Absolute Zero: Absolute Awesome

Hank explains absolute zero: -273.15 degrees Celsius - and the coldest place in the known universe may surprise you.
A correction on our use of the phrase "degrees Kelvin" can be found in this video: • This Is What Climate C... - beginning at 6:43.
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References:
Minimum zero point energy derived from uncertainty principle:
hyperphysics.phy-astr.gsu.edu/...

[@vsbaratinho]

10 years after and still better than most content out there.

[@robiulhaque70]

11 years have passed, and your comment still stands true

[@evanknowles4780]

Did you hear about the time someone chilled down to absolute zero? Well he's 0K now!

[@drainscholar]

+Evan Knowles ._. Its always that joke

[@stefyxoh]

+Evan Knowles Ahaa!

[@vkdeen7570]

wow it is totally not possible to be cooler than that joke....dadum tish

[@DakshGuptaCuriosium]

+Evan Knowles cool joke.

[@2000gmod]

+Evan Knowles ICY what you did there :P But really, we need to chill down with the puns.

[@hwilliams2339]

False. The coldest place in the universe is located in my ex's heart.

[@mikeshaftx]

Savage.

[@TheStargateNerd]

Hits too close to home this one.

[@zoshiesty7150]

+H Williams W

[@jackemled]

Lies, the coldest place in the entire universe ( Not just the observable universe, but the ENTIRE FRIKN UNIVERSE. ) is Hillary Clinton's heart.

[@mikeshaftx]

jackemled So... His ex?

[@ramuk1127]

I gasped every time he said "degree Kelvin."

[@shouryanaik2622]

Me too

[@abirbhavgoswami]

Same

[@jakekerst2455]

Ramuk11 why

[@firstname405]

Because I was taught that the units 'Kelvin' were not a degree like Celcius. Water at 110degC is simply 383.15K (not 383.15degK)

[@TovaHolmberger]

yeah, you write it that way, but he's probably saying degrees to make it more obvious that it's temperature.

[@craftyisaac]

11 years has elapsed, and we now have the James Web telescope that is consistently being cooled just 6 degrees above absolute zero. Crazy how we once thought it may be impossible!

[@EdricoftheWeald]

I can deduce that the coldest place in the universe is my tent when I go camping.

[@vuvuvu6291]

Pee in it. It'll be get colder

[@mech5670]

False, the coldest place in the known universe is the other side of the pillow.

[@marca6597]

Facts

[@icemike1]

Why do you choose to do that 😕

[@B3Band]

Stop saying "degrees" Kelvin!

[@MrBrendan20004]

... But it's correct isn't it? Like Kelvin is the scale, and a single degree of it is the unit of measurement? Could be wrong, never really thought about it.

[@B3Band]

The Kelvin *itself* is the unit (as opposed to Celsius, where "degree" is the unit, and Celsius just tells you what type of degree it is). Would you say that a door is two degrees of meter height?

[@MrBrendan20004]

Well obviously not, but that's not necessarily proof of this little Kelvin conundrum. Why would we say degrees Celsius, degrees Fahrenheit, but not degrees Kelvin?

[@B3Band]

Yes! Don't take my word for it. Look it up for yourself.

[@gorgono1]

So basically if we reach the absolute zero, than we can tell the exact position of atoms and electrons right? And lets say we have a room where it is 0 Kelvin and we put a human in it, then this human will never get old, because at 0 Kelvin there is no motion, all molecules stand still, or will the human just fall apart?

[@AlchemistOfNirnroot]

Zero point energy is the minimum energy of a quantum mechanical system. Also, classical potential of the system is lower than this zero point energy due to the Uncertainty principal. Therefor motion occurs at absolute zero. Therefor you cannot tell the exact position. or momentum of subatomic particles.

[@thymeandspace110]

Also, (and I may be wrong here) But wouldn't the human's heat disperse, causing the room to warm up, even by a fraction of a degree?

[@AlchemistOfNirnroot]

Mintflight12 Well there's thermal equilibrium to consider to the surface (not core) temperature would be affected. I believe both room temp and skin temp affect each other. Not sure what you mean by heat dispersing though - could you give a brief explanation of what you mean.

[@eggkneel1943]

Theoretically; since the human's particles don't attract each other anymore since there is no kinetic energy or maybe any energy to speak of the gravity would pull down the particles to the ground and the human would disperese into it's particle composition and end up as a soup of particles.

