Neil deGrasse Tyson Explains Why Ice Floats

Why does ice float? Seems like a simple question. On this StarTalk explainer video, Neil deGrasse Tyson and comic co-host Chuck Nice are, as usual, bringing complex answers to life’s simple questions.
Neil explains why peculiar things happen to water when it changes state. We explore what happens when water freezes. Chuck gives a visual demonstration of why you usually see 10% of ice above water. You’ll learn why the arctic ice sheets float on the water. And, why the ice we need to worry about is the ice on land and the “runoff.”
We discuss the power of freezing ice (which leads to bursting pipes). Find out more about the density of water. What if bodies of water froze from the bottom up? Neil tells us how a certain property of water protects aquatic life over the winter. All that, plus, Chuck can’t help but bring up the science behind spherical ice cubes used for scotch!
About the prints that flank Neil in this video:
"Black Swan” & "White Swan" limited edition serigraph prints by Coast Salish artist Jane Kwatleematt Marston. For more information about this artist and her work, visit Inuit Gallery of Vancouver inuit.com/.
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About StarTalk:
Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up!
#StarTalk #neildegrassetyson
0:00 - Introduction
1:48 - What Happens When Water Freezes?
3:34 - When Ice Melts
5:36 - Why Pipes Break Below Freezing
7:23 - Densities of Water
8:15 - Why Fish Don’t Freeze In The Winter
10:34 - Pressure-Melting
14:06 - Closing Notes

[@udornyc]

Here is an example of true, internalized knowledge: While explaining how ice functions on a lake 9:10 , Chuck mentions that's a bear's dream (fish being pushed to the surface from the bottom up), and Neil, without batting a lash responds that the bears hibernate and would miss this effect. LOVE IT!

[@ArtemLokhovitskiy]

I actually thought at first they are talking about Bear Grylls

[@WiseEmerald]

That also means ice skating wouldn’t be invented as fast

[@VideosOfEarth]

Neil is amazing because of stuff like this. True!

[@akoblake]

When he said this I wondered about Polar bears ...

[@fredricksonthe96th]

I suppose there wouldn't really be a need for them to hybernate anymore if this were true, huh?

[@sugar1930]

Neil is an educator indeed. He's explained this amongst other concepts over and over again in several videos. Yet he still shows such enthusiasm!

[@alext7074]

But his explanation why we slip on ice is wrong... Unfortunately

[@pulkitmohta8964]

I know! I can't imagine being a teacher/educator and teaching the same stuff every year with a similar enthusiasm

[@alext7074]

@BS - 10GM 720145 Turner Fenton SS no, unfortunately not. Do you slip on ice with your shoes? The surface area of your soles is much bigger than skate blades... How much pressure do you exert under your soles? Not enough to liquify ice, but you slip on ice..

[@alext7074]

@BS - 10GM 720145 Turner Fenton SS I did research it, that's how I know. 🙄

[@TheHuggableEmpire]

@@alext7074 slip or skate..?

[@vddr24]

The look on neils face when Chuck has to get a glass of water is priceless.

[@MeeMee-gz5vp]

Lol yes he reminded me of one of the Muppets

[@judethaddeus9856]

His face didn’t change

[@mortenpaskins6073]

@@judethaddeus9856 exactly

[@jeruakel]

I didn’t notice till you said it but im f***kin CRYING 😭😭😭💀💀💀

[@walterfolk4864]

@@judethaddeus9856lkm m

[@Stick-a-fork-in-Gmorks-tort]

"F it!" - Ice cold H2O (Not a Rap artist but a compound)

[@Andrew90046zero]

Da ice says @@@@@@@@IT!

[@lalboimanlun1230]

Lil ice cube

[@helpinguhelpme]

Chuck's aha moment with sphere ice cube, and Neil's realization of oh they do that, I didn't know it was a thing. lol at the contrast between their reaction.

[@Ryan-ul2xc]

Every time Neil appears in an ad before a KZbin video I always watch it without clicking skip and find its usually more interesting than the video I clicked to watch and always find my way back here 😎

[@Eneov]

At the beginning chuck's "yes we are.." was straight out of invasion of the body snatchers

[@apeiceofgarbage9848]

Hahahahahahahaaaaaaaaahhhh it totally was

[@AJD...]

Year 3030: Chuck has gained sentience through Neil's knowledge

[@linyenchin6773]

... sentience = having sensory experience... he already has sentience. Besides your faulty firm of respiration causing cognitive impairment; why do you mouth-breathers continue to misuse the word "sentient" where *sapient* belongs?

