How cold can it get? 

Pretty sure the coldest spot in the universe is my bathroom floor in the morning.

OK, now I would love a video about negative temperatures please! Thanks for this one too, I had no idea they had come so close to absolute zero.

You can’t drop a gem like “negative kelvin” without a follow up video! Looking forward to it!

What is an absolute privilege.🙏🙏 for all of us who never went to uni.., and certainly no where near a lab.. to get to hear from / share in Fermilab.. way cool👍… cheers

I’d absolutely love to see a video about negative temperatures

Measuring it to be 38picokelvin is another genius.

Dont stop the videos man. Keep them rolling

Definitely want to know more about negative temperatures now!

i like your sense of humor.i also enjoy the way you simplify the concepts without coming off as condescending.Thats a trait of someone that's genuinely intelligent

I love the Fermilab videos. The presentation makes it easy to understand what are often difficult subjects

Never stop making these videos Dr. Lincoln!!! I have learned so much with your down to Earth teaching style. And from that I dug deeper into topics that intrigued me and learned so much more. The way you taught relativity and gravity finally got me past the hurdle I had been having fully understanding those concepts and their implications. Thank you so much and see you on 12/9/22. I'll be prepared with lots of questions if there is a Q&A.

Dude, glad you are still rockin the fermilab vids! Your articulation and humor are Absolute.

I’m more interested in how a thermometer is capable of measuring those temperatures, than how the temperatures were achieved.

Thank you for all the effort you put into your videos

I once saw the coldest place in the known universe. It was in a cupboard in the Physics department at Lancaster University in 2008. At they time, they held the record for the coldest temperature yet achieved. They've lost that record since then, of course, to those Rubidium atoms Don mentioned.

Two new things have been added to my bucket list. 1) A video explaining negative temperatures, and 2) Hearing Dr. Don's rendition of the Frozen theme song.

Fascinating! Excellent vid as always! Keep up the great work! 👍

5:44 Nice colors picked to represent different helium isotopes.

I vote for a video on negative temperatures! 👍

My bedroom at the minute

Dr. Don, we need a video to explain the other end of hot, as with Absolute Zero and the explanation of Planck Temperature. There is stuff on the Internet but a Dr Don explanation would be much better.

I must say Dr. L that this was a very very cool video! Good seeing you back here! 👍👍💥💥

1:56 got a smile back to school days with pupils being told off for using "DEGREES Kelvin" (being an absolute scale rather than relative). The history is more complex, of course. : )

I'd love to see a video on how those nano and pico-Kelvin temperatures are measured. The instruments to measure those crazy cold temperatures must be as amazing as the processes to create the crazy cold temperatures.

Awesome Video as always 🙂

YaY 🎉 Dr Lincoln is back on! I’ve missed you and your wisdom gifts.

I was just talking to my son about this the other day and asking some of these same questions. So glad to have a video on it!

Very interesting. It is mind blowing. The video was centered on the techniques to reach such insane temperatures. I was wondering how you can MEASURE such temperatures. It would be interesting to have a video on the techniques used for that.

Would love to have a video on Negative temperatures. I heard about them while studying lasers, but would like to see other examples.

Good video Dr. Lincoln, thanks.

I love the way he talks, so relaxing

According to my cold-hating husband, it's blooming freezing right now, so much so that he's just put the heating on. I've got it turned off in my room, it's not that cold! Give him until January and he'll be claiming it's as cold as the CMB 😉 Excellent video as ever! I love your explanations. 😀

We would like to see, we need, a video about negative temperatures please!

Loved the presentation. Thank you!

Love these. 🙂 Thanks so much for creating the videos. You're an excellent presenter, too, so... I think Carl would have proudly smiled in quite a congenial gesture of intergalactic amity! 😁 🐲✨🐲✨🐲✨

As always very interesting1 I would definitely be interested in a negative temperature video. How do you measure these ultra low temperatures?

amo estos videos. me gustaría el de temperaturas negativas y también algo sobre computadoras cuánticas y de grafeno. gracias

My warm thanks to your very cool presentation

Excellent video as always. I'd also like to understand more about negative Kelvin!

At 5:50 in the video, you state that the helium 3 diffuses into the helium 4 and that carries away energy causing the helium 4 to be even colder. Don't you mean the helium 3 to be even colder?

When can we expect that negative kelvin video?

Sounds like nothing in the universe can get as cold as those micro, nano and picokelvins in the lab. But isn't the temperature of super-massive black holes technically near or even below a picokelvin?

Mind-blowing ... thank you for the informative video.

Just found Fermilab this morning. What a perfect site for those of us that are curious but ignorant. Great presentations.

Fahrenheit is actually based on the freezing and boiling points of brine, a particular ratio of a mixture of salt and water, because brine's freezing and boiling points are much more stable and consistent then that of water, who's freezing and boiling points can vary quite a bit depending on atmospheric pressure, which varies with altitude and can even vary in a single place (barometric pressure)

Yes more videos! And singing too, anytime. Thank you very much.

Thank you very much publisher another interesting lecture.

These Fermilab videos are excellent.

