I have seriously written two small books as I have treated multiple series as an actual college class with pictures graphs tables and all! Thank you for providing such high level lectures. This is a gold mine and fairly up to date too? Kudos.
Thanks for the compliment. It is up to date as far as the video’s publish date. Things do change, but if there are paradigm shifts, you hear about them.
Great! I went to gaze at the Milky Way this weekend at Joshua Tree National Park. Partly inspired by the fact I hadn’t seen it in a while. I hope many others are inspired to go somewhere remote to do the same after watching your videos.
Jason... may I congratulate you? :-) I come from electronics engineering (almost 38 years ago now) and I literally haven't had any reason to use calculus since about 1989. I'm not ashamed to admit I'm rusty as an old saw with a lot of the mathematics required here... but being eased back into it in small steps through what you've offered here as a whole undergrad "intro to astronomy" has both reminded me of math I already know but had "forgotten" until this, *and* taught me a hell of a lot of math and other stuff I never knew. Seriously, this (all 14 multi-lecture installments) is exactly the sort of "layman with some real education already" presentation that I've been seeking (but finding only partial solutions) for the past 20 years. On top of that, you're a pretty genial presenter who doesn't make a big deal of the inevitable errata and "oops" moments. Having been a teacher myself, I know *that matters*. Mazel tov, mate.
Your channel is a gold mine and I will be back to dig. Right now I just don't have enough time to watch all those awesome cosmic scale length lectures. But I'll find it.
I think what makes your lectures so entertaining (besides your obvious expertise at teaching it) is your genuine desire to share your passion on these topics so others can feel it too. Thank yous = )
I like Sir Rodger Penrose's wild idea about heat death. If all the mass decays, even leptons, and all you're left with are photons, then there's no mass left in the universe. If there's no mass left, there's nothing left in the universe that experiences the passage of time. Without time, there's no way to judge scale, all sizes are indistinguishable. At that point, he imagines, what if the universe just suddenly "decides" that it isn't big at all, in fact it's very, very small, and all that vacuum energy explodes again into a new big bang. Since he's a mathematical genius with a Nobel Prize in black hole stuff, he goes on to describe what kind of gravitational waves you might look for to see echoes of past iterations of this gogol year long cycle. I especially love the impish grin he gets on his face when he says something like this, as if he's challenging you to call him an idiot, after everything he's done :D
00:21 🌌 Introduction to Cosmology & the Cosmological Principle 04:01 🌌 Historical Perspectives on Homogeneity & Isotropy 10:43 🌌 Exploring Homogeneity & Isotropy 19:30 🌌 Albert Einstein's Contributions to Cosmology 21:36 🌌 Einstein's Cosmological Constant & Static Universe 27:36 🌌 The Resurgence of the Cosmological Constant 32:25 🌌 Foundations of the Big Bang Theory 37:13 🌌 Testability & Empirical Evidence of the Big Bang Model 43:36 🌌 Redshift, Scale Factor, & Hubble Parameter 46:05 🌌 Relationship between Scale Factor, Hubble Parameter, & Redshift 50:57 🌌 Universe Expansion: Forever or Collapse 53:05 🌌 Equations Governing Universe Expansion 56:28 🌌 Cosmic Density & Curvature 01:03:33 🌌 Determining Cosmic Density & Curvature 01:05:52 🌌 Density of the Universe 01:08:12 📊 Factors Affecting Hubble Parameter 01:14:21 📈 Evolution of Universe Expansion 01:18:09 🔍 Understanding Age of the Universe 01:22:50 🌌 Implications of Universe's Age 01:28:04 🌌 Understanding Distance in