[@linyenchin6773]

No mouth-breather is human, they are merely intellectual.

[@vargheseeralil8346]

Sometimes I’d see your video title and think “oh I already know why” and then I’d watch the video and somehow I’d still end up learning something that I didn’t know before. Love your content!

[@aaronseet2738]

My business philosophy: Freeze ten cups of water, sell eleven cups of ice. Profit.

[@charlesdick1133]

Outstanding

[@thomaslane1547]

Kona Ice business model works. ;)

[@LawnFlamingoPoop]

My business philosophy: Inject air into it as it's freezing to produce 12 cups, I undermine your business and we become lifelong arch enemies

[@rajatsingh2956]

Your profits will be consumed in the energy required to freeze it. Unless you are in northern Canada or something! 😛😛

[@aaronseet2738]

@@rajatsingh2956 my headquarters is at Antarctica!

[@tanadarko6991]

chuck trying to think of the term upwelling (i'm going to guess) is delightful. Because I love that a COMEDIAN is so thoughtful and educated - a normal person who finds relevancy in science. Love this combo.

[@nikkokp]

chuck is on fire with the jokes today😂😂🔥🔥

[@Blaster00745]

Yeah to the point that he's even sweating 😅

[@LHSlash]

He makes these videos so much better

[@no6021]

No

[@akmalimdad6366]

No he aint hes been so much better

[@AlexHeisEngholm]

Water are you gonna do about it? And instead of he’s on fire it should be, his puns dripping and leaking out. 💧💦

[@2l84t]

I remember as a kid one Winter finding the milk on the front step standing without it's bottle ...... Just carbon dated myself.

[@Cyberplayer5]

The ice cream man cometh....XD

[@constancemiller3753]

The bottle broke and left frozen milk? Cool.

[@ZeroOskul]

1:39 I've long seen Chuck as a dweeb but he actually pays attention and studies on his own. That joy at being on-topic--the prize to which is only in his own knowing that he is on-topic--is very close to nerd. Very close to nerd.

[@adlerfg]

My first coffee cup in the morning, listening to these 2. Priceless. Thank you KZbin for existing!

[@JuanAMota-pu5zx]

Chuck looking for his glass of water. He looks so excited :D. Great video guys!

[@nicklaskowalski]

Love NDT’s while Chuck is running to the freezer to get ice. His eyes are priceless in their expression 😂😂😂. NDT’s resting face deserves its own “not-impressed-slightly-bored-eyes-half-shut” emoji!!

[@IkeOzurumba]

This part was hilarious

[@nicklaskowalski]

@@IkeOzurumba yeah! @ 2:49 pretty much NDT’s resting face 😂

[@loam]

Even though I knew why does an ice float (which is in the title of the video), I watched it because Neil always provides some more interesting information)

[@Alexander-bd2hk]

how he holds back his smile :3 roughly at 2:52 priceless

[@marcelihryniow211]

great vid. Thank you for educating. One more great example is when you hang a mesh with weights on top of an ice cube, in time the mesh will pass through the ice cube leaving it intact

[@tenoki]

Niel deGrasse Tyson: "Ice floats!" Hagrid: "You're a Wizard, Neil deGrasse Tyson!"

[@collincherubim2698]

8:16 Correction: There is a point where "water" is at its densest.

[@mhk5272]

And it's *4 degrees celsius not 3

[@256k_]

@@mhk5272 thank you.

[@fidelecheverria6772]

And skating has nothing to do with pressure heating the surface, that got disproved years ago. It's really complicated and super fun to know why.

[@ktkrelaxedscience]

Both simple and complex at the same time - and easier to understand than many other things. Love it. :)

[@Synster73]

Chuck's getting excited about ice spheres! As always, great information guys!

[@OkOk-tt2dg]

I love these videos, thank you gentlemen.

[@photelegy]

8:53 3°C water is the most dense? I always thought its 4°C, or is it different in the oceans because of the salt?

[@Quartan284]

Ever seen salt used to prevent something form freezing ? ;) Iirc 4°C is pure water. Tap water may have the 3°C Neil was taling about. And someone else in the comment said it was -2°C to -1°C in the ocean.

[@docButik]

yea. I thought also it was 4 C where water is most dense. Called it anomaly of the water in elementary school.