[@ayeshakarim5967]

great!!!!....its interestingly plz tell me when u get the answer..

[@silenthero2795]

"You can't reach Absolute Zero. I know. I tried." - Sub Zero.

[@rafikamin6617]

That sub zero in celsius scale, not in kelvin.

[@CJ-ob2kv]

I guess you could say, we're the coolest planet in the universe?

[@shivarampersaud2332]

Yeah, I guess you could

[@EmmaHopman]

No, the lhc isn't 1st

[@KILLRXNOEVIRUS]

Lol, no and yes all in one XD

[@saveourplanet3728]

@@aaryanbhatia4939 have you seen star's core

[@wisdomwarrior2318]

Great pun!!! So silly

[@crackedemerald4930]

I like how most of the comments talk about ex-girlfriends

[@toddausmus7639]

Pedro Rocha I'm sure they are all perfect guys who did nothing wrong.

[@fandyus4125]

I am sure they never had a girlfriend in the first place lol.

[@ammaralnaaimi5150]

I like your show because it's simple enough for someone who hasn't encountered the topic before to understand it, and yet hinted enough so that the others can research some more independently. Well done Mr scishow, whose name I always forget. Thank you also crewmembers

[@SollowP]

I just love it that you use Celsius, kilograms and the metric scale in your videos.

[@brendenshackelton156]

did you hear about the chemist that was cooled to absolute zero? he was 0K

[@bangbangliu2146]

copied

[@senzubean1358]

Brenden Shackelton ha.

[@dani5645]

Thank you. I’ve been trying to figure out what the Kelvin scale is, for a while, now, and now I finally understand. You have a way with explaining things.

[@margingerich6181]

I just have to say, I've had kind of a tough day, but scishow videos, along with rereading TFIOS, never fail to help, so... thank you, for making this awesome happen. :) also, I like how the comments in this video are actually interesting questions-some of them, at least. You don't find that in many youtube comment sections lol

[@HYN_Media]

Hey. The coldest place in the universe could be a lab on another planet made by aliens that are smarter than us.

[@HYN_Media]

:/ it was a light heated comment. Chill them whiskers

[@bagandtag4391]

If Aliens are smarter than us do they know why is there hair around Litojony's anus?

[@kantoros]

when we say something like that, it generally means "known to man", but no one says that, because it is obvious.

[@notsoold6276]

It does say KNOWN universe, so there may be another lab, so everything here is basically invalidated because we do not know of that alien lab.

[@gabichri]

I don't believe that. Feels like no matter what, we're the most intelligent species in the universe, I mean the effort just to get to the stage we're despite the shit going on in our world... I believe in alien life just not the intelligent status or what ever.

[@Umneriko]

So I guess earth is a pretty cool placeimsorryillgodienow

[@andyyoung7657]

no! dont leave me, I thought your comment was really chillfineillgokillmyselftoo

[@21335186z]

Ican'treadwhatyoupeoplearesaying.

[@andyyoung7657]

GottaGoFa5t

[@doctoraspect5798]

8b64z icanitsreallyeasyifyouknowhowtobreakupwordss

[@samuelpalomera9390]

I love the fact that i had doubts & scishow was the first thing to come up as answer.

[@SidneyJupiter]

Hank: We know the temperature of absolute zero Me: 0 Kelvin Hank: -273 Celsius Me: GODDAMNIT! I thought I had that one!

[@RemziCavdar]

0 Kelvin = -273,15 °C (degree Celsius)

[@SidneyJupiter]

Remzi Cavdar I know it was a joke

[@theredkey3288]

Absolute zero is not impossible. Because it is reached in our house the winter. Absolutely PERFECT for stubbing your toe on a wooden object in winter

[@donenowibz]

This was really helpful. Saved me a lot of research time.

[@darkaquatus]

You should have gone a tad deeper as to what happens to particals when they reach 0 degrees. It's kinda mindblowing and it also tends to be somewhat of a mindfuck.

[@curt62208]

Thank you sir! That is by far the best explanation I've heard to date that makes sense to me concerning absolute zero!

[@KororaPenguin]

I guess you could say that "absolute zero" is also the amount of sympathy Dante had for the treacherous. ;þ

[@seska1245]

Please do a longer episode explaining this in more detail with more research! This stuff fascinates me! Why is it the coldest temperature? Why did the universe decide that's as cold as things get?

[@randomblog7853]

I've decide to freeze myself at -273.15 degrees Celsius. My friends think I will die but I will be 0 k. Anybody? No? 0 k...

[@blakeallen2721]

You're my hero

[@fabulo19]

RandomBlog Wonderful mate

[@Paul-eu6cm]

zer - OK I get it

[@sawairaazhar4994]

That's actually pretty cool !

[@ryliekirby7458]

RandomBlog haha I needed to look at this for 5 mins before I understood it and now I'm laughing about it

[@aidanhauser7432]

Plz make more videos theyre so great im learning so much plz make more ive wacthed all of them

[@lexielevinson7456]

Absolutely loved this video

[@timtitus7861]

"Lots of strange things begin to happen" But, you forgot to mention what they are. As I remember, they include matter being able to pass through other matter without any hinderance. IE, if a superhero had the power of absolute zero, they could walk through walls... hmm, perhaps a bad comparison.

[@jaycee330]

@Kolbe Arreola Yes, that's zero viscosity. Search for "superfluid helium" to see it.

[@peterfireflylund]

It's not "degrees kelvin", just "kelvin". We don't say "degrees volt", either.

[@whopperlover1772]

Degrees Celsius.

[@micheltenvoorde]

+ByteMe That *is* correct, but degrees Kelvin is incorrect since 1967.

[@skylertooley1955]

now degrees kelvin are correct. kelvin is not a proprietary scale. it ranges, thus it has "degree's" get with the times, grandpa.

[@micheltenvoorde]

+skyler tooley Please don't use anonimity to be rude. If I were a grandpa, then it would be an excuse to say 'degrees Kelvin', but as I said, the standard has been to just say 'kelvin' since 1967. See for example physics.nist.gov/cuu/pdf/sp811.pdf.

[@maridagoffri421]

Peter Lund yes , but we saay degrees celsius

[@JazzCanCwalk101]

The Episode of the Absolute Zero gun in The Flash got me here wanting to know about Absolute Zero. Now i'm really interested in it's research and if it s humanly achievable through the use of quantum mechanics or further research of chemicals that could react similar to the boomerang Nebula. THIS IS AWESOME!

[@RobertSmith-ik4vd]

So short and too the point. Love it.

[@VicodinElmo]

Tread lightly, Hank.

[@Mi_Fa_Volare]

Lucas Williams Hey, bist du nicht der eine typ aus Anime Amino?

[@afrog2666]

This episode was very cool hihi

[@mybluemars]

Great stuff Hank, Thank You!

[@pierrevillemaire-brooks4247]

Awesome work guys ! Keep it up. :-)

[@ebenbrooks]

Liquid helium! That stuff is crazy cool! Y'all should do a video on that!

[@vgfxworks]

it's still not enough, it's 4 degrees celsius above 0 Kelvin.

[@shmerox7683]

@@vgfxworks well it doesnt turn solid tho. Thats probably why he wants a vid about it.

[@SpecOpsDoctor]

Pfff, the coldest place on this universe is my classroom... come in from 8-10 o'clock and you will see what is absolute zero.

[@BECAUSEICAN11100]

Well the hottest place is my French class... It's like 5000000 Kelvin

[@theorangehero2441]

+SpecOpsDoctor Don't worry, I'll walk into the classroom, it'll get hot like me. (Not really)

[@giangthanhdat8314]

You would've died at absolute zero.

[@iafozzac]

+Nguyen Vincent take a dictionary and search for "irony", "joke" and "sarcasm" you might get an idea of what's going on here

[@danielgorzel7222]

+Nguyen Vincent u can die after few hours at 10*C if ur naked...

[@fierysword0]

I really love your videos.

[@Nick-nk2iq]

This show is gold..

[@TheCls63]

I know spot where particles have 0 motion, my ex's heart...

[@Warriormanners]

I can literally see the comment you copied lol. This is a stupid joke anyways

[@MegaBallPowerBall]

No. My ex has 0 motion in her heart. No human being could ever come close to that ball of hatred and destruction.

[@Warriormanners]

***** It wasn't funny the first time, so why make the joke again?

[@MegaBallPowerBall]

+Warriormaners It's not a joke. Her heart really does have 0 motion. She is just full of hatred and destruction.

[@muddshshshark]

The soul of a woman was created below Dontcha know?

