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Posts Tagged ‘radiation

“Now I am become Death, the destroyer of worlds”*…


Your correspondent is old enough to remember the Cold War and the Civil Defense efforts (booklets, films, duck-and-cover drills) aimed at “preparing” us for atomic conflict.  It’s a sad sign of our times that they’re re-emerging:  “Where to Hide If a Nuclear Bomb Goes Off In Your Area.”

(If there’s a silver lining in this fallout-laced cloud, it’s that it’s re-directing attention to a problem– a threat– that never actually went away; c.f., Ploughshares.)

* J. Robert Oppenheimer


As we enter the Twilight Zone, we might recall that it was on this date in 1903 that The Times (London) newspaper reported that Marie and Pierre Curie communicated to the Academy of Sciences that the recently discovered Radium…

… possesses the extraordinary property of continuously emitting heat, without combustion, without chemical change of any kind, and without any change to its molecular structure, which remains spectroscopically identical after many months of continuous emission of heat … such that the pure Radium salt would melt more than its own weight of ice every hour … A small tube containing Radium, if kept in contact with the skin for some hours … produces an open sore, by destroying the epidermis and the true skin beneath … and cause the death of living things whose nerve centres do not lie deep enough to be shielded from their influence.

That same year the Curies (and Antoine Henri Becquerel) were awarded the Noble Prize in Physics for their work on radioactivity and radiation.

Marie and Pierre Curie



Written by LW

March 25, 2017 at 1:01 am

“At my age, the radiation will probably do me good”*…


The “banana equivalent dose” (BED) is a measure of radiation used to illustrate levels of emissions.  Bananas contain lots of potassium, which contains 0.01% potassium-40– which is radioactive.  The radiation exposure from eating a banana is deemed “1 BED,” roughly equivalent to 0.01 millirem (mrem).  (Happily, one would never be able to eat enough bananas to be dangerous, as our bodies excrete the potassium we’re consuming before it can do exposure damage.)

The existence of a clearly-understandable unit of this sort allows for easily-understood apples-to-apples (or, bananas-to-bananas) comparisons…

This is also roughly the exposure from having a single smoke detector.


Due to increased altitude; Mt Everest is more like 800 mrem (80,000 bananas) per year.


The granite in the walls is mildly radioactive. By comparison, the Vatican is about 800 mrem (80,000 bananas) per year.


More fruity comparisons at Mad Art Lab‘s “Yellow Alert

* Sir Norman Wisdom


As we peel, we might send thoughtful birthday greetings to Richard Philips Feynman; he was born on this date in 1918.  A theoretical physicist, Feynman was probably the most brilliant, influential, and iconoclastic figure in his field in the post-WW II era.

Richard Feynman was a once-in-a-generation intellectual. He had no shortage of brains. (In 1965, he won the Nobel Prize in Physics for his work on quantum electrodynamics.) He had charisma. (Witness this outtake [below] from his 1964 Cornell physics lectures [available in full here].) He knew how to make science and academic thought available, even entertaining, to a broader public. (We’ve highlighted two public TV programs hosted by Feynman here and here.) And he knew how to have fun. The clip above brings it all together.

– From Open Culture (where one can also find Feynman’s elegant and accessible 1.5 minute explanation of “The Key to Science.”)

email readers click here for video


Written by LW

May 11, 2015 at 1:01 am

In lieu of a graduation address…

… from xkcd:

As we avoid looking too closely at the faces of our watches, we might recall that it was on this date in 1921 at the White House that President Warren G. Harding presented Marie Curie with a gram of radium (worth $100,000 at the time).   Curie died in 1934 of aplastic anemia contracted from exposure to radiation.  Her laboratory is preserved at the Musée Curie.  But because of their levels of radioactivity, her papers are considered too dangerous to handle, and are kept in lead-lined boxes; those who wish to consult them must wear protective clothing.

Curie, with Harding at the White House (source)

They Came from Outer Space!…

source:  NASA, via IEEE Spectrum

For years, scientists have known that satellites and astronauts are vulnerable to “space weather,”  more specifically to  geo-magnetic storms that generate “killer electrons” powerful enough to penetrate shielding, damage spacecraft, and injure spacemen.  But no one has been able to explain just how these nefarious particles are produced… so there’s been no trustworthy ability to predict– and avoid– them.

Now, as IEEE Spectrum and the European Space Agency report, scientists affiliated Los Alamos National Labs and a separate team at the ESA have begun to explain the phenomenon.   The details are referenced in the cited reports; here suffice it to say that the electrons (originating in the Van Allen Belt) are accelerated– to velocities approaching the speed of light– by a combination of Very Low Frequency and (higher amplitude) Ultra Low Frequency electromagnetic waves, themselves excited by the impact of solar storms on the earth’s protective electromagnetic bubble.

And not a moment too soon:  As Philippe Escoubet, an ESA scientist remarks, “These new findings help us to improve the models predicting the radiation environment in which satellites and astronauts operate. With solar activity now ramping up, we expect more of these shocks to impact our magnetosphere over the months and years to come.”

As we re-fit our tin foil helmets, we might recall that it was on this date in 1845 that Stephen Perry patented the rubber band. The milk of the rubber tree had been long used by folks who lived where the trees were native to make shoes, clothes, and “bottles”– which were brought back to England by returning sailors.  In 1820, Thomas Hancock sliced up one of the bottles to create elastic garters and “belts.”   Perry, who owned a rubber manufacturing company was sufficiently taken with Hancock’s idea to file a patent on the rubber band– the first of which were made from vulcanized rubber.  (They are now commonly made of a combination of rubber and latex.)

rubber bands

(It was also on this date in 1950 that Glenn Seaborg and a team of colleagues at UC Berkeley announced a new element, number 98– Californium– a radioactive element the isotopes of which have important medical and industrial uses, as they are powerful point sources of neutrons.)

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