I would just like to thanks Professor Copeland and Brady for taking the time to make this video.

I could listen for hours to the voice of Professor Ed Copeland regardless of the subject and regardless of whether I understand anything or not.

I love these videos. Brady asking "is this the observable universe or the whole universe" shows that there is a big problem with the way we use the word universe. We need some sort of nomenclature that is less ambiguous than "universe" and "Universe" or the cumbersome "observable universe" and "entire universe".

Brady: I'm loving these extended interviews. I know that we have part 3 yet to come, but I'm hoping that you have more of these planned. Nice job!

I like these long interviews. They give me insight into what cosmology really is, and how it's incredibly interesting. I've already decided that if at all possible, I want to be a physicist, and these videos didn't just help me make that decision, they are also helping me figure out what areas of physics are most interesting and suited to how I work. Thank you, Brady, and *Thank you, professor Copeland*.

turned it on to get asleep. got a hang of it and now I'm more awake than anyone ever being

Looking on KZfaq, I note that almost everyone, Christian, Secular, Muslim, is an 'expert' on (a) biological evolution, (b) cosmology/the 'big bang', and (c) philosophy! Except, of course, they're not, so how interesting to learn the latest ideas from someone who actually has knowledge and understanding of the subject on which he speaks. Thanks for uploading.

My favourite physicist

As I listen to Ed late in the evening, a warm, safe feeling surrounds me much like mum calming me when my imagination would run wild. So many questions about "why" interrupt my sleep occasionally, but Ed is like a hand in the deep part of a pool reassuring and giving hope and understanding to purpose and questions that elude me.

Im loving this date with Ed simulation!

The cutaway black text is really pretty bothersome, please overlay it on the video instead.

there is nothing like the sweet smell of physics first thing in the morning

I remember watching this video multiple times right after it was published; I was fascinated by cosmology and enjoyed the professor’s voice very much. It’s been 6 years: I got my bachelor’s in math last year and I am now a master student in math. Tomorrow I have a General Relativity exam. Now I understand much better, especially the pain behind all the calculations required to understand all these facts. I still love the professor’s voice!

I have nothing but admiration for the quality of Brady's work. Even his questions are intelligent and perceptive, and the answers they garner are so illuminating. Although usually fleeting one almost doesn't notice them, but succinctly they garner marvellous interesting narrative from the professor. A truly masterful journalist esp when you compare him to how journalists on broadcast TV blather on, rarely adding value, and indeed often derailing the expert. Brady, proff and Nottingham you really have enriched my life- I get excited every time you post a video, this one was so exciting in that it was lovely and long :)

wtf am i doing here, ten minutes ago i came on youtube looking how to make icecream

When I get tired, I listen to Ed Copeland to get a boost at doing a bit more research before I call it a day. All professors in Sixty Symbols are great, but Ed is the man.

I love the freaking long videos, Brady. Props to Profs Copeshnizzle for taking time out to do it along with Brady for giving it to KZfaq.

Ed Copeland is excellent. He is great at explaining very complex and difficult subjects. His manner and tone are comforting and reassuring. He is one of the best subjects for these interviews.

Was "time" constant through all the process of the bigbang? Is this taken into account when scientists say "I took 10^-x seconds for this to happen". What's the point of reference for that time counting?

Excellent - Great to hear Ed explain this cutting edge stuff so well. Love this longer, deeper format. More like this please Brady!

Brady, thank fuck you are there whenever the audience needs an analogy.

More Ed Copeland interviews. Please!

This is just brilliant! I love the calmness and certainty of Prof. Copeland when he explains these abstract concepts. I hope for many more extended interviews to enjoy. These videos makes the dark nights in Norway a bit more pleasant to endure. (Also the northern lights are quite the cheer up, but then you have to go outside and experience the cold winter night)

Well done again. I'm going to have to listen to this one again as he left me lost more than once. That's OK, though. That's how you learn.

He is one of my favorite scientists. The way he calmly talks about things makes me really hooked to the explanations. Love to watch it before I go to bed.

Accidentaly paused at 16:30 to see the happiest scientist ever :)

As I understand it, the universe never expanded "into" anywhere, but rather space puffed up -or became an aspect- of that initial sub-picometer point of energy. Taken in that sense, the current continuous influx of space which we observe as the accelerating expansion of the Universe is something like space generated by space. As with compound interest, the more space there is, the more space it generates, almost as if space itself is the root source of space. But I suppose that would produce an exponential acceleration, while I gather the current acceleration is something closer to linear. My head hurts trying to contemplate the nature of inflation. Even more-so when I contemplate the fact that something exists rather than nothing, when nothing existing would seem to make a lot more sense, unless the "multiverse" or "brane" is simply an eternal continuum.