This entire video was a tease. Now I want to see dedicated videos on each method of cooling, negative Kelvin temps, and the quantum issues of absolute zero.

dr. Lincoln, you're the man. I would like to always heard deeper insights to these topic´s, like negative temps, as thoroughly as you did with relativity. I didn't know that fermilab is such a big deal. I live in Europe, an thought you are some doctor working at some "doctor facility", and fermilab was your "youtube" lab/ something "made up" name for youtube, but dammit, fermilab is the real deal 8) Absolute gold content, one of the most underrater or more likely, under-watched channels there is

Whenever you upload a video and I notice it in my notification box I get Goosebumps

Haha great job on this one. Especially the cut at the end lol

Amazing video Dr Lincoln ❤

This was amazing. Thank you

Totally want to see the video on negative temperature and see how you'd teach the concept of population inversion. :) Also, make a separate version with the singing. We all wanna hear that!

I like these video's. Don't get too nerdy or arrogant and are very easy to understand. Thank you

Very interesting, great video.

thanks for the video. Very informative.

All I want for Christmas is Dr Lincoln doing a negative kelvin video

every video I seen from this channel is not wasting any time it even goes a little bit too fast for me I am 57 but I can always rewind and go back till I get it. ;)

THANK YOU... PROF. DR. LINCOLN...!!!

Thanks. That was really cool.

With respect, Black hole temp is absolute zero. Subscribed just now. Great video!

Let Dr Don sing the song! LOL, wonderful ending.

I just happened to read this (link shared). Would love to see you explains this. Thanks 😊

superb - as usual

Very interesting! I would love to see a video about negative temperatures.

Yeah Don, we're gonna need that video on negative temperatures

Very interesting. I would love to see a video of the professor singing "Let it go". Please!

Elegant explanations

VERY NICE PRESENTATION !

Fascinating!

I wish Disney would reach out to Dr. Lincoln to make educational animated videos.

Hello. I love your videos and you were able to personally answer a question for me no one else had. How about a video on Dark Matter vs. MOND.

That was the best exercise of editorial control I have ever seen.

Ok, dumb question I guess, but how do whatever contains these low temps keep from becoming brittle like the flower dipped in liquid nitrogen? I assume the gas or liquid is “suspended” somehow by magnets or something but it must still be pretty cold inside these cavities, no? Is a vacuum good enough to keep transfer of temps out of the equation?

Very interesting, but one small detail was left out. What is the theoretical limit imposed by the plank constant?

I was waiting for the song at the end.

If I remember my physics course in school, you cannot actually observe absolute zero. Because the actual measurement of absolute zero would raise the temp above absolute zero. Much like the Schroeder’s cat postulation that by observing the state changes the state.

I really appreciate what I have learned from you >> Science! Sciences' discoveries, inventions educations had changed all the human life better every day.

Hello Dr Don! It would be magnificent if you make an splendid video on negative Kelvin Thank you very much.

I’m geographer but love this channel more than anything ❤❤❤ thank you 🙏

loved thank you

Great video! I love to be educated.

Cold temps is a hot topic! Would love to see a vid on negative kelvin?

You are a national treasure, Don.

Thank you Don. What we mean by molecules/particles vibrating is that bonding is not in perfect frequency synchronicity. That is, the pairing electrons that create a bond do not always couple and fly off as heat and the result of this is that particles momentarily move away from each other and return when bonding resumes. This is a random process dependent upon internal arrangements and external environment. When particles match perfectly in terms of quantity (mass) and kind (bonding angles) the frequency mismatch is minimised, however external environment will still have an affect. To shield from external environment one has to implement the Schwarzschild solution via magnetic field and voila! The coldest place in the Universe. Wait a minute, isn't that a black hole?

All national labs should do something similar to Dr Lincoln/Fermilab videos on their RU-vid channels as well, of course on different subjects and fields.

One of my favourite jokes from Futurama is when they’re on Pluto and Leela says “We’d best get inside, with wind chill it’s 20 degrees below absolute zero”

I did subscribe sir, and thanks for this intresting topic. I believe you're the physics god. It's hard to explain difficult and complicated physics topics in a simplified way like you do. Please can you refer me to a video discussing quatum leap and atomic orbitals it'll be very helpful.

that "0 degrees Kelvin" broke my heart a little bit, but I will let it slide because your content is so good! ^^

"Negative temperatures are just messed up and to explain them would take its own video." Well volunteered Don! I'm looking forward to it!

Thank you. 🇬🇧

Thanks for the topic guys and FAB ending....

Excellent explanation!.. thanks. Could you make a negative Kelvin video? Thanks so much!

I am now absolutely curious to understand what happens at negative Kelvin temperatures. Great video. Thawing. Thanks.

What instruments are required to measure such cold temperatures or are they inferred indirectly?

Good acting Don. It almost looked like you were ready to sing. ;O)- Btw, I do believe the absolute center (Ethereal Wave) of the quantum field is ØK.

Thanks! How about the expanding, or "new" space in void areas b/w galaxies? No particles to oscillate there?

You get extra points for showing and comparing the different temperature scale systems early on.