You Will Get This Wrong Every Time—Balloons With a Memory (Elastic Hysteresis)!

I should also mention that the "memory" I am talking about here is not the permanent deformation that you get from stretching out a balloon for the first time. The type I am showing is totally repeatable every time you blow up a balloon. Notice how the latex band went back to its original position so it was not permanently deformed.

6:32 "And then here's what happens if you keep blowing up the balloon" I was half-expecting you'd literally keep going until it popped in your face.

"Okay, what's your guess?" "I bet it will get smaller" "Okay, give me a min to blow more air into it and then release it, so we can see what will happen" "Sure thing, nothing suspicious about that"

The problem is they didn’t give me my money.

Man, i learn so much from this channel! Thank you!

Robin: "Why does it work?" Batman: "Because science!"

i've discovered something incredible. 6:45 as the volume of the baloon increases, the volume of my headphones decreases

Now I'm thinking if there's any difference between pumping car tires right away to the required pressure vs. pumping above the required pressure first, then release some air to meet the required pressure.

This really "blows" me away...

Action Lab taught me the art of the Hustle 💰💰

So to recap. Balloon 🎈 is difficult to blow up in the beginning. Everybody should know that. This increases pressure until the balloon 🎈 suddenly start to expand making the pressure go down. When releasing pressure same happens just reverse. The interesting 🤔 part is that if the two balloons 🎈 both are beyond this point then the pressure is the same inside and nothing happens. If one balloon 🎈 is below its “I don’t a want to be inflated point” then it will release its air into the other. Right?

@The Action Lab: I can help describe what you are seeing with the stress/strain curve a little bit better - including the why the release at the end acts like it does (I have a Masters in Mechanical Engineering). The first part of the curve (before the first peak) is the “elastic section.” While you are blowing up the balloon here, the balloon’s deformation is completely elastic and should always return to its original state. Interestingly enough, you can actually predict the exact slope of this line with some simple material properties. If you let the air out before reaching the peak, it will follow this exact line back. It will continue to expand elastically until it reaches the first peak - or “Yield Stress” at which the balloon’s plastic will yield, and start to permanently deform. At this point, you have started to permanently alter the bonds of the rubber, and so the rubber becomes weaker, allowing the balloon to continue to expand, even at a lower pressure. As you continue to inflate, the pressure required will start to rise. You are correct in saying that the balloon will not expand much more at this point. At a certain point, it would, of course, go past its limit and pop. Now, for when you let the air out and release the pressure: Despite all of the permanent (plastic) deformation, the material is still elastic, and still has similar elastic properties, despite the massive deformation. Therefore when you let the air out, it will still being to return to its original shape BUT ONLY the amount within its elastic region. Any deformation that occurred after the point that the material yielded (changing from elastic deformation to plastic deformation) is permanent. The curve will then follow roughly the same slope as the original line back, because it is returning from its elastic deformation. Therefore, it will form a line parallel-ish (theory vs actuality) to the elastic region, but start from where the permanent/plastic deformation ended. Great video! This is really cool stuff!

You must be fun at parties.

Please put bubble wrap in vacuume chamber

I think it would be informative to check the pressure again with the probe further into the balloon and with the flow rate decreased. That fast flow of air out with the probe near the neck of the balloon is going to result in a lower pressure because fluid flow causes decreased pressure. It seemed like you were attributing that pressure drop solely to the elastic of the balloon. Perhaps you could make a disk with two holes, one for the pressure probe, and one to let air out. If the probe is deep in the balloon and you get nice laminar flow when you release the air, the probe should be mostly unaffected by the effect of flowing fluid showing a decreased pressure, as in the video that probe was definitely seeing a lot of turbulent flow.

A youtuber with brain, thank God hahaha ❤ I watch every video, love you

this nerd deserves more subscribers, honestly.

I must say, I would have never guessed this! Good thing I didn't do one of my before video predictions lol. Just a nice reminder that you need to actually do the experiment before saying what will happen. I would have told someone that the pressure will always increase due to the increased tensional forces. Great video!

Awesome video! But also something you kind of know in the back of your head if you have blown up balloons: it’s hard to get started, but once you get past a certain point it gets easier. Would love to see a follow up video from some polymer scientist explaining what happens on a molecular level.

Guess we need to change the saying, "Is the balloon half full or half empty."