[@dariusechols751]

These explainers make life worth living

[@paulbrown7735]

I’m a long term fan of Neil but you guys are brilliant together. So glad I found your channel!

[@rykerhaskins1856]

This is an amazing video!!

[@ryanseward2760]

Whenever I get out of cold water now I'm not saying I've shrunk I'm saying I got more dense.

[@MichaelDavis-uu9zh]

Thank you for doing what you do, the masses are more equipped and encouraged to think on their own and it’s a refreshing change!

[@josephmiller1576]

Love this. . I love being educated and have the humble mindset to continue to learn. . .

[@mihaibuteanu8825]

You guys are amazing! Thank you very much!

[@PHutch-me5bq]

Love the info and that Scotch voice!

[@johndurland1966]

Pond hockey players everywhere are so thankful for this!!!

[@fidelecheverria6772]

But in fact that answer was wrong, the actual reason why skating happens is much more complicated and interesting. Dig a little you'll see.

[@rhmoreira]

I've watched so many videos in a roll that i completey forgot to leave a like. I think i was hypnotized.

[@Malloubyn]

Mind blown... as usual

[@fates6922]

"The water freezes on top, protecting the fish below!" You could call that ice insurance.

[@bouqueethius5104]

Yo I'm not there yet but me too

[@ezeenvrbz]

Icesurance

[@catalincostinflorea977]

Thx for the lession

[@brandon893]

Love the new logo for star talk

[@jaymontealegre143]

Niel: ...usually, when you cool something down it shrinks... Chuck: Tell me about it.

[@minirock000]

Chuck, thank you for helping to keep this guy relevant. Your humour and insight contributes exponentially.

[@fyx812]

When I was young, am now 67, I remember my mom's refrigerator was the "OLD STYLE" with cooling tubes serpentining underneath the shelf (stay with me here) There wasn't a fan stirring the cold air around the freezer- just supercooled air laying on the shelf. Years ago, industry made aluminum ice trays, with pull handle partitions (also aluminum), I would fill the ice trays, and the water would begin to freeze slowly, quietly, from the Bottom/Outside, Inward...to the middle, as it did- the edges would be frozen, and the water would SLOWLY FREEZE to the Center--- and the Water would Start to Crest to a Peak to the middle, forming a miniature mountain in each section!! From That time on, I was Fascinated with Science!! Later I tried the Same experiment, with Plastic Icetrays in a Modern Refrigerator with the Cooling Fan blowing Air in the freezer Compartment--- Not the Same Results-- The " FAN" Disturbed the Air and "Flash Froze" the water in ice tray-- Resulting In a flat, cloudy ice cube. P.S. The water that was Frozen Slowly was Transparent. EXPERIMENT: Take a trip to a Ice Company that Freezes 300lb blocks of Ice-- Ask them to show you a Block- 80-90% is Most likely, Transparent!!! COOL...pun intended

[@ahmedrafea8542]

Great show Neil, always entertaining and informative to watch you talk. Just a quick question. Did I hear you say that water is at most dense at 3 c? All my life I learned that it was at 4 C.

[@RishabhTatiraju]

Missing the old intro :( But eventually Neil would be like, "Get over it!"

[@dominiccummings4205]

Hey, what happen to that bumpin intro? I enjoyed listening to the bass at the end of the intro, what happen, man

[@ThinIceGroup]

It was getting old, tbh.

[@madeonearth6506]

The comma, clan.

[@Ironage99]

These 2 are awesome. Funny and such a good combo. Keep it up chaps.

[@juliaward2079]

Love it 😁 i would listen to you two talk just about anything Just makes me happy

[@notarealperson87]

6:04 - after talking to so many other standups, Neil now sees how hard it is for Chuck to keep it clean

[@spasticcreationist7999]

Yaay, another video to make me smarter😂🤙 youre awesome Neil💛😁

[@calumattidore7983]

@Michael disrespecting chuck like that smh

[@tavogp]

I always learn something new in Star talk!!

[@99PTR99]

Every time Chuck gets excited in a video NDT's eardrums cry. The look on his face cracks me up every time!

[@Wolf_The_Dentist_Stansson]

2:10 That explains why the beer explodes in the freezer when you forget about it. Check Edit: 5:49 explains it. Check

[@stylis666]

And it's not wasted at that time apparently, because it's nicely preserved while frozen. You just have to drink it all in one go once it's melted again :p The more you know :p

[@valorienapoletana4063]

Yes, but due to the alcohol in the beer it will freeze slower than water alone... so... you should probably go check your freezer :)

[@mozkitolife5437]

When someone tells you lies, the power is given to them. When someone, like Neil, tells you objective facts with such enthusiasm, the power is given to everyone. Get excited about facts, people. It levels the playing field.