[@tylmomendog]

Did you know that you could be -273.15 C and still be 0k? ;)

[@johntrobee6137]

Yeah, you mean you'd be 0 K.

[@DragonBookWriter]

For everyone here who hasn't already, please look up videos of things being cooled to very nearly absolute zero. I find them incredible!

[@docholiday8029]

Another good video and a great question. There are 2 basic building blocks of reality; power strings and gravity strings. Gravity strings in isolation have no heat. So, a black hole or pulsar which are composed entirely of gravity strings have a temperature of absolute zero. They are the coldest objects in our universe. (You are welcome.)

[@nikrodox]

And the Guinness Universe Record for coldest temperature goes to...

[@arcanebyte6457]

+NikroPlaysGD word you play gd

[@VioletRM]

my ex's heart!!!

[@KobZen]

toilet seat

[@Waltham1892]

The coldest place in the universe is my ex-wife's heart. No, really. We've had her tested....

[@lucasg.5534]

Waltham1892 ouch.

[@Waltham1892]

@Kolbe Arreola Nope, she can still chill a bottle of wine in 12 seconds.

[@Waltham1892]

@Kolbe Arreola That's how I see it...

[@imreplyingtothiscomment2378]

Didn't know this channel was this old

[@rolan638]

"Some pretty weird stuff start happening" wow thank you, that really cleared everything up

[@thetruthfulchannel6348]

"Pretty cool." :D

[@Afrocanuk]

No, don't say degrees Kelvin. Just Kelvin is good enough.

[@Ed-sg4iy]

But, he's on a science channel!

[@vgfxworks]

yes that's right there's no such thing as degree kelvin, it's just Kelvin.

[@EmdrGreg]

I'd love to hear something about how this ties in the the Bose-Einstein condensate. Maybe with pics if there are any, or maybe including how light travels through the condensate.

[@tatejordan385]

Well that is, unless aliens have laboratories.....

[@HotelPapa100]

It was carefully worded: "known universe". Known to humans, that is.

[@tatejordan385]

HotelPapa100 *Sarcasm sign*

[@jassmovie6776]

u missed out the Bose-Einstein condensate.

[@skylertooley1955]

irrelevant

[@Horny_Fruit_Flies]

redundant

[@czajkowski2352]

unnecessary

[@garethhale2597]

"...degrees kelvin", THREE TIMES!? (1:55, 2:32, 2:41) Hank, I suppose I could be wrong, but I learned in Gen. Chem. that the word "degrees"(º) does precede the words "Celsius" (ºC) and "Fahrenheit"(ºF), but not "kelvin" (k). It's just (in this case) "(temperature) kelvin"

[@MegaBallPowerBall]

Every field whether it's politics, science, poker etc has its own language that it uses to operate amongst themselves. He has to explain a very complicated subject to millions of people who don't have a masters degree in it. No one cares except actual scientists (and they probably wouldn't care either except in official papers) care one bit about adding or removing the word degrees from what he was trying to say.

[@garethhale2597]

Understood, but a) Hank is a scientist, speaking in terms of science, and b) his intent in making these videos is to inform people, but in this specific case, he is not entirely correct. Furthermore, the progress of science is based partly on the idea of scientists calling each-other out on mistakes. I realize that Hank likely simply misspoke (because he is human), but I am going to call him on it anyways because it is a mistake. I am not going to dislike the video, or unsubscribe based on a simple grammatical error, but I think a comment is fair. BTW, I still respect him, and watch just about everything he makes.

[@IamGrimalkin]

It's not an error, more an older way of expressing it. Originally everyone called it degrees kelvin.

[@Ed-sg4iy]

No, it is an error. Like saying ATM Machine or PIN Number.

[@isodoublet]

"Understood, but a) Hank is a scientist, speaking in terms of science, and b) his intent in making these videos is to inform people, but in this specific case, he is not entirely correct." He's a scientist, but not a physicist, which is something that people should keep in mind. This video was completely wrong. The nomenclature was the least of its problems.

[@Corestore16]

Could you guys do an episode on the edge of the universe? What science tells us about its boundaries, and what it would be like? Thanks!

[@DustyGweneira]

I love your show! What software do you use to edit the episodes?

[@TheMrCarnification]

2:48 "pretty cool" yeah Hank, absolute zero is pretty cool

[@masihawadiwala1109]

L l l

[@NathanHieu]

Say my name. "Heisenburg" You're goddamn right.

[@gliding_eagledurand2675]

This was super cool! :)

[@Spyderdemonge]

Very interesting video, I subscribed to your channel. Thanks for the info!

[@stevew278]

everyone knows the coldest naturally occurring temperatures are found in a girls heart

[@chihuhahuana4863]

-4K

[@nbSailent]

um no

[@DakshGuptaCuriosium]

degree kelvin??!! hahahahahaha

[@whopperlover1772]

What's funny?

[@hakuni123]

+ByteMe Absolute temperature is measured in Kelvins, [K], not degrees kelvin [°K]. Not that big of a deal, if you ask me..

[@skylertooley1955]

kelvin is a scale. so degrees of kelvin are correct.

[@isodoublet]

Dude's a biochemist, not a physicist. Not even the worst error in the video.

[@earljohnsanchez2493]

@@skylertooley1955 I know I'm late but Kelvin is a unit not a scale

[@hydrogeddonn]

Me and my teacher talked about this, they say that time "stops" at absolute zero, everything lacking energy to move, and losing heat, plunging everything into absolute zero. I postulated that the traits of metals to conduct more at colder temperatures, that the remaining sunlight and solar wind would penetrate earth at a higher velocity than normal, before running out due to the stop of fusion. But, gravity and electronic charges would remain theoretically, allowing a frozen yet moving galaxy.

[@francoputin5785]

Your show is super cool

[@avtaras]

Can 10 trillion degrees celsius burn every single substance in space?

[@25EllisDee25]

no

[@jimsagubigula7337]

+ARIVILIAR It can burn the things that can be burned. There are some materials that don't get combusted.

[@25EllisDee25]

Jim Sagubigula at 10 trillion degrees, oxidation is the least of your worries.

[@jimsagubigula7337]

25EllisDee25 If you want something to combust, you need oxygen. If you don't have oxygen, things won't combust. No matter the temperature.

[@mxmotovlogs2332]

ARIVILIAR you would have to reach above the Planck temperature which It is approximately 1.41679 x 10^32 Kelvin. That's roughly 100 million million million million million degrees 100000000000000000000000000000000000000000000000°kelvin

[@Ed-sg4iy]

There is no such thing as "0 degrees Kelvin", genius. Nor is there such thing as "X degrees Kelvin". KELVIN DOESN'T USE DEGREES. WHY ARE YOU TRYING TO SCIENCE??????

[@arte0021]

why does it not? what makes it different from Celsius and Fahrenheit?

[@jertnmoose4755]

I love Scishow. Period.

[@SirDeanosity]

How can anyone be sure of the meaning of a principle that has the word uncertainty in it.

[@Requnium]

+SirDeanosity 4head.

[@usetobeasurferchick]

i really have an issue with all the "can'ts", "cannots", and "impossibles" you used in this otherwise interesting episode. if science has taught us anything, it has taught us that one generations "can'ts" is another generation "cans". try saying "as far as we know at this time...". I think this would be more useful to budding science enthusiasts. cause you never know when or who will break the next "impossible" belief!!!!

[@kanchansarda8195]

dreamwalker12 all my respect are with you👏👏

[@mr.evasion]

Eliminating the impossible is the crux of all science As far as I know We can only demonstrate a function

[@SocietalBlackSheep]

I hate when scientists say "impossible" because there have been many instances where something was deemed impossible by scientists only to be proven wrong later. A better thing to say would be "not that we currently know of"

[@MrAlRats]

No. There are no instances where something was deemed impossible by scientists only to be proven wrong later.

[@games1004]

Al Rats ... and I watched another science KZbin video just the other day where Einstein and a number of other scientists originally thought that nuclear power just “wasn’t going to happen” before they discovered the reason for radioactivity in minerals. There are many examples of “impossible” turning out to be a lack of understanding in the ways of the universe... and it won’t be the last example either. Humans (with all levels of intelligence, us included) have a bad habit of speaking in absolutes (always, never, etc.) Many of our comments “this will always/never happen because...” are wrong. Just because we haven’t “observed” or “experienced” something yet doesn’t mean it “can’t.”

