This is part three of a four part guest post by ‘Lucy Skywalker’.
Lucy Skywalker recaps: In Part One I described my visit to Graeff’s seminar. In Part Two I described some of his experiments in detail. Now in Part Three I will at last discuss how he developed theoretical backing to his experimental evidence. And in the final instalment (we decided to split it) I will consider the implications of this work, and plans for developing and replicating the experiments. Together with Graeff and Tallbloke, I firmly insist that, in accordance with Scientific Method, replication is crucial; and that without clear experimental backing, no theory is sacrosanct.
BACKGROUND TO GRAEFF’S THEORETICAL WORK
Reading Graeff’s book, with his life story set alongside his scientific work, helped a lot. Surviving the fire bombing of Hamburg in World War Two drove him to work proactively for non-violence (the Blue Rose) and peaceful energy sources. He could take nobody’s word as gospel, not even in Science – he liked to get things to work for himself. He ran his own company.
When he retired, he wanted to return to his youthful fascination, and devise an experimental challenge to the Second Law. It actually had nothing to do with gravity. His interest with gravity only arose when his instruments recorded a tiny but clear negative temperature gradient in a vertical column of air, that “should not” have been there at all. But he believed his instruments were trustworthy. So he devised new experiments to focus on this anomaly. Over ten years, he devised essentially hundreds of variations on the basic experiment.
I came to see his gradual acquisition of scientific understanding from the inside, and this helped me grasp his theory. In the end I was surprised with how utterly logical and simple it all was, and how easy to calculate – and I still wonder why other physicists have not discovered this before. Perhaps it looked too simple to be true. But it was arrived at by a whole lifetime of experience.
It has been good to see so much interest on the thread following my first post. But it is not directly related to Graeff’s theorising, which follows directly from trying to explain his experimental work. So I want to ask folk to clear their minds of previous ideas, to allow the simplicity of his ideas to percolate. Well, that is as I see things!
Graeff was grateful for not being a trained physicist, for as he said:
“Through his knowledge of the laws of physics, a physicist would be totally convinced that The Second Law of Thermodynamics, one of the very few basic laws of physics, was correct, now, in the past and in the future. A physicist so indoctrinated and convinced would never try to measure something possibly contradicting this belief. And if he would in his work somehow stumble on an experimental result indicating a possible contradiction to The Second law, he would not doubt The Second Law but the correctness of his measurements. Only someone like me, an engineer… would try such an outrageous undertaking.
“It reminded me about the method I used when I tried to come up with a new idea, a new invention. When you try to invent something, many advisers would propose [that you] look up all the patents already published in the field of your interest. This might give you new ideas… I used to do just the opposite. I never looked at existing patents, because I felt that they would stifle my imagination… So I always followed my own thoughts [first].”
Graeff was getting consistent results, always showing this negative gradient that should not be there. He started thinking. It had to be gravity, causing air molecules, as they fell and lost potential energy, to gain kinetic energy which is warmth. But how to prove it? How to calculate it? How to explain it? How to develop a mathematical-physical theory?
One bitterly cold New Year’s Eve, Graeff found himself stranded at Pittsburgh airport. With 24 hours free, he relaxed. He watched the decorative pebbles… and suddenly, his physics mind took off. The plane might be grounded, but his mind was soaring. He could see and feel the molecules in the pebbles vibrating, affected by the gravitational field so that the molecules at the bottom of the pebbles ought to be warmer than the molecules at the tops of the pebbles (and would be, without conduction and convection). Wouldn’t this be similar to the gas molecules whose negative temperature gradient he’d been puzzling over?
“Could I not simply calculate the potential energy at the top, deduct its potential energy which it would have when it reached the bottom, when it was stopped there, before being turned around for its upward swing, and convert this energy difference into a temperature increase of the molecules involved?”
