You must really be a "legend in your own mind", and now, a self-proclaimed
"time-nuts" cop.  -

Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Charles P. Steinmetz
Sent: Wednesday, July 10, 2013 1:59 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] How dangerous if a Rb lamp broken?

Perrier wrote:

Please keep your political comments to yourself and off the list (however
humorous you might think they are).  This is simply not the place for them.

Thank you,

Charles

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
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and follow the instructions there.

Public perceptions of risk change with time.

In WWII, Radium dial watches, aircraft instruments, dial and switch
markings, were ubiquitous. But so were explosives, bombs, bayonettes, and
a bunch of other things. So people didn't have the luxury of concerns over
minor things.

Now that is not so.

-John

===================

I just tried calling your cell because you seem to be the "legitimate"
person to ask.  I don't read all the time-nuts postings but has anyone ever
brought up the most logical aspect of ionizing radiation for the group: the
radium dial wrist watch? or are they all too young to have experienced that?
I think I got one for Christmas when I was 12 or 13.  I'm still here at 74!
I do think that all reflector's are at their best when they are
entertaining---maybe not exactly on topic!

Regards,

Lee Mushel    I live about 20 miles from the Mississippi and 50 miles north
of the Illinois border.  We simply try to enjoy life, our garden, our
flowers, our dogs and our cats.  Best to stay away from neighbors and social
media!

----- Original Message -----
From: "Mike Feher" mfeher@eozinc.com
To: "'Discussion of precise time and frequency measurement'"
time-nuts@febo.com
Sent: Wednesday, July 10, 2013 7:00 AM
Subject: Re: [time-nuts] How dangerous if a Rb lamp broken?

You're still here, but what about the young women who painted those watches who aren't?  The problem was that they needed sharp points on the brushes to fill the tiny voids in the hands.  So they twirled the brush tips between their lips.  They could probably bring back radium dials today with no problem, because of automation. 

Bob - AE6RV

From: Lee Mushel herbert3@centurytel.net

I wonder if that would be possible? I bet the government paperwork would
make the watches costs far out of reach for most people.

Tom
WA3PZI

----- Original Message -----
From: "Bob Stewart" bob@evoria.net
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Wednesday, July 10, 2013 11:25 AM
Subject: Re: [time-nuts] How dangerous if a Rb lamp broken?

You're still here, but what about the young women who painted those watches
who aren't? The problem was that they needed sharp points on the brushes to
fill the tiny voids in the hands. So they twirled the brush tips between
their lips. They could probably bring back radium dials today with no
problem, because of automation.

Bob - AE6RV

From: Lee Mushel herbert3@centurytel.net

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

The watch workers were a tragedy, based on ignorance of the risks. At the
time, there were probably only a handful of people who'd ever sustained
injury from radioactive materials. It's not clear that the bosses even
knew the women were putting the brushes in their mouths or that they knew
the risks.

These kind of things do happen. Consider Asbestos, DES, Thalidomide,
Phen-Phen, Avandia, etc.

However, that does not excuse the media, "public interest" groups, or
especially government for hyping risk totally out of proportion for their
self-serving political ends.

I think the bigger risk from a broken Rb bulb would come from the glass
shards.

-John

===============

We had a Lab in Bldg 6 at MIT (Physics Dept.) that had an old Soapstone
sink in it. I remember talking to an Old-Timer (now this was in the early
60's) who told me that sink was used to clean the bones of deceased
Watch Company workers. They were then tested for Radioactivity levels.

It was a long time before I could get myself to go near that sink, never
mind use it !!

73, Dick, W1KSZ

On 7/10/2013 9:12 AM, J. Forster wrote:

In brief,

Gamma rays are just another form of light... that is to say photons.  What makes
them special is they are much higher energy than visible light.  What makes them
potentially dangerous is they have enough energy to knock electrons off of many
atoms, turning them into ions that could combine chemically in your body in ways
that wouldn't normally happen.  If it happens to the right molecule... say a DNA
strand... it could cause a mutation that could result in cancer.  Most such
mutations result in premature cell death, and are harmless... unless there
happens to be millions of them all at once.

Your body is mostly water.  Somewhere around 45 to 60% by weight.  The rest of
your weight are minerals and things like bone.