[@MrAlRats]

Yes, there were many very good reasons for believing that nuclear power cannot be harnessed for practical purposes. It was the discovery of the neutron and specifically the possibility of a nuclear chain reaction which changed everything. Nobody said it was impossible; just very, very unlikely to be practical. However, some things are truly impossible according to the laws of physics.

[@biohazard724]

Violating the laws of physics is not possible. Acceleration beyond light speed is impossible. Time travel is impossible. Absolute Zero is impossible.

[@markus031098]

Yes, thank you for that correction.

[@davidbadiola3005]

i love the eye roll at 'continue getting smarter'

[@TheRealHelvetica]

So we can't get to 0 degrees Kelvin. But we can go into negative Kelvin.

[@JayFoth]

0 Kelvin is when all motion stops... as the video says... it can't get any colder than that.. so no.. You can't have negative Kelvin.. even if you were to reverse the movement of any molecule it would still be moving, which would still mean it has a fraction of heat... think of Kelvin as an absolute.. nothing can get colder.. it is either 0 or higher.. can never be lower.. 273.15 Kelvin is when H2O (water) freezes.. 373.15 Kelvin is when H2O evaporates.... also Kelvin does not have degrees like Celsius and Fahrenheit.. it is strictly Kelvin

[@TheRealHelvetica]

Josh Fotheringham No no no, you don't understand. Negative temperatures aren't cold. They're actually the hottest things we have ever observed in our universe.

[@JayFoth]

no no no... 1000000000+ Kelvin is the hottest thing ever... We are not talking about a graph here where x has a range of -100 to 100... Absolute Zero is just that.. the absolute coldest temperature there is because no movement between atoms exists... heat is registered by the movement of atoms and molecules.. if that movement is stopped.. there is no heat.. Think of Kelvin as molecules moving when higher than 0... there is no "negative" because no movement is the coldest you can get.. as i said even if you reverse the movement.. it is still moving and thus generating heat.. which is above 0.. the absolute number... or better known as ABSOLUTE ZERO.. because there is absolutely zero movement... Kelvin is a linear line with nothing going below 0... if you can't understand that.. go to Grade 9 Chemistry Class and learn a thing or two about science again.. You are being too close minded especially after listening to this guy explain how Absolute Zero works

[@TheRealHelvetica]

Josh Fotheringham How am I being close minded here? I think someone needs to go back to grade 12 physics. We define temperature as a transfer from a high energy state to a low energy state. When I say negative temperatures are the hottest things we have ever observed, it's because it will always transfer energy to a positive temperature regardless how hot it is. So, you may ask. What makes negative temperature so different from just a generally really hot positive temperature? Well, the more energy you put into a positive temperature system the more disorderly it becomes. The more energy you put into a negative temperature system the more orderly it becomes.

[@TheRealHelvetica]

Here's a better way to phrase it. Negative Kelvin isn't necessarily below zero as it is beyond infinite.

[@awesomesauce446]

What's interesting is that the measure of Kelvin moves up and down by the same amount as Centegrade/Celcius, the scale merely begins at a lower temperature.

[@charlietuba]

In addition to the Kelvin scale there is the Rankine scale which uses the same degree unit as the Fahrenheit scale.

[@jakebenson1449]

This is great!

[@DontYaTalkSIlly]

I read a few articles on some scientists breaking the limit of absolute zero and getting weird results. Its a good read.

[@personan6525]

I saw that too. While not very convincing, it makes me wonder what SciShow's chilling response would be.

[@ronnycook3569]

While superconducting gets a passing mention, a discussion of superconductivity in general and how it works would be interesting. As long as we're messing about in the low temperature realm, something about bose-einstein condensates might also be an interesting topic - possibly expand with other weird forms of matter such as plasma, neutronium, metallic hydrogen, degenerate matter...

[@ekenig]

You should do a video on the recently discovered negative kelvin temperatures

[@MischievousBastard]

Dude, vintage Hank!

[@AuthenticDarren]

What i would really like to know (and there may have already been a video on this) is: 1. How EXACTLY was the temperature of absolute zero ascertained? (like how exactly did they come up with figure of -273.15°C?) and 2. How EXACTLY was the speed of light ascertained? A brief scetchy response to my first question was given here but I still don't see exactly what methods, materials and calculations were undertaken in the 19th century with only relatively primative equipment. Similarly I understand that the speed of light was determined before even absolute zero with even less technology and even as much understanding of how the universe ticks as we have today in the 21st century.