Cosmic Time 01:40:50 🌠 Cosmic Microwave Background: Observational Evidence for the Big Bang 01:43:20 🔥 Thermodynamics & the Cosmic Microwave Background 01:49:23 🌌 Big Bang Theory & Black Body Radiation 01:53:36 📡 Discovery of Cosmic Microwave Background Radiation 02:00:04 🔍 Confirmation of Black Body Radiation 02:11:04 🌌 The Universe at Redshift 1100 02:12:54 🎇 Formation of Cosmic Microwave Background 02:17:03 📏 Measurement Techniques & Anisotropies 02:26:26 🔍 Interpretation of Planck Data 02:32:51 🌌 Big Bang Cosmology: Parameters of the Universe 02:36:06 🌌 Cosmic Microwave Background & Structure Formation 02:38:40 🌌 Journey of Light Through Space & Time 02:40:44 🌌 Significance of Cosmic Microwave Background 02:42:08 🌌 Elements of the Big Bang Model 02:46:52 🌌 Overview of Particle Physics in Cosmology 02:54:28 🧱 Formation of Matter in the Universe 02:55:38 🔍 Exploring Early Universe Conditions 02:58:02 ♨ Nucleosynthesis inthe Early Universe 03:03:32 🕒 Evolution of the Universe in the First Microsecond 03:07:03 🌌 Epochs of Temperature Evolution 03:14:29 🌌 Origin of the Universe's Chemical Composition 03:16:45 🌟 Impact of Recombination on Cosmic Evolution 03:19:01 🔬 Observational Confirmation of Nucleosynthesis 03:20:24 📊 Empirical Validation of Big Bang Theory 03:26:05 🌠 Formation of Stars & Galaxies 03:31:08 🧬 Key Evidence for the Big Bang 03:36:59 🌌 Understanding Galaxy Clusters 03:39:16 🔭 Probing Dark Matter & Inter-cluster Medium 03:48:48 🌌 Formation of Large-Scale Structure 03:53:56 💻 Simulating Large-Scale Structure Formation 03:58:03 🌌 Overview of Dark Matter Distribution 04:01:28 🌀 Modeling Cold Dark Matter & Galaxy Formation 04:05:07 📊 Comparing Simulation Results with Observations 04:09:02 🌌 Mapping Large-Scale Structure Formation 04:12:27 🌠 Impact of Cosmic Microwave Background on Structure Formation 04:19:22 🌌 Understanding the Composition of the Universe 04:22:08 🌠 Exploring Early Universe Cosmology 04:25:38 🔄 The Flatness Problem in Cosmology 04:38:10 🌐 Addressing the Horizon Problem 04:40:16 🌌 Understanding the Horizon Problem 04:44:51 🌀 Exploring the Monopole Problem 04:51:10 🔍 Understanding Unification of Fundamental Forces 04:57:34 🌠 Exploring the Planck Epoch 05:00:47 🌌 The Early Universe: Planck Epoch & Grand Unification Epoch 05:03:46 🚀 The Inflationary Epoch 05:06:46 🔄 Solving Early Universe Problems 05:14:26 📊 Mechanism & Observational Evidence of Inflation 05:22:23 🌌 Understanding the Planck Epoch & the Beginning of the Universe 05:25:43 🕰 Insights into the Early Moments of the Big Bang 05:29:00 🌌 Exploring the Fate of the Universe through General Relativity 05:37:40 📐 Mathematical Approximations in Understanding the Universe's Evolution 05:43:36 🌌 Cosmological Parameters & Dark Energy 05:50:18 🔭 Matter Density in the Universe 05:54:20 📈 Universe Geometry & Expansion 05:55:04 🔍 Detecting Deceleration Parameter 06:04:28 🌟 Understanding Standard Candles & Distance Modulus Equation 06:08:25 📊 Plotting Distance Modulus against Redshift 06:11:41 🏆 Nobel Prize-Winning Discovery & Conflicting Teams 06:17:31 🌌 Consensus on Dark Energy & Universe's Energy Budget 06:24:44 🔮 Speculations on the Future of the Universe 06:25:27 🌌 The Stellariferous Era & the End of Star Formation 06:27:02 🌠 Future of Solar Systems & Galaxies 06:28:50 🌌 Proton Decay & End of Matter 06:31:05 ❄ Heat Death of the Universe
Thanks for the great lesson! I feel you explain things way better than most people. You do it in a way I can actually understand (for the most part haha). The older I get the more I realize I don't know! I just find this all so fascinating! Am trying my hardesr to learn. Sometimes I think maybe I am way dumber than I thought I was. This all takes time to learn, right? I hope I am not the only one. It is a lot to soak in! I really respect people who really know about the cosmos!