The molecules in your body are mostly free space... that is to say vacuum... a high
energy gamma photon is more likely to pass right on through your body than to
hit anything. And if it does hit something, it is most likely going to be water,
or bone.  Think back to the last time you had an X-Ray.  What showed up?

When you look at a normal light source, say a candle, what you are seeing is a spray
of photons radiating out in all directions from the source.  There are so many
photons that the light source appears to your eye to be continuous.  When a light
source gets small enough, it appears dim, and if it is dim enough, it starts to
appear grainy.  The grains you see are individual photons.  Your eye doesn't see
all of the visible photons that strike it, perhaps only 50%...

Eyes are amazing!

One of the earliest ways of measuring radioactivity was the geiger-muller tube.  It
can count individual gamma photons that strike the tube.  Even still, some of the
gamma photons will pass right through, and not be counted.  It catches about 30%, as
I recall.

A source like a radium dial watch will make a geiger counter clatter pretty good,
but you can still hear the clicks caused by individual photons.

If the radioactive source was emitting photons at the same rate as a candle, the
geiger counter tube would be completely overwhelmed, and you would not be able to
count the deluge of photons hitting it.

The moral of this story is that the probability of any given gamma photon, that
irradiates a human body, even hitting something is small.  The probability of
anything it hits being more interesting than water is even smaller, and the
probability of it doing dangerous damage is terribly small.

It is only when the flux of gamma photons becomes quite large that these
probabilities start to tip into the direction of likely damage, or cancer.

A tiny, low flux source of radiation, like a radium dial watch, is highly
unlikely to cause you any harm... it could happen, but the odds of it doing so
make winning the lottery look like a sure thing.  The odds drop very quickly
the farther the watch is from your body... its one of those radius squared
things.

-Chuck Harris

Lee Mushel wrote:

I once read that if you were to wear a radium dial watch face down you would
get a radiation burn on your arm.  I wonder who would do such a thing.  I
also wonder if the writer knew what he was writing about or if he was just
speculating.

Regards.

Max.  K 4 O DS.

Email: max@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Woodworking site
http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html
Music site: http://www.maxsmusicplace.com

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----- Original Message -----
From: "Chuck Harris" cfharris@erols.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Wednesday, July 10, 2013 11:48 AM
Subject: Re: [time-nuts] How dangerous if a Rb lamp broken?

In message 5DEED07BE9DE486C9E668636A2949A62@BACKROOM, "Max Robinson" writes:

You would.

He did.

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

The dials of most of the old "radium" dial watches have burns in them
caused by the hands being parked for long periods of time as the watch
invariably failed and stopped.  The crystals are similarly "etched"
from their exposure.  The gamma photons did the deed...

I have one such watch that was given to me by an uncle who was a physicist
and was part of the Marshal Island H-Bomb tests.  He was given the watch by
the US Army, and wore it daily until it set off the alarms on one of the
experiments he was working on.... After that, it sat on a shelf for 20 years
before being given to me.  No burns when it was put away, and a very
distinct burn after sitting 20 years.

So, yes, it would burn you, but at the rate that gamma comes off of a
watch dial, it would take a long time, and your body would have naturally
replaced the cells many times over the duration of the burn.

-Chuck Harris

Poul-Henning Kamp wrote:

I wonder what that is? How come the digits don't show the same burn that the
hands do? They certainly remained in the same position for longer than the
hands.

Hmmm?

Tom

----- Original Message -----
From: "Chuck Harris" cfharris@erols.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Wednesday, July 10, 2013 3:41 PM
Subject: Re: [time-nuts] How dangerous if a Rb lamp broken?

The stuff that turns color is the dial paint. The numbers are painted on
top. When the hands move, they expose the underlying paint to view.

-John

=============

The dial is painted, the hands are actually metal frame, and the
luminous paint is a wax that is put on the hand kind of like a
soap bubble.

The luminous material in the paint is very dead, as the hands and
digits no longer glow at all.  I guess there is a limit to how long
ZnS:Cu can take the exposure and still glow.

-Chuck Harris

Tom Miller wrote:

This isotope of radium has a half-life of 1600 years.  It isn't dead, or
even noticeably less radioactive.

Most probably it has burned out the binder that holds the ZnS:Cu material
together and on the digits and hands.

-Chuck Harris

Bill Hawkins wrote: