Does this channel pay KZfaq NOT to interrupt the lecture? Dr. Lincoln, it's always a pleasure to listen to your lessons.

When my dog gets a treat from my left hand she was expecting to be in my right, it blows her little mind...completely. That is what this video is doing to me! Thank you Dr. Don!

It is amazing that we've come in a century from the point where Eddington was asked whether it was true that only 3 people understood general relativity, and answered "who is the third?" (may not be true, but), to the stage where the general public can follow beautiful youtube videos dealing with topologies of the universe. GR is nowadays seemingly something for schoolchildren!

So well explained, and enlightening! Thank you so much.

"It's a complicated calculation but a straightforward one". Not falling for that one again.

I wish this man was my science teacher when I was in high school. Now at the age of 40 I love listening to his presentation here in KZfaq. It's so calming and informative at the same time. 😃

More videos are welcome on Space and Universe. The subject is very complex but, still easy to follow your slow and precise narration.

A fascinating presentation. This has filled in some of the gaps I had in my understanding of what I have picked up here and there all these years.

This guy is a really great presenter. One of the best on you tube. Whoever does the scripts does a great job as well.

"Space is big. Really big. You just won’t believe how vastly hugely mindbogglingly big it is. I mean you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space." -Douglas Adams

What a good explanation. Space, physics, astronomy, all they are fascinating.

Dr., sir i found your channel by chance. This is best explanation ever.

When you consider that the furthest man has been from earth is just 1.3 light seconds... Blows my mind

One of my favorite quotes by Douglas Adams: > Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

A very complex subject explained in a simple manner, great lecture

It is "mind-blowing" and in all rational aspects, seemingly inconceivable. Might as well be infinite if the visible universe is 92 billion light years in diameter but its actual size 250X that. Great video explained thoughtfully and clearly. Bravo Professor Lincoln!

I really appreciate the style of these presentations. Very clear concise and "straight forward" Thank you Dr. Lincoln..

I try to measure how much I love this channel and keep coming up with infinities in my calculations! Please make more videos Dr. L! You're the BEST!

Absolutely perfect explanation thanks for video Dr.

Respect Sir ! Appreciate Your knowledge in Astrophysics. Great work !

One of the best channels on youtube

Have never ran into this channel, and just saw this in my feed, so I thought I’d give it a go. Was beyond fascinated with the science taught. You got a new sub out of me! Tyvm! Looking forward to binge watching your channel now 👍

Thank you for this video. Great content!

Thanks a lot for your excellent presentation. Instructive, concise, and easy to understand. Just wonderful!

I have been fascinated with space since I was a child. Unfortunately I’m physics and mathematically challenged. Thanks for making this awesome knowledge understandable for people like me.

The entire video, the entire series, the entire Fermilab channel is fascinating, and we are so fortunate that you chose to share the fascination of physics with me and other physics aficionados.

It's amazing how philosophers like Aristotle and Ayn Rand have reached the same conclusions. Brilliant individuals!

Fantastic video and a new subscriber. Thanks Dr. Lincoln.

I can watch these videos over and over cause Ill never really grasp the grandiosity of it, lol. Its just mindbending, that humans are capable of such feats. Thanks Mr Lincoln for the great moderation. :)

The thing I liked the most is realistic admission that yet we don't know a great deal. Every answer presents a new query about nature.

Many thanks, great joy to watch your videos.

Fascinating stuff. He really does well explaining to the viewer in layman terms about a subject that most people know nothing or only a little about. Plus those of us who have a passion for learning more about life , the multiverse and everything

This was a really good video about truly mind-bending astronomical ideas. Thank you for creating and putting this video on KZfaq.

I was looking over the calculations on the chalkboard behind you and it appears you forgot to carry over the 1.

What I find interesting (and humbling) is that all those plants/systems/galaxies/etc. that we do see, and will never get to visit, are just the tip of the iceberg. Beyond are many, many, many more that we won't even know exist - ever.

Yes it goes on forever.

