| Thursday,
November 18, 2010
A short dialog on TSA:
RE: Finding the furor odd -
Truly, I am less bothered by the radiation exposure
than by the simple tyranny of it all. I don't believe the pictures are safe
in the meaning that they won't be identified to personal information and
that they won't be put up on the internet in due time. I was unclear in that
the "safety" I meant had little to do with radiation.
However, if I flew often the unknown radiation levels
might concern me more.
R, Rose
Sure but why is this worse than what you've been
putting up with for years? I tried to warn people when it first started.
Jerry Pournelle
Chaos Manor
RE: Finding the furor odd -
When the shoe-bomber incident occurred I was in a
small town in Oregon. On the way home I rather expected that some
overreaction would have everyone taking their shoes off. You must realize
the demographic of all travelers on the small MD were of a demographic that
just would never be a danger. The worst was the yappy min-pin who was
permitted out of his carry case in the waiting area.
My parents had warned me that "Little Ceasar" was
running security. He was a recently activated reservist who had never been
in the regular army or seen real action. (basically a wanna-be.) He took a
personal interest in searching "random" carry-ons, and of course mine was
selected.
This was actually amusing as mine was packed as full
as it could be with handmade cheeses from a local co-op, my favorite
cranberry candy from a small factory, and other small items peculiar to the
region. It also carried a selection of small toys, books, and children's
music tapes, to entertain my young daughter.
Less amusing was that he broke one of the toys and
didn't care.
I was mostly amused at his overreaction, not realizing
yet that the entire nation was similarly overreacting.
I was not traveling with a computer.
My next few trips were near enough that it was more
fun to take the car and a companion, (at my expense,) and enjoy a few days
of leave after the work was done, so the increasing aggravation of travel
was something I heard about but didn't experience.
Then reality set in.
Actually, Lindbergh was an annoyance and I often
caught a commuter plane to LA and it was easier to go through security in
the commuter terminal. Once in LA I was already past the security perimeter
and was never stupid enough to change that.
Other airports were far more obnoxious but things like
3 oz of liquids or gels didn't bother me. I stifled my tongue out of
practicality but definitely began to develop a resentment against the TSA.
The simple arrogance would be enough. The idea that they act as if they are
important individuals is laughable. It annoyed me that it was now better to
check luggage than manage with my (2) carry-ons. I figured the airlines were
taking advantage of the circumstances to do what they already
wanted--restrict carry on. I also was annoyed that twice my luggage was
damaged and getting a claim settled proved more effort than I was willing to
keep up with. I travel with few valuables and was able to keep most of those
in my purse with me.
I now avoid flying whenever practical.
Last year my now teenage daughter and I flew out of
Logan. Given its sorry role in 9/11 I figured it would be the worst one. Not
so. The wandering security guard was much more interested in flirting with
my daughter and was an amusing conversationalist. (At least until his
partner came by and pretty much dragged him away in embarrassment.) The
worst was the line was so slow, but we were amused by the guard through most
of it. We had to take our computers out of their cases, take off our shoes,
etc, but were otherwise treated like people instead of cattle. I appreciated
the humor that our TSA screeners approached my need for special assistance
as I have a handicapping condition that was flaring and making my fingers
almost useless and standing for any length of time an exercise in pain. They
were courteous, provided a chair for me. This was the only airport where I
actually appreciated that the screeners and guards felt they were serving us
rather than being our masters.
My last trip through terminal 2 at Lindbergh was
nasty. This was before the pat down and before the new scanners. The TSA
personnel we encountered were rude, distant, arrogant, (add whatever
derogatory adjective you wish and I am sure it would have fit someone we
encountered.)
My resentment grows.
If I had been in the Oceanside gentleman's position I
am certain that I would no longer have been able to restrain my aggravation.
I will have to be prepared next time I must fly...I am thinking that the
bathing suit idea is basically a good one. At least I will choose how much
skin I will show, no one will be leering at me through a monitor, (with the
pictures being recorded,) and I will not endure pat down behind a
screen...let it be done in front of all. I have nothing to be ashamed of and
they do.
I think that those with the experience, training, or
wit, to see how easy it is for a real bad guy (willing to die,) to
circumvent airline "security" are actually few. My children think they are
being protected and wonder that I have objections. If I just adjusted how
"I" thought about it, then I would feel much better about it. (choke.)
I think the small insults have just added up to the
point where this was a last straw for many travelers. I resented long ago
but was able to work my way through the system without creating a furor. But
this grabbing our dignity inch by inch just reached the mark where I feel
pushed too far and now must come out swinging.
Maybe the citizens are a sleeping lion who is about to
awake. I only hope so.
