'Bouncy' sulfur hexafluoride gas in tennis balls?

Testing myths about gas inside tennis balls.
Note: I should have added that all of the gases tested would have the same bounce height in a perfect no-loss system. The reason that SF6 bounces higher is because it heats less during compression, lowering the amount of possible thermal loss. Argon heats more during compression, and can lose more energy because of thermal transfer from the gas into the cylinder walls, where it is not restored upon decompression. Things are more complex in a tennis ball, though: Most of the losses are in the rubber shell, and not in the thermal dissipation of the fill gas. It's hard to estimate, but I'd say that the highest fill pressure, with a high-gamma gas would prove to be the most bouncy since it would cause the rubber shell to deform the least. The amount of compression in a tennis ball is very low, and any effect due to the gamma of the gas will be extremely small. Fill pressure will have a dramatically bigger effect.

General adiabatic resources:

[thethoughtemporium]

That was fascinating! I knew sf6 was a good insulator for highvoltage but had no idea it had all these other interesting properties.
My favorite bit "I haven't built a mass spectrometer *yet*"

[LeicaCat]

Imagine playing fetch with your dog using tennis balls filled with SF6. Rover chomps a bit too hard on the ball and suddenly his bark drops by an octave. 😁

[realcygnus]

This is one of the few truly great channels out there, & has been from the get go.

[marshmallow_fellow]

The vintage tennis ball is from before they invented colour

[aaaardvarkkkk]

I almost never comment on Youtube videos, but I just wanted to leave a note to say that you're an absolute inspiration! I graduated with an engineering degree but stopped after my Bachelor's degree because university just wasn't what I'd hoped it would be. I was dreaming of an environment of exploration and free inquiry and got a bunch of calculus exams instead.

The content you publish on this channel is exactly what I always wanted from my engineering program. You dive fully into a topic and share all of the interesting surprises and tidbits you learned along the way. Your subject isn't necessarily chosen for some eventual business application or profit -- it's chosen because it's fun! You're not afraid to share your mistakes or errors of judgment, which makes the findings even more valuable and helps the viewers learn too. You don't waste time with elaborate introductions or self-aggrandizement. Although the content can be quite technical, you approach it with a thoughtful and respectful tone that's neither patronizing nor intentionally obfuscated. It's perfect. You're a shining example of what engineering and science is all about.

Please keep up the fantastic work! I'll be watching!

[dizzolve]

I think it's time to start a build series on the Mass Spectrometer

[Namerson]

>..and fill it up from my tank of SF6
Of course you have a massive tank of SF6, shouldn't have been surprised

[ChrisJ-mfcj]

The fact that with my ADHD I just sat here watching a 21 minute video dealing with the air inside tennis balls, is a testament to your ability to teach or explain the driest of subjects. To be clear, I’m not educated in any field near the topic of this video nor do I have interests other than killing a bit of time while I wait on a friend at the doctor office. Don’t even know why i clicked on this video. But dammit you made it worth my time and did a wonderful job all around!

[TechIngredients]

I smiled as you ran through the "weight of the vacuum" segment, suspecting your debate to include it or not...kudos!

[spookywizard]

"a mass spectrometer would be the ideal instrument, but since I haven't built one of those YET"

what a boss

[sjenkinsnm]

SF6 is used in my industry to extinguish electrical arcs in circuit breakers.

[MushookieMan]

"I wouldn't call it exhaustive"

[samykamkar]

"Have to admit I put a little bit of oxygen in here to help my chances", of course, a classic Ben Krasnow move! Love the video and super interesting as always!

[sasjadevries]

Finally someone who mentions buoyancy when doing precise measurements!
This is why a kilogram of metal (or stones) is indeed heavier than a kilogram of cotton (or feathers) in atmospheric conditions.

[SVanHutten]

It is customary to correct for the effect of buoyancy on weight measurements, for instance when a quantity of a liquid is weighed in order to know precisely its volume or density in the lab. Nice to see you mentioning and illustrating this not very much known fact. Also, this very effect makes any balance that measures force to be accurate only if the density of the stuff weighed is the same of the calibration weight; a commonly forgotten (and seldom corrected for) issue.

[JakeBiddlecome]

Pretty sure this guy keeps McMaster Carr in business. And I love that he doesn't have a mass spectrometer, not because he hasn't bought one yet, but because he hasn't BUILT one yet. Engineers are the best people.

[zorgatron]

The buoyancy of the vacuum in the syringe kinda blew my mind. Neat stuff.

[ml.]

They don't use hydrogen in them anymore due to the Hindenball disaster.

[jomiar]

I work with equipment that has a pure argon atmosphere, so this gave me quite a lot to think about! I love your work, and your methodical approach to "weekend projects". You are an inspiration to me, sir!

[Disc]

The “pulling a vacuum changes the weight of the system” thing blew my mind. Thanks