Dear Don, You routinely blow my mind, my mind hurts.... THANK YOU FOR THAT! I LOVE the videos! I think it's wonderful that you're doing them. And, thanks for that, too! 😊

i'm glad that you came back with another wonderful lesson

The most beautiful thing about the conversation is infinite possibilities, Merry Christmas!

A very good and "simple" explanation of the seize of the universe, and that is very good with numbers this big 👍

I think the thing that is mind blowing is not just how big it is, but that no matter which direction, you're always looking towards the beginning.

I’ve watched maybe 6-7 videos of this person. So far this is the best one, because it’s the most comprehensible one, the others not so much.

This channel is amazing. This contents should be in every school

Awesome presentation, Dr Lincoln 😃

Brilliantly explained! I have heard so many attempts to convey this topic and this was the most salient and clearly conveyed of them all. Well done! x

Thanks for all these great vids. Fermilab is my favorite science channel! Dr. Don explains it well!

Absolutely impressive explanation. A complex topic explained in simple words. Thank you!

Thank you sir!

Brilliant expose and breakdown. I love this channel to the edge of the universe...and back.

Amazing. Kudos for the simple way of explaining. It blew my mind, I always considered a closed “infinite” universe, now I have two other views to take into consideration. Congratulations!

So in other words we have no idea. Since it is to big to see if it is curved or flat all we can use to define it's size is Incomplete math equations. Still great lecture.

It's really, really difficult to explain complex topics in simple terms. And to do it with wicked humor is truly enjoyable.

Fascinating facts in a beautiful and easy to understand style. Thank you Mr Dan. I also love the intriguing novels of your name sake, Mr Dan Brown.

Humans tend to think in terms of everything having a beginning and an end. To think that the universe just keeps going, with no end, is mind blowing.

Fascinating thought processes!

Amazing lecturer. We often hear these facts being quoted, but to explain how we *know* them to be true without endless reams of mathematical proofs and in terms most people can understand, is a real gift

Fascinating but completely incomprehensible to me. I'm thankful that I came across this video because now I have a place I can go to learn as much about the universe that I'm capable of learing.

Eight minutes? I knew that? Don't think I could pass your Monday quiz sir. I actually attended a lecture given by Carl Sagan at Cornell University. Amazing

"I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.” - Douglas Adams

Don Lincoln knows how to explain the complicated in simple and visual terms. He's brilliant and I love his videos.

Just saw your video for the first time, I AM HOOKED!

13:22 I think you meant to say " If the universe is flat" :) You have one of my favorite YT channels thank you so much !

Quantum physicist walks into a bar. Bartender says, "Weren't you here tomorrow?" Quantum physicist says, "No, but I'll be back yesterday."

This helped me understand so much better thx I think this is my 2nd or 3rd watch over the months but it clicked more each watch. Sometimes it takes me awhile lol

This stuff is above my pay grade, but you make it interesting and much simpler to understand. Thanks and subscribed.

I knew this was my new favorite science series when he read my mind and knew I was immediately pondering "yo mama" jokes 🤣. Excellent series!!

Absolutely the size of the universe is measurable, the problem is Stanley just hasn’t made a tape measure big enough yet. Until then this was a great video! Thanks

Great detail and explanation. Thank you

Totally enjoy the presentation and the presenter. So informative. Ok, so now what is on the other side of the edge of the universe?

“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.” ― Douglas Adams, The Hitchhiker's Guide to the Galaxy

Hooked on the vids Big D. Wish they came out more often.

Regardless, wherever you go in space, there you'll be.

Talking about all that lightyears, light days and the rest got me thinking and confused too. You could do a video on if there was no black holes would the universe be bright or flooded with light? Would be worth a watch.

Thank you!!!

Welcome back, Doc, we missed you!

This channel and PBS SpaceTime give me my cosmology fix.

Thank you!!

Nice explanation, but somehow the creation hypothesis seems more plausible now. The complexity and size of it all seems unfathomable, and a intelligent 'Designer' unavoidable.

I enjoyed this, learned something, thank you.

Fully enjoyed this explanation simple and down to earth . yup space is very big and getting bigger, till when ?

Brilliant video…well done by excellent presenter !

