mind watching more about Planck and the CMBR though I know there isn't a lot more to talk about right now.
Keep up the great work. Your work is greatly appreciated!
Brady: thank you for asking questions we all have!
I really like Prof Copeland's way of explaining things. You can tell that he has a really solid understanding of the fundamentals.
Why does this line up with earth and our solar system?
The only question I have too... more than an anomaly
@@mirrariz4248 Only because we are the observer. Everything we see becomes a perfect sphere around us
This was the best explanation of the CMB I've seen on YT yet. Fantastic video.
Please someone answer this question if you can. If this light was released a few hundred thousand years after the big bang, how did we (our matter) get to where we are now, before this light reached us? The universe doesn't expand faster than light does it? If it did the light would never reach us. Wouldn't we have to out run it for some of the 13 billion years then slow down for it top catch us up? Which I know doesn't make sense.
Let me try to (partially) answer your question. You seem to imagine that we are at a 'location' where we weren't in the past. On the large scale (galactic supercluster level) we aren't moving and haven't moved - much. The expansion of the universe is the expansion of space, not specifically objects moving apart - even though it seems that way. This means that there is no central point in the universe. Everything on a large scale, appears to be moving away from us, so it SEEMS like we're in the middle, but if you were to go to a galaxy 10 billion light years away in any direction you choose, it would look the same. You'd still appear to be in the middle. The universe appears to be spherical, with us at the centre. But, due to the finite speed of light, you could never get to the 'edge' - not even theoretically.
As for the universe expanding faster than the speed of light (c), think of it this way: Nothing can move past another thing faster than c. But picture a galaxy 5 billion light years away, moving away from us at 55% of the speed of light (this might not be an accurate figure - I'm going from memory) relative to us. Now imagine that a galaxy 10 billion light years from us is moving apart from the first galaxy at 55% the speed of light. Add the 2 velocities together and you get 110% of the speed of light - which should be impossible. But it's not, because nothing on a local scale is moving apart at more than 186 thousand miles per second (c). It's the SPACE which is expanding, and the accumulation of sub c velocities (on a large scale) CAN exceed c. This is why we estimate the size of the universe to be some 90 billion light years across, not 2 x 13.8 billion, which you might expect. Just remember that it's the SPACE which is expanding!
finlarg if the relative speed between 2 galaxy is 110% c then how are we able to se the photons released by galaxy
Deepanshu Gajbhiye Because we are seeing photons from it when it was younger and closer. If it only came into existence 'now', we would never see it - it would be beyond our horizon.
but i cant understand how that photon is able to reach us also i dont think that that photon can exceed speed of light bcoz it will require very high energy and extremely low mass as E=MC2 then c= sq root of E/M
Deepanshu Gajbhiye You're mistaken to think of 'that photon'. Photons are continually streaming from all stars and galaxies. When we look at a galaxy which is 10 billion light years away, we are seeing it as it appeared when it and the universe were only 3.8 billion years old. All of the photons it emitted after that point, haven't reached us yet. In the far future, it will disappear from sight, because of the expansion of the universe. This does not mean it has ceased to exist, but it means that the expansion we talked about before has caught up with us.
This guy is so likable. He speaks so clearly and has such a pleasant attitude. I really enjoy his videos.
Many of the questions below fall into place one you recognize the "axis of evil" puts Earth near or at the center of the universe.
The Axis of Evil is only there when you're particularly looking for it. It's been now pretty much proven without doubt that these where data fllukes.
@@Raydensheraj
Nope!......Planck CONFIRMED the anomalies and the data showing the Earth centered universe. :-)
Brady, you always ask the questions I am thinking. It helps me get the most out of the topic! Thanks for the great questions!
Wish I had this quality of professors at my university. Mine seem more worried about gender neutral pronouns.
@ thomas: I initially read your comment too quickly and thought you said "gender neutral protons"!
Sixty Symbols videos are always great, but I feel like Professor Copeland outdid himself with the explanations in this video. Thank you, Grady and Professor Copeland!
Brady's videos are awesome. They are extremely interesting and extremely informative. They encourage people to learn, and as everything is explained everyone should be able to understand. Brady, you are awesome.
When I am bored or sad or down for any reason, I always come here ( to this channel) and listen to Prof. Copeland talk
Hi Brady! :) You are doing a wonderful work as always! This is one of the most interesting videos you ever made and I would be really thankful if you could add English subtitles :D
Thanks :)
Brady, thank you for showing the sheer level of fascination and wonder that all of your interviewees bring to their respective fields. A question for you: have you considered doing any bits on the professors' reactions to fringe propositions? Asking Prof. Copeland, for example, about Plasma Cosmology; or, say, Dr. Aboobaker about ID?
