Use a radioactive eyepiece!

The Kodak Ektamate and Ektar lenses all use thorium glass. Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

On Jan 30, 5:22*pm, RichA wrote:
The Kodak Ektamate and Ektar lenses all use thorium glass. *Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

There once were some World War II lenses that used radioactive glass,
but that is long gone. Any surplus from the days of digital Group III
fax machines would not use lenses made from that kind of glass -
because the glass isn't made any more.

John Savard

On Jan 30, 10:46*pm, Quadibloc wrote:
On Jan 30, 5:22*pm, RichA wrote:

The Kodak Ektamate and Ektar lenses all use thorium glass. *Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

There once were some World War II lenses that used radioactive glass,
but that is long gone. Any surplus from the days of digital Group III
fax machines would not use lenses made from that kind of glass -
because the glass isn't made any more.

John Savard

I've got the same kind of lens (different focal length, same
dimensions) and it is radioactive. Unless they had fax machines in
WW2...

On 1/31/13 8:45 PM, RichA wrote:

Unless they had fax machines in WW2...

Machines recognizable as "Fax Machines" have existed since 1881.

On Jan 30, 8:46*pm, Quadibloc wrote:
On Jan 30, 5:22*pm, RichA wrote:

The Kodak Ektamate and Ektar lenses all use thorium glass. *Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

There once were some World War II lenses that used radioactive glass,
but that is long gone. Any surplus from the days of digital Group III
fax machines would not use lenses made from that kind of glass -
because the glass isn't made any more.

I see that some radioactive glass was used even in the 1960s, so I'm
mistaken...

http://www.bnphoto.org/bnphoto/LostS...adioactive.htm

John Savard

"Quadibloc" wrote in message
...

On Jan 30, 8:46 pm, Quadibloc wrote:
On Jan 30, 5:22 pm, RichA wrote:

The Kodak Ektamate and Ektar lenses all use thorium glass. Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

There once were some World War II lenses that used radioactive glass,
but that is long gone. Any surplus from the days of digital Group III
fax machines would not use lenses made from that kind of glass -
because the glass isn't made any more.

I see that some radioactive glass was used even in the 1960s, so I'm
mistaken...

http://www.bnphoto.org/bnphoto/LostS...adioactive.htm

John Savard
=================================================
Good that you can admit it, Savard. It's really quite painless, isn't it?
Nobody is going to beat you to death over it now. You are mistaken
about relativity, too, but that's because you are hopeless at algebra.
Your pal Bill Owen hasn't come to your rescue, either. He's gone away
to think about it. He's only been gone three weeks. Perhaps he's gone
away to forget about it.


"Quadibloc" wrote in message
...
(begin quote)
At the end of Section 3 we find the transformation derived:

tau=beta(t-vx/c^2),
xi=beta(x-vt),
eta=y,
zeta=z,
where beta=1/sqrt(1-v^2/c^2).

With trivial algebraic manipulation we can derive the inverse
transformation:

t=beta(tau+v(xi)/c^2),
x=beta(xi+v(tau)),
y=eta,
z=zeta.
(end quote)
===============================================
Not only is Savard hopeless at simple algebra, he quotes the drool of some
unnamed moron who is equally hopeless.
Perhaps he can show, step-by-step, his trivial derivation, like this:
xi = beta(x-vt)
Divide both sides of the equation by beta
xi/beta = beta(x-vt)/beta
Since beta/beta = 1,
xi/beta = 1*(x-vt)
Add vt to both sides of the equation
xi/beta +vt = (x-vt)+vt
Since vt - vt = 0,
x = xi/beta +vt

Why is Savard multiplying xi by beta instead of dividing?

-- This message is brought to you from the keyboard of
Lord Androcles, Zeroth Earl of Medway.
When I get my O.B.E. I'll be an earlobe.

On Feb 2, 4:03*pm, Quadibloc wrote:
On Jan 30, 8:46*pm, Quadibloc wrote:

On Jan 30, 5:22*pm, RichA wrote:

The Kodak Ektamate and Ektar lenses all use thorium glass. *Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

There once were some World War II lenses that used radioactive glass,
but that is long gone. Any surplus from the days of digital Group III
fax machines would not use lenses made from that kind of glass -
because the glass isn't made any more.

I see that some radioactive glass was used even in the 1960s, so I'm
mistaken...

http://www.bnphoto.org/bnphoto/LostS...adioactive.htm

John Savard

That's a very interesting link about radioactive glass.

Of all the possible bad elements, it seems thorium exposure is among
the least dangerous, especially when encapsulated within glass..

On Feb 2, 7:03*pm, Quadibloc wrote:

I see that some radioactive glass was used even in the 1960s, so I'm
mistaken...

John Savard

I believe it was still available ( or t least listed in the Schott
catalog) in the 70s.

http://www.richardfisher.com

On 31/01/2013 00:22, RichA wrote:
The Kodak Ektamate and Ektar lenses all use thorium glass. Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

The half life of natural Thorium 232 is 3x the age of the Earth and
something similar for Lanthanum 138 rare earth glasses. The only worry
with the latter is that uranium was often present as an impurity.

--
Regards,
Martin Brown

On Jan 31, 12:20*am, Martin Brown
wrote:
On 31/01/2013 00:22, RichA wrote:

The Kodak Ektamate and Ektar lenses all use thorium glass. *Pretty
harmless just sitting around but I wouldn't want to press my eye to
one for any length of time.

http://www.surplusshed.com/pages/item/l3759.html

The half life of natural Thorium 232 is 3x the age of the Earth and
something similar for Lanthanum 138 rare earth glasses. The only worry
with the latter is that uranium was often present as an impurity.

--
Regards,
Martin Brown

A banana offers a thousand times as much radiation as any thorium
glass.