RUclips autoplay always seems to choose your videos to play for the last two weeks if it doesn't choose Lexi Friedman at night, and I am not an Subscriber (yet). I do have quite good and calm dreams and my head is filled with stuff about cosmology when I wake up 😊
Same here haha this starts playing after whatever relaxing song I was listening to ends. The other night I dreamed that I was listening to the radio at work and one of these lessons was on something like a podcast, while I was discussing these subjects with someone who was skeptical about cosmic expansion. I remember the person in my dream arguing that if nothing can be faster than light then how come the universe could and me trying to explain how the space "fabric" is not material so the rule doesn't apply or something like that
Still dont get the horizon problem. If everthing started from the same stuff and expanded outwards why wouldnt it end up in the same state despite being unconnected?
6:24:57 it's so funny... you just keep going with the projected age of the universe... and then keep going, and keep going... the last bit is pretty bleak. Makes you appreciate being alive today thought. = )
I always hear that nothing existed before the big bang. Not even space or time. I've heard some physicists say that we do have some reason to believe that radiation as well as quantum energy fields existed before the big bang. Thats something. Doesn't radiation need space to exist in? Can radiation exist without a place to exist in? I would like to know if you have any insights or thoughts on this.
Interesting that you found something that says radiation would exist before spacetime. But really, what is actually meant is that the paradigm of string theory or M theory would state that there exist 11 or so dimensions, some are like space and some are like time. However only the four spacetime coordinates that you know and love are “linear” and not “looped” or “compactified”. The compactified dimensions are still there today but are only noticeable when measuring on extremely small lengths or extremely short times. When they matter they are “bigger” than our familiar x-y-z-t. These little dimensions are in loops so exist “before” the onset of the ones we know and use. Quantum fluctuations in these loops are what give rise to our dimensions.
@@JasonKendallAstronomer so in essence your saying the reality and 4 perceived dimensions are really just high dimension representations only in our current active reality? Much like flat land and our three dimension realities entering theirs.
3:20:00 expansion stretches photon because they do NOT have a length associated with it. The only invariant length is the Compton wavelength in the restframe …but photons have no restframe…. Hence. The wavelength is a property of the observers frame….so it is we who are changing over time
@@JasonKendallAstronomer Disclaimer: not an asshole or scientist, just an enthusiast. 😄 In one of your videos you commented that you think dark matter might be a universal constant.
Huzzah! That certainly is an opinion I held that should be addressed. I’d have to say that opinion is something I no longer agree with. It’s very clear it’s not. However, that’s more of a thing with dark energy.
Okay, I know it's like a little kid daydream... But wouldn't it be nice to reseruct Einstien... Raise him up till he was in his twenties, raise your hands and go okay do what you need to change the world... Then once he did go... ok, pick up where you left off after general relativity with modern scientific information. My head snapped up where I once heard a Psychology professor offhandedly mention him as a case study in occupational burnout after general relativity.. he had visibly aged way past someone his age, and his advances and research never reached near the same bar afterwards. Just *imagines* it'd be so nice to have a fresh Einstien...
I have one question about the inflation idea (which I do see might be perfectly valid as an explanation for a lot of other things): Is there something about a "big-bang origin" of all we see today that *precludes* all of it having been in the thermal contact necessary for it all to have evolved as it has... *without* such inflation to account for the near-total isotropy it shows today? Seriously. It all actually *was* in exactly the needed absolutely intimate thermal contact before "inflation" began, wasn't it? Am I mistaken about anything here?
Unfortunately no. The universe doesn’t “reflect” our light back. Nor is the shape of the Cosmos spacetime spherical, closed and small such that we see the backs of our heads by looking out in one direction!
![Eminem - Somebody Save Me (feat. Jelly Roll) [Official Music Video]](http://i.ytimg.com/vi/Vwa0HenQMi4/mqdefault.jpg)
I have seriously written two small books as I have treated multiple series as an actual college class with pictures graphs tables and all! Thank you for providing such high level lectures. This is a gold mine and fairly up to date too? Kudos.
Thanks for the compliment. It is up to date as far as the video’s publish date. Things do change, but if there are paradigm shifts, you hear about them.
I made it to the end. Thanks for making this content available to the public. 👍🏼
You watched all fourteen long vids? Great!
I watched the first seven when they were many smaller parts and the last seven after the Great Compression.
You’re the first person who’s confirmed it!
Great! I went to gaze at the Milky Way this weekend at Joshua Tree National Park. Partly inspired by the fact I hadn’t seen it in a while. I hope many others are inspired to go somewhere remote to do the same after watching your videos.