Could it be that simple??? Graeff got pen and paper in his motel room. “I did not have any physics book with me, but I knew the potential energy Ep of a body was equal to its weight W multiplied [by] its height difference H, so I wrote down
Ep = W x H
and as weight W equals mass M x gravity factor g, I added the next line
Ep = W x H = – M x g x H ………..[negative because g and H are measured in opposite directions]
Wonderful! Ep would have a dimension of energy like Joule. This energy would have to be converted into a temperature increase of the molecules involved, because where else could it go? This increase I would call T(Gr), or the temperature increase due to the effect of gravity. To calculate the temperature increase of a body due to an amount of energy added is a very normal calculation for an engineer, as the temperature difference equals the energy introduced divided by the mass of the body M and its specific heat c. So I could write down
dT = T(Gr) = Ep / (M x C)
Combining the two equations I got
T(Gr) = – M x g x H / (M x C) = – gH/C
This would also mean that the temperature at the top should be lower than on the bottom. Now for the first time I had a formula… and if it was correct, then T(Gr) depended only on the gravity factor g, the vertical height H and the specific heat C. It became interesting… maybe I could calculate the value for air right here in my motel room… I knew that for gases, there were two values for specific heat (Cp at constant pressure, and Cv at constant volume). I remembered that for air, Cp was about 1000 J/kg,K… it would have to do for now. Remembering g=9.81, it was easy to calculate… and I got quite excited when I wrote down
T(Gr) for air = – gH/C = -10 x 1 / 1000 = -0.01K/m !!
I was happy because I knew my instruments were capable of measuring this. But was it a reasonable value? During a plane flight the pilot would sometimes announce a temperature of -40°C at a height of about 10,000m. My newly calculated temperature gradient would mean a difference of 100K over that height… a bit high but still in the same ballpark. And would not convection tend to lower that difference? The value I had just calculated could only exist in air without any movement. It sounded quite reasonable.”
BUT THERE IS STILL A PUZZLE!
On getting access to accurate figures, Graeff calculated that T(Gr) for air should be -0.014K/m. There was just one problem: why was this figure about a fifth of the value he was actually measuring?
It took another two years for that solution to arrive.
One day Graeff woke up knowing he had the answer.
In a nutshell, the factor of five represents the “degrees of freedom” of the nitrogen and oxygen that make up nearly all the atmosphere.
According to equipartition, a phenomenon well-known to physicists and chemists, energy has to be distributed equally between all “degrees of freedom” of the molecule in question. Degrees of freedom are the number of different ways or directions in which a force can operate. First there are the linear dimensions x, y and z for each atom. Then there are the rotational dimensions equivalent to each linear direction, in navigation and flight these are called roll (roll sideways), yaw (change direction) and pitch (change elevation). Then there are other vibrational effects that can apply to molecular bonds. But according to Quantum Physics, some of these may not apply… if the temperature is too low for the threshold of activation, as it were. Thus air has five degrees of freedom, not six, at normal temperatures.
The effect of the degrees of freedom kicks in with Graeff’s experiments, because gravity only operates along one of these degrees. And with the collisions (equally applicable to solids, liquids and gases), the energy has to be spread equally. Thus it happens that the specific heat given in tables has to be divided by the number of degrees of freedom in order to be applied correctly here. Therefore,
T(Gr) = -gH / (C/n) = -gHn/C
where n is the number of degrees of freedom. Now it is finally possible to calculate the theoretical temperature gradients.
For air, T(Gr) is about -0.07K/m.
For water, T(Gr) is about -0.045K/m.
It is clear from the graphs that these theoretical temperature gradients, now including the degrees of freedom, match pretty well what experimental results were yielding.
Graeff has managed to obtain interesting results for metals, but details are not in his book, and I have not studied his work in detail here – it must involve conduction as a factor. His work shows a high level of consistency, with quality and quantity of results obtained in other different experimental setups. Everything seems to fit his pattern of discoveries – and the results tend to reinforce each other. Even the slightly “high” figure for water (-0.05K/m, where theory says -0.045K/m) could logically be a slightly contaminating effect of “convection-inhibited” air in the insulation (theory for air says 0.07K/m). So I feel I can support Graeff when he says that while formerly he would hedge his bets and say “it appears” to be gravity, now he feels the onus is on others to show that it is not gravity-induced temperature gradients he is observing, measuring, and calculating with such precision and fit.
IMPLICATIONS – REWRITING THE SECOND LAW!?
So – Graeff has demonstrated both experimentally and theoretically that a modification of the full statement for the Second Law is needed, and that this is possible without contravening the essence of the Second Law. Graeff has written out his proposed modification here pp11-12 and here p17. I won’t dwell on the wording here. Maybe it needs tweaking. We can easily focus on it too much. I am happy to leave that to the professionals. Most important is to grasp the principle, as explained above.
But in essence, the Second Law applies to closed systems where there is no external force at work. However, since gravity IS an external force to all systems on this planet, we must now remember to take the molecular gravity factor into account where appropriate.
Graeff’s modification of the Second law statement is clearly of importance to Climate Science. But we will leave that discussion, together with questions of replication, until the final part.
Web content produced from documents provided by Lucy Skywalker.