Subject: | |
From: | |
Reply To: | |
Date: | Mon, 23 Oct 2006 10:33:13 -0400 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************
Hi,
I agree with Ian. Years ago we installed an exhibit at the Boston
Museum of Science with two suck clear cylinders that were about 35 feet
long. This was to show dropping a feather in a vacuum. The wall
thickness was 1/2 inch. They worked fine.
I also agree with Ian about being careful with any pressure or vacuum
device to avoid undue mechanical stress.
John Bowditch
Ann Arbor Hands-On Museum
-----Original Message-----
From: Informal Science Education Network
[mailto:[log in to unmask]] On Behalf Of Ian Russell
Sent: Monday, October 23, 2006 9:00 AM
To: [log in to unmask]
Subject: Re: Clear cylinders and pulling a vacuum.
ISEN-ASTC-L is a service of the Association of Science-Technology
Centers
Incorporated, a worldwide network of science museums and related
institutions.
************************************************************************
*****
Here in the UK it is possible to buy long Perspex (=Plexiglass) tubes
with 30cm diameter. I have successfully produced a high-vacuum
exhibit using this material. Mine used only a short length of ~30cm
tube, but a longer length should be equally resistant to external
pressure. Be careful to avoid bending forces though. Even with thick
walls, it is possible to see inside with perfect clarity because this
material is very precisely formed and highly transparent.
There's a photo of my version here (scroll down to "Silence of
space") http://www.interactives.co.uk/hands_rumbo.htm
[log in to unmask] * http://www.interactives.co.uk
*
Give people facts and you feed their minds for an hour.
Awaken curiosity and they feed their own minds for a lifetime.
*
Ian Russell
***********************************************************************
More information about the Informal Science Education Network and the
Association of Science-Technology Centers may be found at
http://www.astc.org.
To remove your e-mail address from the ISEN-ASTC-L list, send the
message SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]
***********************************************************************
More information about the Informal Science Education Network and the
Association of Science-Technology Centers may be found at http://www.astc.org.
To remove your e-mail address from the ISEN-ASTC-L list, send the
message SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]
|
|
|