I wish there was a way to properly honor those who made it all the way through.
Hard to find this kind of awesome material on the internet. Thanks to you sir :D
Glad you enjoyed it!
Jason... may I congratulate you? :-)
I come from electronics engineering (almost 38 years ago now) and I literally haven't had any reason to use calculus since about 1989.
I'm not ashamed to admit I'm rusty as an old saw with a lot of the mathematics required here... but being eased back into it in small steps through what you've offered here as a whole undergrad "intro to astronomy" has both reminded me of math I already know but had "forgotten" until this, *and* taught me a hell of a lot of math and other stuff I never knew.
Seriously, this (all 14 multi-lecture installments) is exactly the sort of "layman with some real education already" presentation that I've been seeking (but finding only partial solutions) for the past 20 years.
On top of that, you're a pretty genial presenter who doesn't make a big deal of the inevitable errata and "oops" moments. Having been a teacher myself, I know *that matters*.
Mazel tov, mate.
Your channel is a gold mine and I will be back to dig. Right now I just don't have enough time to watch all those awesome cosmic scale length lectures. But I'll find it.
Add it to a playlist and come back to it each day, it'll even track where you left off.
You are an excellent teacher. Thank you
You nailed it
I think what makes your lectures so entertaining (besides your obvious expertise at teaching it) is your genuine desire to share your passion on these topics so others can feel it too.
Thank yous = )
I like Sir Rodger Penrose's wild idea about heat death. If all the mass decays, even leptons, and all you're left with are photons, then there's no mass left in the universe. If there's no mass left, there's nothing left in the universe that experiences the passage of time. Without time, there's no way to judge scale, all sizes are indistinguishable. At that point, he imagines, what if the universe just suddenly "decides" that it isn't big at all, in fact it's very, very small, and all that vacuum energy explodes again into a new big bang. Since he's a mathematical genius with a Nobel Prize in black hole stuff, he goes on to describe what kind of gravitational waves you might look for to see echoes of past iterations of this gogol year long cycle. I especially love the impish grin he gets on his face when he says something like this, as if he's challenging you to call him an idiot, after everything he's done :D
Your content never fails to amaze me and ignite my hunger for knowledge about the universe. Thank you for sparking my curiosity.
00:21 🌌 Introduction to Cosmology & the Cosmological Principle
04:01 🌌 Historical Perspectives on Homogeneity & Isotropy
10:43 🌌 Exploring Homogeneity & Isotropy
19:30 🌌 Albert Einstein's Contributions to Cosmology
21:36 🌌 Einstein's Cosmological Constant & Static Universe
27:36 🌌 The Resurgence of the Cosmological Constant
32:25 🌌 Foundations of the Big Bang Theory
37:13 🌌 Testability & Empirical Evidence of the Big Bang Model
43:36 🌌 Redshift, Scale Factor, & Hubble Parameter
46:05 🌌 Relationship between Scale Factor, Hubble Parameter, & Redshift
50:57 🌌 Universe Expansion: Forever or Collapse
53:05 🌌 Equations Governing Universe Expansion
56:28 🌌 Cosmic Density & Curvature
01:03:33 🌌 Determining Cosmic Density & Curvature
01:05:52 🌌 Density of the Universe
01:08:12 📊 Factors Affecting Hubble Parameter
01:14:21 📈 Evolution of Universe Expansion
01:18:09 🔍 Understanding Age of the Universe
01:22:50 🌌 Implications of Universe's Age
01:28:04 🌌 Understanding Distance in Cosmic Time
01:40:50 🌠 Cosmic Microwave Background: Observational Evidence for the Big Bang
01:43:20 🔥 Thermodynamics & the Cosmic Microwave Background
01:49:23 🌌 Big Bang Theory & Black Body Radiation
01:53:36 📡 Discovery of Cosmic Microwave Background Radiation
02:00:04 🔍 Confirmation of Black Body Radiation
