Simply put, what’s inside a ping-pong ball? Ordinary air? Or some sort of gas with a different density than air?
This came up in a chat with a friend recently. I’ve tried a few search engines, and the old GQ threads. Any help would be appreciated.
Tanks, wolfstu.
Most ping pong balls I’ve seen have a little tiny hole in them somewhere, from, I assume, the manufacturing process. So they’d be filled with just normal air, at the ambient pressure.
Of course, these are the run of the middle Wal-Mart style balls. I have no idea if the professional ping-pongers out there use different kinds.
It’s regular air.
IANAProfessional, but I have a regulation table in its own “ping pong room” where I play against my fiancee constantly. We’ve become good enough to recognize the difference between various brands and models of ping pong balls. Three star ping pong balls have smaller seams, better bounce, consistent size and weight, and thinner walls. They are of a noticeably higher quality. They also make trick volleys a breeze. One star balls are cheaper and of lesser quality. They are prone to losing their shape and losing their bounce quite rapidly with aggressive play.
By the way, I’ve never seen a ping pong ball with a deliberately manufactured hole. Do you remembre what brand you saw, Smeghead?
The official governing body of table tennis in the USA,
USA Table Tennis has this to say about balls used in competition.
That’s it. So as long it weighs the right amount (and there’s no variance listed) and it’s the right material, you’re ready to play competitive table tennis.
The rules for racquets (as they are officially known) are longer, but as along as the blade is flat and 85% wood you can play with a 10 foot pole as a handle if you want.
I wouldn’t recommend this.
Okay. Good response, but as yet no direct confirmation of the nature of the gas inside. But, lack of any mention of a gas other than air provides a strong implication that it’s only air inside. For example, it is more likely that a site would say “Ping-pong balls are filled with a 40%-hydrogen/60%-air mixture at 101 kPa” than “Ping-pong balls contain air”. After all, if the latter is true, it would seem almost self-evident, wouldn’t it?
So far the discussion steers one strongly, though without certainty, towards ‘air’. However, a friend of mine has told me that in the past he has observed the following:
A) If a ping-pong ball is held above the flame of a (cigarette) lighter, it will burst, causing a 'pop’ing sound. (This, I argued, can be explained by the air inside expanding and bursting the ball due to increased pressure from heating.)
B) If a hole is poked in the ball, and the flame held to the side of the hole, a flame can be seen coming out of the hole.
My friend brought both of these as evidence that the ball contains at least some Hydrogen. I find it difficult to answer point ‘B’, but I cannot imagine that ping-pong ball manufacturers should go to so much trouble to put H-gas in the ball. It wouldn’t be all that easy. Of course, it’s not exactly an insurmountable challenge, either, but air would be cheaper, without a doubt.
So what about it? Can anyone defeat my buddy’s flame argument?
Thank you. And if anyone can find a s/cite that mentions the composition dierctly, please post it here.
Dunno the brand - just the ancient ones lying around my grandma’s basement when I was a kid.
As for hydrogen, I seriously doubt it. Remember the Hindenberg? Obviously it’s not the same situation, but what on earth would be the point? Why go to that much trouble? They’re just ping-pong balls, fer cryin out loud.
If, and that’s a huge if, the “flame coming out of the hole” test is confirmed, I’d speculate that it’s caused by the heat of the flame evaporating and igniting some volatile chemicals from the plastic. If it was pure hydrogen, of course, you’d have a mini-bomb on your hands.
It’s the same exotic gas used in bubble wrap.
That would be my guess, too. Ping pong balls are one of the few things still made from celluloid, which has flammability problems for other uses, and probably volatilizes pretty easily.
Here’s a badly worded and hard to read description of ping pong ball manufacture. It’s seems they inflate them into molds by steaming them to blow them up with hot air:
To test whether there is flamable gas in a ping pong ball, you could compare the look of the flame from a ball with a new hole with the look of a flame from a ball where the hole was poked a day earlier. Any flamable gas would have a chance to escape the hole in that amount of time.
If it turns out there is a flamable gas in the balls, it still isn’t necessarily Hydrogen. Maybe volotile chemicals escape from the celluloid.
Is there any particular reason why a table tennis ball would need to be filled with a particular type of gas? Tennis balls aren’t inflated with any special gases. Footballs (take your pick American or the rest of the world variety) aren’t inflated with hydrogen. Any ball with a bladder is just filled with regular old air?
Wouldn’t adding something other than normal air (for lack of a better term) drive up the cost of manufacturing table tennis balls, which are made by the millions?
Yes, it would. That’s why I’m so skeptical.