A Scientific Riddle w/o an explanation

[wacki]

I've posted this problem several times and no one has com up with an answer:

Take a quarter (25 cent piece, american currency) place it on a wood table. Shake a budweiser or coors light can that is unopened untill the pressure builds up enough that you can no longer squeeze the can. Put the beer can, perfectly centered over the quarter(make sure the bottom of the beer can does not touch the quarter). Once the beer can is over the quarter, quickly "pop" the top or swiftly open the can of beer. If you do it perfectly no foam will come out of the can. If you do it imperfectly, the beer may foam up to the lip of the can and some may spill over, but only a few drops worth of beer. Try it and see, then try to explain it scientifically.

For those of you that think I'm pulling some kind of childish joke to get people wet, put on a raincoat and try it on a wooden chair (with no upholstery) outside, before you waste my, and other peoples time by posting usless posts.

Seriously tho, if anyone knows the explanation please post it here.

Thx,
wacki

 

[pyrojunkie]

Bud Light?

 

[ZeroNine8]

have you tried the same exact experiment without a quarter? If you do everything else exactly the same, it won't (or shouldn't) foam much either.

 

[Matthias99]

Dammit, you're going to make me have to buy canned beer just to try this.

 

[uart]

(make sure the bottom of the beer can does not touch the quarter)

In which case the Quarter can have no effect. Ditto to what ZeroNine8 says, try the experiment without the quarter.

 

[CTho9305]

Originally posted by: uart

(make sure the bottom of the beer can does not touch the quarter)

In which case the Quarter can have no effect. Ditto to what ZeroNine8 says, try the experiment without the quarter.

Didn't you read his post? You have to try it before posting useless posts based on science rather than psuedoscience .

 

[ZeroNine8]

One possible explanation for this phenomenon could be that when you set the can down on the hard wooden table, the impact causes the carbonation bubbles that are 'stuck' to the sides of the can to release and float up to the top. When most of the bubbles not in the liquid, but above it, then the release of pressure is just carbonated gas leaving through the opening. When the sudden release occurs with bubbles in the liquid, the rush to the surface causes foaming. This is why you can't use an upholstered or other soft surface, as the impact of setting the can down probably wouldn't knock the bubbles loose. I know this is the explanation of why you can shake up a soda/beer can, *thump* it a couple times on the top and open it with no foam. The quarter is probably just a distraction

 

[LurchFrinky]

Originally posted by: wacki
If you do it perfectly no foam will come out of the can. If you do it imperfectly, the beer may foam up to the lip of the can and some may spill over, but only a few drops worth of beer. Try it and see, then try to explain it scientifically.

Your question has an illogical form. It isn't that a certain phenomenom can't be explained by science, it's that your 'experiment' doesn't subscribe to the scientific method.

For example: Try flipping a coin and letting it fall onto a smooth, hard surface. If you do it perfectly, it will always land with the 'heads' side up. If you do it imperfectly, it will land with the 'tails' side up, but it will never land on its edge.

Your experiment automatically discounts unfavorable results as being "imperfect". Wouldn't shaking a can of beer, gently placing it over a nickel on a steel table be considered imperfect? Exactly how perfect does the experiment have to be? In order to have independently verifiable results, you will need to specify the physical properties of the table, the kind (brand?) of beer, and the dynamic motion describing the can opening procedure, among other things.

There is no answer to the question as you have stated it. Try restating your question properly.

 

[rjain]

This works for the same reason that you tap a can or bottle with your fingernail before opening it. As was said before, the fact that the quarter isn't allowed to interact with the system indicates that it has no relationship to the experiment. The scientific explanation of why you don't get any foam when you do the experiment is that you discard the runs when you get foam. In a universe where beer cans don't foam when opened, no beer cans foam when opened, amazingly enough.

It's so well understood that it's part of common behaviors.

 

[dkozloski]

Back in the days that it took a church key(opener) to open a beer, the story went that if you rapped the edge of the can with the church key a beer would not foam over and spray. Sometimes it worked and sometimes it didn't. This looks to me like an area where a lot of research is required. I suggest you assemble lots of friends(researchers) and lots of beer and see how many times you can duplicate the experiment before the cops arrive.

 

[LurchFrinky]

I realize this is talking about soda and not beer, but still.

Foaming cans of soda

 

[buleyb]

Personally, I like how it has to be an american quarter....Canadian quarters don't have the right mystic energy I guess....

 

[sao123]

Maybe if your not a cheap ass and use one of those golden dollar coins instead of a quarter the beer can will have compassion and become bottomless. :beer:

 

[ZeroNine8]

Originally posted by: sao123
Maybe if your not a cheap ass and use one of those golden dollar coins instead of a quarter the beer can will have compassion and become bottomless. :beer:

:beer:

 

[blahblah99]

I just tried it without the quarter and the beer flew outta the can all over my face and into my nose!

