3 Perplexing Physics Problems

  • Published on Nov 20, 2019
  • Why does shaken soda explode? Does ice melt first in fresh or salt water?
    Thank you Squarespace for sponsoring this video. Go to squarespace.com to save 10% off your first purchase of a website or domain using code: VERITASIUM
    This video features experiments that have been shown to me by science teachers over the years. Does ice melt fast in salt water or fresh water was an experiment introduced to me at the Utah Science Teachers' conference. The ring of metal over a chain demo came from a teachers event in Florida. The idea shaking a carbonated drink increases pressure came from an email.
    Special thanks to Petr Lebedev for building the pressure gauge.
    Links to literature are below:
    Victims of the pop bottle, by Ted Willhoft. New Scientist, 21 August 1986 p.28
    Carbonation speculation
    The Physics Teacher 30, 173 (1992); doi.org/10.1119/1.2343501
    Agitation solution
    The Physics Teacher 30, 325 (1992); doi.org/10.1119/1.2343556
    Filmed by Cristian Carretero, Jordan Schnabel, Jonny Hyman, and Raquel Nuno
    Music from epidemicsound.com "Seaweed" "Quietly Tense" "Mind Shift" "Observations"

Comments • 6 093

  • Axle Cremer
    Axle Cremer 37 minutes ago

    Hemp straws are the way to go.

  • rwk92877
    rwk92877 Hour ago

    5:30 Anyone else see the fly on his hand jump through the hoop when he dropped it? lol!

  • jtyrellv
    jtyrellv Hour ago

    I feel like you'd be the perfect person to explain haloclines.

  • Mathieu Lavoie
    Mathieu Lavoie 2 hours ago

    Apex of the video is when the fly on his hand passes through the ring in slowmo as he releases the ring!!!
    Such skilled fly.

  • aser hasan
    aser hasan 4 hours ago

    Why salted water takes more time to dissolve than fresh water?
    Seems to be relevant to your experiment! Isn't it?

  • Jonathan
    Jonathan 5 hours ago

    I love when you make me think about and see depth into a topic I have taken for granted.

    VIKTOR BIHAR 5 hours ago

    So, looks like movie creators put someone's voice on slowmo to make it sound big.

  • Michael Everson
    Michael Everson 6 hours ago

    But why do some straws rise up out of fizzy drinks?

  • Robin Wallace
    Robin Wallace 6 hours ago

    What a great video, thank you. I watched because I was little worn out from constantly watching climate change videos even though that is a favorite subject of mine. So of course I was enlightened by the melting ice demonstration. I've read that the sea ice is extending around part of the Antarctic and have wondered why in a so called warming environment how this could be happening when it would suggest that the sea temperature is actually cooling. So as it turns out the ice is more than likely floating in a layer of cooler fresh water thus lasting longer.
    Now I have a great deal more to consider because of this. Will the extended life cycle of slowly melting ice reflect more light and help prevent warming? Does this mean that the more melting and faster movement of glaciers with a termination point at sea level have the ability to actually mitigate some of the warming we are told will happen? Do the models take this into account? Why am a told that melting ice creates seductive currents but actually the two differing types of water don't mix well at all?
    Thank you so much.

  • Anita Burke
    Anita Burke 7 hours ago

    My son and I used to boil warm tap water in a plastic syringe. Most of the gas was dissolved air, but it was still cool to watch:
    Fill a plastic syringe about half way with warm tap water. Put your finger over the hole, and draw back on the plunger. If you've ever seen high school physics demonstrations with shaving cream or marshmallows in a Bell jar, the principle is similar - you are reducing the pressure inside the syringe.
    Once you do it a few times, it's not as dramatic, which leads me to conclude that (1) the reduction in pressure is not that much, and (2) most of the "boiling" that you see at first is dissolved air coming out of solution
    ⚗⚗⚗🤓 have fun and remember, Safety First! 🚧🤓⚗⚗⚗

  • Rob Clizbe
    Rob Clizbe 7 hours ago

    If both classes of water were constantly agitated, preventing the ice cube in the salt water from self insulating from the room temp water, then what would the result be? Since salt lowers the freezing temperature of water, shouldn't the cube in the salt water melt more quickly?

  • hayden heller
    hayden heller 7 hours ago

    The slow-mo sound drive me crazy for some reason. Stop already!

