Posted by Morris Dovey on October 14, 2009, 8:48 pm
That wasn't what I observed (as a computer guy). I saw a shift of focus
from the value women brought in the traditional homemaker role to the
value of the paycheck they brought home - a shift that appeared to me to
be promoted almost entirely by women. No one likes to be (or appear to
be) lacking value, and the transition seemed (in terms of societal
change) almost abrupt. The number of people wanting jobs grew very much
faster than the number of jobs.
A scenario I observed at a couple of major firms was a freezing of wages
for existing jobs, and an effort to absorb the new labor (at lower wages).
Inflation was a balancing force (and ultimately peaked in double digits)
and things began to stabilize with wage dollars that had a significantly
reduced purchasing power. I'm sure I'm not saying this very well, but it
would seem that the real value of wages can't exceed the real value of
what's produced without destroying the production mechanism.
I think a large middle class reflects the ability of a society to
produce large real value. If we want a large middle class, then we will
need to find a way for all to be significantly more productive. If we
can not or will not, our situation cannot improve.
DeSoto, Iowa USA
Posted by Bruce Richmond on October 15, 2009, 4:22 am
I think your timing is a bit off. The two earner household was firmly
in place during the 1960's before computers were all that common.
There were no PCs at that time, just mainframes. IMO the 2nd earner
was added so that the family could afford some of the upscale things
that they just couldn't afford on a single income. The service sector
was only able to grow after there was enough disposable income to
support it. The movement from manufacturing was not intentional.
Posted by Axel Grease on October 14, 2009, 7:29 pm
Ahhh. Sorry. I have been missing a critical point and made an invalid
asumption about which media you are trying to use. I better understand what
you are up to now... making hot air... not hot liquids. That makes a lot
of difference. That approach was abandonded early-on back in the 70s.
Gasses (mostly air) , as a transfer media, were generally viewed as too
lacking in concentrated mass to be efficient. It took took much air flow
(or compression problems) compared to the return in transferrable BTUs...
even when using a FREE power source (Sun/UV). Gasses have too much
*insulation* (space) between the molecules to lend themselves to rapid
heating by concentrated forms of *insolation* (I know you will understand
the difference, Mr. Dovey, but other readers need those 2 spellings pointed
Due to their inherant densities, pumping liquids through a heat gathering
tube always gave better results.
Yes. The early days of Mother Earth News magazine were much better than the
But with discretion, one could still learn about some superb products. One
of my favorites was PermaChink... an acrylic chinking material for log
homes. Great stuff.
O/T and disasterously sad, but interesting...
I remember the dying days of the single-earner family... the 1960s. Our
society did less deciding (implies a reasonable amount of high level
thought process) than you describe. They passively made a fatal error...
letting the mass media think for them... particularly in the case of TV.
Americans never quite "got it" that TV really has only one goal... to "sell"
goods and ideas. It became a stupendously sucessful propaganda dispenser
and sloth promoting sytem ever developed. Americans were ignorant and
gullible enough to swallow the garbage spewed through TV... hook, line, and
sinker... miserably and lazily squandering their brain power and
discretionary time by watching cartoons, sitcoms, and soap operas instead of
inventing and building toward a better future. Even people who saw
themselves as intelligent and choosey by watcing travelogues, News, and
documentaries were essentially wasting their lives whenever the television
droned on in front of them in their favorite couch or easy chair.
As Dinah Shore used to sing - "See the USA in your Chevrolet".
What she did not sing was - "That will make oil companies and politicians
powerful enough to enslave you while TV keeps your mind asleep ... idle
instead of working to find better alternative fuels. Watch TV long enough
and you will soon lose the knowledge, intelligence, and the FREE WILL to use
any of them."
But that didn't rhyme, so I suppose Dinah would never have be allowed to
Posted by Morris Dovey on October 14, 2009, 7:41 pm
Axel Grease wrote:
No worry - I hadn't made a point of /what/ I was heating; and the method
should provide the same advantages for heating water or oil.
My initial projects all involve providing heat for liquid-piston
Stirling engines in a context where cost and (apparent) simplicity have
a much higher priority than efficiency - in a development context
limited to woodworking tools and and an average budget of (typically)
less than US$/day. My CNC router can cut decent grooves in aluminum
(but not in iron or steel) so I'm working with aluminum. :)
Originally I thought I might try using flat panel collectors, but the
Carnot efficiency (E <= 1 - Tc/Th) was so terrible that I decided to
switch to concentrating collectors which would deliver the same amount
of energy, but at a much higher temperature.
Heh - then I realized how inefficient my concentrator was due to the
(what should have been obvious) reflection, convection, and re-radiation
losses. I spent a couple of days being really unhappy about it all, and
then had this idea for improving the collector efficiency.
Fortunately, I don't need rapid heating and the aluminum/air transfer
approach seems adequate for the application.
When it finally soaked in that I had, perhaps, an improvement that might
be applied to more systems, and kinds of systems, than I was working on
I was pretty pleased with myself and all the folks here in
alt.solar.thermal who were willing to remain patient while I asked my
stupid physics questions.
I know more than I understand, but that's not new. :)
DeSoto, Iowa USA
Posted by Robert Scott on October 14, 2009, 5:03 pm
I've been wondering about this method. On one hand having a groovy surface
increases the chance, as you say, for multiple reflections and heat conversion
at each reflection. However a groovy surface also by necessity has a longer
average thermal conduction path before the heat can be carried away to do some
good. The bottom of the groove is nice and close to the collection fluid (or
air), but the peaks of the grooves are further away, and any heat collected near
the tips of these peaks has to travel lengthwise through the peak. This means
the average surface temperature will be higher, increasing conduction and
re-radiation losses. How does one go about measuring which of these two effects
As for optical measurements, how about using a photographic light meter to
measure the "brightness" of the collector in full sun? If the grooves are doing
any good, the light meter should register less light than from a flat black
surface. Or just look at it with your eyes. Set a flat black panel next to a
grooved panel in direct sun and see which panel looks darker.