====
http://www.usatoday.com/travel/news/
2010-11-17-airportpatdown_N.htm?csp
=Daily%20Briefing
"First it's passengers' shoes, then liquids, then
laptops, then whole-body scans and now thorough pat-downs," says Geoff
Freeman, executive vice resident of the U.S. Travel Association, which
represents nearly 1,700 companies in the travel industry. The group says
it has received an unprecedented 1,000 e-mails and phone calls in the past
week from travelers opposed to TSA screening methods. "Travelers are
saying: 'What's next?' What's the vision, and when does it get better?' "
"Government officials cannot strip search or pat
down "people unless the government agents have a reasonable suspicion the
person they're searching or strip searching ... (is) involved in some kind
of criminal activity," John Whitehead, president of the Rutherford
Institute, says. "Why would airports be any different?"
This may be why the furor. Before it was just our
stuff, or a rude and obnoxious pretender to authority; now it is our very
person that is being violated.
R, Rose
If there are any citizens left to awaken. I tried
to warn everyone when this first started: the purpose of TSA is to convince
Americans they are subjects, not citizens. I see no reason to change my
views. Now true, most of the TSA people believe themselves to be good guys
dedicated to the safety of the US, just as the kind of SF fans who volunteer
"to work security" at SF conventions probably believe they are good people.
SF convention chairmen have learned never to allow those who volunteer to
work security to be involved in any way in security operations. The TSA
recruits them. I am sure it also gets some good people, but enough will be
police manqué or time servers, or both.
It may be that this will awaken the American
people. Perhaps. But I fear your children are typical of a generation
accustomed, with good reason, to think of authorities as enemies who must be
obeyed, not partners in a self-governing republic. The TSA is a large part
of this accustomization.
==
Yeah, one more TSA OMG...
Jerry:
It's been hard not to read about the TSA's amazing
assaults on our dignity as US citizens lately. But this one just floored me.
The article is about John Pistole's testimony before the Senate Committee on
Commerce, Science and Transportation concerning the TSA -
http://www.cnn.com/2010/TRAVEL/11/17/airport.security/index.html?hpt=T2
After surprisingly neutral comments on Pistole's
testimony, the end of the article contained the following two items:
=-=-=-=-=-=-=-=-=-=
Apparently the TSA agents are 'offended' at the
public's response to their activities -
The mood among security officials is "anger over the
way the media is playing this story," according to a senior Homeland
Security official.
"You had a dutiful [transportation security officer],
someone who works on the front lines to protect this country from a
terrorist attack, someone who did everything by the book and according to
his training, and he was accosted and verbally abused by a member of the
traveling public," the official said. "The fact that some in the media would
hail the traveler as a kind of folk hero is shameful."
THEY are angry???
=-=-=-=-=-=-=-=-=-=
The second, however is the pièce de résistance -
Pistole, addressing a Senate Homeland Security
Committee hearing on air cargo safety, veered off topic to plead with the
American public to see airport security "as a partnership."
"Those security officers there are there to work with
you, to ensure that everybody on that flight has been properly screened," he
said. "Everybody wants that assurance, so just try to be patient, work with
our folks. They are there to protect you and your loved ones, and let's make
it a partnership."
I am at an absolute loss to decide whether I am more
horrified/outraged to realize that this bureaucrat thinks I ought to believe
this non-sense or that someone in the position of power he obviously
occupies apparently believes it himself!
John L.
But of course they are angry. They mostly believe
they are good guys. Or want to believe that. Or want us to believe that.
Much like Vidkung Quisling.
==
Backscatter X-ray
Jerry:
I've been following the discussions of radiation dose
in backscatter x-ray scans, and realizing I don't have enough information to
reach a conclusion. Most important, I had no idea what the photon energy
used was. The dose from a scanner is commonly compared with the dose from
cosmic rays during an airplane flight, which could be a bit misleading. If
the scanner uses a low enough energy, it's quite possible the x-rays would
never penetrate the skin and contribute nothing to effective dose. Between
this very low energy and the energy you see with cosmic rays, there is a
huge range of photon (or particle, in the case of cosmic rays) energies,
with a range of dose effects from uniform whole-body dose to all the energy
concentrated in the epidermis.
But in the news articles, specifications like the
photon energy have been rather hard to find.
I did a bit of googling, and came across the Wikipedia
article on backscatter x-ray. It led me to a document that is very useful,
despite some interesting and mildly irritating redactions.
Radiation Safety Engineering Assessment Report for the
Rapidscan Secure 1000 In Single-Pose Configuration
http://www.tsa.gov/assets/pdf/jh_apl_v2.pdf
This is the first place I've seen any information on
the photon energies used by these instruments.
According to the document, the Rapidscan Secure 1000,
presumably a typical backscatter x-ray unit, uses an x-ray beam of 50KVP out
of the master (front) and slave (rear) unit, with beam hardness of 1.16 mmAl
and 1.63mmAl, respectively. This yields a diagnostic quality x-ray beam,
capable of penetrating the body and yielding an image on film, given enough
photons to make an image.
