[time-nuts] How dangerous if a Rb lamp broken?

[Max Robinson]

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 at maxsmusicplace.com

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


> 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 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!
>>
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