  • bas steyn
    bas steyn 8 hours ago

    You can also roll the bottle gently on it's side to get those bubbles off

  • ofvoypo mukoweza
    ofvoypo mukoweza 8 hours ago

    5:26 and the insect takes off:)

  • obsolete professor
    obsolete professor 9 hours ago

    Explain this... Why is it that when you drag a garden hose down a straight sidewalk it hangs on something and kinks a dozen times?

  • paintBallprepperTMV AwomanIsAntichrist

    Yes time has a structure there is a generational gap in all living things. Old trees new trees a baby and 90year old live on earth at the same time. So my question is we're is the evolutionary generational gap were are the half evolved creators walking with us there should be different stages right in front of us. Oh yes for those who don't believe in God go ahead and stop time.

  • Bouiri Amine
    Bouiri Amine 15 hours ago

    Who the hell is retarded enough to dislike a video like this one?

  • Rad_itya 2
    Rad_itya 2 15 hours ago

    Fresh water is faster melttt

  • Kael Denna
    Kael Denna 15 hours ago

    so if I put my mouth around the bottle and blow into it hard to create 3 atmospheres of pressure before drinking, I can drink a soda while at equilibrium and therefore it will taste flat?
    does this also mean fizzy drinks feel flat in Venus' atmosphere?

  • ASrocks all rounder
    ASrocks all rounder 17 hours ago

    Pls make a vedio and explain why are some things transparent while others are not

  • Steve McNutt
    Steve McNutt 23 hours ago

    For some reason my Labatt Blue in a bottle has very often boiled over as I take the first couple drinks. If I'm careful not to put any vacuum to it as I take the first couple drinks it never happens. But if I'm distracted it often overflows and beer soaks my coosie and makes a small mess on the floor. What's different about Labatt? What is happening when you pull a small vacuum during a drink and quickly release? Again it's a minimal transition. Thanks in advance.

  • Sergio
    Sergio Day ago


  • Br4dyboyzkid
    Br4dyboyzkid Day ago

    The new mark rober

  • bruenor82
    bruenor82 Day ago

    real takeaway is that derek got really rich

  • Andrew Drury
    Andrew Drury Day ago

    So when I drop a fizzy drink in the shop, and put it back on the shelf, do I not have to feel guilty about losing any fizz?

  • PsychoLucario
    PsychoLucario Day ago

    its the loss of pressure that causes the bottle to explode, the dissolved co2 rapidly falls out of solution, explodes out, foams the drink and the foam gets choked in the bottle neck

  • Joonha Shcal
    Joonha Shcal Day ago

    Wow, actually something I can solve. Carbonation comes from H2CO3 that is dissolved in the water. The atmosphere inside the bottles is pure CO2. There is no way for the H2CO3 to turn into H2O and CO2. The pressure inside the bottle is already at the maximum so to speak. Yay! Middle school chemistry!

  • payrim Dwein
    payrim Dwein Day ago

    I learned a lot of stuff from you veritasium, thank you
    could you please make a video about Tensors in physics? I never heard that until yesterday that i was in university

  • Rama Regis
    Rama Regis Day ago

    My whole life I have been aware of the pressure inside the bottle increase at a point it could break it if I shake it too much 🤦🏻‍♂️


    11:04 that's for impressing someone 😆👍

  • I changed my name after I waited 90 days

    Ah yes,

    *Enslaved CO2*

  • Anshil Agarwal
    Anshil Agarwal Day ago

    Plz explain in next video

  • Vinicius Tinti
    Vinicius Tinti Day ago

    How about dropping aerogels inside carbonated drinks? Will it nuke?

  • dovregubben78
    dovregubben78 Day ago

    There may be a situation where shaking a carbonated beverage bottle actually reduces the pressure inside it. If you allow the bottle to reach equilibrium at room temperature, then rapidly chill it, you will increase the solubility of CO2. The rate at which CO2 can enter solution is limited by the surface area at the interface between gas and liquid, so it should take some time for the pressurized CO2 to enter solution. Shaking significantly increases that surface area, thus allowing gas and liquid to reach equilibrium at the lower temperature faster. I don't have a pressure gauge handy to test this hypothesis though...

  • Nathan Lewis
    Nathan Lewis Day ago

    I thought you were an environmentalist? I think no straw is better than paper or plastic straws.