I love the way Professor Ed Copeland explains concepts. So interesting and pleasant, I could listen all day. :)

It would be really great to have this precise interview (and ones on related concepts) repeated yearly. Same form, same physicists, same subjects. That would make an accessible and engaging record of how the picture evolves. It’s already fascinating to see the speculative comments of these amazing folks at Nottingham from, say, before and after the observation of the Higgs particle, the results from LIGO, etc...

I have a astronomy exam tomorrow, it also has this kind of things about the Big bang and inflation. We were taught that the inflation was caused by the electoweak and strong forces separating, and that area of equivalent of atom expanded to the size equivalent of the solar system, but havent been taught about the reheating. Im quite sad it was one semester course only, because it was (and is) extremely interesting. And after I've watched this I should go back revising...

Great video, as always! Brady, if I can make one suggestion it would simply be that the questions posed to the interviewees be made through a microphone, or at least have subtitles for those bits. I often watch these at low volume when my kids are sleeping so sometimes I can't hear them clearly or have to temporarily turn up the volume to hear the questions. Cheers!

Such an excellent professor, no wonder I can hear his speeches for more than 20 minutes without losing attention and remembering virtually everything he said, with a full understanding of the subject explained. I really thank you Brady for uploading those one on one interviews with Copeland regarding those subjects, even though some of those were already discussed in this channel.

I am thoroughly enjoying these longer videos! They are some of the best and most interesting ones. I would really love to hear the interviewees talk about their research in some more depth as well! Excellent content.

Have just subscribed after watching a few Sixty Symbols vids. All the professors are thoroughly engaging in the field of science they are describing. Professor Copeland sounds like a hero voyager who's returned from a deep dive in an ocean of mathematics and theories and is regaling us with key events from his adventures. Although wonderfully explained, I couldn't help but get flashbacks to Monty Python's Life of Brian where Brian is trying to escape the centurions and lands in a place where various soothsayers and prophets are talking to random people in words many of us can't understand but are nevertheless transfixed by the narrations.

Thank you for another great video. To me these longer videos are far more entertaining and educational

marvelous video! Prof. Copeland explains things so well. side note: with very soft-spoken speakers, Brady, could you maybe up the audio range?

I actually really like these long and extended interviews, you should more Brady! Also, Professor Copeland being brilliant as usual!

I'm loving periodic, numberphile and sixty symbols. Even these extended bits are keeping me stuck to the screen. Thank you Brady, thank you professors, thank you university of nottingham.

Mate, All I can say is, don't stop with any on this vids. All of them are absolutely brilliant

This is the second best grapefruit related video on KZfaq.

I honestly can't tell you how much I appreciate your videos man. Thank you!!! Such a great discussion.

A wonderful video for sure ! Its a pleasure to meet such a professor ! He has a way to simplify things into easily understandable words that otherwise nobody of us the average people would be able to comprehend ! Respect to both gentlemen for making it possible and of course to sixty symbols a huge thanks for posting it !

I really enjoy the videos with Professor Copeland, because he is easy to understand. No dialect that gets into your way. For a non-native speaker his way of speaking makes it easy to follow him.

This is so thoroughly interesting and fascinating! Thank you very much for sharing, it's a great pleasure to listen to and learn from professor Copeland. There are only few people to explain rather complex content in such engaging way!

I think it's a bit misleading to say the acoustic peaks in the CMB map perfectly into the predictions of inflation. Inflation predicts (almost) scale invariant spectra which don't have any peaks in it. The peaks come later from the way sound waves propagate in the baryon-photon plasma at the time when atoms formed and the universe became transparent. Once you account for the known physics of baryon-photon plasma you get an almost scale invariant primordial spectrum which indeed supports inflation, but the way Copeland says it a layperson might be left with the impression that it is inflation that produces the peak structure.

Brady, you ask the greatest questions.

Fantastic! Speaking as a physics undergrad, I think these videos are great; explaining the theories in simple terms so everyone can get a basic understanding. Hopefully I'll be able to contribute to these ideas in the future!

I really like these longer videos =) There are some things in this video's editing I could do without however. I flinched every time the screen suddenly went black to display a word, and I don't think it really helped my understanding or got me more interested - please just skip it next time. (That's my opinion in any case) The graphics were mostly nice, but some of them seemed a bit misplaced - like the slicing and squeezing of the grapefruit... why did you do that? I would prefer if it only cut to graphics when it really helped for explaining. I wouldn't mind just watching the professor talk in the couch for 30 minutes. You obviously put a lot of work in these videos, which I why I figured I'd give my feedback on it. Everything else was perfect as always =) I wouldn't mind seeing him talk about these subjects for several hours (or more shorter videos) if that's possible =)

So what was that sound before and after the video..that grumbling....sounded familiar...is it background radiation or something?