[@WYXYXYW]

Beautiful! Thank you 🎵✨💜

[@buzzsmith8146]

You guys are having way too much fun! Thanks.

[@Sei783]

I feel like Chuck's purpose is to play the wide-eyed unremarkable to Neil's brilliance.

[@AMPStorm]

"brIllIaNcE"

[@tedl7538]

He's like a Shakespearean jester.

[@KaliCush]

Thanks Chuck, now I want Scotch on the rocks!!

[@carultch]

Waiter: so, what'll it be, gentlemen? Guy 1: Scotch on the rocks Guy 2: Samuel Adams Guy 3: I'll have a Samuel...Jackson Guy 1: You know something, I'll have a Samuel Jackson too. Guy 2: Me three. Waiter: three Samuel Jacksons, coming right up.

[@_CrisE]

Brilliant explanation... as always!

[@ricardoramirez2587]

new star talk intro, I like it

[@coreysaylor4736]

Not exactly related, and maybe I'm dumb and everyone knows this already but... Why does freezing water make it expand? Doesn't heat make things expand? Molecules move faster and all that?

[@ajn465]

I know water is the exception to that rule and I was really expecting that to be the actual topic here

[@christianharriot1578]

When water freezes, the crystal structure of the ice takes up more room than the liquid. Thermal expansion is still a thing but it is confined to a current state of matter not the transition between states. An ice cube at freezing is larger than it will be below freezing.

[@coreysaylor4736]

@@christianharriot1578 Oh I see. Thanks!

[@thetramp123]

Ice floats because it's friends with water and water is like "I got you, bud" and holds ice up.

[@ANewHorizon]

You saved me 15 minutes, thank you.

[@Kha89478]

Makes sense

[@jesseburley8349]

The most amazing thing about him I've noticed is that he is so patient he spends his life re explaining his knowalge over and over and gifting fellow humankind with what he probably considers common sense.

[@sevens3]

@6:00 Now is that "you keep taking the temperature lower and lower" with CONSTANT pressure, or is that with an ALSO changing (I would assume, increasing, was what was meant to be implied, if so) pressure?

[@shiwambandhoe5488]

The force that is exerted from within the pipe increases as the volume wants to increase more and more. So yeah the pressure also increases, until the pipe is unable to withstand the pressure and just snaps

[@manalidesai4347]

its 4 degrees not 3 when anamollous behaviour is seen dear Neil

[@pulkitmohta8964]

I had the same concern

[@zlac]

@@pulkitmohta8964 Everything he says could be just as wrong! One more error like this and we'll unsubscribe, NEIL! :D

[@pulkitmohta8964]

@@zlac I won't unsubscribe because of few small errors made by a human being

[@lucass.4365]

Same 👍

[@Markle2k]

He’s also got the slippery ice thing wrong. The ice at rinks is too cold for the pressure to melt it. It is a combination of friction heating and lower Van der Waals forces at the surface. There is always a quasi-liquid layer on top because the ice molecules aren’t surrounded on all sides, so they aren’t as strongly bound to each other.

[@jameskerry41]

"In the Artic- the Artic where Santa Claus lives" ....lol too cute

[@pulkitmohta8964]

Arctic*

[@displayname6796]

@@pulkitmohta8964 lol

[@AdrianoBatti]

Love the show - thank you! Learning so much!

[@lucasboulanger5568]

Great video as always! On the same topic, does anybody know exactly how do "ice tsunamis"/ice shoves form? I'm very curious about this one and there isn't a lot of info about them on the internet

[@elthomas_]

The pressure exerted by an ice skate is actually no where near enough to melt the ice. There are theories that either there is always a thin film of water on the ice, or that the surface molecules of ice behave like water.

[@wood4sheep]

Ice IS slippery.

[@wood4sheep]

www.nsf.gov/news/special_reports/water/popup/wg_icespeed.htm someone at NSF should fix that dead link.

[@alext7074]

Correct, I've left a couple of replies saying the same. Plus, we slip on ice wearing normal shoes. The pressure under the sole is a fraction of the one under skates.. Nowhere near enough to liquify ice.

[@vincevvn]

Yeah I thought that explanation didn’t make any sense.

