Friday, October 29, 2010

An old explanation, for an old saying...

There's an old saying 'close enough for all practical purposes...' which has a very good physical model/explanation.
If you are in a classroom with an equal number of males and females, separate the two sets and have all the males stand on one side of the room, and all the females on the other.
At a given command, have each set of people move toward each other, so that each line of people exactly halves the distance between them.
In theory, no matter how many times you repeat this command, the two groups will never reach each other...
In practice, you will find that after a relatively few number of instances, the two groups will be close enough together 'for all practical purposes.'   :)

Got a particle accelerator in your desk drawer?

Not a facetious question: yes, you do, if you have a roll of Scotch tape (the old kind, not the newer 'Magic Transparent' stuff).

It's been known since the precursor to the current tape was invented in the 1930's that if you quickly peeled off the tape from its roll, it emits a very faint blue light. You can actually see this if you want to take the time a trouble: take a roll of this tape (the package-sealing size works well) into a completely dark room, like a closed closet with no lights. Wait about 30 minutes, so that your eyes become adjusted to the lack of light (see 'rhodopsin' or 'visual purple' on the web for the reasons). Then, very quickly peel back a length of tape from the roll -- you should clearly see a faint blue light coming from the region where the tape is being pulled from the roll. The reason: the all-important conservation of mass/energy: the breaking of molecular bonds at this boundary causes electrons to change their energy state, and the excess energy is emitted as photons: particles of light in a particular blue part of the spectrum.

(PS: a similar phenomenon can be observed -- in the same 'dark closet scenario' -- with two people: one observer and one person crunching/chewing peppermint hard candies. The same blue light phenomenon can be observed, although in this case, there are concommittent dangers - deflection of proper attention if the members are sexually attracted, and the danger of tooth or filling damage from crunching hard candies.

So, back to the 'particle accelerator' thing:
it has recently been discovered and reported that this same 'peeling Scotch tape off the roll' function -- if done at high and continuous speed in a vacuum -- actually generates a relatively coherent beam of X-rays, strong enough for example to image human finger bones on photographic plates.
Reference: http://www.sciencenews.org/view/generic/id/64111/title/Tale_of_the_tape_
So, your roll of Scotch packing tape is really, a particle accelerator (X-ray machine) in disguise (well, given a good vacuum and the right equipment to peel it off.)
The physical explanation for this phenomenon is still unknown.


Ladle Rat Rotten Hut (Little Red Riding Hood)

For those who have forgotten, or those too young ever to have seen this classic piece, I reprint it here. For reasons which may be called 'meaning dissonance' the piece is actually rather hard to read, since the well-known words of the story are replaced by similar-sounding words of totally different meaning. The best way I think to enjoy the piece is to present it to someone and have them try to read it aloud -- just read the words as written and not try to gather any meaning from them. The results are pretty hilarious.

Ladle Rat Rotten Hut: Annulled Furry Starry


Wants pawn term, dare worsted ladle gull hoe lift wetter murder inner ladle
cordage honor itch offer lodge, dock florist. Disc ladle gull often worry ladle
cluck wetter putty ladle rat hut, end fur disc raisin pimple colder Ladle Rat
Rotten Hut.

Wan moaning Rat Rotten Hut's murder colder inset: "Ladle Rat Rotten Hut, heresy
ladle basking winsome burden barter end shirker cockles. Tick disc ladle basking
tudor cordage offer groin murder hoe lifts honor udder site offer florist.
Shaker lake, dun stopper laundry wrote! Dun stopper peck floors! Dun daily-doily
inner florist, end yonder nor sorghum stenches dun stopper torque wet strainers."

"Hoe-cake, murder," resplendent Ladle Rat Rotten Hot, end tickle ladle basking
end stuttered oft. Honor wrote tudor cordage offer groin murder, Ladle Rat
Rotten Hut mitten anomalous woof.

"Wail, wail, wail," set disc wicket woof, "evanescent Ladle Rat Rotten Hut!
Wares or putty ladle gull goring wizard ladle basking?"

"Armor goring tumor groin murder's," reprisal ladle gull. "Grammars seeking bet.
Armor ticking arson burden barter end shirker cockles."
"O hoe! Heifer blessing woke," setter wicket woof, butter taught tomb shelf, "Oil
tickle shirt court tudor cordage offer groin murder. Oil ketchup wetter letter,
end den -- O bore!"

Soda wicket woof tucker shirt court, end whinney retched a cordage offer groin
murder, picket inner widow end sore debtor oil worming worse lion inner bet.
Inner flesh disc abdominal woof lipped honor betting adder rope. Zany pool dawn
a groin murder's nut cup end gnat gun, any curdle dope inner bet.

Inner ladle wile Ladle Rat Rotten Hut a raft attar cordage end ranker dough ball.

"Comb ink, sweat hard," setter wicket woof, disgracing is verse. Ladle Rat
Rotten Hut entity bet rum end stud buyer groin murder's bet.

"O grammar," crater ladle gull, "wart bag icer gut! A nervous sausage bag ice!"
"Buttered lucky chew whiff, doling," whiskered disc ratchet woof, wetter wicket
small.