Brady: Thanks so much for this series! I've really enjoyed it. You may want to update the description/annotations, on this video when you get the chance; I had to search through your channel to find the third video in the series (on Dark Energy).

I've been waiting for the third part of the interview for what feels like forever!

There is something about the soothing voice and easy going mannerism of Professor Copeland that makes it a real pleasure to listen to him.

A fantastic interview with a fantastic mind. Thanks, Brady + Copeland!

great ideas loved it! hangin out for part 3 :)

I love this long format. Cheers! It's probably a lot easier to edit too, lol.

Thank you - I still don't really understand but I know a bit more about what it is that I don't really understand. It's a start!

I agree, these longer videos are great. This is one of the best and most interesting so far. Just fantastic, thanks so much and look forward to many more!

I'm not sure this has made me much wiser, but I could listen to Ed all day. Thank you, :)

these extended interviews are great. If the regular videos are like a science snack, this is a three course meal.

professors voice i so enjoyable:)

Ed's voice is so soothing.

Professor Copeland is brilliant at explaining very complex principles, I feel I understand the universe a little more now :)

I could listen to these lectures for hours.

I don't understand how scientists can talk about minutes or seconds after the big bang. Wouldn't time dilation due to the immense gravity and velocity mess with that? Are scientists able to account for it, and therefore give accurate numbers, or is it just an analogy, like quarks having color, where it helps us understand what's going on?

these three videos are brilliant. Professor Copeland has a rare capacity to explain very complicated theories in a very simple way. Congratulations.

Big question here: 1. What we are seeing in the sky it is what happened billions years ago. Because light of the stars took time to reach us. 2. We can observe the universe size is accelerating. 3. Would it be possible the universe was accelerating millions years ago. But stopped accelaring but we don't know because the information didn't reach us yet.

24 min Copeland!!! I'm truly grateful for these in depth videos.

love those videos. they are not only highly informative in the fundamental sense but all sense fill me with awe and wonder which is what I consider to be my 'spiritual' side being fed. Go Brady & Ed Copeland!

Lovely, even for a layman like me. Keep these videos coming, please! I am grateful! And thanks, Ed!

That's amazing. Great work again!

prof copeland is amazing. thanks for sharing. thanks for explaining inflation in such lighthearted way!! really enjoyable

Wonderful, brilliant breakdown and explanation. Bravo

These long videos are great!

Ed Copeland is wonderful. He has to be the best conveyor of complex subjects in physics, he makes even a simpleton like me feel they have grasped a little slice of it.

Really enjoyed this one. Professor Copeland does a very well job of explaining (his voice's so smooth :P ), and i also enjoyed the editing :)

Far out Ed's voice is so relaxing it put me to sleep haha

I like the style of this video in particular, Brady.

more please. love these long videos, thinking I might apply to nottingham university next year when I finish my AS levels

I am really enjoying these videos, it's exiting to learn about the models and theories that are currently being tested. Can't wait to actually learn in depth about such subjects and to see how the mathematics provides this evidence. As always, thanks Brady!

I like how he is calm. Plus, with how he explains, I don't feel like an idiot. He doesn't sound cocky! I feel like learning this stuff is cool!

This was exceptional! I would love it if you gave all the professors the chance to talk in depth about the things that they are passionate about.

why did you squeeze the grapefruit???

I can listen to this guy forever. Good job Brady.

Thank you very much for this very interesting video!

I really enjoyed this. Thank you.

My favourite Sixty Symbols video.

Thank you for the opportunity to watch this.

I think this is the first time i have heard a comprehensive explanation of why the cosmic microwave background radiation CMBR has fluctuation. I was a bit annoyed at times when my teachers stated the cosmological and couldn't answer why the CMBR isnt 100% homogeneous.

Oh how I love these videos! Thank goodness for such interesting people talking about such interesting topics. And of course we have Brady guiding it all behind the scenes ;)

Professor Copeland in this video you have provided an excellent apologetic. Thank you

That was just great! thanks for that, so informative !

What a great professor, explanations of these complex theories are clear an concise and waffle free. If my physics professors would have been like that, I would probably stayed in the physics field for life.

No grapefruits were harmed in the making of this video. . . 16:14 you monster!!!! lol Such an awesome video, ty!

i freaking love the editing in these videos

ty guys i've learn so much...

I really enjoyed this video!

Wish I could +1 this many time, great topic and explained very well. So nice to hear real scientist speak and say things like "I don't know" instead of these commercial scientist that speak all the time and have explanations for everything even if no one knows the answer. This is one of my favorite youtube channels by far.

Thats really opens up your mind into new ways and different possibilities to think about our universe beginning. Interesting

Great stuff but Brady please mike yourself up too - your questions are hard to hear but are very pertinent to the explanations that Ed then gives.

Ed, you are basically a super hero for physics