Then I tried it again with the quarter AFTER I cleaned up myself and it went all over my face again!!!!

 

[wacki]

Originally posted by: LurchFrinky
I realize this is talking about soda and not beer, but still.

Foaming cans of soda

Your question has an illogical form. It isn't that a certain phenomenom can't be explained by science, it's that your 'experiment' doesn't subscribe to the scientific method.

For example: Try flipping a coin and letting it fall onto a smooth, hard surface. If you do it perfectly, it will always land with the 'heads' side up. If you do it imperfectly, it will land with the 'tails' side up, but it will never land on its edge.

Your experiment automatically discounts unfavorable results as being "imperfect". Wouldn't shaking a can of beer, gently placing it over a nickel on a steel table be considered imperfect? Exactly how perfect does the experiment have to be? In order to have independently verifiable results, you will need to specify the physical properties of the table, the kind (brand?) of beer, and the dynamic motion describing the can opening procedure, among other things.

There is no answer to the question as you have stated it. Try restating your question properly.

The link is good info to know, I haven't tackled the riddle as they did. However when I said "perfectly" I meant following my instructions to the T. In all (well done) scientific experiments everything that you do is recorded, and only one variable is changed at a time. If so much as one thing is changed, then the experiment fails or goes slightly wrong. That is why I was as specific as I was, and mentioned perfectly, so you guys could follow the scientific method. I'm sure Barfusser (my favorite) beer works just the same as Budweiser and coorslight, but I haven't tested it. So I disagree that my question is illogical and not subscribing to the scientific method, I included every variable I could think of at the time I originally posted this, but time. And describing motion is sometimes difficult to do accurately in text, so I infered that as well with the word "perfectly". Basically, I meant that once you opened the can once without foam, you could easily repeat the same thing and never get foam. I'm too tired right now to continue this conversation.

ZeroNine8, you might be right, it may just be a distraction, or there may be something more to it. Thats what peaks my interest I guess.

I will probably follow dkozloski's advice this weekend and get back to you guys afterwards with a lab style report.

But just to let you guys know,
I've have attempted it on a wood chair with a quarter with success
and on the same wood chair without a quarter without success.


I will do the experiment again this weekend.

I will have a stopwatch to time the shaking, the time interval between shaking and opening, I will use the same beer throughout, the same surface, the same quarter, and place the beer on the chair with the same velocity.

If anyone thinks there are any other variables say them now so I won't have to repeat the experiment in the future.

I know I may sound like I have know life right know but I've been doing this trick at parties for years and no one has given me a good explanation. The experiment won't cost anything, because most of my friends are alcoholics anyway. I'm a whiskey and rum person myself.

 

[DrPizza]

When you do the experiment this weekend, record it with your web cam... (Make sure you're really close to the computer and keyboard when you do it). Before you start, make sure your cam is recording. And, make sure you state what the hypothesis of your experiment is on the recording. "I am going to prove that if you..."

I think I've seen every funny video on the internet at least 5 times each by now. That'll give me one more to watch.

 

[jackschmittusa]

Temp could be a variable. You would have to take them out of the refridgerator one at a time. It would be difficult to achieve a like velosity each time without some dropping mechanism. The shaking would be the problem with repeating a constant. Easy to count strokes, but acceleration and velosity would be subjective. Perhaps do it in time with music.

 

[Cogman]

I must disagree with the site that says tapping the can before opening it will not stop it from overflowing. the site said so itself that zillions of bubbles are created when you shake it. Well, tapping it a couple of times tends to pop those bubbles, also the fact that you are shaking the can a little also prevents the carbon-dioxide from rejoining with the liquid that is in the can. Another thing you are effectivly doing is raising the heat, Another key factor in mixing gas with liquid is a low tempature.

 

[capybara]

Originally posted by: blahblah99
I just tried it without the quarter and the beer flew outta the can all over my face and into my nose!

Then I tried it again with the quarter AFTER I cleaned up myself and it went all over my face again!!!!

you guys read this and still - in the quest for science - you gonna keep trying this!
now thats bravery!

 

[DrPizza]

Originally posted by: capybara

Originally posted by: blahblah99
I just tried it without the quarter and the beer flew outta the can all over my face and into my nose!

Then I tried it again with the quarter AFTER I cleaned up myself and it went all over my face again!!!!

you guys read this and still - in the quest for science - you gonna keep trying this!
now thats bravery!

You'd think that blahblah would have learned not to lean over it when opening it after the first time....