On 29 Jun 2009, at 17:16, Agnes Becker wrote:
> Dear All,
>
> I am working for a children's science TV programme and we want to
> recreate the buoyancy of the Dead Sea. I know the dead sea has a
> salt density of 1.24kg/L but the salt is not just sodium chloride.
> The proportions according to wikipedia are:
This is astonishing easy to do, actually - or at least, it was when I
did it on How2, years ago!
Call your local industrial salt supplier (check the yellow pages), and
ask for a bag of 'Dead Sea mix'. That's it. Done.
They sell the stuff to the health spa industry for floatation tanks.
In Glasgow, my local supplier even stenciled the sacks 'Dead Sea
(dried)', because they thought I might be amused. They were right, I
was.
You can also buy 'North Sea (dried)', which is used by the shellfish
industry for cleaning mussels before they're packed for sale.
It's quite a dramatic demo, by the way - takes a while to dissolve all
the salt, but your subject will be clearly more buoyant than expected.
Make sure you have a shower close to hand, as you'll want to rinse off
after bobbing around in the paddling pool. Also, mix the salt into
water - there's quite a lot of fine dust involved, and it's a heck of
an eye irritant. If you have *any* cuts on your fingers, wear rubber
gloves while sloshing the mixture around.
--
Jonathan Sanderson
"If I had more time, I would have written a shorter letter" (Pascal)
**********************************************************************
1. To suspend yourself from the list, whilst on leave, for example,
send an email to mailto:[log in to unmask] with the following message:
set psci-com nomail -- [include hyphens]
2. To resume email from the list, send an email to [log in to unmask] with the message:
set psci-com mail -- [include hyphens]
3. To leave psci-com, send an email to [log in to unmask] with the message:
leave psci-com -- [include hyphens]
4. Further information about the psci-com discussion list, including list archive, can be found at the list web site: http://www.jiscmail.ac.uk/lists/psci-com.html
5. The psci-com gateway to internet resources on science communication and science and society can be found at http://psci-com.ac.uk
6. To contact the Psci-com list owner, please send an email to mailto:[log in to unmask]
**********************************************************************
|