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 • 6 143

  • KandaPanda
    KandaPanda 2 hours ago

    Question: f'ing magnets.....how do they work?

  • Richard Nedbalek
    Richard Nedbalek 3 hours ago

    This video should have been sponsored by an eco-friendly laundry detergent manufacturer! 🤣

  • Suhrit Pradhan
    Suhrit Pradhan 4 hours ago

    So help me understand something.
    If I keep the bottle open for long time such that its pressure is equal to atmospheric pressure and then if I put a mentos in the drink, there would be no reaction right? Since the excess carbon has already left?

  • Roaminghomosapiens
    Roaminghomosapiens 4 hours ago

    That's a cockring

  • Michael Scharf
    Michael Scharf 5 hours ago

    At 7:34 you see a green layer on top but no red layer....

  • Michael Scharf
    Michael Scharf 6 hours ago

    The fly at 5:25 is funny

  • EllieTube
    EllieTube 6 hours ago

    who was not perplexed by any of this?

    RES KEN 7 hours ago

    KFC employees - "your order sir ?"
    Me - "a non equilibrium beverage"

  • Gemini Jake
    Gemini Jake 8 hours ago

    Boooo paper straws! Boooo! Lol

  • That Guy
    That Guy 8 hours ago

    Maybe start with a bottle that isn’t already shaken up that might help you understand.
    It is really common sense
    No need to try and figure something out that is easily understood if you just use your brain 🧠

  • URAsoreloser1
    URAsoreloser1 8 hours ago +1

    This validates my tendency to squeeze partially empty 2 liter soda bottles between pours. Less air space for the CO2 to escape and drink stays fizzy longer.

  • Henrik Larsen
    Henrik Larsen 8 hours ago

    So the ice cube experiences an underwater equivalent of chill factor (wind taking away warm surface air)?

  • Chris BigBad
    Chris BigBad 8 hours ago

    nice n all. but please don't go all king of random on us, will ya? I'd be missing the aerogel and stuff.

  • L D
    L D 9 hours ago

    Thanks !! As a kid we would shake cans until they exploded. So .... that is the exchange of gas as nucleation? 👀 👀

  • Skelassassin
    Skelassassin 10 hours ago

    What if you used salt water ice cubes? Would they the result be the same or different?

  • S S
    S S 10 hours ago

    That sound is soooooooo

  • Ab
    Ab 12 hours ago +1

    Nicely explained, you make science fun (:

  • iBadger
    iBadger 14 hours ago +1

    I think you can dip the paper straws in water, then put it in a carbonated drink. A soaked straw should have little to no air which would act as a nucleation site for the Carbon-di-oxide otherwise.

  • Divergent Droid
    Divergent Droid 15 hours ago

    I have another TWO for you! I double Dare you to answer me because after you read this your mind will be Toast and I bet you Wont! In science Physics Laws Require Proof.. so much to the extent Nothing in physics can contradict these Laws without a physical demonstration in physics that proves the new claim.. thats the way it's taught to us all right.. . you with me so far.. good. Question 1) How can a Molten core of Earth produce Gravity when 1) a moving fluid has no defined mass and 2) any metal heated to molten levels Cannot produce a magnetism? and Question 2) How can there be a pressurized atmosphere next to a vacuum without a barrier separating the two where equilibrium fails to take place? That is Impossible and Breaks the second Law of Thermodynamics assuming the idea were real but of course it's silly. Both of those things Cannot be demonstrated in Physics. WE are Taught a Fantasy that does Not conform to the rules of physics as we know them. Earth Cannot be a spinning sphere in space.

  • Richard Jesch
    Richard Jesch 16 hours ago

    New (possibly) perplexing problem. I thought this one out before hand and was elated to discover I was right. Here it is: You have a helium balloon in your car attached to the gear selector (or anywhere it is attached by a string and free to move forward or backward). Begin driving the car. During acceleration which direction does the balloon move relative to the car? What happens when you apply braking? Enjoy.

  • Jø Kərr
    Jø Kərr 17 hours ago

    Paper straw? PAPER STRAW?!?! Am I the only one who has never seen, nor heard of a straw being made of paper? That seems like the worst material to make a straw out of. Either they are a west coast thing, or Florida (where I live) is behind the times, but I'm cool with that because as I said, paper seems like that last material you would want to use to siphon liquids.

  • nolastname
    nolastname 18 hours ago

    Witchcraft !!!

  • Angus Shaw
    Angus Shaw 18 hours ago

    Never seen a paper straw before tbh

  • Tessee
    Tessee 18 hours ago

    Everyone knows if you ShAkE uP a CaRbOnAteD DRinCc

  • Azriel Jale
    Azriel Jale 19 hours ago

    What kind of animal drinks his carbonated beverage with paper straw?
    Like....just drink with your mouth.

