Neil deGrasse Tyson Explains Thermodynamics of Water

Why does ice float? On this explainer, Neil deGrasse Tyson and comic co-host Chuck Nice get beyond the tip of the iceberg when it comes to ice floating, the thermodynamics of water, and how other objects float.
How do boats made of steel manage to float? We break down buoyancy and how heavy things still float. Find out how water molecules interact with each other at different temperatures and when water is at its densest. How does water function to protect life? You'll learn the important difference between water and other substances. We explore what happened to the Titanic and what would win: freezing cold water or an indestructible container. Discover more on another StarTalk explainer!
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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
0:13 - Why does ice float?
0:58 - How do steel boats float?
3:37 - How dense is water?
11:25 - How do fish survive the winter?
13:45 - How much does ice expand when frozen?
14:45 - The scientific accuracy of 'Titanic'
16:31 - Why pipes break in the winter
17:19 - When water ceases to freeze...
21:52 - What contributes to buoyancy?
22:47 - Why canoes won't sink
24:09 - Closing notes

[@StarTalk]

What's one thing you didn't think would float?

[@mikeshivak]

Airplane?

[@Broken-xi5io]

"They all float"

[@caonabo2]

A stone. I have an anecdote: once I had to built some concrete anchoring blocks for a pump installatin in a dam's lake. So, I calculated everything but sill make a mistake, because tge blocks were moving. What hapened? I used the weight per cubic meter on concrete, which is about 4.2 tons, but forgot about Archimides law. The concrete anchors recieved an upwards push equal to the weight of the water it displaced (1 cubic meter). Now, 1 cubic meter of water weight 1 ton, therefore you have to deduce 1 ton off the 4.2 tons of the concrete, leaving the block actually weigting only 3.2 tons submerged in water. Solution? Just added 4 more 1 cubic meter concrete blocks and problem solved.

[@dankerman321]

Diesel fuel... saw 55 gallon drums of diesel fuel for a generator being delivered to a small island in Fiji. They rolled it off the boat... drums floated, pushed to shore and rolled up the beach.

[@caonabo2]

@@dankerman321 diesel is less dense than water, that's why it floats.

[@JoeStuffzAlt]

Chuck's questions and statements have gotten really good.

[@BibboSama]

Nah fr my boy getting better🤣

[@StarTalk]

Aging like fine wine.

[@gabrielmugisha3196]

Chuck needs a hon degree in astrophysics

[@laroycarter2662]

Yes he's getting better I can't tell if he's just not playing dumb as much or if he's actually learning and getting smarter either way he hasn't gotten any funnier

[@mshafer2006]

I love these explainer videos. Learn so much from these. Plus, I love how they are so easily digestible.

[@melindaortiz9741]

Agree

[@StarTalk]

Someone has to make the information accessible!

[@mollybell5779]

Oh, these guys. So much genuine laughter. It's good for the soul, and even healing. I am grateful that they post so often. I get to learn while simultaneously having my spirits lifted. What a great combo. Very interesting explainer, this one. I learned a lot, and laughed a lot. Thank you, StarTalk. 😁❤️

[@StarTalk]

Everything you described is why we do it! Glad you're enjoying :)

[@kirktown2046]

Haha, part of the magic of Star Talk is Chuck still manages to play the foil after so long. This one made me laugh a few times, thanks guys, you're the best!

[@LukeSumIpsePatremTe]

Just learned a new meaning for foil

[@StarTalk]

He's hiding his true power level!

[@aaronbailey3942]

He should have added, “ when water gets into a ship, it stars to sink because the density starts to equalize”

[@1MarkKeller]

Yep, filling all those airy voids with water.

[@Chickenandrice485]

Can't get enough of you guys! Completely making my day!

[@StarTalk]

These comments make ours :)

[@philipberthiaume2314]

I was a lifeguard for several summers when I was going thru university. One of the most fun things we did was play watermelon polo. The watermelon would keep depth, it would neither float or sink as it was almost all water. Until someone moved it would stay in place, so it was three dimensional as we played in a 3 meter depth pool.

[@1MarkKeller]

Kool!

[@stephanienirenberg7426]

My son and I were hysterical during this one and during laughter my son breaks into a shocked noise because of water and its refusal to become ice. Loved this one!

[@BePositiveMindset]

Chuck! I asked my dad the same thing. He replied "There's a lot more ocean than boat!".

[@StarTalk]

Your dad's a smart man.

[@nelsoncardo2110]

Chuck is a genius! No normal person would have figured that out. 18:34

[@taliachetty5417]

Agree

[@Bouzoukos]

Loved this long episode!!! We need more of these!!!

[@makaveli1216]

Such a great video for me to watch today literally right before delivering a lecture to my Intro Oceanography students on the topic of the Chemistry and Physics of Water. The steel ship, iceberg, and Titanic examples helped a lot!

[@StarTalk]

So glad it was helpful!

[@gitanod3045]

Neil, I was waiting and hoping you would get to submarines when explaining the idea of less dense/more dense. It would have been a great idea to show the less dense/more dense concept

[@nimrodlevy]

Loved this longer explainer!

[@rychron]

This was so good! The part about the indestructible container blew my mind! Love watching you guys, keep up the great vids :)

[@andhowe6093]

It’s so fun watching you guys,I love your explainer videos 😆!

[@michaelsullivan6854]

These 2 guys together is GOLD, More please !

[@lolanelson9634]

This was mega fascinating! I can’t wait to be a know it all, and share this info!

[@xtm123]

Neil and Chuck, the dynamic duo. You guys have a great chemistry!

[@videosofeverything3876]

That was good stuff about water density. I learned something new and interesting after a very long time.

[@Tyler_McK35]

Love these videos. He makes everything so understandable

[@taliachetty5417]

Always look forward to these videos👌

[@RDEnduro]

This show is legendary 🙌 my phone wanted me to put these hands instead of the word legendary lol

[@environmentalcanadian2338]

I love Star Talk ... even when it's about ice. :) Cheers, Calvin.

[@nickdane1347]

Would love an episode about discovering longitude and the evolution of a clocks

[@hilaryfernando1300]

Superb explainer sir. Love watching your videos. Hilary from Sri Lanka

[@Nobleking97]

Who else loves it when Star Talk appears on the top of your FYP

[@hussainyasmin]

Love the explainer!! Mind blowing facts! Thank you Startalk! Does the water at the bottom of the lake always stays at 4 degrees then in case of a big lake?

[@bertdrake]

I wake up to these videos. Science and comedy in one always start my day off the right way.

[@andythrush3341]

Love you, Chuck! You are invaluable to the program. Nice program Gents.

[@doporto8100]

Sweet, just in time. Got something 2 listen 2 on the way 2 work!

[@gsav1320]

This show is the best on the internet no doubt. Come for the information stay for the two great personalities and jokes

[@Yaroslav_Tselovanskyi]

This is the best formaat of videos on this channel, DON'T CHANGE A THING!

[@Joncoxjohnxdxnl]

Neil and Chuck make science so much fun, learning something with a good laugh thank you! 😅✌

[@ariannanorris-landry4428]

Thanks for the amazing explanations and the FUNNIEST just when needed.

[@dannylgonzal]

I loved the water 201 bit. I was just about to ask this.

[@Mbartel500]

A solid steel needle can “float” on water due to surface tension, not due to the density of steel or water.

[@doubleRprodutions]

Incorrect, the very fact that something is held by surface tension, means it is less dense than the water it's sitting on, so much so, that it doesn't break the tension.

[@ASJC27]

@@doubleRprodutions I think you need to brush up on what density is, because you are the one who's incorrect. Steel needle. Density of steel: ~8 gr/cc. Density of water: ~1 gr/cc. 8 > 1, hence a steel needle should sink, and it will if you let go of it below the water surface. But if you place it on the surface, it's small enough that the added force of surface tension will hold it up.

[@Mbartel500]

@@doubleRprodutions sorry, but you are incorrect. If you put a thin needle into the water point first, it will sink. If you lay it on the water, on it's side, it will stay on top due to the surface tension. A solid steel needle is more dense that the equivalent volume of water, yet it floats on top, if you put it on the surface to take advantage of the surface tension. You should research a fact, before telling someone they are wrong when they quote that fact.

[@FusionDeveloper]

You are right Mike Bartel. I just have to make this joke from Monty Python. B: What also floats in water? Villager: Bread! Another Villager: Apples! Another Villager: Uh...very small rocks! Another Villager: Cider! Another Villager: Uh...great gravy! Another Villager: Cherries! Another Villager: Mud! Another Villager: Churches! Churches! Another Villager: Lead! Lead! King Arthur: A Duck! Villagers: (in amazement) ooooooh!

[@doubleRprodutions]

@@ASJC27 See my reply to @Mike Bartel

[@ReVision..]

Great episode! Thanks Neil and Chuck!

[@thetechconsultant]

I’m glad he asked that question because I was definitely thinking it lol

[@Nitelifebuzz]

6:40 - Neil is partially embarrassed, but still near tears from laughing too hard. This is the good stuff they usually truncate to keep these explainers under 15 mins.

[@ngnatural]

You guys went IN! I love it

[@TJ-hs1qm]

Hey Dr. Tyson. Could you please give us a heads up of the current state in nuclear energy science and the controversy surrounding it? 🙏

[@doubleRprodutions]

Didn't you see the first fusion reaction the other day?

[@milosstojanovic4623]

@@doubleRprodutions it's not 'the first' but the new one. They are exploring new methods for colliding particles to see how efficient it would be. We are still long way from efficient fusion.

[@doubleRprodutions]

@@milosstojanovic4623 Definitely, but it's a good start! 😁

[@SIMxv]

I love this show so much!

[@Xiph0s55]

Chuck that haircut is SUPPPPPPER fresh

[@HaiderKhan-nc9gf]

Great video. Loved it and learnt from it. But the heart of the whole matter remained a mystery. Why water starts expanding below 4°C? You told us the effects of that expansion. But not the reason of it. Thanks

[@c.v.v.-mx6989]

I believe it is because of its atomic arrangement. The atoms/molecules in water arrange in such a way that when it freezes there are empty spaces between the atoms. So, no matter how cold it gets, atoms in ice never get as close as they do in other solids; they even stand farther away from each other, which is way we say that it expands.

[@SelfReflective]

Why is red redder than blue? Some questions don't have an answer. Water is just anomalous that way.

[@timothyvenable3336]

I think because God knew what he was doing!

[@averageaf4321]

I love it when Chuck figures out what Neil is going towards, just a few words before Neil says it!

[@guilberematos]

Outstanding lesson!

[@hukeaz]

Thank you guys! I have such an affinity for water! This was very interesting and informative. Aloha!

[@StarTalk]

Water is essential!

[@pjg6019]

You guys are amazing. I was laughing out loud while learning. Thanks

[@BogdanTomin]

I love your explainers! :) Btw it seems to me that you literally had the explainer called "Why ice floats" 😁

[@kittiruffle4488]

Would you guys be willing to do these live? It would be so awesome to be able to ask questions and comment live. Please!!!

[@rf7946]

Neils presence always makes me instantly happy.

[@MikeG-nz8gt]

This is a rerelease of part of an older video. I still enjoyed it though. Great content.

[@etrus0645]

great vid but there is so much more to explain about the phase shift of water to ice. I would have liked to know what molecular forces align water into a crystal. if a block of ice can be made without cloudiness and ground into a mirror and if the outer layer of a block of ice has a variable snowflake pattern.

[@michaelflores451]

Wow. This episode was pretty damn cool.

[@jeremysmith5183]

I saw the screen title "Aquatic Winters" and was very intrigued as to why you would be discussing The Poseidon Adventure, brilliant film though it is, but now I understand ...

[@Chemy.]

I would like an explainer for the electromagnetism of the water, i mean, everything related to radiation, radio signals and so on

[@matejlaskomulej]

Great vid you guys, as always. The question I was missing is the following. Is there any other molecule we know of with the same same special property (albeit at a different temperature), ie. it gets denser with the dropping temperature on the entire interval from zero kelvin to let's say plasma temperatures except on some small part of that interval, or even that it's at its densest at some positive temperature [in Kelvins]?

[@AJD...]

For anyone wondering WHY ice is less dense than liquid water: Water molecules have 2 hydrogen atoms and an oxygen atom. When there are multiple water molecules floating around, the hydrogen atoms make what we call hydrogen bonds with oxygens of other molecules. Think of these bonds as an extra pair of rope ties. When you lower the temperature down, these rope ties straighten up and get longer than they were. This decreases the overall density of the substance. Interestingly enough, this property also makes water a universal solvent. A property which in and of itself - supports life.

[@craigtaylor4613]

Not just density, because as chuck says metal is more dense, but Archimedes principal comes into play, as the shape of the hull weights less that the water it displaces

[@sonkamehameha1572]

Chuck you are the peoples champ. Neil you are the best teacher in the world!! I love these random science drop. Even though I knew some about a topic you help us understand that there is more to it. NEVER STOP LEARNING🤘🔥🤘

[@kennyhoward9113]

I love all the content. Your explanations of global warming and the way you guys put it into a language I can visualize has made me understand reality. Thanks for helping me be curious

[@scottakam]

Good stuff. There are several species of trees with higher density than water that do not float. Teak for example.

[@gustavofigueiredo1798]

Almost 25 minutes of "explainer"? Nice!

[@maryrochon9083]

Oh you two are so great! I have been watching for so many years. My favorite shows are the Neil n Chuck shows HANDS DOWN! 💛🧡❤💜

[@habi0187]

I missed the explanation for this odd behaviour of water which is related to that fact that water is a dipol and in ice the molecules are sorted in a special way so that a positive pole always is surrounded by negative and vice versa and this structure needs more space than a liquid with slow moving molecules.

[@MisterIncog]

I thought Neil would mention it but whatever. I don’t know it very well, but like watermolecules need some structure to catch on before turning into ice. Regular water have other molecules than water, like minerals and ions and stuff, so it catches to that. But distilled water doesn’t, so if you put in a bottle and lower the temperature to a freezing point and below it won’t freeze. But once you smack the bottle it goes wooosh and freezes. There are cool videos of how it look on the net, action lab has one, look it up.

[@oldcowbb]

19:06 i'm pretty sure it will only decrease the freezing temperature to a certain degree, not indefinitely, it's call an isochoric process

[@timk5867]

There is actually a few species of wood like ebony that sink in water

[@cherylnicowski3006]

You guys are so funny I could listen to y'all day I,m still laughing while I learn !!!

[@Nipplator99999999999]

Chuck Nice had me on the edge of my seat, waiting for him to show the intelligence he hides for comedic effect. I literally just cheered for him making Neil show that amount of proud astonishment.

[@CarryTruck]

There is an other explainer about why ice floats, nonetheless always love the explainers!

[@kimmckenna7557]

I just watched the broham one its so true..I actually unless the title boggles my mind..I honestly won't watch unless it Doctor Neil and like no other comedian Mr Chuck. You guys are the peanut butter..love it.

[@wayneray2815]

This was interesting and informative. On another note, what ever happened to Suzy Q's? I never see them in stores around here. Bring back the Suzy Q's. We need a Cosmic Queries video about that, LOL.

[@gps1539]

I like this and most of the explainers, educational and a good giggle. Maybe good to follow up on why ice expands i.e. it crystalizes and the structure then takes up more space. Also I believe water is not unique as some semiconductor materials also expand when they freeze, like silicon.

[@manos8010]

If you have an indestructible container, the water will eventually freezes. But it will become a phase two (or greater) of ice, that has greater dencity than liquid water, so it takes less volume. This will happen at a pressure of 6000 atm. So the correct answer is, the container wins and water increase the pressure until it reaches the 6000 atm mark, then it becomes a deferent type o ice.

[@user-di6wr6br2t]

Wow! I had no idea that there are so many differnet types of ice! 😯

[@marios8977]

You are right, I wonder why Neil didn’t mention it!

[@oksyar]

I love Neil... I've studied water from so many sources but after this video i truly understood why sometimes when i take coke out of freezer, it seems liquid but as i open it, it instantly starts to freeze up that's because coke needed more room to freeze which the tight bottle wasn't letting it and as soon as it gets more space, it freezes up.

[@roichir7699]

It is called supercooling.

[@JigarGada]

I seriously hit like 👍 at @18:37

[@nephiilim]

Whoa! That was dope! What thinking too chuck. I was thinking of that answer as soon as you said "lemme guess"

[@jeannieortiz3604]

You guys are so funny .... I am always laughing in tears while getting my science learning on .... : )

[@1MarkKeller]

This show is edutainment at it's finest!

[@ahadonyt]

Neil and Chuck - best duo ever

[@SteveC38]

Nice Job, Fellas!

[@dwaynep6174]

Recently learned about Hydrogen Bonding in chemistry which is the culprit for water being so weird. Loved this

[@jamesmountz2915]

I cant help wondering why neil did he not explain displacement the way ive always heard it explained. It makes it so much easier to understand. If the amount of water being displaced by the object weighs more than the object than the object will float. Then people can visualize all the water a steel boat displaces and quickly understand how that much water is a lot heavier than the steel ship because like neil said the inside is hollow.

[@astitvasrivastava1159]

I think the density explanation is complete in itself. Saying that ship as a whole has low density than the water (due to the air present in the hollow chambers) is pretty simple to understand. Explaining water displacement (Archimedes' principle) would require shedding some light on gravity also. Simply visualizing how water is being displaced might not help in all cases (e.g. a needle vs. a toothpick, where density plays a major role).

[@Games_and_Music]

When he was leading up to that, i was saying to myself "because of displacement", but he didn't say it, nor did he mention volume. He almost went there when he mentioned the ice cube 10% thing, but he still didn't name it directly. Same for the ending about the styrofoam canoe tips, i thought now he was going to introduce displacement, as i thought it would be easy to understand, styrofoam has air bubbles trapped inside it, thus preventing the displacement, because loose air would simply be pushed out by the incoming water and make the canoe itself denser than water and sink it. Then again, Neil is more of a generalist, he doesn't really do deep dives into many topics, but knows enough to tell something about it. Not that displacement is some obscure advanced concept, but he might've forgotten about it at that moment, or purposely avoided the 'traditional' explanation.

[@Games_and_Music]

@@astitvasrivastava1159 It wouldn't have taken much to add it to the explanation though. He was getting close with the canoe as well, because if you flip the canoe quickly, it'll float, because it kept the air inside. But if you tip it, or capsize it long enough to fill up with water, it will sink, which is how the water displaces the air, the more water it takes, the more air gets pushed out, the heavier it gets. Most people are familiar with that concept without having thought about the theory. Then he could've mentioned the styrofoam having air trapped inside it, preventing the displacement. Sorry for posting this part of the post again, but it felt incomplete if i didn't repeat what i said in the other post.

[@Padcast]

That's why your in the comments.

[@sapelesteve]

Interesting video Neil & Chuck. However, Neil was wrong when he said that all wood floats. Many woods will sink when placed in water. Lignum vitae being a prime example. Others include any wood that has a density greater than that of water, including Cocobolo, Coralwood, Ebony, Eucalyptus Mahogany, Gaboon, Greenheart, Grenadilla (Mpingo), Ironwood (black), Satinwood (Ceylon), and Water gum.

[@raymondscalf2712]

Nice piece of information

[@daviddawson1718]

Most wood floats, but not all. There are outliers. That said good explanation, and thanks for teaching me things that I either didn't know or had forgotten since college.

[@Bigbillyrayfan]

Where does ice get the energy to break things? Polar molecule thing?

[@jeffreysherman8224]

"Cal'el was messin' around!" "...with 'the help.'" Neil, you're out of pocket for that one! 😂😂😂

[@xandergreene1748]

Lord nice, nice work.

[@elizabethclouse151]

Chuck has come so far from when he first became a constant on StarTalk

[@udopiarecords]

This was great! I just had an unanswered question that felt appropriate: How is it that sometimes you leave a water bottle or soda in the freezer, and you take it out when its very cold but still liqiud, then you smack it on a hard counter top and watch it all insta-freeze before you?!?

[@tintiniitk]

This still missed the one thing that I was expecting NDT to explain i.e. why exactly water expands on freezing or in other words, why its density falls on freezing. But interesting video nevertheless.

[@ryanseward2760]

It's partially do to the polarity of a water molecule. So the oxygen is partially negative charge while the hydrogens are partially positive. As they get closer together the like charged ends don't like being next to each other so they rearrange to form the solid rigid structure and distance themselves back out to increase the volume.

[@1MarkKeller]

@@ryanseward2760 Interesting! I hear there are different forms of ice with different densities too.

[@mckerrowsiding]

I am old enough to have had a milkman deliver milk to our front door. In Montreal in the winter that meant we would often have the cardboard stopper popped off the bottle as the milk froze. So the dairies did know about displacement of freezing milk

[@tylerbird9301]

I love it when chuck gets his aha! Moments and neil is just "correct ✅

[@mattevans-koch9353]

Ok you two, here is a question for you-When I put an ice cube in my scotch whisky, does it still float 10% above the surface or does it float lower because the water is thinned by the alcohol? Thank you and I'll finish my drink now. Great video by the way.

[@001dres]

Recently you explained the alignment of the H2O molecule changes and that is why the molecule takes up more space. Should have been in this specific video, don’t you think?

[@infinatep1mp737]

Here's a question. As water gets colder you need more and more pressure to keep it liquid. Is there a force/temperature limit it will not pass and will remain liquid? Or is this a Infinate problem? Colder=more pressure needed to keep it liquid?

[@habi0187]

We'll all this thought experiments definitely end at 0 Kelvin nothing gets colder since the molecules stop moving.

[@Mr12Relic]

12:31 Someone once tried to correct him that it's "fish" not "fishes" and he explained that the double plural is used when referring to multiple kinds of fish, such as tuna and salmon collectively.