JackC

I learned AutoCAD LT in a couple of afternoons from the tutorial that came with the software. It's easy. You could try A9Cad which is free and does the same job in much the same way but it does have more bugs than your average anthill.

The effects of real turbulence cannot be neglected but in my limited experience, the very day I completed my first canopy control course, my succeptibilty to "turbulence" reduced by at least 80%. Having your feet together (especially crossed) was said to be a contributory factor to this because it can promote an asymetrical body position that leads to a sort of pendulum action on final where people make a minor heading correction, then the canopy swings back and they need to correct again, then it swings back and they correct and swing and correct and swing and finally they land complaining about how "the turbulence is really bad today". The better option is to get your last turn done high enough so that you can have 5seconds of no input at all to let the canopy settle down and fly before you need to flare. Any minor corrections can be done with harness input and you can't do with your legs stuck together. Having said that, if you are gonna biff in big style, feet tegether for a nice PLF might not be a bad option.

Being in the best position to fly your canopy is probably more important than adopting the best position to survive the impact that results from not being able to fly your canopy. I reckon a good position should look a bit like the attached. Sitting in the harness with your feet apart and knees bent, so you can initiate harness turns easily, and ready to run out the landing, slide or PLF if needed. Arms up on rear riser ready to correct and flare at the right moment.

On exit, curl your legs up round your own arse and push your arms all the way over your head. It should help stop you going so far head down and prevent unwanted front flippage. Just remember to stretch your legs out again when you level out or you'll be backsliding. Your legs are your biggest control surface, the quicker you can aware of what they are doing the better. Apart from that, just relax and enjoy it.

And that is the unfortunate truth. Population is the real problem and there is not a thing you can do about it.

I have no idea what you mean here. Then why have 10,000 stations if you think they should all read the same? In that case 1 should be enough to satisfy you, yes? Great! Now some data says antarctica is warming, some says cooling, but on average the data says warming. But this didn't pass your smell test, implying that you don't trust it. Why not? Maybe, maybe not. If warming resumes next year and runs so the underlying average maintains the general upward trend it has done for the last 100 years, will the cooling period still be a problem? There have been other extended cooling periods in the last 150 years over the background warming trend, why is this one special? Agreed The mechanisms are understood but the interactions between them are chaotic. That makes them extremely difficult to predict and prone to errors that get larger the further ahead you try to predict. You do the best with what you've got. Yes. Close enough. Agreed; because chaotic systems are very difficult to predict. In general terms you can say it should on average trend this way in the range of x to y, but in specific terms you can't say "hmmm, next year Los Angeles will be 0.000432 degrees warmer than last year but New Jersey will be 0.0000975 degrees cooler". Scientists generally are more interested in the research, publication in scientific journals is a necessary evil. PR through more mainstream media is treated with the same distrust skydivers treat media wuffos to report the latest "death plunge from 15000ft". Interesting link, thanks. The conclusion, Dickens said, is that something other than carbon dioxide caused much of the heating during the PETM. "Some feedback loop or other processes that aren't accounted for in these models -- the same ones used by the IPCC for current best estimates of 21st Century warming -- caused a substantial portion of the warming that occurred during the PETM. This is quite possible and if true it means the PETM and the current AGW systems are forced by different mechanisms. That's reasonable when you think that dinosaurs didn't have SUVs or coal fired power plants. And why is that? Like you said, the mechanism for AGW is settled. To deny it, you'd have to be a loon.

Why would I want to debate with someone who doesn't understand the physics of the system despite having his mistakes pointed out be three different scientists and engineers, and rather that try and understand he resorts to insults and name calling?

+1

Quite so, you are a lawyer after all. I am a scientist so when I see science tactics at work, I get an idea about what's going on. But when I see lawyer tactics going on, I run a fucking mile. Is that not as you might expect with only 25 metrological stations in an area of 14 million sq km? If a study is made using a mere 1000 data points, people here are quick to point out how it isn't statistically significant and they want to see 10,000 points. In this case someone did fill in those extra data points with satellite temperature readings. But when the new data shows warming instead of cooling and all of a sudden it doesn't pass your smell test; well I smell lawyer tactics. Of course, I'm a scientist. If I have a theory and it doesn't reflect reality, the theory is wrong. And if I am wrong, I want to know about it. But in the case of AGW, the mechanism is proven as far as anything can ever be proven. CO2 is a greenhouse gas, the concentration of atmospheric CO2 is increasing and thermodynamics works. If any of that is proven wrong, then pretty much everything we know about science is wrong too, and I think we might have noticed if that was the case. Can you prove it wrong? That's political/media bollox written by people who sieze a perfectly good study and warp it beyond recognition because they do not know their scientific arse from their scientific elbow. I pay only passing attention.

Law students are trained in the case method, and to the lawyer everything in life looks like a case. ~ Edward Packard, Jr. Did it ever occur to you that these scientist might be telling the truth?

Incorrect. Satellites measure radiance which is inverted to infer temperature. That radiance comes mostly from the planets surface, not the atmosphere. Separately identified yes, and they usually are. But that does not mean they cannot be used together.

Well, he is a part of the academic elite. Their thoughts are so complex and wonderful that mere mortals should simply bow in assent and do as they are told. In other words: "Don't you worry your pretty little head about it." When you explain, and they get it wrong, so you explain in simpler terms, and they get it wrong, so you explain in even more simple terms, and they finally get it, then they go back to the original problem and get it wrong, so you explain, and they get it wrong, so you explain in simpler terms, and they get it wrong, so you explain in even more simple terms...etc etc... So eventually you give up and get slagged for being one of the arrogant academic elite. It's no wonder there is a shortage of science teachers, who the fuck would sign up for that on a daily basis?