  • James Clark
    James Clark 19 hours ago

    Physics of Dark matter

  • Leyzr
    Leyzr 20 hours ago

    ...i enjoyed learning about all this stuff i will never use. well... maybe the ring one for a magic trick :P

  • ManTheTroika
    ManTheTroika 20 hours ago

    When the salt is added to the fresh water the temperature changed to dissolve it. The explanation that the water from the ice doesn't sink because of density may be true, but is there more to this? Adding salt is used to change the freezing point and melt ice. To prove the rate is caused by the natural convection current in the fresh water, the experiment could be repeated using a laboratory stir rod in each cup to force roughly equivalent convection current. It would be interesting to do the experiment with all 4 cups at the same time, and see which is fastest and which is slowest. Could it be possible that the fastest and slowest would both be salt water?

  • mrnnhnz
    mrnnhnz 21 hour ago

    the reason I like drinking fizzy drinks is that they're fizzy. So no, I've now got even less reason to hate paper straws - they make my drink more fizzy is good, and you can add that to the they're-better-for-the-environment reason too.

  • Rishabh Mutha
    Rishabh Mutha 22 hours ago

    Can we make a sonic device that agitates the soda and generates nucleation sites? So basically a sound wave with enough freq and wavelength to agitate the soda.
    It would be so much fun to go around stores nucleating soda bottles without anyone ever knowing.

  • Mark Barton
    Mark Barton 23 hours ago

    Upvote the fly! He is amazing!!!!!!!!!!!!!!!!!!!!!!

  • Kevin Wells
    Kevin Wells 23 hours ago

    Just found you - through Smarter Everyday actually. Now I have two channels to keep my brain at least a little more active. Great video.

  • Martin Ninov
    Martin Ninov Day ago

    1 is silly, 3 is neat but boring, 2 is the only really interesting one...

  • Aenayus White
    Aenayus White Day ago

    convection is whats melting the ice the water is being replaced with warmer water thus starting a small cycle like a locomotive

  • Aenayus White
    Aenayus White Day ago

    omg did yall see that fly i wonder if it was watchin the ring fall real time n flew threw it just for the fun of it what are flys eyes natural fps?

  • ralph sampson
    ralph sampson Day ago

    So, does a paper straw make the beverage go "flat" quicker?

  • Przemyslaw Sliwinski

    When I take a dry ice and a germanium lens can I remotely freeze a glass of water?

  • raincandy3
    raincandy3 Day ago

    So why is salt used to melt ice on the road?

  • Tim Podhorn
    Tim Podhorn Day ago

    Very interesting...

  • Stacy Mackenzie
    Stacy Mackenzie Day ago

    I could give you a theory which may enlighten you while destroying any illusions you have about yourself and who you are. But screw that.

  • Micah Navarro
    Micah Navarro Day ago

    Why does homeboy remind me of less accent-y Elon Musk?

  • Daniel Fullington

    I thought the Mentos trick only worked on Diet Coke? Wouldn't nucleation on the surface of a Mentos be the same for any carbonated beverage?

  • Chip Chapley
    Chip Chapley Day ago

    btw, i only new the pressure didn't increase because the plastic doesn't explode from you shaking it........ why it doesn't increase is whats confusing to me though.... imma watch the rest and hope for a answer..

  • m090009
    m090009 Day ago

    5:29 omg did you see how fast was that fly and the aerial acrobatics that it did, it flew through the ring and diagonally. Maan that's awesome

  • Kero Kero
    Kero Kero Day ago

    Suggestion: Do a better explanation than "what-if" on: starting fire with moonlight

  • Eskaypi Amazing
    Eskaypi Amazing Day ago

    Also what about insulation

  • Gareth M
    Gareth M Day ago

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

  • Shimon Fridman
    Shimon Fridman Day ago

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

  • kettenfett
    kettenfett Day ago

    the fly took that hit like a champ.

  • Dan
    Dan Day ago

    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 Day ago

    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 Day ago

    P increases duh

  • Lui
    Lui Day ago

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

  • antony Pizarro
    antony Pizarro Day ago

    Why my peepee small??

  • Rakan Alshamrani

    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 Day ago

    feels like taking some coke

  • Asrat Mengesha
    Asrat Mengesha Day ago

    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 Day ago

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

  • Chris Busenkell
    Chris Busenkell Day ago

    thanks for your time, another great video

  • Art Freeman
    Art Freeman Day ago

    One of the best channels and contents on the internet