I'm keen to see how each deals with the woo in hir field.
Be that as it may, congratulations for being so amazing!
I wouldn't say a science geek, but a more humble human being... definitely :)
Astronomy, Cosmology and Physics, when well understood, usually leaves someone in awe and it changes a person for the better.
It's using the Mollweide map projection, it exists to enable more accurate proportions (so one area on the map of a certain area should have about the same mapped area as any other), at the expense of being less accurate in terms of shape.
It is of course possible to map the data to any map projection, but using one that favours proportions over shape makes a little more sense in this case because it makes it easier to compare different spots.
it's because he seems patient and soft spoken. calm and professional. exactly what a professor should be. =]
This is the clearest most understandable explanation I have yet heard about the beginnings of the Universe & the forces & energies involved in its expansion/inflation. Trying to reconcile the extremes of scale is taxing.
Please thank Professor Copeland for his patient & thoughtful explanations.
7:42 thank you so much brady for asking this question and appearing "silly" in front of a specialist in the field, I have asked myself this plenty of times but as I dont study cosmology I always thought it was just too technical for me to understand. Thanks!
Another excellent and interesting video, thanks Brady and Prof. Copeland
WOOOOW! Brady you saved my day! I was bored so I looked loaded youtube and first video on my subscription list was from SixtySymbols and it was 17 minutes long! Thank you for your work!
Hi Brady, will you be putting up an uncut version of this video? Would really like to hear the rest of Professor Copeland's explanations :)
brady always asks the best questions.
The universe was opaque from the very start until the 380 ky epoch. The fluctuations in the inflation field led to fluctuations in the plasma that persisted until decoupling, at which point the spectrum became permanently fixed (ignoring cooling and matter interference) with those fluctuations embedded.
Have they talked about peculiar velocity and how it doppler shifts the CMB? Also the consequences of having a natural "rest" frame in which the CMB is isotropic? I'd like to hear more on that.
You have so many videos, one of copelands videos gave me such a profound sense of appreciation of space. I self realized as a grain of sand grown of this great wave that happened to wash to the surface on a great wave. I wish I could’ve book marked that video
This might be the best explained sixtysimbols video so far. I have understood almost everything :)
You are right, and I am quite sure he knows Kelvin is not counted in degrees, but just to clarify for people who might have heard/ thought it was this way. Also note (can't remember if he said this in the video) that the Celsius scale scales the same way the kelvin does, so the unit "Kelvin" \\Is the same as\\ the unit "Degrees Celsius", only with different datums.
Great to watch this after the latest discoveries and, of course, Brady's videos. A storyline of possible discovery!
I love the way Brady asks questions.
The way in which we measure temperature is by monitoring radiation from the target object, or reflecting radiation off the target object. The radiation itself is bound by the speed of light.
That said you make an interesting point about the temperature being roughly the same everywhere. I had made a misconception about what they were talking about, as I thought the were talking about the edge of the observable universe.
Great explanation. This makes the CMBR much more understandable.
The Univers is 2,73K or to be very exact 2,7255K. The temperature differences between cold and hot spots is within 200 microK. The cold spot means CMB signal basically missing compared to reagions nearby. Nice interview!
In portuguese we say the corresponding to "X degrees Kelvin" much like we also say "Y degrees Celsius". This is because it helps your public better grasp the context of the sentence and is considered confusing/incorrect if not applied.
(character limit)
What I'm struggling to understand is the difference between your capitalised how and why questions. It seems to me that in this case the two are equivalent. I could easily be wrong and I'm sorry if I'm not more helpful, but your original question intrigued me :)
Penrose actually published a paper on certain observed anisotropies in the CMB data from WMAP a while back, which suggested the effects of a universe prior to the big bang. It's on arXiv somewhere! He also has some popular lectures on youtube about the theory. He's a pretty sound guy.
Most photons can xfer heat in some way, depending on the material (I'm glossing over a lot due to char limit):
Microwave (and some RF): EM dipoles in food rotate to align with fluctuating EM field, called dielectric heating. Also see ion-drag.
Infrared: causes vibrations in the molecules.
Visible/UV: typically absorbed by electrons, then can be re-emitted at lower energies to xfer heat.
Microwaves are nice because they can penetrate deeper into food. Also note they run at high energy: ~1 kW.
Brady is so frickin' good at asking questions.
The photoelectric effect shows that light interacts as a single particle, or quanta (not as a wave) and the energy is proportional to its frequency, as in E = hf (with E = energy, h = Planck's constant and f is the frequency). So what does the frequency refer to in this context ?
And just to 'warn' you: I have had not only different but contradictory answers to this question from several qualified physicists.
And you might also like to describe the size and shape etc of a quanta of light.
08:00 "This is what makes this so cool" Truly a man who loves science. Well done lesson on CMB and Plank without the maths.
I haven't started the video yet; I'm basking in anticipation of the next seventeen minutes. More long physics!
I met Roger Penrose in Oxford and he was talking about these ring features in the CMB from colliding black holes from BEFORE the big bang. I asked him about the Planck data which he said he was looking forwards to seeing, as these features were seen in the WMAP data. Any ideas about this? It's not a theory I've heard much about.
This, yes, THIS!
1. Does the CMB have a rest frame, and are we moving relative to it? (Possible dipole explanation, but it breaks everything else...)
2. COBE -> WMAP -> Planck -> ??? What's next in exploring the whole-sky CMB?
3. What have we learned (since BICEP2) about E-mode and B-mode CMB polarization? Will this finally end all talk about cosmic strings?
4. Does CDM have any imprint on the CMB? If so, what is it and where is it? If not, why not, and what does it tell us about possible CDM candidates?
So many fundamental questions!
since redshift has 'concluded' that the objects are receding from us, (one of the roots of the big bang concept), i'm trying to ask if anything else can potentially cause the observed shift in absorption lines? how good is the geometric method of distance measurement beyond a certain limit? regarding gps - aren't corrections required on top of those predicted by the relativity theories?
For the first time in my life, i actually understand the Cosmic Background Radiation. I was always so confused by the seemingly random 380,000 years and the ability to distinguish original background radiation from all other sources of heat in the universe. Thank you Brady and Ed.
I'm "assuming" that it's uniform because the premise was that the universe, including every field in it, was isotropic. The wavefunction only gives a probability distribution in the Copenhagen Interpretation, which requires something to "observe" it, but if there's nothing else there, it stays as a coherent wavefunction, and will still be uniform. In other interpretations, there also needs to be something else to interact with it non-uniformly. We don't see that, so something must be off.
Brady, regarding the spectrum part of this video, you really should make a Fourier transform video with James Grime and then building on top of that videos on formats like JPEG and MP3 with James Clewett. Oh, Wavelets would be huge while you're at it but first things first.
Yay! Thank you Brady for this, been wanting a CMB video for a while.
Was hoping you'd do a video on this, thanks Brady!
When they say very small variations of temperature in the CMB radiation, are they talking about density of photons or about wavelength of photons?
I remember reading that there are predictions for String Theroy in the Cosmic Microwave Background. Are those predictions met or is it still not detailed enough?
Best explanation i have seen so far. Great!
From what I have read, standard model proponents say that the Higgs fields hadn't set up until after the universe exceeded the schwarzchild radius in size.
What is the viewpoint of the map? Is it a 2D view of a spheroid universe as seen from the outside (like looking at a a globe from one angle)? I have a hard time figuring out how they can read temp differences at, for example, 1 light year out, 2 light years out, 3, 4, etc all the way to the edge of the observable universe, and in every direction. Then to place this info on a simple 2D map. Or are the measurements only taken at the outermost limit?
Conformal topology :-) It preserves the angles even through the transformation. Local scale in every direction is constant.
What are the units measured by the Kelvin scale, which happen to exactly correspond to degrees C, called? Not, "how do you say it," but, "what is that unit called?"
Thanks for making these Brady!
Could you maybe also explain how to read this map, since I assume they measured a spherical map nominal to the surface of the earth. But did they choose to represent it as an elliptical surface?
Very well explained and informative to untrained ears, relevant and discuss-able to professionals
Just curious, what's going on with the equations behind Dr. Copeland? It looks like something involving gravitational potential, maybe, but I don't know what that V(phi) is supposed to be. At first I thought it was Verf and was some kind of error function.
On the graph you show at 15:05, why is the uncertainty so big when the angular scale is bigger?
Search The Origin of Helium and the Other Light Elements. Burbidge.
Redshift is (roughly) proportional to distance as light interacts with (the plasma of) the intergalactic medium and decreases slightly in energy as it does so. Although Halton Arp has found some discordant redshifts which further complicate the issue.
Prof. Copeland could totally do a relaxation series. His voice is amazing. Here he is describing THE most violent event in the entire history of the universe and my pulse rate and blood pressure are probably the lowest they've been all day.
they used to be called degrees absolute, before they were changed to kelvins in the late '60, I wasn't correcting the prof(even if he was wrong in that one regard), I was only trying to lessen the tension the guy above me was showing.
