3 Perplexing Physics Problems

  • Published: 20 November 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 • 6 109

  • Gareth M
    Gareth M  1 minutes back

    Is there an optimum size of ring and length of chain?

    • Shimon Fridman
      Shimon Fridman  8 minutes back

      so if you dropped a different rough surface like a rock would it fiz up like when you put the mentos in?

      • kettenfett
        kettenfett  26 minutes back

        the fly took that hit like a champ.

        • Dan
          Dan  43 minutes back

          So what you're saying is that the pressure in the bottle didn't increase when you shook it because you had already shaken it.
          Kind of feels like cheating, but okay.

          • Edan Tal
            Edan Tal  2 hours back

            is it work the same with suger????

            please answer me!!!
            no one drinks salt water and we all drink some kind of suger water...

            • Edy Banciu
              Edy Banciu  4 hours back

              P increases duh

              • Lui
                Lui  4 hours back

                Papers straws make my drink more fizzy when it comes out the top? I see this as an absolute win!

                • antony Pizarro
                  antony Pizarro  4 hours back

                  Why my peepee small??

                  • Rakan Alshamrani
                    Rakan Alshamrani  4 hours back

                    astronauts move in the orbit of the earth but what if they where in the middle of space? would they die because of the low amount of gravity causing the blood to stop its movement? because we know that 400 km from the ship to earth that the gravity=8.7 units but what if it was 0.0 units would the blood stop moving through the body? and what if we made a suit that can protect the movement of you blood during the event of a 0.0 units in space.

                    • kelvyn charlie
                      kelvyn charlie  7 hours back

                      feels like taking some coke

                      • Asrat Mengesha
                        Asrat Mengesha  8 hours back

                        Do they stack( suck into) some air into the battle with drink so that it can explode when opened just like exploding Tyre releases air? Thanks.

                        • creativefeather
                          creativefeather  9 hours back

                          So, if I found some super smooth ice cream, my root beer floats wouldn't go nuclear?

                          • Chris Busenkell
                            Chris Busenkell  12 hours back

                            thanks for your time, another great video

                            • Art Freeman
                              Art Freeman  12 hours back

                              One of the best channels and contents on the internet

                              • Axle Cremer
                                Axle Cremer  14 hours back

                                Hemp straws are the way to go.

                                • rwk92877
                                  rwk92877  14 hours back

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

                                  • jtyrellv
                                    jtyrellv  15 hours back

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

                                    • Mathieu Lavoie
                                      Mathieu Lavoie  16 hours back

                                      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  18 hours back

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

                                        • Jonathan
                                          Jonathan  19 hours back

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

                                          • VIKTOR BIHAR
                                            VIKTOR BIHAR  19 hours back

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

                                            • Michael Everson
                                              Michael Everson  19 hours back

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

                                              • Robin Wallace
                                                Robin Wallace  20 hours back

                                                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  20 hours back

                                                  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  20 hours back

                                                    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  21 hours back

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

                                                      • bas steyn
                                                        bas steyn  21 hours back

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

                                                        • ofvoypo mukoweza
                                                          ofvoypo mukoweza  21 hours back

                                                          5:26 and the insect takes off:)

                                                          • obsolete professor
                                                            obsolete professor  23 hours back

                                                            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  1 days back

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

                                                                • Rad_itya 2
                                                                  Rad_itya 2  1 days back

                                                                  Fresh water is faster melttt

                                                                  • Kael Denna
                                                                    Kael Denna  1 days back

                                                                    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  1 days back

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

                                                                      • Steve McNutt
                                                                        Steve McNutt  2 days back

                                                                        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  2 days back

                                                                          THERE IS NO POLL WERE YOU ARE POINTING VERA

                                                                          • Br4dyboyzkid
                                                                            Br4dyboyzkid  2 days back

                                                                            The new mark rober

                                                                            • bruenor82
                                                                              bruenor82  2 days back

                                                                              real takeaway is that derek got really rich

                                                                              • Andrew Drury
                                                                                Andrew Drury  2 days back

                                                                                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  2 days back

                                                                                  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  2 days back

                                                                                    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  2 days back

                                                                                      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  2 days back

                                                                                        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 🤦🏻‍♂️

                                                                                        • INNOVATION & INITIATIVE Diy

                                                                                          11:04 that's for impressing someone 😆👍

                                                                                          • I changed my name after I waited 90 days

                                                                                            Ah yes,

                                                                                            *Enslaved CO2*

                                                                                            • Anshil Agarwal
                                                                                              Anshil Agarwal  2 days back


                                                                                              Plz explain in next video

                                                                                              • Vinicius Tinti
                                                                                                Vinicius Tinti  2 days back

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

                                                                                                • dovregubben78
                                                                                                  dovregubben78  2 days back

                                                                                                  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...