[@stk1975]

when you cool something down it shrinks, tell me about it LOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOL

[@MarcoS-ue7og]

The bears hibernate, Neil thought of that in 1 second. Wow brilliant :) Love it

[@BJamesThompson]

Could you possibly do a video on the albedo effect or the effeciency of igloos etc?

[@BlockBlazer]

Chuck needs to use his "scotch voice" and say "I'm Batman".

[@stylis666]

Hahahaha! This made me laugh way harder than it should!

[@acohyeah6572]

"Where Santa Claus live..." Santa Claus real confirmed

[@stefandewet2414]

Best show ever gentlemen, I love your energy and discussions.

[@elvisgarcia3047]

Chuck always reads my mind. My man chuck becoming a scientist

[@Seeds-Of-The-Wayside]

2:49 My face when my son tells me all about Pokemon

[@rcade1262]

Chuck's high again 👀

[@Allwayzworkin]

💯 😂

[@CesarRodriguez-ix1yd]

Neil looks high at 2:47 😂😂

[@rcade1262]

@Андрей Бахарковскй really?

[@rcade1262]

@@CesarRodriguez-ix1yd lol u are correct my friend

[@jimjimmyjam8242]

I love this channel, thank you for the videos

[@TheKeenMechanic]

Very "cool" :) video. I really enjoyed it and would highly recommend to my friends to watch.

[@therealdamancy]

should have talked about 17 different type of ice as well

[@pier-lucgaranddion1527]

Like the most treacherous and dangerous form of them all, black ice! ...oh. I'm sorry! o___o

[@gonderage]

that wouldve needed its own episode or two

[@kevinharnan8378]

Ice 9

[@GhettoHuerta]

Ouuu that new intro doe!!

[@tyffehhh]

hey Neil! you, Chuck, & the ice are my. ASMR for the evening! 🥰

[@ejmtv3]

Love the new quiet intro.

[@simateix6262]

My scotch voice, Im dying lol

[@humanrightsadvocate]

*8:20** CORRECTION -* Water reaches a density peak at 3.98 °C (39.16 °F) - so, if you're going to round that number, it's more accurate to say 4 °C.

[@alext7074]

Also Neil's explanation why skates slip on ice is wrong.. Unfortunately

[@thelifeandtimesofjames4273]

Smashed it Chuck. That comment about being a home owner made me lol.

[@JRose-dz1gf]

I've been listening to one of these discussions before bed every night, and I feel considerably more intelligent already. I can't wait to read his book as well.

[@ramz3119]

what a Ice Video

[@devinlauwerier404]

My phones dieing and i'm just like,"Bring it in Y'all!!"

[@foifoifoi610]

Dying *

[@flamingosextet8649]

I remember this grin high school chemistry. Do any other known liquids have this property? Thinking about exoplanets and possibilities for life...

[@bradleypetschow8802]

Intro is awesome 🔥

[@martino.9481]

Wasn't it 4° C when water was densest?

[@alext7074]

Yes, it's 3.9something, so very close to 4 if we round up.

[@randydicotti3975]

I still have the very best topic for Neil to explain that EVERYONE will love to hear him explain. Just need to ask ;-)

[@pirobot668beta]

Another way the force of freezing water helps life; it breaks down mountains into dirt. Water in cracks freezes, fracturing the stone. More cracks and freezes, more gravel that tumbles down the river to become soil. Erosion would take so much longer if not for 'frost heave'.

[@fjprofis]

Always amazing teacher!!

[@travisberg9031]

Neil, buddy, yes, ice expands with great force, but what Actually causes a lose to burst, or more often, a fitting, is the fact that water cannot be compressed. When you plug one end of a pipe (the shut off on your sink), it blocks the water from displacing the ice and the pressure formed therein will burst a fitting. Also, since the early '90's PEX is standard supply lines for all commercial and residential. Is incredible plastic. Check it out. Its in Your house... Love you man. Thanks for everything.

[@erikyahirvillamilsanchez9135]

Hi ! StarTalk, I fan here from México, I had certain knowledge about those features about ice but why is it like that ? I mean is there another compound that behaves like it ? Or is it unic to water.

[@isaachoffman6450]

When water freezes, intermolecular bonding causes the molecules to arrange themselves in a structure less dense than if the molecules were freely moving.

[@ukietheoverlord3159]

Neil & Chuck are the best!

[@mirza1221]

Nice Intro,Goes with the theme