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Author Topic: Silly experiment of dubious value.  (Read 2885 times)

Offline Geezer

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Silly experiment of dubious value.
« on: 29/01/2010 05:39:11 »
I don't know if anyone else has tried this, but:

If you drag an expanded polystyrene cup filled with coffee (milky is better) slowly across a table so that it begins to resonate, you will observe wonderful standing waves on the surface of the coffee, and even some spherical drops of coffee that jump right out of the coffee. You have to press the cup on to the table to initiate the resonance.

I used to impress my colleagues at work by demonstrating this phenomenon. They pretended that they were not impressed, but I know they really were.

I have not conducted this experiment with tea. Perhaps I can obtain a research grant for that.


 

Offline RD

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Silly experiment of dubious value.
« Reply #1 on: 29/01/2010 07:29:19 »
Standing wave patterns also appear in the coffee cup if you vibrate the table at the right frequency, e.g. ...



If you use a vibrator in Starbucks you'll probably be asked to leave the premises  :)


[Further reading ... http://en.wikipedia.org/wiki/Vibrational_modes_of_a_drum#Animations_of_several_vibration_modes]
« Last Edit: 29/01/2010 08:42:20 by RD »
 

Offline Don_1

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Silly experiment of dubious value.
« Reply #2 on: 29/01/2010 11:41:04 »

If you use a vibrator in Starbucks you'll probably be asked to leave the premises  :)


How do you know? Personal experience?
 

Offline rosy

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Silly experiment of dubious value.
« Reply #3 on: 29/01/2010 13:57:20 »
I'm fairly sure Dave's already used this as a kitchen science..
 

Offline rosy

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Silly experiment of dubious value.
« Reply #4 on: 29/01/2010 13:57:35 »
Infact, here it is:
http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/cup-fountain-1/

Quite an old one, I think the video would probably be prettier done with the current camera..
 

Offline Geezer

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Silly experiment of dubious value.
« Reply #5 on: 29/01/2010 22:57:59 »
Infact, here it is:
http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/cup-fountain-1/

Quite an old one, I think the video would probably be prettier done with the current camera..

Bu**er! I wonder if he'd be willing to share the Nobel Prize with me.
 

Offline Don_1

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Silly experiment of dubious value.
« Reply #6 on: 01/02/2010 10:37:36 »
I'm not sure this would have been worthy of a Nobel prize.

But perhaps it might be worthy of a no bell prize.
 

Offline RD

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Silly experiment of dubious value.
« Reply #7 on: 01/02/2010 10:45:41 »
IgNobel even.
 

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Silly experiment of dubious value.
« Reply #7 on: 01/02/2010 10:45:41 »

 

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