Global Warming? are humans to blame?

If you have a bachelors you would have done more courses than I ever did.
I got bored halfway through 2nd year and retired to the bar. I proved that
beer+girls > lectures.

LOL again, louder.
I would only pose problems that would be useful to me and that
I don't have time to do myself.

For example, the accuracy of my computations of the 2D planing equation
are limited by my use of rational approximations of the sine and cosine
integrals. See equation (2) of the report in the boatdesign thread:
http://www.boatdesign.net/forums/at...06-p2d-simple-2d-planing-program-p2d_flat.pdf

Of course, there are slow ways to get better accuracy, but the rational
approximations in Abramowitz and Stegun (equations 5.2.14, 5.2.16, and
5.2.88 ) are very fast to compute and give about 6 figure accuracy.
I need an extension of that rational approximation that gives another one or two sig figs.


The estimation of the length of an ellipse is a very old problem. In a splendid
bit of inspired "amateur" mathematics, an Iranian chemical engineer
recently found a very good approximation to the complete elliptical
integral of the 2nd kind. See equations (42) and (43) on page 18 in a thread here at bdn:
http://www.boatdesign.net/forums/at...ut-inclined-underwater-hull-form-lsp_flat.pdf

Is it possible to do better with fewer operations. Is it possible without that
pesky 1/4 power?

I've got millions of problems for nerds, Yob
It's just that I prefer doing them myself.

I find people who are committed to environmental conservation amusing.
I like to think of them as "tectonic plate deniers".

No, it's just disinterest and misanthropy on my part. And an unshakable
belief that volcanoes will bring greater climatic change than humanity's farts.

 

http://arxiv.org/abs/1101.2832

In this article posted by Boston (from Cornell. One of my daughters graduated from Cornell), it states in more simple language this:
Population growth has slowed but still more people each year. CO2 emmissions are increasing at an increasing, unsustainable rate. Improvements in combustion designs, though reducing polutants emmitted, are insufficient to reduce the overall increase.

Okay
I only drive my van about once a week. I walk to the store or I bycicle on my 1950 classic 3 speed British Raleigh with 28.5 inch rimmed tires. My boat is an all electric trailer-sailer. My 3/4 ton capacity Dodge Ram 250 only weighs 4000 lbs and gets 17 miles per gallon with it's small block 318 cu inch V8.
My home is all electric, except the stove and clothes dryer are gas.
Am I doing enough as an individual to reduce my footprint?
Or do I have to endorse the current hysteria?

 

I sped read the PDF and certainly didn't do the computations. One thing did standout as an omission in the wing planforms.
I failed to notice a cycloid. Cycloids are similar to ovals in construction but much simpler to calculate. Would a cycloid planform work?

http://en.wikipedia.org/wiki/Cycloid

 

Leo
Do you have a planimeter?
It's not an obsolete device in calculus.

Oh! Congratulations on being self educated. Mostly, so am I. I earned my degree piecemeal. Self directed is a more difficult school, since you must discipline yourself to study rather than accepting assignments and answering roll calls in a supervised class. The greatest advantage is self reliance in thought process and less social brain washing. Congratulations!

 

If I thought it would amuse me, I would prefer that you act hysterically and post the video on YouTube.

I don't see the future of humanity being based on DNA and little bags of water.
Maybe the future belongs to those with the best artificial organs that can
handle different climates and atmospheric composition. Boffins are working
on the easy bits right now...
http://www.youtube.com/watch?v=TW78wbN-WuU

 

A cycloid might have some minimal property for some esoteric applications
where you want a prescribed length (or behaviour) of the leading edge or
trailing edge. The benefits might not necessarily be aerodynamic.

Construction of the wing shapes is not a problem for me. I am only
interested in the quick and accurate calculation of the linearised lifting
surface integral and the mathematics: engineering aspects are irrelevant.

You must have come across this guy if you did some number theory...
"I am interested in mathematics only as a creative art." - G.H. Hardy.

That's my view too. But I have to earn a living so I also have to prostitute
myself to engineers and naval architects. Fortunately, I can do it from home
alone, and not down at the dock or "The Sailors Arms".

 

global warming and rising temps have always happened here. but there has never been this drastic of fluctuation so quickly before. yes the glaciers have melted before,yes they have grown before, but never this fast. co2 even though it has been high before, has never been this high. the last was a half million years ago.that was caused by earths orbit changing a little, the sea rose, which released the co2 from the oceans where the algae had it trapped.this warming trend is not part of our cycle cause of the timing. its way to soon for that cycle to be hitting us now. so what is the ONLY thing in the calculations that are different?.....us. and the only thing we do to raise the co2 is burn fossil fuels....this jus an opinion,, jus a hippie listening quietly to everyone...


Jim

 

Interesting video.
Some day my wife and I want to share a cyborg body. Non human. We want to be the pilot brains of an intersteller ship. The ship would be our body.

It makes no sense to send a 200 lb man to the stars, when 16 lbs of brain would do. No muscles to atrophy. Less opportunity for desease. Fewer nutrients and oxygen required and better monitored.
We maintain our heath physically, emotionally, and psychologically in hopes some day when these bodies are worn out, we'll be suitable volunteers.

Crazy?

 

As I sort of suggested, a planimeter will determin the integral since it measures area, and the integral can be defined as the area under the curve in the diagrahm. Since the planimeter is a tracing tool, it's better to trace 4 circuits and divide the result by 4 to get a more accurate area...integral

 

granted, the planimeter is a "cheat", but you already know how to approximate mathematically. The planimeter area will support and refine your calculations.

 

No, but I have a few splines and plumb bobs that I use to take the lines
from rowing shells and kayaks.

Working on ships while studying would have taken greater effort!
I sat at home with my family while watching B-grade sci-fi

But, to stay on topic, the idea of trying to model the whole earth's climate
is a noble one, but almost impossibly difficult. A little humility is in order. I'd
be more confident of predictions if we had a better understanding of
turbulence at smaller scales.

On the other hand, the evidence for rapid change in some areas is
undeniable. Nothing will be done about it. Billions will die.

 

I want to know who came up with the idea that we have to keep the planet at some nearly constant state? (It wasn't you was it, hippy?)

Me too. I'm just louder.

 

planimeters are cheap on ebay. er sometimes.
Yes, I posted about the error of relying on and limitations of computerized models and over simplification, but it was ignored.
In Christanity only the Pope claims infallibility. In science, all scientists must apparently be super humanly omniscient.
I'm not anti science or anti scientist. Just incredible at the current arrogance!
The planimeter is a valuable time saver in calculations. It's rather amazing how by sliding and rolling it calculates areas from perimeters. I like using mine.

 

I refute misinformation when and where I can. Hence my posts this thread.

 

If I could get 10 decimal place accuracy, I'd use one!

I don't have much use for a planimeter. Once I transfer offsets I have taken
from actual hulls into a computer, areas are calculated automatically. (I
don't need the offsets to copy designs to build, I just use them for
hydrodynamic calculations).