There is no "backscatter setting" on an x-ray machine.
You turn on the power, a lightning bolt hits a piece of tungsten, and out
come photons. What you do with them once they emerge from the tube is up to
you. (Yes, I'm glossing over some details, but they don't matter.) If you
beam x-rays at a person, some of the photons are going to scatter in various
directions. At a photon energy of 40 KeV, most of the beam attenuation we
see is due to photons being scattered out of the direct beam. Since they
don't reach a detector on the other side of the subject being irradiated,
this counts as beam attenuation. Beam attenuation coefficients at 40KeV are
0.25 total, of which 0.18 represents Compton scattering. Another .02
represents Rayleigh scattering, so total scattering of one form or the other
represents 80% of photons removed from the beam. (Radiological Health
Handbook: "Mass Attenation Coefficients for Gamma Rays in Water" P. 133)
This attenuation coefficient of 0.25 has units of
cm^2/g so if you multiply by the density of water, you get units of 1/cm. A
beam of this energy going through 30 cm of airline passenger will be
attenuated by a factor of 1800. One photon of the beam out of 1800 will make
it through to a detector on the other side of the patient. Radiation
scattered from the target, on the other hand, might be more useful. Using
the Compton and Rayleigh scattering coefficients, the first centimeter of
skin will scatter 18% of the incident beam in some direction. At low
energies, a good fraction of the beam will be scattered back toward the beam
emitter. At 40-50 KeV, probably about a third of the energy is scattered
backward. If you have a whole wall as a detector, you can probably capture
5% of the total beam energy as backscattered radiation. 5% doesn't sound
like a lot, one in twenty is huge compared with 1 in 1800. This means you
can get about the same amount of useful information with 1% of the incident
dose to the subject.
So according to the report linked above, each scan
results in a total dose of 1.55 microrem. I'm inclined to believe the people
doing the survey knew what they were doing. Because of the beam energies
involved, this isn't quite a uniform whole-body dose -- The beam loses about
half its strength for each inch of tissue it penetrates -- it isn't soft
enough that all the dose will be concentrated, for example, in the
melanocytes of your skin.
As convenient as it would be to be able to object on
the basis of health and safety, I guess we're left with "only" arguments
about modesty, human dignity, and whether we're citizens or subjects.
None of which seem to carry much weight in certain
sectors of the political ecosystem.
. ......Karl
Thank you for running the numbers. We are left
"only" with arguments about freedom. Freedom is not free.
==
Subject: cumulative inflight radiation exposure
Pilot wrote:
"Mr. Strohm points to a study disputing my point about
cumulative inflight radiation exposure. My best rebuttal is a closet full of
flight suits faded from green to brown by radiation, each one with a green
strip on each shoulder where they were covered by my parachute straps."
This would imply that parachute straps are an
effective barrier to ionizing radiation. I think the fading is more likely
to be from plain old ordinary visible light.
S. Walker
That would have been my comment as well. I suspect
UV does more bleaching than actual ionizing radiation. Of course UV and
X=rays are both photons, but then clouds and oceans are largely water
molecules.
===========
: Why 3D Camera Technology Will Be The Future,
Jerry
I'm on the road - my first air trip in ten years. I
found the following summary of the 3D landscape:
http://benchmarkreviews.com/index.php?
option=com_content&task=view&id=12371&Itemid=8
Pretty interesting.
Ed
=============
Rock Throwers Unite!
: My new favorite unit of energy -
Dear Dr. Pournelle,
I’ve been doing some frivolous thought experiments
recently, the results of which I thought you and your readers might enjoy.
This whole thing got started by an email from my
father (a fellow engineer) this morning in which he felt he’d share this
tidbit of information he’d come across somehow – the muzzle energy of the
main cannons on the HMS King George V battleship from WW2 was 85,000
foot-tons. “No wonder a broadside moved the ship sideways!” was his comment.
A little searching on the wiki-monstrosity and I found the fully laden
weight of that vessel, around 44,000 tons. “No kidding! It’d move the ship
sideways by a bit less than two feet!” was my initial reply. While I was at
it, I looked up the muzzle energy of an Iowa-class battleship’s 16” / 50
cailber main cannon – 130,000 foot-tons for the armor piercing stuff, based
on wikipedia’s published numbers. But on the same page it listed the
different kinds of ammunition available for the 16” gun – Armor Piercing,
High Explosive, and Mk 23 nuclear shell. (!!!) That bore some further
investigation. The best figures I could find for the yield for a Mk23 nuke
shell was “15-20 kilotons”. Okay, call it 17.5 kt for our purposes. On a
whim, I figured I’d try to convert that number into our new favorite ‘foot
tons’ unit of energy. So… 1 ton TNT = 4.184x10^9 Joules, 1 lb-ft = 1.356-ish
Joules… the number I came up with was 27 BILLION foot-tons.