02:11:04 🌌 The Universe at Redshift 1100
02:12:54 🎇 Formation of Cosmic Microwave Background
02:17:03 📏 Measurement Techniques & Anisotropies
02:26:26 🔍 Interpretation of Planck Data
02:32:51 🌌 Big Bang Cosmology: Parameters of the Universe
02:36:06 🌌 Cosmic Microwave Background & Structure Formation
02:38:40 🌌 Journey of Light Through Space & Time
02:40:44 🌌 Significance of Cosmic Microwave Background
02:42:08 🌌 Elements of the Big Bang Model
02:46:52 🌌 Overview of Particle Physics in Cosmology
02:54:28 🧱 Formation of Matter in the Universe
02:55:38 🔍 Exploring Early Universe Conditions
02:58:02 ♨ Nucleosynthesis inthe Early Universe
03:03:32 🕒 Evolution of the Universe in the First Microsecond
03:07:03 🌌 Epochs of Temperature Evolution
03:14:29 🌌 Origin of the Universe's Chemical Composition
03:16:45 🌟 Impact of Recombination on Cosmic Evolution
03:19:01 🔬 Observational Confirmation of Nucleosynthesis
03:20:24 📊 Empirical Validation of Big Bang Theory
03:26:05 🌠 Formation of Stars & Galaxies
03:31:08 🧬 Key Evidence for the Big Bang
03:36:59 🌌 Understanding Galaxy Clusters
03:39:16 🔭 Probing Dark Matter & Inter-cluster Medium
03:48:48 🌌 Formation of Large-Scale Structure
03:53:56 💻 Simulating Large-Scale Structure Formation
03:58:03 🌌 Overview of Dark Matter Distribution
04:01:28 🌀 Modeling Cold Dark Matter & Galaxy Formation
04:05:07 📊 Comparing Simulation Results with Observations
04:09:02 🌌 Mapping Large-Scale Structure Formation
04:12:27 🌠 Impact of Cosmic Microwave Background on Structure Formation
04:19:22 🌌 Understanding the Composition of the Universe
04:22:08 🌠 Exploring Early Universe Cosmology
04:25:38 🔄 The Flatness Problem in Cosmology
04:38:10 🌐 Addressing the Horizon Problem
04:40:16 🌌 Understanding the Horizon Problem
04:44:51 🌀 Exploring the Monopole Problem
04:51:10 🔍 Understanding Unification of Fundamental Forces
04:57:34 🌠 Exploring the Planck Epoch
05:00:47 🌌 The Early Universe: Planck Epoch & Grand Unification Epoch
05:03:46 🚀 The Inflationary Epoch
05:06:46 🔄 Solving Early Universe Problems
05:14:26 📊 Mechanism & Observational Evidence of Inflation
05:22:23 🌌 Understanding the Planck Epoch & the Beginning of the Universe
05:25:43 🕰 Insights into the Early Moments of the Big Bang
05:29:00 🌌 Exploring the Fate of the Universe through General Relativity
05:37:40 📐 Mathematical Approximations in Understanding the Universe's Evolution
05:43:36 🌌 Cosmological Parameters & Dark Energy
05:50:18 🔭 Matter Density in the Universe
05:54:20 📈 Universe Geometry & Expansion
05:55:04 🔍 Detecting Deceleration Parameter
06:04:28 🌟 Understanding Standard Candles & Distance Modulus Equation
06:08:25 📊 Plotting Distance Modulus against Redshift
06:11:41 🏆 Nobel Prize-Winning Discovery & Conflicting Teams
06:17:31 🌌 Consensus on Dark Energy & Universe's Energy Budget
06:24:44 🔮 Speculations on the Future of the Universe
06:25:27 🌌 The Stellariferous Era & the End of Star Formation
06:27:02 🌠 Future of Solar Systems & Galaxies
06:28:50 🌌 Proton Decay & End of Matter
06:31:05 ❄ Heat Death of the Universe
This is incredible! A goldmine of information! Thanks for providing it!
Thanks for the great lesson! I feel you explain things way better than most people. You do it in a way I can actually understand (for the most part haha). The older I get the more I realize I don't know! I just find this all so fascinating! Am trying my hardesr to learn. Sometimes I think maybe I am way dumber than I thought I was. This all takes time to learn, right? I hope I am not the only one. It is a lot to soak in! I really respect people who really know about the cosmos!
RUclips autoplay always seems to choose your videos to play for the last two weeks if it doesn't choose Lexi Friedman at night, and I am not an Subscriber (yet). I do have quite good and calm dreams and my head is filled with stuff about cosmology when I wake up 😊
Well, what would you like to hear about to help you dream about distant shores around the cosmos?