Also, wile I know what you are saying to be the official position, I don't really agree with it since the whole Kelvin scale is an expansion based on the Celsius scale like the Rankine scale is one for the Fahrenheit scale.
But that's assuming that a wave function can be completely uniform, isn't it? I mean it's probability density is just that - the probability that a particle will be at a given location at a given time. If the particle is phasing in and out of its specific locations as determined by its probability density, isn't it possible that 2 particles can potentially be closer together and form its 'bond'?
And even if its wave function is uniform, it's nonzero, hence its probability density is as well.
I understand your coment and I think it's a good question. My answer is those things are observable, you can "see" how those things are in nature like the speed of light or how the energy of light transfers to heat; but what has not been understood is why they behave the way do to begin with.
From what I gathered up from other sources, the Universe cooled down to 3000K after about 380.000 years (and even for that first "few" years time, the whole universe expanded). I get, that the distiribution of energy (and thus light) was quite uniform at that time, but even looking from total opposites of a transparent sphere: Shouldn't the light have passed shortly after 380.000x2 years? Or did the space expand with a speed much greater than the speed of light?
15:32 Your question is correct, except that it's actually the cold spots that form structures. This is in spite of the contracting gas getting a little warmer. It happens because the light coming to us from the densest patches must climb out of a gravity well, and in doing so has its wavelength stretched. You then have two opposite and competing effects and gravity wins.
Great Scott! Light from cold and heat from dark.
Brady, Can you do a video explaining the Standard Model?
How did you determined north and south in the map, or was it completly arbitrary?
... we can only see as far as light can travel since it was radiated (and that far out, things generally balance out to look pretty much similar...) but the universe goes on and does not have a boundary in the spatial dimensions we comprehend, as a flat person wouldn't be familiar with the concepts of "inside" or "outside" the balloon... and the homogenization of the background radiation could be vaguely paralleled with the increasing transparency of the stretching balloon material...?
I'm not sure if you are joking, but I think it would be a good scheme to have the nice compact videos and then always have the option to watch a longer one with extra details. Its like a zoom knob for science.
Absolutely agree with you! But i love your choice of the word "devolve" ;)
It's a so-called Mollweide projection. As you probably know, any 2D map of a sphere distorts some aspects. For example, a Mercator projection of the Earth distorts the sizes and shapes of countries near the poles. Cosmologists use a Mollweide projection for the CMB, because this projection doesn't distort the sizes of the temperature fluctuations. See also wiki.
By the standard equation relating temperature to energy (E=kT/2) that particle would have a temperature of 2Eu/k where Eu is the total energy of the universe and k is boltzmann's constant.
There are 2 problems with this. 1st E=kT/2 does not work for a single particle, it should be applied to macroscopic collections of particles. (Essentially temperature has to be "felt" by other particles, if there is only one there is nothing to fell hot!).
cont...
Actually random thought, wouldn't places appear to be warmer than closer objects (despite actually being roughly the same temperature)? Or am I making another misconception?
This channel should be pumped into schools.
This should have been in two parts. A viewer questions video should also be made.
Excellent video! I appreciate what you do, Brady. Hearing this stuff straight from the horse's mouth, as it were, is incredible. I wonder if all your questions are equally inspired, even the ones that don't make the final cut.
Every time Professor Copeland said "degrees Kelvin," I cringed a little, but I love hearing from him. :D
I love Prof. Copeland. I don't know what it is but I think he's awesome.
remember E=MC^2. But what he was talking about is that after the basic forces froze out, then you got quarks, electrons etc., then you got protons neutrons, etc., then after 380,000 years you got atoms.
Ed Copeland rocks! And I love the board full of equations in every sixtysymbols video! xD
Can anyone tell me why WMAP and Planck's model are an elongated sphere? Is this the shape of the areas that we can detect or is this the shape of the universe?
so basically background light is light coming from time,is there any possibility to see/verify what there really is in more recent time in those regions of space corresponding to that sources?I'm not sure this question makes sense.
I like this guy's voice, it's so calming.
OK I get how the CBM came into existance and what we can read of the measurements, what I don't get is: Why can we still measure the CBM radiation?
From my understanding we can 'sense' radiation only, if it's headed towards us. Like when it's emitted (a fire or the sun in case of light and warmth), or reflected in the right direction.
If the radiation departed the moment atoms formed, shouldn't the CMBR be long gone at speed of light, without anything out there to deflect it back to us?