[@bingahgread]

There were a bunch of different experiments used to measure the speed of light dating back as early as the 1600s, a lot of these using measurements of various celestial bodies such as eclipses on the moons of Jupiter. One of the more modern and accurate measurements was made using a rotating mirror. It used a beam of light reflected off a mirror which would then travel a known distance, hit another mirror and bounce directly back, reflect again off the first mirror and then back to the original source of the light. Now if the first mirror is stationary the beam of light will always come back to its original source, but if it is rotating it will return at a slight angle to the source. If you know the speed of rotation of the mirror you can determine the time that the light took to travel, and use this to determine its speed. For a little bit better explanations (with pictures): en.wikipedia.org/wiki/Fizeau%E2%80%93Foucault_apparatus

[@Chemdawg0360]

OMG that's so cool, I love it! :)

[@claudiadeyta6907]

Can you do a video on zero-point energy?

[@aleynaa4118]

aradığım her yer yerde sen varsın adamım

[@MightbeLumi]

Subscribed, awesome.

[@victorstroganov8135]

No one: Aliens: Yeah, we have -1 Kelvin

[@hazardousmaterial5492]

0 degrees kelvin-the temperature required for a gaming PC to not overheat during the summer

[@comcastjohn]

I love your show. I do get smarter everyday, but then I forget what I have learned in a few hours or at least by the end of the day. 😞 I suffered a head injury (TBI) overseas and now I cannot transfer short term memory to long term anymore. It sucks!

[@JatPhenshllem]

You remember this comment?

[@comcastjohn]

@@JatPhenshllem nope. Not even the video.

[@JatPhenshllem]

@@comcastjohn Whoa dude. Sorry about that. Do you remember this comment now?

[@JatPhenshllem]

@@comcastjohn How do you cope, though?

[@comcastjohn]

@@JatPhenshllem kind of. If I watch the video again, I recognize some parts but mostly not. Unless something REALLY sticks out, it’s gone. It’s been getting worse over the decades. I get 15 to 20 migraines a month now. The VA says I cannot live alone so I am with family. It really sucks as I have been so used to living on my own since I was 17.

[@Pyrolonn]

I'd really like to see a sci-show about high temperature superconductors. It seems anything about it is highly technical. The best I can figure is the atomic structure forces copper oxides into thin sheets where various dopants donate electrons into a narrow channel in which the rigid ceramic allows the electrons to resist the normal heat and form the cooper pairs required for superconductivity.

[@paulneg7855]

You should do a temperature unit!

[@MsMiker1]

All temperature units (Fahrenheit, Celsius, Kelvin, etc.) are measured in DEGREES. For example: 94 degrees Fahrenheit = 34.4 degrees Celsius. Or: 223.15 degrees Kelvin = - 50 degrees Celsius. I hope i answered your question :)

[@hydrogeddonn]

THANK YOU!

[@xZise]

Previously it was degree Kelvin, but as Kelvin is an absolute scale (2 K is twice as warm as 1 K, 2 °F/°C isn't (!) twice as warm as 1 °F/°C) it was dropped.

[@SgtAwesome97]

for those of you who dont know, 2.7 kelvin is about -270.45 degrees celsius, or about -454.81 degrees fahrenheit.

[@swinkscalibur8506]

hmmm no mention of bose-einstein condensates. Looks like a great topic for another video.

[@GenieWeinerDog]

Ever heard of the Eradanus Supervoid? It's an area in space that is only a fraction of a degree away from absolute zero. Some people say that it could be a pathway to an alternate universe

[@NicholasCobalt]

To measure the temperature of something at 0K we would either need to add energy to the system causing it to be above 0K or measure the energy lost as it becomes 0K which would also require us knowing the objects exact energy at a time prior to reaching 0K otherwise we would be unsure of it's temperature without the previous problem arising. The problem with reaching to absolute zero is that mass will become energy, while you may reach 0 energy you'd likely find yourself with 0 mass as well.

[@motherfuckerjones3854]

You wanna reach absolute zero? Just turn your pillow over.

[@0011peace]

+Bloodbath and Beyond Fahrenheit is he only that is truly degrees. If you take water freezing 32 F and water boiling 212 there is 180 F separate them this is a half circle First thermometers were circular and water moved peg 1 full 180 degrees. Degree can't be used directly as measurement of height. In Linear measurements degree is used for angle.