"O grammar, water bag noise! A nervous sore suture anomalous prognosis!"

"Buttered small your whiff," inserter woof, ants mouse worse waddling.

"O grammar, water bag mousey gut! A nervous sore suture bag mouse!"

Daze worry on forger nut gull's lest warts. Oil offer sodden throne offer
carvers an sprinkling otter bet, disc curl end bloat Thursday woof ceased pore
Ladle Rat Rotten Hut end garbled erupt.

Mural: Yonder nor sorghum stenches shut ladle gulls stopper torque wet strainers.

Wednesday, October 27, 2010

Chernobyl and Nuclear Power - part II

OK, I orginally planned to write a long article about the Chernobyl disaster, but soon realized that there is little I can add to the detailed analysis and account found on Wikipedia at the link accessible on the header line of this post.
Interesting points I would highlight:
the disaster was caused by a culture of neglect, incompetency, disregarding legal and written procedures for both the constuction and operation of the facility, and indeed in all aspects of design, manufacture, construction, operation and regulation of these plants.
The specific RBMK design of the Chernobyl reactors only exists in the (previous) Soviet Union, and would not be allowed to be built in the West.
The 'final score' on the incident is somewhat controversial, since data from the incident has been slanted or outright fabricated for politcal purposes.
As far as actual, verified scientific data goes:
An international assessment of the health effects of the Chernobyl accident is contained in a series of reports by the United Nations Scientific Committee of the Effects of Atomic Radiation (UNSCEAR). These are available online for those who wish to read or download them.
In the aftermath of the accident, 237 people suffered from acute radiation sickness, of whom 31 died within the first three months. Many of these were the 'first responders.'
The UNSCEAR and IAEA reports state specifically that "there has been no increase in the rate of birth defects or abnormalities, or solid cancers (such as lung cancer) "
There is a statistically estimated figure that approximately 4,000 additional cases of thyroid cancer may occur througout the lifetimes of all individuals exposed. These cancers are among the most easily treated and have the highest survival rates of any cancer types, typically  the five-year survival rate of thyroid cancer is 96%, and 92% after 30 years.
There is no evidence of long term genetic effects in human or animal populations in the region (which would be expected, since any genetic anomalies would only last one generation, and then die off).
The Prypiat Exclusion Zone is open for tourism with proper permits, and many web photo logs show the current state of this abandoned contryside.
There are still life-long residents of the area which refused to be evacuated  -- some hiding in the woods, to later return to their homes.
I highly recommend the book Medvedev, Grigori (1989). The Truth About Chernobyl. VAAP. First American edition published by Basic Books in 1991. ISBN 2-226-04031-5 (Hardcover). At the time of the Chernobyl disaster in 1986, Medvedev was deputy director of the main industrial department in the Soviet Ministry of Energy dealing with the construction of nuclear power stations. Since Medvedev knew the Chernobyl plant well, he was sent back as a special investigator immediately after the 1986 catastrophe.

PS: This cannot happen in the West

PPS: One of the descriptions of a plant worker  -- who (like all of them) knew nothing of what was occurring, went up a stairway leading to Reactor Room #4 of the plant, while the disaster/meltdown was occurring-- he looked out into the huge reactor containment room, where the gigantic steam explosion had just occurred, the graphite containment of the reactor core was burning and on fire, and the core was melting down...
The air in the huge room was filled with the bright blue light of Cerenkov radiation, and all the brightly burning graphite blocks...
He said it was 'very beautiful'.
He died a few days later from the direct radiation exposure he received. A coworker of his -- right behind him on the stairway, but who did not go into the reactor room -- survived.

Saturday, October 23, 2010

Super-K !

The Super-Kamiokande (full name as Super-Kamioka Nucleon Decay Experiments) is a neutrino observatory near the city of Hidu, Japan. It's located more than 3,200 feet underground. Contained in a stainless steel tank more than 135 feet tall and 128 fee in diameter, are almost 14,000 photomultiplier tubes, to record the very occasional interaction of a neutrino, with an atom in a molecule of the more than 50,000 gallons of ultra-pure water with which the tank is filled.

Here is an very cool photograph of the tank being filled, complete with a boat with two technicians in it... click on the photo for full image.
PS: the light shining on the underwater photomultipliers, reminds me greatly of Monet's 'Water Lily' series of paintings...

Tuesday, October 19, 2010

Remembrance



I saw an old friend the other day

In San Francisco by the Bay
It took me back to only yesterday
The years somehow let slip away
We laughed and talked about the days gone by
And brushed a tear away with a sigh
We promised not to let it be this long
Like the old refrain from an old, old song.

Remember old friends we’ve made along the way
The gifts they’ve given stay with us every day

Looking back it makes me wonder
Where we’re going and how long we’ll stay
I know the road brings rain and thunder
But for the journey what will we pay?
I often think the times get crazier

As this old world goes round and round
But just the memory makes it easier
As the highway goes up and down

Lately word’s been coming back to me
There’s a few I will no longer see
Their faces will be seen no more along the road
There’ll be a few less hands to hold
But for the ones whose journey’s ended
Though they started so much the same
In the hearts of those befriended
Burns a candle with a silver flame
-- Mary McCaslin, "Old Friends"