  • Einstein WasRight

    Re: pop fizzing -- pouring pop onto ice generates a lot of fizz due to the irregular surface of the ice cubes. This can be reduced by pre-rinsing the cubes with water before pouring on the pop, and it can be almost eliminated by rinsing the ice cubes twice. An alternate fluid for pre-rinsing the cubes is an alcoholic beverage, such as vodka or rum or whiskey, in which case you probably wouldn't pour out the rinsing fluid!

  • Jonas
    Jonas Day ago

    I think I just saw tubgirl 10:59

  • Persona non grata

    So help me out here. Does the CO2 boil or precipitate? does it matter?

  • Fernando Spinelli

    Very interesting

  • Swapna Mohapatra

    Sir , please drop a capillary tube to demonstrate shape of liquid surface during free fall..

  • Johannes Vermeer

    Is it the same thing if we eat mentos and drink carbonated drinks ?

  • Brennan Probasco

    If you can’t make the pressure go past equilibrium, then why can some bottles explode when you put mentos in them and close the cap?

  • Liam Kelly-Payne

    Hey, just thinking, with the ice melting slower in saltwater, wouldn't another factor be water's high specific heat capacity, hence with the saltwater the ice can cool down the water more, as it requires less energy?

  • Manuel Neuwirth
    Manuel Neuwirth Day ago

    What about the case of a deadorant spray can? When it is like half emptied, rested long enough for equlibrium and then you shake it, the can gets colder. The bottom part of the can, where the liquid is localized doesn't fell colder before shaking, so it is not just that it would feel colder because the liquid touched the can surface.
    I assume the pressure within the can decreases because more of the propellant gets dissolved in the liquid and therefore the temperature decreases.
    If this is the case, why does shaking the spray can influence the equlibrium while the soda bottle is not impressed at all?

    • Da Os
      Da Os 7 hours ago

      re-read your post. you answered your own question. sort of.

  • DanielInfrangible

    I can't watch your videos without thinking about your two front teeth under UV . . . I love them. (You're videos. Not your teeth. Though I'm sure they're fine teeth).

  • Trash Bxtch
    Trash Bxtch 2 days ago

    God damn that chain sound is sexy

  • JuanJo Monterrosa
    JuanJo Monterrosa 2 days ago

    Interesting Channel, I watch USclip scientist disclosure and I improve and completely máster english add suscriber I found out about this Channel at through Karen Liz Mejía of La Ciencia detrás de

  • Peter Milanovski
    Peter Milanovski 2 days ago

    LoL the tiny air bubbles? Where? Don't you mean CO2 bubbles?

  • Marco De la o
    Marco De la o 2 days ago

    Let's get something clear. Technically you added energy to the liquid in the bottle by shaking didn't you? That being said even if by the smallest almost inconceivable amount wouldn't the pressure increase?

  • Jacob Delloma
    Jacob Delloma 2 days ago

    What’s the science behind being able to predict a pitch in baseball

  • Dechawat Arsanam
    Dechawat Arsanam 2 days ago

    Nope. Guess correct. I study physics. Very simple.

  • William Scavone
    William Scavone 2 days ago

    A fizzier straw = yummier beverage. Compare the fizz in a glass bottle (or glass cup with ice) and a plastic bottle. If you want the truer "classic" taste of a popular soda, the best bet is the glass container. I'd rather drink, therefore, from a glass straw than a plastic straw, so it releases more of the yummy CO2 as I drink. Paper just gets damp...

  • Jack Chandar
    Jack Chandar 2 days ago +3

    Why then does a carbonated beverage bottle "firm up" when shaken and left sealed, as if there were a larger outward force and therefore pressure?

    • sukhoy
      sukhoy 7 hours ago +1

      I guess because the bottle was NOT in equilibrium, before shaken

  • bacon bits
    bacon bits 2 days ago

    Prove that gravity is real

  • Stevie Newm
    Stevie Newm 2 days ago

    I made my set of magic ring and chain!
    You need as light a chain as possible. If it is too heavy it will not fling up and over the ring. A heavy ring also helps a lot.
    Works every time!

    FUMIF HONDURAS 2 days ago

    thanks for my next science fair project :)

  • iamthinking2202 _
    iamthinking2202 _ 2 days ago

    The ice in the salt water seemed to become clearer even though it melted slower..

  • Chris Greacen
    Chris Greacen 2 days ago

    Why is a bike more stable when moving than when still?

  • Jishnu N Krishnan
    Jishnu N Krishnan 2 days ago

    Can you freeze Alcohol?

    WESTON HEEREN 2 days ago

    I do the loop and chain trick the first day of school every year