Same here haha this starts playing after whatever relaxing song I was listening to ends.
The other night I dreamed that I was listening to the radio at work and one of these lessons was on something like a podcast, while I was discussing these subjects with someone who was skeptical about cosmic expansion. I remember the person in my dream arguing that if nothing can be faster than light then how come the universe could and me trying to explain how the space "fabric" is not material so the rule doesn't apply or something like that
Still dont get the horizon problem. If everthing started from the same stuff and expanded outwards why wouldnt it end up in the same state despite being unconnected?
If there was not space before Big Bang then how did BB Occured and how our Universe started to expand? If something expands it need space doesn't it?
Quarks come from James Joyce
6:24:57 it's so funny... you just keep going with the projected age of the universe... and then keep going, and keep going... the last bit is pretty bleak. Makes you appreciate being alive today thought. = )
I always hear that nothing existed before the big bang. Not even space or time. I've heard some physicists say that we do have some reason to believe that radiation as well as quantum energy fields existed before the big bang. Thats something. Doesn't radiation need space to exist in? Can radiation exist without a place to exist in? I would like to know if you have any insights or thoughts on this.
Interesting that you found something that says radiation would exist before spacetime. But really, what is actually meant is that the paradigm of string theory or M theory would state that there exist 11 or so dimensions, some are like space and some are like time. However only the four spacetime coordinates that you know and love are “linear” and not “looped” or “compactified”. The compactified dimensions are still there today but are only noticeable when measuring on extremely small lengths or extremely short times. When they matter they are “bigger” than our familiar x-y-z-t. These little dimensions are in loops so exist “before” the onset of the ones we know and use. Quantum fluctuations in these loops are what give rise to our dimensions.
@@JasonKendallAstronomer so in essence your saying the reality and 4 perceived dimensions are really just high dimension representations only in our current active reality? Much like flat land and our three dimension realities entering theirs.
thank you 😌✨
3:20:00 expansion stretches photon because they do NOT have a length associated with it. The only invariant length is the Compton wavelength in the restframe …but photons have no restframe….
Hence. The wavelength is a property of the observers frame….so it is we who are changing over time
Thanks for the note!
Are you a dr, Jason? Simple curiosity
Ph D. Is that how you mean?
I’m curious how your opinion of dark matter has changed since we’ve apparently recorded a galaxy with almost none.
Which opinion do you perceive that I have which you think should be addressed?
@@JasonKendallAstronomer Disclaimer: not an asshole or scientist, just an enthusiast. 😄
In one of your videos you commented that you think dark matter might be a universal constant.
Huzzah! That certainly is an opinion I held that should be addressed. I’d have to say that opinion is something I no longer agree with. It’s very clear it’s not. However, that’s more of a thing with dark energy.
Okay, I know it's like a little kid daydream...
But wouldn't it be nice to reseruct Einstien... Raise him up till he was in his twenties, raise your hands and go okay do what you need to change the world...
Then once he did go... ok, pick up where you left off after general relativity with modern scientific information.
My head snapped up where I once heard a Psychology professor offhandedly mention him as a case study in occupational burnout after general relativity.. he had visibly aged way past someone his age, and his advances and research never reached near the same bar afterwards.
Just *imagines* it'd be so nice to have a fresh Einstien...
it's the voice
Thumb up emoji...
If inflation actually happened the. It is probably impossible to detect the curvature of the universe even if it exists.
Wonderfull source :)) You made my week
"bouncy doodle whackers" =photons
I have one question about the inflation idea (which I do see might be perfectly valid as an explanation for a lot of other things):
Is there something about a "big-bang origin" of all we see today that *precludes* all of it having been in the thermal contact necessary for it all to have evolved as it has... *without* such inflation to account for the near-total isotropy it shows today?
Seriously. It all actually *was* in exactly the needed absolutely intimate thermal contact before "inflation" began, wasn't it? Am I mistaken about anything here?
are there any baby pictures of the Milky Way in those deep field photos????
Unfortunately no.
The universe doesn’t “reflect” our light back. Nor is the shape of the Cosmos spacetime spherical, closed and small such that we see the backs of our heads by looking out in one direction!
👍👍👍👍