The temperatures shown are from sattelite data and not disputed - the peak was 1998 and since they have come down. You can hold your hands over your ears and pretend it aint so, but its the fact. 2005 was not warmer then 1998 - full stop. I'm not holding my hands over my ears, the data is what the data is. The correlation between satellite and surface data seems good so we should be able to have some confidence in the earlier data where no satellite data exists. Clearly there are many periods where the temperature began to fall (1878, 1884, 1900, 1940, 1960, 1980, 1990, 2002). Nevertheless, over the whole 150 year period, the temperature rose considerably. You can hold your hands over your ears and pretend it aint so, but it's a fact.

You are posting graphs that are out of date and incorrect. You should know that yoour 2005 claim is not correct and that the updated graphs I posted are the consensus from 3 out of 4 institutions which measure global temperatures. Temperatures have not increased since 1998 - you are really tring to muddy the waters. I looked up the reference for your satellite graphs and they claim the data came from the Hadley Centre for Climate Research and the University of East Anglia so I chased it up. It seems you are cherry picking the last 10 years from a graph that runs for 150 years. That's not very honest. Here is the full graph: http://www.cru.uea.ac.uk/cru/data/temperature/nhshgl.gif

Tell me more about your insulator. How thick is it? How much does it weigh? How well does it conduct heat? How well does it radiate heat? It doesn't matter what the numbers are. Do the algebra not the arithmetic. But I sense you are just trolling at this point so there is no point in continuing.

How? Jeez, haven't we gone through this already? The sun heats up the earth. The earth radiates IR back into space. The CO2 either absorbs the IR and reemits it back to the earth (or out into space) or the CO2 reflects it directly back to earth. It happens slowly enough for the whole system to be largely in thermal equilibrium. Or rather than send us round chasing our tails explaining high school physics for the umpteenth time, you can always drive google and take some personal responsibility for your own education.

Ok, how does CO2 come into play here? Before we get to CO2 lets go back to the oven. If the oven is set to 80degC, the water heats up until it reaches 80degC right? Now the heat source (the flame in the oven) will remain constant and the reason the oven sits at 80degC is because the heat going in from the flame matches the heat leaking out through the oven door. Now if I stop some of the heat leaking out by wrapping my oven in a thermal insulator, the temperature must rise until the heat going in matches the heat leaking out again*. Then the whole oven, water and all, must settle at some higher temperature. In my analogy, the earth is the oven, the sun is the flame and the CO2 acts as a thermal insulator by stopping heat from leaking off into space. Really, this is high school stuff. Are you sure you have a chem degree? * remember: the amount of heat that can flow though a thermal insulator is dependent on the temperature gradient across the insulator, the higher the temperature gradient the greater the flow and the more the insulating boundary layer is, the less heat can flow. So to get the same heat flow across a more insulating layer, the temperature gradient must be larger.

Must've been that OTHER JackC that wrote this, then. You wrote: Then read again what I wrote bearing in mind that heat and temperature are not the same thing. What I have said is correct but if you are so desparate to get something over on me, I take back any mention I may have made that says CO2 always leads to a temperature increase. CO2 in and of itself does not always lead to a temperature increase. Retaining more heat always leads to a temperature increase. In the case of AGW, CO2 causes more heat to be retained. Happy now?

Is the oven set above or below 212 degF? For simplicitys sake, below. Are we are understanding the concept of thermal equilibrium yet?

Ok, I'll play along with you. The temperature of the water goes up. And where does it stop?

Where are you putting the control volume for your energy balance? If your control volume is simply the jug of water, what relevance does it have in this conversation? You are putting a jug of cold water into a hot oven. Assume the energy is coming from the flame at the base of the oven. What happens to the temperature of the water?

What happens if you put a jug of water in an oven?

That is what is happening. The CO2 stops IR radiation from being radiated into space by 1) absorbing it and warming up the air, 2) re-radiating the absorbed IR either back to the earth heating it up or out into space 3) reflecting the earth emitted IR back to the earth heating it up. The temperature changes due to CO2 increases happen relatively slowly so that the system at any given instant is more or less in thermal equilibrium. There is never a big thermal discontinuity like your theory would need if it were true. Right, it's not possible and that is because you have misunderstood the physics of the system.

No. You worked out how much you could raise the temperature of the water given enough heat to raise the temperature of the air by 1 degree. This is all well and good but not particualrly useful since the air and water in this sytem will be in thermal equilibrium. This means that on average, if you measure a temperature rise of 1 degree in the air, the water will have equalled the temperature rise and also risen by 1 degree. What you cannot say it that because the air has raised it's temperature by 1 degree, the water will have only raised it's temperature by 0.0009 degrees. You only have to put a jug of water in an oven to see that this is rubbish. Since the system operates as a whole in thermal equilibrium, the equation you need is dQ=(c_water * m_water + c_air * m_air) * dT. Given a heat change dQ, you can then work out dT. That is, if calorimetry were the right tool for the job, which it ain't since we don't have a closed system. If you really do have a masters in chemistry, you should not need to be told this stuff, it's high school level work.

As shown in the calculation above, a one degree change in air temperature will equate to 0.0009 degree change in sea temperature, probably less. Wrong. Heat flows until they are in thermal equilibrium. What does thermal equilibrium mean?