I was expecting him at the start to go all Hitchhiker's Guide on us. "Space is big, really big. You won't believe how enormously big it is. You may think it's a long walk down the street to the chemist. But that's just peanuts compared to space. Listen..."

You have that special talent to explain complex subjects in a more easy way to understand ! That is sure a gift Dr. Lincoln... I enjoy a lot to watch your video''s here ! Thank you !

Excellent presentation!!!

it will be interesting to hear how the quantic mechanics affects all these experiments and calculation, as an observer of the experiment we know that will always affect the outcome

What a great thought experiment! Brought down to an easy to digest level. Thanks a million Doc Linc!

When you get to the end of the internet, you are almost there.

Enjoyed this, cheers!

Q if you removed the expansion of the universe and substituted the universe is it a flat, saddle, or spiracle? either as part of the redshift or intensity what would that show ChatGPT If you were to remove the expansion of the universe and consider a non-expanding universe, you would be working with a simplified model that doesn't represent the real universe as we observe it. In such a simplified, non-expanding universe, the concept of curvature (whether it's flat, saddle, or spherical) becomes more straightforward and can be determined based on the geometry of space. Here's how you would determine the curvature: Flat Universe: In a flat universe, the geometry of space is Euclidean, which means that parallel lines remain parallel, and the angles of a triangle add up to 180 degrees. Light rays travel in straight lines. In this case, if you look at a very distant light source, you would not observe significant distortions in the intensity of light or the redshift due to curvature. Saddle Universe (Hyperbolic): In a negatively curved universe (saddle-shaped or hyperbolic), the geometry is non-Euclidean. Light rays would travel along curved paths, causing the intensity of light from a distant source to exhibit observable distortions, and the redshift of light would also be affected by the curvature. Spherical Universe: In a positively curved universe (spherical), the geometry is also non-Euclidean. Light rays would travel along curved paths, but in this case, they would converge, causing the intensity of light from a distant source to exhibit observable distortions, and the redshift of light would also be affected by the curvature. In a non-expanding universe, the determination of curvature would primarily depend on the properties of space itself and the geometry of light rays, as opposed to the combined effects of cosmic expansion and curvature in the real, expanding universe. However, it's important to emphasize that the real universe is observed to be expanding, and the observations we make are consistent with a nearly flat geometry on large scales. The concept of cosmic expansion is a fundamental aspect of modern cosmology and is supported by a wide range of observational evidence. In the context of our observed universe, the concept of curvature is intertwined with cosmic expansion and cannot be separated from it.

wow. this is the perfect teaching video. thank you.

I’m pretty sure that he is saying that “Objects in mirror may be closer than they appear.” Still like the explanation though.

excellent and accessible presentation.

Where can i pick up one of those Einstein Tee's you're wearing? Knowing where and how would make me infinitely happy to do so. Thanks and Happy New Year 2023.

Dr. Lincoln actually explained how the universe can be measured in terms this Arkansas educated man understood! I don't believe anyone could have been any more informative in such a small allotment of time. Loved it!!

This was the best explanation of the cosmic microwave background. I think I finally understand it. Might have to watch it a few more times though :)

I don't know much about this but it seems to me that if the universe has an edge, then it isn't an Universe.

What I've never really seen in a video about this stuff is an explanation of A) If the universe is closed off, what is it closed off from? (yeah, I know that's probably more of a philosophical question, or it's multiverses), and B) (this is what I really want explained) is that, if the universe is flat or saddle shaped, what does that mean in regards to us living in three dimensional space? In other words, we live in three dimensional space but they always use a two dimensional example to show flat or saddle-shaped space. Soooo, if space is "flat" does that mean that they're just saying that it is relatively longer than it is "thick," like were living inside a giant, long, skinny, box of space?

This channel is so freaking awesome 😂😍😍, best physics Prof.

This is so fascinating! And the funny part is that I was thinking just a couple of hours ago about how to prove the universe doesn't end (has no edge, no boundary). Then BAM 2 hours later this video drops in front of me about the very concept I was thinking about. I think I'm destined to solve this. :)

Mind blowing that an actual calculation can be made - but what is on the other side of the edge?