Date: Tue Aug 18 15:40:57 2009 Back to Contents ------------------------------------------------------------------------

Author: Urs Lauterburg

Subject: Re: jumping disks



Me too I have ordered a sample batch and got it a few days ago. They
seem to come from Sweden (not to be confused with Switzerland). It
seems as if somebody there has found out how to make these things
again. Mine seems to work OK. They jump about 70cm or so. Did the old
ones also jump about that high?

Nice little surprising things and a neat demo too


Urs Lauterburg
Physics demonstrator
Physikalisches Institut
University of Bern

>I received the jumping disks in the mail a couple of days ago (they
>may have come sooner but I was out of town).
>They work as advertised with the caveats listed on the website. They
>are fairly small and they have sharpish edges. They are fairly stiff
>and take some push to get to pop. In chilly San Francisco, it takes
>a long time to heat them up enough for them to hold their "loaded"
>position. I found that by keeping them in my pocket, they would be
>close to being warm enough without waiting an excessive time for
>them to warm up enough.
>I think that the rubber poppers probably teach conservation of
>energy better, but metal discs are more interesting in a material
>science kind of way.
>Zeke Kossover
>PS I also bought the Beta Pen
> which is a
>pencil that uses metal rather than graphite as its writing medium.
>As a novelty it succeeds and might make an interesting material
>science presentation, but it is a rather unpleasant writing
>----- Original Message ----
>> From: "Marc "Zeke" Kossover"
>> To:
>> Cc:
>> Sent: Thursday, July 30, 2009 3:48:06 PM
>> Subject: Re: [tap-l] jumping disks
>> From: Marsha Hobbs , sent: Thursday, August 31, 2006 7:18:02
>> PM
>> >A few years ago we gave away jumping disks at science
>> >presentations. I seem to recall they were from Edmund. Are they available
>> >anywhere these days?
>> Yep, you are reading the date right. Marsha asked about jumping disks three
>> years ago. As I recall, we didn't find any suppliers for her. As I
>>was wandering
>> around, I found some for sale at Grand Illusions, the fun Brit toy site
>> I ordered some
>> today and am waiting patiently for them to come in.
>> Marc "Zeke" Kossover

From Tue Aug 18 15:40:57 2009