So I responded to my father’s email “That’s nuthin!…”
and left it more or less at that.
I became sort of fixated on that figure of 27 billion
foot-tons of energy out of a 17.5 kiloton nuclear bomb all evening. I
quipped in my earlier email "If you can't get it done with 27 bn foot-tons,
it isn't getting done." So I tried to think up a task you could actually
*do* with that much energy...
My first thought was "you could probably *actually*
move a mountain." The question is, how far? To answer THAT question, you
have to know the weight of your mountain. Well, I tried to google "average
mountain weight" and didn't get anything terribly satisfactory, as you might
imagine. One of the biggest issues of figuring out how much a given mountain
weighs is defining exactly how big it is, especially how "deep" it is... But
then I thought Aha! I know of a "mountain" that we know exactly how big it
is, because it is actually a single rock. Ayers Rock in Australia is just a
giant stone plopped in the middle of an arid plain, smack in the middle of
the continent. It is estimated to weigh 4 million tons. So how far up in the
air could we throw it with our 27 bn foot-tons? Easy division - 6750 feet
high. (!!!)
Ayers rock throwing - it's like anvil shooting on
steroids!
Let's throw it higher. The biggest H-bomb ever
detonated was the Tsar Bomba, a HALF SCALE bomb test that the Soviets
carried out in some unfortunate corner of Siberia. It had a yield of 50
Megatons. That's 77,000 Billion foot-tons, in our new favorite measurement.
So how high could we punt Ayers rock with that bad boy? ... Okay. We run
into another situation where the units fail to make sense anymore. The
answer is 19 million feet, give or take. To put it in more reasonable units,
that's 3650 miles. Straight up.
I'm not sure if the 'rule of thumb' for delta V
required to reach Low Earth Orbit (9.5 - 10 km/sec) holds for a thing the
size of Ayers rock, but if it does, that means that we could send Ayers rock
into LEO with a 50 mt H-bomb. When you calculate the delta V for a thing
weighing 4 million pounds to which you apply 77,000 Billion foot-tons of
energy, it comes out to (please forgive my flagrant switching between metric
and Imperial units) 10.72 km/sec.
We don't have to do it. It is enough to know that we
can. ;)
Fun with math!
Regards,
Mike Smith
See Mail below
==========
no need to repeal Obama-care
was watching news last night, and was a segment on all
the waivers that have been issued so far, and it occurred to me, no need to
rpeal Obama-care, we just need a wavier for republicans. that way those 16k
new IRS agents can concentrate on getting dems to pay their taxes
Martin Rose
“The ultimate result of shielding man from the effects of his folly is to
fill the world with fools.” Herbert Spencer
=============
The basic physics of global
warming
Jerry;
I appreciated your comments about the character
assassination of Freeman Dyson.
While it is important to refute particular details, I
believe that Global Warming skeptics should take the time to educate the
public about the basic physics that dictate the equilibrium temperature of
the planet. Few lay people understand that the Earth's temperature is
ultimately dependant on only three variables, the misnamed "Solar Constant,"
the Earth's Albedo and the Earth's Emissivity. More importantly; it should
be explained that because the equilibrium temperature is proportional to
these three variables raised to the one-fourth power, the Earth's
equilibrium temperature and climate is extremely insensitive to any changes
in these variables.
Describing the basic physics of the Earth's energy
balance to the public would also provide an opportunity to raise valid
questions about the science of global warming. Although skeptics such as
yourself and me take note of changes in the Solar Constant, a far more
significant factor is potential changes in the Earth's albedo. Very few
climate change alarmists devote much attention to the question of changes in
the Earth's albedo and when they do, the focus on the emissivity of surfaces
in urban areas that are far to small to have a consequential effect on the
planet's energy balance.
Finally; the process of evaporation or water,
convection of water vapor into the upper atmosphere, and the radiation of
heat energy into space as the water vapor condenses is an energy transport
mechanism that effectively short circuits the greenhouse effect. Why is this
energy transport mechanism ignored by most global warming modeling programs?
Jim Crawford
Most climate models do not take account of clouds,
because they don't have the ability to do that. Newer computers make models
with clouds more constructible, but when that's tried the results don't
correlate well with the results of the "trusted" models. I am told that
there is a furious debate about this among climate scientists, but it's
being kept out of the public eye. Eventually it has to come out.
Warming water produces water vapor...
=============
"The dastardly event would have been edited from
history."
<http://www.nature.com/news/2010/101116/full/news.2010.611.html>
- Roland Dobbins
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